USEPA REGION V

CENTRAL REGIONAL LABORATORY

536 South Clark Street

CHICAGO, ILLINOIS 60605

MARCH 1990

CONCURRENCES

TEAM LEADER	Signed Babu Paruchuri	3/21/90
SECTION CHIEF	----------------------------
QA/QC COORDINATOR	Signed David A. Payne	3/21/90
LABORATORY DIRECTOR	Signed	3/21/90

METHOD 524.2DS (Revision 0)

METHOD OF PURGEABLE ORGANIC COMPOUNDS IN WATER BY

CAPILIARY COLUMN GAS CHROMATOGRAPHY/MASS SPECTROMETRY

1. SCOPE AND APPLICATION

1.1 This is a general purpose method for the identification and simultaneous measurement of purgeable volatile organic compounds in any finished drinking water, raw source water, or drinking water in any treatment stage. Ground and surface water are also included. This method is applicable to a wide range of organic compounds and includes the following:

Compound	Chemical Abstract Service Registry Number
*Acetone	67-64-1
*Acrolein	107-02-8
*Acrylonitrile	107-13-1
Benzene	71-43-2
Bromobenzene	108-86-1
Bromochloromethane	74-97-5
Bromodichloromethane	75-27-4
Bromoform	75-25-2
Bromomethane	74-83-9
*2-Butanone (MEK)	78-93-3
n-Butylbenzene	104-51-8
sec-Butylbenzene	135-98-8
tert-Butylbenzene	98-06-6
*Carbon Disulfide	75-15-0
Carbon tetrachloride	56-23-5
Chlorobenzene	108-90-7
Chloroethane	75-00-3
Chloroform	67-66-3
Chloromethane	74-87-3
2-Chlorotoluene	95-49-8
4-Chlorotoluene	106-43-4
Dibromochloromethane	124-48-1
**1,2-Dibromo-3-chloropropane (DBCP) a.	96-12-8
1,2-Dibromoethane (EDB) a.	106-93-4
Dibromomethane	74-95-3
1,2-Dichlorobenzene	95-50-1
1,3-Dichlorobenzene	541-73-1
1,4-Dichlorobenzene	106-46-7
Dichlorodifluoromethane	75-71-8
1,1-Dichloroethane	75-34-3
1,2-Dichloroethane	107-06-2
1,1-Dichloroethene	75-35-4
cis-1,2-Dichloroethene	156-59-2
trans-1,2-Dichloroethene	156-60-5
1,2-Dichloropropane	78-87-5
1,3-Dichloropropane	142-28-9
2,2-Dichloropropane	594-20-7
1,1-Dichloropropene	563-58-6
cis-1,3-Dichloropropene	10061-01-5
trans,-1,3-Dichloropropene	10061-02-6
Ethylbenzene	100-41-4
Hexachlorobutadiene	87-68-3
*2-Hexanone	591-78-6
Isopropylbenzene (cumene)	98-82-8
4-Isopropyltoluene	99-87-6
Methylene chloride	75-09-2
*4-Methyl-2-Pentanone (MlBK)	108-10-1
Naphthalene	91-20-3
n-Propylbenzene	103-65-1
Styrene	100-42-5
1,1,1,2-Tetrachloroethane	630-20-6
**1,1,2,2-Tetrachloroethane	79-34-5
Tetrachloroethene	127-18-4
Toluene	108-88-3
1,2,3-Trichlorobenzene	87-61-6
1,2,4-Trichlorobenzene	120-82-1
1,1,1-Trichloroethane	71-55-6
1,1,2-Trichloroethane	79-00-5
Trichloroethene	79-01-6
Trichlorofluoromethane	75-69-4
1,2,3-Trichloropropane	96-18-4
1,2,4-Trimethylbenzene	95-63-6
1,3,5-Trimethylbenzene	108-67-8
*,** Vinyl Acetate	108-05-4
Vinyl chloride	75-01-4
o-Xylene	95-47-6
m-Xylene b.	108-38-3
p-Xylene b.	106-42-3

* These volatile compounds areeither not regulated by National Primary

Drinking Water regulations 40 CFR141 or not required by 40 CFR141 for  monitoring of drinking water supplies. They are included because they  are either priority pollutants or part of the Contract Laboratory   Program (CLP) Target Compound List (TCL).

** These 3 volatile compounds currently exhibit unacceptable accuracy  and precision method validation data. Any reported method detection  limit data and detectable concentrations will be qualified by symbol   "J" (estimated concentration) until problems have been eliminated.   This will not occur for vinyl acetate since this volatile is being  removed from the CLP TCL because of unacceptable interlaboratory performance.

a. DBCP and EDB can be readily determined by EPA Method 524.2  within its accuracy and precision of measurement; however, 

Method 524.2 data for the 2 volatiles cannot be used for 40

CFR141 compliance purposes at public water supplies. 40

CFR141 specifically requires use of Method 504 (having  detection limits of 0.01 ug/L or less) for DBCP and EDB.

b. Concentrations will be reported as the sum of m + p xylene. 1.2 Applicable Concentration Range. CRL 524.2 is generally applicable to   ground surface, and drinking waters having volatiles between 0.25 and  25 ug/L. The methodology is intended for the analysis of waters  having trace volatile contaminants. After initial screening of any  water of unknown composition to detect the presence of any volatile  concentrations, analysis of a sample will be done within the stated  calibration ranges of the test procedure so long as any volatile   concentration does not exceed 50 ug/L. If a volatile is between 25 and 50 ug/L a sample will normally be  tested using the specified sample aliquot of 25 ml. A second   determination will also be done, after sample dilution to quantitate   volatiles between 25 and 50 ug/L. If one or more volatiles are present at concentrations exceeding 50  ug/L, sample aliquots will be diluted (and detection limits raised)  so that high concentration volatiles can be accommodated without   degradation and destruction of the analytical system. The decision to determine 25 ml aliquots (with small detection limits), in addition to the smaller aliquots used to identify and quantitate the large concentration volatiles, will be made on a case-by-case basis in relation to program needs after consultation with program managers.

1.3 Inefficiently Purged Analytes. Acrolein, acrylonitrile, and the  ketones (acetone, 2-butanone, and 4 methyl-2-pentanone), and any  other water miscible volatiles, are inefficiently purged from water  at room temperature and will not be detected at low concentration (1  ug/L), but can be detected and measured at higher concentrations.   Method Detection Limits of 1 to 5 ug/L are provided for these  compounds with an applicable concentration range between 5 and 125  ug/L.

1.4 The gaseous volatiles (chloromethane, vinyl chloride, etc) and carbon  disulfide are imprecisely measured when compared to other volatiles.  Method detection limits of 0.5 ug/L have been established for these  compounds. 40 CFR141 requires a detection limit of 0.5 ug/L or less for vinyl chloride.

1.5 Target Compounds. Section 1.1 of CRL Method 524.2 provides the  volatiles that can be determined and reported to the data user. If  specific programs or projects (drinking water, Superfund TCL, NPDES  priority pollutants) mandate that not all section 1.1 volatiles are  to be reported, then either specialized "Quant I.D. Files" or  analysis reports will be developed for each program or project. CRL  Method 524.2DS will still use the calibration standards, surrogates,

and matrix spike compounds described below as a routine.

1.6 Analytes that are not separated chromatographically, but which have  different mass spectra and non-interfering quantitation ions, can be  identified and measured in the same calibration mixture or water  sample (Section 10.1.2). Analytes which have very similar mass  spectra cannot be individually identified and measured in the same   calibration mixture or water sample unless they have different  retention tunes (Section 10.1.3). Coeluting compounds with very  similar mass spectra, typically many structural isomers, must be  reported as an isomeric group or pair. Two of the three isomeric xylenes (m/p xylenes) are not resolved on this capillary column, and  must be reported-as an isomeric pair and as total m/p-xylene. Special   attention must also be given to compounds which have similar  retention times and MS ions. Examples are ethylbenzene and  m/p-xylene; 1,2,3-trichloropropane and bromofluorobenzene; 2- and  4-chlorotoluene; 1,3- and 1,4 dichlorobenzene, and any or all  dichloropropanes or dichloropropenes. These compounds normally require manual identification and integration.

1.7 Method Detection Limits

1.7.1 Method Detection Limits (MDLS) are compound and instrument  dependent and vary from 0.02-5.0 ug/L. A practical working MDL  under the conditions at CRL is 0.25-5.0 ug/L for most  compounds. MDL's for certain compounds are larger than 0.25  ug/L as discussed above. All MDLs are listed in Table 2. See  Attachment 7 for the entire analytical procedure and   calculation of the MDL.

1.7.2 The MDL for a parameter may differ from those listed,  depending upon the nature of interferences in the sample  matrix.

1.7.3 Detection limits reported by CRL are dependent upon the  sensitivity of a particular instrument. CRL detection limits   are updated annually or whenever new instrumentation is  initiated; the current update is found in Table 2.

1.7.4 The MDLs for the "D Mix" components are substantially  different than the EPA 524.2 revision 3.0 target compounds.  The chromatographic characteristics of these compounds require   higher MDLS. Vinyl acetate, 1,1,2,2-tetrachloroethane, and 1,2-dibromo-3-chloropropane also have higher MDLS.

1.7.5 CRL detection limits will be adjusted accordingly if samples  are diluted. For example, if a sample is diluted 3:1 and the   previous CRL detection limit for a parameter was 0.5 ppB, the  adjusted detection limit reported will be 1.5 ppb.

1.7.6 The MDLs listed in Table 2 will be used as benchmarks for  additional quality assurance practices. Approaching or   exceeding the listed MDLs should indicate to the analyst that  a problem exists (i.e. , instrument sensitivity) . The source  of the problem should be determined before the analysis of  real samples can begin. This method is restricted to use by or under the supervision of  analysts experienced in the operation of a purge and trap system and  a gas chromatograph/mass spectrometer and mass spectral   interpretation. Each analyst must have demonstrated the ability to  generate acceptable results with this method.

2. SAFETY

2.1 The toxicity or carcinogenicity of chemicals used in this method has  not been precisely defined; each chemical should be treated as a  potential health hazard, and exposure to these chemicals should be  minimized. Each laboratory is responsible for maintaining awareness  of OSHA regulations regarding safe handling of chemicals used in this  method.

2.2 The following method analytes have been tentatively classified as  known or suspected human or mammalian carcinogens: benzene, carbon  tetrachloride, 1,4-dichlorobenzene, 1,2-dichloroethane, hexachlorobutadiene,1,1,2,2-tetrachloroethane, 1,1,2-trichloroethane, chloroform, 1,2- dibromoethane, tetrachloroethene, trichloroethene, and vinyl chloride. Pure standard   materials and stock standard solutions of these compounds should be  handled in a hood. A NIOSH/MSA approved toxic gas respirator should  be worn when the analyst handles high concentrations of these toxic compounds.

3. SUMMARY OF METHOD

3.1 Volatile organic compounds and surrogates with low water solubility  are extracted (purged) from the sample matrix by bubbling an inert  gas through the 25 mL sample. Purged sample components are trapped in  a tube containing suitable sorbent materials. When purging is  complete, the sorbent tube is heated and backflushed with helium to   desorb the trapped sample components into a wide bore capillary gas   chromatography (GC) column interfaced to a mass spectrometer (MS) . The column is temperature programmed to separate the method analytes  which are then detected with the MS. Compounds eluting from the GC  column are identified by comparing their measured mass spectra and retention times to reference spectra and retention times in a data base. Reference spectra and retention times for analytes are obtained by the measurement of calibration standards under the same conditions used for samples. The concentration of each identified component is measured by relating the MS response of the quantitation ion produced by that compound to the MS response of the quantitation ion produced by a compound that is used as an internal standard. Surrogate analytes, whose concentrations are known in every sample, are measured with the same internal standard calibration procedure. Dilutions are accomplished by removing an aliquot of the sample and diluting to 25 mL total volume with reagent water.

4. SAMPLE COLLECTION, PRESERVATION, AND STORAGE

4.1 SAMPLE COLLECTION, DECHLORINATION, AND PRESERVATION

4.1.1 Collect all samples in 4 x 40 ml vials. Four(4) additional  vials should be collected for the matrix spike and matrix   spike duplicate. If samples contain residual chlorine, and measurements of the concentrations of disinfection by-products (trihalonethanes, etc.) at the time of sample collection are desired, add about 25 mg of ascorbic acid to the sample bottle before filling. Fill sample bottles to overflowing, but take care not to flush out the rapidly dissolving ascorbic acid. No air bubbles should pass through the sample as the bottle is filled, or be trapped in the sample when the bottle is sealed.  Adjust the pH of all samples to <2 by carefully adding one drop of 1:1 HCl for each 20 mL of sample volume. Seal the sample bottles, PTFE-face down, and shake vigorously for 1 minute.

4.1.2 The samples must be chilled to 40 C on the day of collection and maintained at that temperature until analysis. Field samples that will not be received at the laboratory on the day of collection must be packaged for shipment with  sufficient ice to ensure that they will be at 40 C on arrival at the laboratory.

4.2 SAMPLE STORAGE

4.2.1 Store samples at 40 C until analysis. The sample storage area  must be free of organic solvent vapors.

4.2.2 Analyze all samples within 14 days of collection. Samples not  analyzed within this period must be discarded and replaced, unless after consultation with project management or applicable regulations, it is determined that the analysis may  be performed. If the samples are not acidified the aromatic compound data must be qualified when analyzed after 7 days.

5. INTERFERENCES

5.1 During analysis, major contaminant sources are volatile materials in  the laboratory and impurities in the inert purging gas and in the sorbent trap. The use of non-polytetrafluoroethylene (PTFE) plastic tubing, non-PTFE thread sealants, or flow controllers with rubber components in the purging device should be avoided since such materials out-gas organic compounds which will be concentrated in the trap during the purge operation. Analysis of the laboratory reagent blank provide information about the presence of contaminants. When potential interfering peaks are noted in laboratory reagent blanks, the analyst should consider possible sources and eliminate the contamination. Subtracting blank values from sample results is not permitted.

5.2 Interfering contamination may occur when a sample containing low concentrations of volatile organic compounds is analyzed immediately after a sample containing relatively high concentrations of volatile compounds. The next sample's results should be carefully examined for evidence of cross-contamination. If contamination of the next sample is suspected, then the sample should be re-analyzed to determine, if in fact the positive result was due to contamination.

5.3 Special precautions must be taken to determine methylene chloride. The analytical and sample storage area should be isolated from all atmospheric sources of methylene chloride, otherwise random background levels will result. Since methylene chloride will permeate through PTFE tubing, all gas chromatography carrier gas lines and purge gas plumbing should be constructed of stainless steel or copper tubing.

6. APPARATUS AND EQUIPMENT

See Attachment 1.

6.1 SAMPLE CONTAINERS

40 mL screw cap vials (Pierce #19832 or equivalent) each equipped with a PTFE-faced silicone septum (Pierce #12718 or equivalent).

6.2 PURGE AND TRAP SYSTEM

The purge and trap system consists of three   separate pieces of equipment: purging device, trap, and desorber.  Systems are commercially available from several sources that meet all  of the following specifications.

6.2.1 The Tekmar LSC 2000 and ALS 2016 all glass purging device  (Figure 1) is designed to accept 25-mL samples with a water column at least 5 cm deep. Gaseous volumes above the sample must be kept to a minimum (< 15 mL) to eliminate dead volume effects. A glass frit should be installed at the base of the sample chamber so the purge gas passes through the water column as finely divided bubbles with a diameter of < 3 mm at the origin.

6.2.2 The trap (Figure 2) must be at least 25 cm long and have an inside diameter of at least 0.105 in. Starting from the inlet, the trap should contain the following amounts of adsorbents: 1/3 of 2,6-diphenylene oxide polymer, 1/3 of silica gel, and 1/3 of coconut charcoal. Before initial use, the trap should be conditioned overnight at 1800 C by backflushing with an inert gas flow of at least 20 ml/min. Vent the trap effluent to the room, not to the analytical column. Prior to daily use, the trap should be conditioned for 10 minutes at 2000 C with backflushing.

6.2.3 The desorber (Figure 2) must be capable of rapidly heating the trap to 1800 C either prior to or at the beginning of the flow of desorption gas. The polymer section of the trap should not be heated higher than 2000 C or the life expectancy of the trap will decrease. Trap failure is characterized by a pressure drop in excess of 3 pounds per square inch across the trap during purging or by poor bromoform sensitivities. The

desorber design illustrated in Figure 2 meets these criteria.

6.3 GAS CHROMATOGRAPHY/MASS SPECTROMETER/DATA SYSTEM (GC/MS/DS)

6.3.1 The GC must be capable of temperature programming and should  be equipped with variable-constant differential flow   controllers so that the column flow rate will remain constant  throughout desorption and temperature program operation. The column oven must be cooled to 100 C; therefore, a subambient oven controller is required.

6.3.2. Column -- 30 m x 0.53 mm ID DB-624 (J & W  Scientific, Inc.) fused silica capillary with a 3  um film thickness (or equivalent). See Attachment 2.

6.3.3 The interface between the Tekmar purge and trap system and the  GC is a zero dead volume union with a short uncoated   deactivated section of 0.53 mm fused silica tubing.

6.3.3. The wide-bore column (ID > 0.53 mm) has the capacity  to accept the standard gas flow (15 mL) from the  trap during thermal desorption, and chromatography  can begin with the onset of thermal desorption. A  jet separator is used to separate the carrier gas  from the compounds of interest. The compounds then  travel into the ion source of the MS.

6.3.4 The mass spectrometer must be capable of electron ionization  at a nominal electron energy of 70 eV. The spectrometer must   be capable of scanning from 35 to 260 amu with a complete scan  cycle time (including scan overhead) of 2 sec or less. (Scan  cycle time = Total MS data acquition time in seconds divided  by number of scans in the chromatogram). The spectrometer must  produce a mass spectrum that meets all criteria in Table 3   when 25 ng or less of 4-bromofluorobenzene (BFB) is introduced  into the GC. An average spectrum across the BFB GC peak may be  used to test instrument performance.

6.3.5 An interfaced data system is required to acquire, store,  reduce, and output mass spectral data. The computer software   should have the capability of processing stored GC/MS data by  recognizing a GC peak within any given retention time window, comparing the mass spectra from the GC peak with spectral data  in a user-created data base, and generating a list of   tentatively identified compounds with their retention times  and scan numbers. The software must allow integration of the  ion abundance of any specific ion between specified time or  scan number limits. The software should also allow calculation   of response factors as defined in Section 8.2.7, calculation  of response factor statistics (mean and standard deviation),  and calculation of concentrations of analytes using either the  calibration curve or the equation in Section 10.2.

6.4 SYRINGES

6.4.1 Two 25-mL glass hypodermic syringes with Luer-Lok tip.

6.4.2 Micro syringes - 5, 10, 25, 50, 100, 250, 500 uL.

6.4.3 Syringes - 1.0, and 5-mL, gas tight.

6.5 MISCELLANEOUS

6.5.1 Standard solution storage containers --15-mL bottles with  PTFE-lined screw caps.

6.5.2 Mininert vials, 1 mL and 5 mL with caps.

6.5.3 Analytical balance capable of accurately weighing to 0.0001g.

7. REAGENTS AND CONSUMABLE MATERIALS

7.1 TRAP PACKING MATERIALS

Three (3) component traps are purchased directly from external  sources such as Tekmar or Supelco. Traps should contain Tenax,  Silicagel, and Charcoal as specified in 6.2.2.

7.2 REAGENTS

7.2.1 Methanol -- Demonstrated to be free of analytes.

7.2.2 Reagent water -- Prepare reagent water by passing tap water  through a filter bed containing about 0.5 kg of activated   carbon, by using a water purification system, or by boiling  distilled water for 15 minutes followed by a 1-hour purge with  inert gas while the water temperature is held at 90°C.A slow continuous purge is recommended.

7.2.3 Hydrochloric acid (1+1) -- Carefully add a measured volume of  concentrated HCl to an equal volume of reagent water.

7.3 STOCK STANDARD SOLUTIONS

These solutions may be purchased as   certified solutions or prepared from pure standard materials using  the following procedures. one of these solutions is required for  every analyte of concern, every surrogate, and the internal  standards. A useful working concentration is about 1-5 mg/ml.

7.3.1 Place about 9.8 mL of methanol into a 10-mL ground-glass  stoppered volumetric flask. Allow the flask to stand,   unstoppered, for about 10 minutes until all alcohol-wetted  surfaces have dried and weigh to the nearest 0.1 mg.

7.3.2 If the analyte is a liquid at room temperature, use a 100-uL  syringe and immediately add two or more drops of reference   standard to the flask. Be sure that the reference standard  falls directly into the alcohol without contacting the neck of  the flask. If the analyte is a gas at room temperature, fill a  5-mL valved gas-tight syringe with the standard to the 5.0-mL mark, lower the needle to 5 mm above the methanol meniscus,  and slowly inject the standard into the neck area of the  flask. The gas will rapidly dissolve in the methanol.

7.3.3 Reweigh, dilute to volume, stopper, then mix by inverting the  flask several times. Calculate the concentration in ug/ml from   the net gain in weight. When compound purity is certified at  96% or greater, the weight can be used without correction to calculate the concentration of the stock standard.

7.3.4 Store stock standard solutions in 15-mL bottles equipped with  PTFE-lined screw caps. Methanol solutions prepared from liquid   analytes are stable for at least 4 weeks when stored at 4°C.  Methanol solutions prepared from gaseous analytes are not  stable for more than 1 week when stored at <0°C; at room  temperature, they must be discarded after 1 day.

7.4 PRIMARY DILUTION STANDARDS

Use stock standard solutions to prepare   primary dilution standard solutions that contain all the analytes of  concern (without the surrogates and internal standards) in methanol.  The primary dilution standards should be prepared at concentrations  that can be easily diluted to prepare aqueous calibration solutions  that will bracket the working concentration range (0.5-25 ug/L).

Store the primary dilution standard solutions with minimal headspace  and check frequently for -signs of deterioration or evaporation, especially just before preparing calibration solutions. Storage times

described for stock standard solutions in Section 7.3.4 also apply to  primary dilution standard solutions. The primary dilution standards should be prepared so that all the target compounds of 524.2 revision 3.0 minus the 6 gases are in one solution at 12.5 ug/ml. The six (6) gas components in a separate solution at 12.5ug/ml and the "D Mix" compounds in a third solution at the concentrations specified are in Attachment 3. A general procedure with specifics once the 200 ug/ml intermediate standard is prepared is also included in Attachment 3. It should be noted that certain suppliers (Supelco) may provide the  standards in multiple vials. The vials should be handled so that the  final mixture in each vial is in concentrations as described above.

7.5 SOLUTIONS FOR INTERNAL STANDARDS, SURROGATES AND MATRIX SPIKES.

7.5.1 A solution containing the internal standards and the  surrogates is required to prepare laboratory reagent blanks   (also used as a laboratory performance check solution), and to  fortify each calibration standard and sample. Prepare a  fortification solution containing fluorobenzene, chlorobenzene-d5, and toluene-d8 (internal standards) in  addition to benzene-d6, BFB, and 1,2-dichlorobenzene-d4  (surrogates) in methanol at concentrations of 5 ug/ml of each.  A 5-uL aliquot of this solution added to a 25-mL water sample  volume gives a concentration of 1 ug/L of each. The internal standard (IS) and surrogate compounds are obtainable from different sources and in different concentrations. All six(6) compounds should be placed into the same solution. All  threaded cap joints on storage vials should be wrapped with  teflon tape. The final working concentration should be 5 ug/ml. These and all VOA standards in methanol should be stored below 0°C.

Solution A. Fluorobenzene and 1,2-Dichlorobenzene-d4. Start with Supelco mix at 2000 ug/ml. Transfer 1 mL of the   2000 ug/ml mix to a flask or vial containing 3 mL of methanol. Mix by gentle inversion. This solution's  concentration is 500 ug/mL.

Solution B. Chlorobenzene - d5

Chlorobenzene-d5 is acquired as the neat material. Use the  gravimetric procedure described in Section 7.3 to prepare a   solution. As a guide 100 uL of neat chlorobenzene-d5 in 100  mL of methanol provides a solution of 1.107 ug/uL. This provides a cross-check for the gravimetric procedure. Solutions C&D&E. Toulene-d8, Benzene-d6, and BFB. These compounds are typically provided in methanol at a  concentration of 5000 ug/ml from the EPA.

Fill a 10 mL volumetric flask with approximately 8 mL of  methanol. Transfer 100 ul of solution A to the flask. Transfer   45 ul of solution B to the flask. Transfer 10 ul each of solutions C, D, and E to the flask. Dilute to volume. Mix by  gentle inversion. The concentration of this solution is now 5   ug/ml. Transfer to a 5 mL mininert vial with cap and label as  indicated in the last paragraph of attachment 3.

MS/MSD Solutions

(1,1-Dichloroethene, Trichloroethene, Benzene, Toluene, and  Chlorobenzene) These solutions are purchased from external sources Ultra  Scientific (1000 ug/ml). Fill a 10 ml volumetric flask with  7.0 ml of methanol. Transfer 1 ml of the MS/MSD solution to the volumetric. Mix by gentle inversion. Transfer to a 5 ml  mininert vial with zero headspace. The concentration of this   solution is now 125 ug/ml. Two ul of this MS/MSD solution in  25 ml of sample provides a concentration of 10 ppb.

7.6 PREPARATION OF METHOD (LABORATORY) BLANK (MB)

Fill a 25-mL syringe with reagent water and adjust to the mark with  no air bubbles. Inject 5 uL of the fortification solution containing  the internal standard and surrogates into the reagent water. Transfer   the MB to the purging device. See Section 11.1.2.

7.7 PREPARATION OF METHOD DETECTION LIMIT STANDARD (MDL) 

Prepare this exactly like a calibration standard (Section 7.8). This  is a calibration standard that is treated as a sample. This sample  should be prepared at 0.5 ppb (the lowest calibration point).

7.8 PREPARATION OF CALIBRATION STANDARDS

7.8.1 Five calibration standard solutions are required, 0.5, 1.0,  5.0, 10.0, and 25.0 ug/L, to cover the concentration range of   interest. one calibration standard should contain each  analyte of concern at a concentration of 2-10 times the method detection limit (Table 2 ) f or that compound. The other calibration standards should contain each analyte of concern   at concentrations that define the range of the method. Every calibration solution contains the internal standards and surrogates at the same concentration  (1 ug/L for a 25-mL   sample).

7.8.2 To prepare a calibration standard, add an appropriate volume  of the primary dilution standard (containing analytes and   surrogates) to 25 mL of reagent water in a 25 mL syringe. Use  a microsyringe and rapidly inject the methanol solutions into the syringe. Remove the needle as quickly as possible after  injection. Mix by inverting. Transfer to the Tekmar purge and   trap vessel immediately. Rinse the syringe several times with  reagent water before refilling for the next standard. See  Attachment 3A.

7.8.3 Preparation of Continuing Calibration Standard. The continuing  calibration standard is prepared the same way as the 5 ug/L   (midpoint) standard of the initial calibration curve. See  Section 7.8.2.1 and Attachment 3A.

7.8.4 Preparation of BFB Tune Solution. Transfer 65.5 uL of neat  BFB by microsyringe to 20 mL of methanol in a 25 mL volumetric  flask. Mix by gentle inversion. Transfer 25 uL of this  solution to a 10 nL volumetric flask filled with 9.5 mL methanol. Dilute to volume. Mix by gentle inversion. Transfer  this solution to a 10 mL (or 5 mL ) mininert vial with cap.   The concentration of this solution is 12.5 ug/ml. 2 uL of this  solution is added to 25 mL of water in a 25 mL syringe to  prepare a 25 ng tune solution. Analyze as described in Section  12.

8. CALIBRATION

8.1 Demonstration and documentation of acceptable initial calibration is  required before any samples are analyzed and is required  intermittently throughout sample analysis as dictated by results of  continuing calibration checks. After the initial calibration is  successful, a continuing calibration check is required at the   beginning of each 12 hour period during which analyses are performed.

Samples may also be analyzed following an initial calibration, if  time permits.

8.2 Initial Calibration

8.2.1 Tuning the M.S.- Calibrate the mass and abundance scales of  the MS with calibration compounds and procedures prescribed by   the manufacturer with any modifications necessary to meet the  requirements in Section 8.2.2. See Attachment 4.

8.2.2 Introduce into the GC (either by purging a laboratory reagent  blank or making a syringe injection) 25 ng of BFB (see Section   7.8.4)and acquire mass spectra for m/z 35-260 at 70 eV  (nominal). Use the purging procedure and/or GC conditions  given in Section 11.3. If the spectrum does not meet all  criteria in Table 3, the MS must be retuned and adjusted to  meet all criteria before proceeding with calibration. An average spectrum across the GC peak may be used to evaluate  the performance of the system. Evaluate any spurious   chromatographic peaks as possible contamination and take appropriate action.

8.2.3 Purge the standard solutions (low to high concentrations)  using the procedure given in Section 9. Prepare the standards   as described in Section 7.8.

8.2.4 Check the performance criteria for the first calibration  solution. Examine the stored GC/MS data with the data system   software. Figure 3A shows an acceptable total ion chromatogram.

8.2.4.1 GC Performance. Good column performance will produce symmetrical peaks with minimum tailing for most  compounds. If peaks are broad, or sensitivity poor,  some possible remedial action may be necessary.

8.2.4.2 MS Sensitivity. The GC/MS/DS peak identification  software should be able to recognize a GC peak in  the appropriate retention time window for each of  the compounds in calibration solution, and make correct tentative identifications.

8.2.5 If all performance criteria are met, purge an aliquot of each  of the other calibration solutions using the same GC/MS   conditions.

8.2.6 If the criteria are not met take remedial action to improve  the GC/MS performance.

8.2.7 Calculate a response factor (RF) for each analyte, surrogate,  and isomer pair for each calibration solution using the   appropriate internal standard. Tables 1 and 1A contain  suggested quantitation ions for all compounds. This  calculation is supported in the GC/MS data system software. RF  is a unitless number, but units used to express quantities of   analyte and internal standard must be equivalent.

RF =     (Ax)(Qis)

             (Ais)(Qx)

where:

    Ax  = integrated abundance of the quantitationion of the analyte.

    Ais = integrated abundance of the quantitationion of the internal standard

   Qx  = quantity of analyte purged in ng or concentration units.

   Qis = quantity of internal standard purged in ng or concentration units.

8.2.6.1 For each analyte and surrogate, calculate the mean  RF from the analyses of the calibration solutions. Calculate the standard deviation (SD) and the  relative standard deviation (RSD) from each mean (M) :

RSD = 100 (SD/M) .

If the RSD of any analyte or  surrogate mean RF exceeds 35%, either analyze  additional aliquots of appropriate calibration   solutions to obtain an acceptable RSD of RFs over the entire concentration range, or take action to improve GC/MS performance. If the RF value over the working range is constant  (< 35% RSD), then the RF can be assumed to be  invariant and the average RF is used for calculations.

8.3 Continuing Calibration Standard.

Verify the MS tune and initia calibration at the beginning of each 12-hour work shift during which analyses are performed using the following procedure.

8.3.1 Introduce into the GC (either by purging a laboratory reagent  blank or making a syringe injection) 25 ng of BFB and acquire   a mass spectrum that includes data for m/z 35-260. If the  spectrum does not meet all criteria (Table 3), the MS must be  retuned and adjusted to meet all criteria before proceeding  with the continuing calibration check.

8.3.2 Purge a medium concentration calibration solution (5 ug/L)  (see Section 7.8.3) and analyze with the same conditions used   during the initial calibration.

8.3.3 Demonstrate acceptable performance criteria.

8.3.4 Determine that the absolute areas of the quantitation ions of  the internal standards and surrogates have not decreased by   more than 50% from the areas measured during initial  calibration. If these areas have decreased by more than this  amount, adjustments must be made to restore system  sensitivity. These adjustments may require cleaning of the MS  ion source, or other maintenance and recalibration.

8.3.5 Calculate the RF for each analyte and surrogate from the data  measured in the continuing calibration check. The RF for each  analyte and surrogate must be within 25-35% of the mean value measured in the initial calibration. If these conditions do  not exist, remedial action must be taken which may require  re-initial calibration. Refer to section 11.3.4.1

8.4 Method Performance

8.4.1 The method detection limit (MDL) is defined as the minimum  concentration of a substance that can be measured and reported  with 99% confidence that the value is above zero. Its  calculation is described in Section 14 (also see Table 2). The MDL will be updated annually (more often if major changes in  tuning, modifications affecting analyses, etc take place) .   The MDL actually achieved in a given analysis will vary depending on instrument sensitivity and matrix effects.

9. PROCEDURE

9.1 OPERATING CONDITIONS AND SAMPLE ANALYSIS

Attachment 2 includes all operating conditions for the GC and Tekmar  units. See Figures 3A and 3B for a representative ion chromatogram.  Attachment 6 is a flow chart scheme for the analysis.

9.1.1 After achieving a tune and an appropriate calibration as  described in Section 8, proceed with sample analysis. Check  and record the pH of each sample to insure perservation with  HCl. Optionally check for oxidizing agents with starch iodide paper.

9.1.2 The suggested order for sample analysis is as follows:

BFB tune blank

Calibration Standard(s)

Method Blank (MB)

Field Blank (if any)

Sample

Samples

Matrix Spike (MS)

Matrix Spike Duplicate (MSD)

MDL Standard

9.2a SAMPLE INTRODUCTION AND PURGING

9.2.1 This method is designed for a 25-mL sample volume. Adjust the  purge gas (helium) flow rate to 40 mL/min. Attach the trap   inlet to the purging device and open the syringe valve on the purging device.

9.2.2 Remove the plunger from a 25-mL syringe. Warm the sample to  room temperature, open the sample bottle, and carefully pour   the sample into the syringe barrel to just short of  overflowing. Replace the syringe plunger, invert the  syringe, and compress the sample. Vent any residual air while adjusting the sample volume to 25.0-mL. Add 5 uL of the  internal standard surrogate solution to the water.

9.2.3 Attach the sample syringe to the syringe valve on the purging  device. Be sure that the trap is cooler than 25 oC, then open   the chamber valve and inject the sample into the purging  chamber. Close the valve and initiate purging. Purge the sample for 11.0 minutes at ambient temperature.

9.2b SAMPLE DESORPTION

9.2.1 After the 11-minute purge, place the purge and trap system in  the desorb mode and preheat the trap to 180 oC without a flow  of desorption gas. Then simultaneously start the flow of  desorption gas at 15-mL/min for about 4 minutes, begin the temperature program of the gas chromatograph, and start data  acquisition.

9.2.2 While the trapped components are being introduced into the gas  chromatograph, the Tekmar ALS unit automatically drains the   samples from the purge vessels.

9.3 GAS CHROMATOGRAPHY/MASS SPECTROMETRY

Acquire and store data over the mass range 35-260 AMU with a total  cycle time (including scan overhead time) of 2 seconds or less. Cycle  time must be adjusted to measure five or more spectra during the   elution of each GC peak. See Attachment 4.

9.3.1 Single ramp linear temperature program for wide bore columns  with a jet separator. Adjust the helium carrier gas flow rate   to about 15 ml/min. The column temperature is reduced to 10°C  and held for 5 minutes from the beginning of desorption, then  programmed to 160°C at 6°C/minute, and held until all  components have eluted (approximately 2 minutes).

9.4 TRAP RECONDITIONING

After desorbing the sample for 4 minutes, recondition the trap by returning the purge and trap system to the purge mode. Wait 15 seconds, then close the syringe valve on the purging device to begin gas flow through the trap. Increase the trap temperature to 200°C. After approximately 11 minutes, turn off the trap heater and open the syringe valve to stop the gas flow through the trap. When the trap is cool, the next sample can be analyzed. This is automatically  accomplished with the Tekmar LSC 2000-ALS 2016.

9.5 TERMINATION OF DATA ACQUISITION

When all the sample components have eluted from the GC, terminate MS  data acquisition. Use appropriate data output software to display  full range mass spectra and appropriate plots of ion abundance as a   function of time. If the response for any m/z of a compound of  interest exceeds the working range of the system, a dilution of the  sample with reagent water is required. A portion of the sample is  transferred by syringe to a 25 mL syringe. Reagent water is then  added to bring the total volume to 25 mL. The sample is then analyzed as above. If a high concentration sample is reported, the analyses immediately following the run in question should be carefully  examined for carry-over effects. Subsequent samples may also have to  be reanalyzed if cross-contamination is suspected.

10. QUALITATIVE AND QUANTITATIVE IDENTIFICATION

10.1 IDENTIFICATION OF ANALYTES

Identify a sample component by comparison of its mass spectrum (after  background subtraction) to a reference spectrum in the user-created  data base.The GC retention time of the sample component should be   within three standard deviations of the mean retention time of the compound in the calibration mixture.

10.1.1 In general, all ions that are present above 10% relative  abundance in the mass spectrum of the standard should be   present in the mass spectrum of the sample component and  should agree within absolute 20%. For example, if an ion has a relative abundance of 30% in the standard spectrum, its  abundance in the sample spectrum should be in the range of 10  to 50%. Some ions, particularly the molecular ion, are of  special importance, and should be evaluated even if they are  below 10% relative abundance.

10.1.2 Identification requires expert judgement when sample  components are not resolved chromatographically and produce  mass spectra containing ions contributed by more than one  analyte. When GC peaks obviously represent more than one  sample component (i.e., broadened peak with shoulder(s) or  valley between two or more maxima), appropriate analyte  spectra and background spectra can be selected by examining  plots of characteristic ions for tentatively identified  components. When analytes coelute (i.e., only one GC peak is   apparent), the identification criteria can be met, but each  analyte spectrum will contain extraneous ions contributed by  the coeluting compound. Because purgeable organic compounds  are relatively small molecules and produce comparatively   simple mass spectra, this is not a significant problem for  most method analytes.

10.1.3 Structural isomers that produce very similar mass spectra can  be explicitly identified only if they have sufficiently   different GC retention times. Acceptable resolution is  achieved if the height of the valley between two peaks is less than 25% of the average height of the two peaks. Otherwise, structural isomers are identified as isomeric pairs. Two of the three isomeric xylenes are not resolved on the wide bore

capillary columns.

10.1.4 Methylene chloride and other background components appear in  variable quantities in laboratory and field reagent blanks, and generally cannot be accurately measured. Subtraction of the concentration in the blank from the concentration in the sample is not acceptable because the concentration of the background in the blank is highly variable.

10.2 CALCULATIONS

10.2.1 Complete chromatographic resolution is not necessary for  accurate and precise measurements of analyte concentrations if   unique ions with adequate intensities are available for  quantitation.

10.2.2 Calculate analyte and surrogate concentrations.

Cx = (Ax)(Qis) 1000

            (Ais)RF V

where:

    Cx = concentration of analyte or surrogate in ug/L in  the water sample.

    Ax = integrated abundance of the quantitation ion of  the analyte in the sample.

    Ais = integrated abundance of the quantitation ion of  the internal standard in the sample

    Qis = total quantity (in micrograms) of internal standard added to the water sample.

    V = original water samples volume in mL.

    RF = response factor of analyte from the calibration.

The RF used is dependent upon which calibration   is current i.e. the initial or continuing (daily).

10.2.3 Alternatively, use the GC/MS system software or other  available proven software to compute the concentrations of the   analytes and surrogates.

10.2.4 Calculations should utilize all available digits of precision,  but final reported concentrations should be rounded to an  appropriate number of significant figures (one digit of  uncertainty). Experience indicates that three significant  figures may be used for concentrations above 10 ug/L, two  significant figures for concentrations from 1-10 ug/L, and one   significant figure for concentrations below 1 ug/l.

10.3 TENTATIVELY IDENTIFIED COMPOUNDS

10.3.1 A library search shall be executed for non-target 524.2S  sample components for the purpose of tentative identification.   The most recent version of the EPA/NIH Mass Spectral Library  is used. The library search routine should not use  normalization routines that may misrepresent the library or  unknown spectra when compared to each other.

10.3.2 Up to 10 substances of greatest apparent concentration not  listed in Table 1 will be tentatively identified via a forward search of the EPA/NIH mass spectral library. Compounds with  response less than that of the nearest internal standard  (1 ug/L) are not required to be searched in this manner. A  tentative identification may only be made following a visual   verification by the analyst.

10.3.3 Guidelines for making tentative identification.

10.3.3.1 Relative intensities of major ions in the reference  spectrum (ions greater than 10% of the most abundant  ion) should be present in the sample spectrum.

10.3.3.2 The relative intensities of the major ions should  agree within + 20%. (Example: For an ion with an  abundance of 50 percent of the standard spectra, the  corresponding sample ion abundance must be between  30 to 70 percent.)

10.3.3.3 Molecular ions present in reference spectrum should  be present in sample spectrum.

10.3.3.4 Ions present in the sample spectrum but not in the  reference spectrum should be reviewed for possible  background contamination or presence of co-eluting  compounds.

10.3.3.5 Ions present in the reference spectrum but not in  the sample spectrum should be reviewed for possible  subtraction from the sample because of background contamination of co-eluting compounds. Data system   library reduction programs can sometimes create these discrepancies.

10.3.4 If in the opinion of the mass. spectral specialist, no valid tentative identified can be made, the compound should be reported as unknown. The mass spectral specialist should give additional classification of the unknown compound, if possible, (i.e. unknown aromatic, unknown hydrocarbon, unknown acid type, unknown chlorinated compound) . If probable molecular weights can be distinguished, include them.

11. QUALITY CONTROL

11.1 Initial Demonstration of Accuracy and Precision

At least once per year, or when an analytical system is initiated, a Quality Control (QC) reference sample for each volatile parameter of interest is obtained from EMSL-Cincinnati, USEPA (if available) and measured to determine accuracy and precision of system. If not available from EMSL-Cincinnati, a QC reference sample concentrate (or calibration standard concentrate from a source other than currently used calibration standards) must be obtained from an independent external source.

11.1.1 Prepare a QC reference sample to contain 10 ug/L of each volatile parameter of interest.

11.1.2 Analyze the QC reference sample 4 (or more) times following the calibration and analysis procedures of Sections 8.0 and 9.0. Accept results only if routine data validation procedures provide acceptance.

11.1.3 Tabulate all results and calculate the average recovery (X) in ug/L and %, the standard deviation in ug/L, and the relative standard deviation (RSD) in %.

11.1.4 It is a goal that X should be between 80-120%. Volatiles cannot be considered acceptable if X is outside the range of 75-125%, except for the problem compounds. The goal for % RSD is lot, however the % RSD of the values should be less than 15%, except for the problem compounds. The Summary of Method 524.2 should state which volatiles cannot meet the + 20 % accuracy criteria because of common lab contaminants, (ex. acetone, methylene chloride), poor performance, (ketones, carbon disulfide), poor sensitivity of analysis (tetrachloroethane,1,2-dibromo-3-chloropropane), instability of gases (ex. chloromethane, vinyl chloride) . It is the intent of method validation to demonstrate acceptable precision and accuracy and provide a flag for corrective action. At the same time, we cannot expect the analysis to be in control 100% of the time for all 68 target compounds.

11.1.5 See Tables 4, 5, and 6 for current method validation data for available QC reference samples. See Tables 4a, 5a, and 6a for the data for the compounds not in the QC reference samples. These were tested using independent calibration standards.

11.2 Estimation of Method Detection Limits (MDL's)

Analyze 7 or more replicates of a calibration standard containing 0.5 ug/L of the sensitive volatile compounds and 1 to 5 ug/L of the less sensitive volatiles (Ketones, vinyl acetate, acrolein, acrylonitrile, etc.) . The MDL solutions should contain all surrogates and internal standards. Accept results only if routine data validation procedures provide acceptance.

11.2.1 Calculate and tabulate all results including n (number of acceptable results), average recovery (x) in ug/L and %, standard deviation in ug/L, and relative standard deviation (RSD) in %.

11.2.2 The mean recovery should be between 80 and 120% with an RSD of less than 15% for each volatile; however, the problem compounds (carbon disulfide, Ketones, gases, and late eluting compounds of high molecular weight) may not achieve these criteria.

11.2.3 The tabulated standard deviations are used to estimate MDL's using the procedure of Section 13.2 of EMSL-Cincinnati Method 524.2 or of Appendix B to 40 CFR 136. Suggested CRL MDL's to the nearest 2 significant figures are then tabulated to provide self-consistent detection limits for similar types of compounds. Selfconsistent MDL's cannot be less than the estimated values.

11.2.4 The current MDL's provided in table 2, are the detection limits which will be used on a day-today basis.

11.3 Daily Quality Control

11.3.1 The GC/MS mass and abundance scales must be initially calibrated and tuned using PFTBA, and subsequently, if the BFB criteria cannot be met. On a routine basis BFB is analyzed daily to confirm the calibration and tune.

11.3.2  25 ng of BFB is purged with mass spectra acquired for m/z 35-260. If the spectrum does not meet all criteria of Table 3, analyses cannot proceed until corrective action is taken, and acceptable mass spectra is obtained for the analysis of 25 ng BFB.

11.3.3 No analysis may be initiated without an appropriate 5-Point Initial Calibration, as described in Section 8.23, for reference.

11.3.4 If an initial 5-Point Calibration Curve has not been tested on the day of sample analysis, a continuing calibration standard containing all volatile compounds of interest is tested. This typically contains 5 ug/L of most volatiles with a larger concentration of the insensitive volatiles (acrolein, ketones, etc.). A continuing Calibration Standard is tested every 12 hours thereafter for each analysis set. if the Continuing Calibration Standard's response factors (RF) are deemed accurate relative to the reference 5-Point Initial Calibration Curve, this daily standard is used for instrument calibration (response factor) and every 12 hours thereafter.

11.3.4.1 Acceptance criteria for the Continuing Calibration Standard results are:

a) % difference in RF between daily standard and RF of 5-Point Curve are less than 25%,except theproblem compounds (ketones, gases, carbon disulfide, methylene chloride, insensitive compounds) are allowed to have a difference of less than 35%. Reference Table 2 for these compounds *.

b) Any designated site-specific contaminants should have RF %D's <25% for a RCRA or Superfund Site.

c) Any volatile regulated by 40 CFR141 must have a difference in RF's of less than 25%. See Table 2 for a list of these compouds.

d) Because more than 50 target volatiles exist for this method, not all volatiles may be in control 100% of the time. The analyst has discretion in

initiating sample analyses with 5 volatiles exceeding the 25% or 35 % criteria, so long as the out-of-control volatiles are not expected to be detected in a sample. If a volatile is detected in a sample for quantitation with unacceptable % difference in RF'S, the analysis must be repeated prior to reporting what is considered valid results.

e) If the % difference in RF's are deemed unacceptable for the volatiles, sample analysis cannot be initiated, corrective action must be taken, and a 5-Point Initial Calibration Curve analyzed as appropriate.

11.3.5 A method blank (reagent water containing internal standards and surrogates) is tested after the BFB check, and every 12 hours, thereafter, in an analysis set. The method blank must contain volatiles at levels less than their MDL'S, except for the defined common lab contaminants (acetone, methylene chloride, 2-butanone). No values may be reported in an analysis set unless blank values are less than 10% of sample values. No sample analysis can be initiated with unacceptable blank values exceeding their MDL, except methylene chloride (5 ug/L) , acetone (10 ug/L), & 2-butanone(5ug/L). A goal of 1 ug/L is suggested for methylene chloride. Site specific information must always be considered when evaluating MDL data.

11.3.6 No sample analysis may be initiated without acceptable 25 ng BFB tuning checks, laboratory blank results, and Continuing Calibration Standard RF's. Acceptable RF's and blank results are required every 12 hours thereafter in an analysis set.

11.3.7 Each sample, standard, and blank is to be spiked with the 3 surrogate compounds (d6-Benzene, 4-Bromofluorobenzene, and d4-l,2-Dichlorobenzene) of table 1B, each at 1 ug/L concentration. Acceptable recoveries are 75-125% recovery. As data are accumulated the acceptable recovery range may be revised as appropriate

11.3.8 Field blanks, if submitted, (designated as ROX on CRL Analysis Request Forms) are to be tested in the same way as submitted samples. Results will be reviewed, in conjunction with lab blanks, to validate and qualify any data as appropriate. % Surrogate recoveries will be reported with each set of sample results.

11.3.9 With each set of submitted samples, matrix spike (MS) and matrix spike duplicate (MSD) audits will be performed. The MS and MSD compounds will be those of the current CLP Statement of Work and will be added at 10 ug/L (section 7.5.1). The recovery of each MS and MSD volatile will be tabulated after subtraction of any volatile in the unspiked sample aliquot. Acceptance criteria are 75-125% recovery for the MS results. Four of the five compounds must meet this criteria. An RPD of 25% between the MSD and MS results is also necessary.

11.3.10 The absolute area of each internal standard response will be tabulated in a run sequence as part of sample analysis records. Allowable variation in internal standard area response versus the day's continuing calibration standard is 50-150% recovery with a goal of + 30% deviations. No sample analysis results may be reported with internal standard responses exceeding +/- 50% variation.

11.3.11 Method Detection Limit Standard The primary function of the MDL standard is to audit the instrument performance qualitatively on a per batch basis at a level near the MDL level. The analyst is expected to use the MDL point as a reference.

11.4 Quarterly QA

11.4.1 QC Reference Samples

At least 1 QC Reference Sample will be tested quarterly with goals of 20% allowable errors and with no values exceeding 25% errors for concentrations greater than 4 ug/L.

11.4.2 The Initial Demonstration of Accuracy Precision and MDL'S. These will be done yearly, or each time new instrumentation systems are initiated.

12. PREVENTATIVE MAINTENANCE

12.1 In general, the instrument log book will delineate the preventative  maintenance, service problems, modifications, etc. It is extremely important to document these items.

12.2 The analyst should constantly be aware of changes in instrument  performance such as an increase in background, changes in response, etc. The schedule for preventative maintenance is dependent upon  instrument usage, types of samples, etc.

12.3 Computer equipment should be kept as clean as possible. Filters  should be changed frequently.

13. ANALYTICAL AIDS

13.1 If ion contamination of the primary quantitation internal standard is  suspected, the analyst should calculate any affected compounds with  one of the other available internal standards.

13.2 Care should be taken when evaluating the quantitation reports.  Carefully note any identical retention times, scan numbers, or areas  for mis-identification and/or quantitation.

13.3 All samples should be disposed of according to current EPA  regulations in force at that time.

14. REFERENCES

 

1. "Standard operating Procedure for Volatile Organic Analysis by Purge  and Trap GC/MS 624 NS". USEPA, Region V, CRL, Chicago, Illinois.

2. "Method 524.2 Rev. 3.0 Measurement of Purgeable Organic Compounds in  Water by Capillary Column Gas Chromatography/Mass Spectrometry",  1989, USEPA, EMSL, Cincinnati, Ohio.

3. Federal Register, Friday, October 26, 1984, Vol. 29 No. 209, pp  198-199.

 

 

TABLE 1. MOLECULAR WEIGHTS AND QUANTITATION IONS FOR METHOD ANALYTES

COMPOUND	MWa	PRIMARY QUANTITATION ION	SECONDARY QUANTITATION IONS
Internal Standards and Surrogates: see Attachment 1B
Target Analytes
Benzene	78	78	77
Bromobenzene	156	156	77,158
Bromochloromethane	128	128	49,130
Bromodichloromethane	162	83	85,127
Bromoform	250	173	175,252
Bromomethane	94	94	96
n-Butylbenzene	134	91	134
sec-Butylbenzene	134	105	134
tert-Butylbenzene	134	119	91
Carbon tetrachloride	152	117	119
Chlorobenzene	112	112	77,114
Chloroethane	64	64	66
Chloroform	118	83	85
Chloromethane	50	50	52
2-Chlorotoluene	126	91	126
4-Chlorotoluene	126	91	126
Dibromochloromethane	206	129	127
1,2-Dibromo-3-Chloropropane	234	75	155,157
1,2-Dibromoethane	186	107	109,188
Dibromomethane	172	93	95,174
1,2-Dichlorobenzene	146	146	111,148
1,3-Dichlorobenzene	146	146	111,148
1,4-Dichlorobenzene	146	146	111,148
Dichlorodifluoromethane	120	85	87
1,1-Dichloroethane	98	63	65,83
1,2-Dichloroethane	98	62	98
1,1-Dichloroethene	96	96	61,63
cis-1,2-Dichloroethene	96	96	61,98
trans-1,2-Dichloroethene	96	96	61,98
1,2-Dichloropropane	112	63	112
1,3-Dichloropropane	112	76	78
2,2-Dichloropropane	112	77	97
1,1-Dichloropropene	110	75	110,77
cis-1,3-dichloropropene	110	75	110
trans-1,3-dichloropropene	110	75	110
Ethylbenzene	106	91	106
Hexachlorobutadiene	258	225	260
Isopropylbenzene	120	105	120
4-Isopropyltoluene	134	119	134,91
Methylene chloride	84	84	86,49
Naphthalene	128	128
n-Propylbenzene	120	91	120
Styrene	104	104	78
1,1,1,2-Tetrachloroethane	166	131	133,119
1,1,2,2-Tetrachloroethane	166	83	131,85
Tetrachloroethene	164	166	168,129
Toluene	92	92	91
1,2,3-Trichlorobenzene	180	180	182
1,2,4-lrichlorobenzene	180	180	182
1,1,1-Trichloroethane	132	97	99,61
1,1,2-Trichloroethane	132	83	97,85
Trichloroethene	130	95	130,132
Trichlorofluoromethane	136	101	103
1,2,3-Trichloropropane	146	75	77
1,2,4-Trimethylbenzene	120	105	120
2,3,5-Trimethylbenzene	120	105	120
Vinyl Chloride	62	62	64
o-Xylene	106	106	91
m-Xylene	106	106	91
p-Xylene	106	106	91

a Monoisotopic molecular weight calculated from the atomic masses of the isotopes with the smallest masses.

"D Mix" compounds. See Table 1A

 

TABLE 1A Additional "D Mix" Compound Data for *524.2DS

	CAS	Primary Quant. Ion	Secondary Quant. Ion	MW	RT (min)
Acetone	67-64-1	43	58	58	4.53
Acrolein	107-02-08	56	55	56	4.11
Acrylonitrile	107-13-1	53	52	53	6.17
2-Butanone	78-93-3	43	72	72	8.60
CS2	75-15-0	76	---	76	4.58
2-Hexanone	591-78-6	43	58	100	15.69
4-Methyl-2-Pentanone	108-10-1	43	58	100	13.92
Vinyl Acetate	108-05-4	43	---	86	7.44

 

 

TABLE 1B INTERNAL STANDARD AND SURROGATE DATA

CRL MODIFIED 524.2DS METHODOLOGY

	MW	Primary Quant. Ion	Secondary Quant. Ion	Ret. Time
Internal Standards
Fluorobenzene	96	96	77	10.66
Toluene-d8	98	98	100	13.84
Chlorobenzene-d5	117	117	119	16.83
Surrogates
Benzene-d6	84	84	82	10.02
4-Bromofluorobenzene	74	95	174,176	19.38
1,2-dichlorobenzene-d4	150	152	115,150	22.68

See Attachment 5 - (ID File listing) for relative retention times of all analytes.

* Column - DB624 30 m X .53 mm

Retention Time is expressed as minutes.

TABLE 2: METHOD DETECTION LIMIT (MDL) ESTIMATES (4 pages) -

SEE QC COORDINATOR FOR HARD COPY.

 

 

TABLE 3. ION ABUNDANCE CRITERIA FOR 4-BROMOFLUOROBENZENE (BFB)

Mass (M/z)	Relative Abundance Criteria
50	15 to 40% of mass 95
75	30 to 80% of mass 95
95	Base Peak, 100% Relative Abundance
96	5 to 9% of mass 95
173	< 2% of mass 174
174	> 50% of mass 95
175	5 to 9% of mass 174
176	> 95% but < 101% of mass 174
177	5 to 9% of mass 176

 

 

TABLE 3A

Standard Preparation for 25 mL water

	0.5 ppb	1.0 ppb	5.0 ppb	10 ppb	25 ppb
524.2 Mix	1 uL	2 uL	10 uL	20 uL	50 uL
Gases Mix	1 uL	2 uL	10 uL	20 uL	50 uL
D Mix	1 uL	5 uL	10 uL	20 uL	25 uL
IS-Surr. Mix	5 uL	5 uL	5 uL	5 uL	5 uL
---------------------------------------------------------------------------------------------------------------------------------------
D Mix Concentrations (ppb)
Acetone Acrolein Acrylonitrile 2-Butanone	5 ppb	25	50	100	125
---------------------------------------------------------------------------------------------------------------------------------------
CS2	15 ppb	2.5	5	10	12.5
---------------------------------------------------------------------------------------------------------------------------------------
4-Methyl-2-pentanone 2-Hexanone Vinylacetate	1 ppb	5	10	20	25

 

524.2 + GASES Standard mix concentrations - 12.5 ug/ml

IS-surr mix concentrations - 5 ug/ml

D mix concentrations

Acetone, Acrolein, Acrylonitrile - 125 ug/ml

2-hexanone, 4-methyl-2-pentanone, Vinylacetate - 25 ug/ml

Carbon disulfide - 12.5 ug/ml

MS/MSD     -

125 ug/ml each of 1,1-dichloroethene, trichloroethene, benzene, toluene, and chlorobenzene (See section 7.5). Add 2ul to 25ml to provide a final concentration of 10 ppb for each MS compound.

 

TABLE 4: 2 UG/L VOLATILE CONCENTRATIONS METHOD VALIDATION DATA

EMSL-CINCINNATI QC REFERENCE SAMPLES - 2/90

( 2 PAGES )

TABLE 4A: METHOD VALIDATION DATA INDEPENDENT CALIBRATION STANDARDS - 2/90

( 1 PAGE )

TABLE 5: 10 UG/L VOLATILE CONCENTRATIONS METHOD VALIDATION DATA EMSL-

CINCINNATI QC REFERENCE SAMPLES - 2/90

( 2 PAGES )

TABLE 5A: 10 UG/L VOLATILE CONCENTRATIONS METHOD VALIDATION DATA

INDEPENDENT CALIBRATION STANDARDS - 2/90

( 1 PAGE )

TABLE 6: 20 UG/L VOLATILE CONCENTRATIONS METHOD VALIDATION DATA EMSL-

CINCINNATI QC REFERENCE SAMPLES - 2/90

( 1 PAGE )

TABLE 6A: 20 UG/L VOLATILE CONCENTRATIONS METHOD VALIDATION DATA

INDEPENDENT CALIBRATION STANDARDS - 2/90

( 1 PAGE )

FIGURE 1. PURGING DEVICE

FIGURE 2. TRAP PACKINGS AND CONSTRUCTION TO INCLUDE DESORB CAPABILITY

FIGURES 3A AND 3B: 524.2DNS CHROMATOGRAMS ( 2 PAGES )

SEE QC COORDINATOR FOR HARD COPIES.

 

 

ATTACHMENT 1.

Instrumentation

Tekmar Model LSC 2000 Purge and Trap Unit

Tekmar Model ALS 2016 Automatic Liquid Sampler

H.P. 5840A Gas Chromatograph

H.P. 5985 GC/MS/DS system

Software RTE-6/VM Rev. E.00.02 E-series on H.P.-1000 computer

H.P. 2397A Processor w/screen and printer

 

ATTACHMENT 2

G.C. Conditions

TEMP1	10 oC
TIME1	5.00 min
RATE	6.00 oC/ min
TEMP2	160 oC
TIME2	2.00 min
INJ TEMP	200 oC
TCD TEMP	250 oC
AUX TEMP	250 oC
CHT SPD	0.00
ZERO	10.0
FID SGNL	+B

Helium Flows

    Column 15 mL/min

    Make-up Gas 15 mL/min

Column

    J & W 30 m x .53mm DB624 3um film thickness

Tekmar Conditions

Standby 30oC	LSC Value 100oC
Purge 11 min	LSC Mount 40oC
Desorb preheat 180oC	LSC Line 100oC
Desorb 180oC for 4 min	ALS2016 valve 100 oC
Bake 11 min at 200oC	ALS2016 Line 100 oC Autodrain - On
Purge Flow 40 mL/min Helium
Purge Pressure 150 kPa

 

ATTACHMENT 3

STANDARD PREPARATION

To prepare the 524.2DS extended parameters list standard solutions, the following guidelines are suggested.

1. The 524.2DS standards are typically obtained in the diluted form in methanol at 2000 ug/ml concentrations from external suppliers. This includes all compounds listed in the method 524.2 ver. 3.0 parameter's list. The extended list parameters ("D mix") are available from various sources. A general scheme for dilution to working volumes are described. All standard solutions in methanol should be maintained below 0°C. 524.2 parameters - working solution of 12.5 ng/ul stock at 2,000 ug/ml. 1 ml of stock is diluted to 10 mL of methanol in a 10 ml volumetric flask. Fill the flask with approximately 8.5 ml of methanol. Add 1 mL of stock standard and dilute to volume. Mix by gentle inversions. This solution now contains a concentration of 200 ug/ml.

Transfer 0.5 mL of the 200 ug/ml solution by syringe to a 10 mL flask. Pipet 7.5 mL of methanol into the flask. Mix the flask by gentle inversion. Immediately transfer the solution to a 5 mL Mininert vial (leave zero headspace) with a mininert top. This concentration is now at the working standard level of 12.5 ug/mL.Extended parameters - "D mix Compounds".The extended list consists of Acetone, Acylonitrile, 2-Butanone,

Carbon Disulfide, 2 Hexanone, 4-Methyl-2-pentanone, and Vinyl Acetate. The working solutions' concentrations vary by 3 groups of

compounds as follows:

Group 1	Group 2	Group 3
125 ug/ml	25 ug/ml	12.5 ug/ml
Acetone	2-Hexanone	Carbon Disulfide
Acrolein	4-Methyl-2-pentanone
Acrylonitrile	Vinyl Acetate
2-Butanone

Prepare all three (3) groups of compounds in one working solution. These stock solutions are typically available in 5,000 ug/ml concentrations from external suppliers.

Add approx. 7 ul of methanol to a 10 mL volumetric flask.

Group 1 (125 ug/ml) add 250 ul of a 5000 ug/ml stock to the 10 ml volumetric flask.

Group 2 (25 ug/ml) add 50 ul of a 5,000 ug/ml stock to the 10 mL volumetric flask.

Group 3 (12.5 ug/ml) add 25 ul of a 5,000 ug/mL stock to the 10 mL volumetric flask.

Dilute to volume with methanol. Mix by gentle inversion.

Internal standards and surrogates. A working solution of 5 ug/mL is required. The commercially available stock solutions are available at a concentration of 2,000 ug/mL in 1 ml vials. Add approximately 90 ml of methanol in a 100 ml volumetric flask. Add 1 ml of the stock of each compound of interest. Dilute to volume with methanol. This concentration is 20 ug/mL.

Add 3 ml of methanol to a vial. Remove 1 ml of the 20 ug/ml solution and add it to the 3 mls of methanol. Mix gently by inversion.This solution's concentration is now 5 ug/ml.

Label all standards with the name of the standard, date prepared, initials of person preparing the standard, the concentration and the solvent.

METHOD FILE LIST ( 1 PAGE )

ATTACHMENT 5 ( 22 PAGES )

ATTACHEMENT 6 ( 1 PAGE )

ATTACHMENT 7 ( 2 PAGES ) - SEE QC COORDINATOR FOR HARD COPY.