Analysis of Perchlorate in Groundwater by Electrospray Ionization Mass Spectrometry/Mass Spectrometry
Koester, C.J.; H.R. Beller*; R.U. Halden
Lawrence Livermore National Laboratory, Livermore, CA
Environmental Science & Technology, Vol 34 No 9, p 1862-1864, 2000

An electrospray ionization mass spectrometry/mass spectrometry (ESI/MS/MS) method was developed to measure part-per-billion (µg/L) concentrations of perchlorate in ground water. Selective and sensitive perchlorate detection was achieved by operating the mass spectrometer in the negative ionization mode and by using MS/MS to monitor the ClO4- to ClO3- transition. The method of standard additions was used to address the considerable signal suppression caused by anions that are typically present in ground water, such as bicarbonate and sulfate. ESI/MS/MS analysis was rapid, accurate, reproducible, and provided a detection limit of 0.5 µg/L perchlorate in ground water. Accuracy and precision of the ESI/MS/MS method were assessed by analyzing performance evaluation samples in a ground water matrix (4.5-75 µg/L perchlorate) and by comparing ion chromatography (IC) and ESI/MS/MS results for local ground water samples (<0.5-35 µg/L perchlorate). Results for the performance evaluation samples differed from the certified values by 4-13%, and precision ranged from 3 to 10% (relative standard deviation). The IC and ESI/MS/MS results were statistically indistinguishable (P > 0.05) for perchlorate concentrations above the detection limits of both methods.

The Analysis of Perchlorate in Well Water by Suppressor Based Ion Chromatography
Kildew, Brian R. (Alltech Associates, Deerfield, IL); Raaidah Sarri-Nordhaus
Pittcon 2000: Pittsburgh Conference on Analytical Chemistry and Applied Spectroscopy [50th], 12-17 March 2000, New Orleans, LA

The analysis of perchlorate in well water is simple and accurate by suppressor-based ion chromatography. The methacrylate-based anion exchanger column with either carbonate/bicarbonate or carbonate/bicarbonate in p-cyanophenol provides good peak shape with a short retention time for perchlorate. The detection limit for perchlorate can be reduced to the low parts-per-billion range using the methacrylate-based anion exchanger column with these mobile phases.

Anion-Selective CHEMFETs
Wroblewski, Wojciech (Warsaw Univ. of Technology); M. Dawgul (Institute of Biocybernetics and Biomedical Engineering); W. Torbicz; Z. Brzozka (Warsaw Univ. of Technology)
Optoelectronic and Electronic Sensors II
The International Society for Optical Engineering (SPIE), Bellingham, WA. Proceedings of SPIE, Vol 3054, p 197-203, 1997

This paper presents the first nitrite- and perchlorate-selective chemically modified field effect transistors (CHEMFETs) based on a plasticized PVC membrane containing anion-sensitive receptors. The designed sensors exhibit good selectivities for primary ions over other inorganic anions. These microdevices can be applied in the determination and monitoring of nitrite and perchlorate anions, even in the presence of some interfering ions.

http://www.ch.pw.edu.pl/~dybko/papers/ele/paper5.htm

Application Note: Analysis of Low Concentrations of Perchlorate in Drinking Water and Ground Water by Ion Chromatography
Dionex Corp., Sunnyvale, CA
Application Note 121, 4 pp, Jul 2000

According to a Dionex application note, perchlorate was determined in drinking water down to ~2.5µg/l levels by ion chromatography. Sample (1000 µl) was analyzed on an IonPac AS11 analytical column (25 cm x 4 mm i.d.) equipped with an IonPac AG11 guard column (5 cm x 4 mm i.d.) with 100mM-NaOH as eluent (1 ml/min) over 12 minutes and suppressed conductivity detection. The calibration graph was linear up to 100µg/l with a detection limit of 2.5µg/l. The note contains chromatograms.

Application of Capillary Electrophoresis for the Determination of Inorganic Ions in Trace Explosives and Explosive Residues
Kishi, T.; J. Nakamura; H. Arai, Natl. Res. Inst. Police Sci., Tokyo, Japan
Electrophoresis, Vol 19 No 1, p 3-5, Jan 1998

Trace perchlorate explosives on a pair of cotton gloves were extracted with H2O and analyzed by capillary electrophoresis in a fused-silica capillary, with detection of chloride, nitrate and perchlorate. Residue from a homemade chlorate explosive (potassium chlorate plus fuel) was dissolved in H2O and analyzed in a similar manner, as was an aqueous extract of a residue from an emulsion explosive.

Automatic Liquid-Liquid Extraction Flow Injection Analysis Determination of Trace Amounts of Perchlorate With Spectrophotometric Detection
Ensafi, Ali A.; B. Rezaei, College of Chemistry, Isfahan University of Technology, Isfahan, Iran
Analytical Letters, Vol 31 No 1, p 167-177, 1998

The authors propose an extractive flow injection analysis for rapid, sensitive, and selective determination of perchlorate by spectrophotometric detection. The method is based on the extraction of perchlorate with Brilliant Cresyl Blue on methyl isobutyl ketone at pH 6.0. Perchlorate can be determined in the range of 0.008-1.00 µg/ml with a limit of detection of 0.003 µg/ml and rate of 30 ± 5 samples/hour. The effects of reagent concentration, pH, manifold variables, and diverse ions are completely studied. The method was tested for the determination of perchlorate in salt samples.

Catalytic Determination of Perchlorate Using a Modified Carbon Paste Electrode
Neuhold, C.G.; K. Kalcher; X. Cai; G. Raber
Analytical Letters, Vol 29, p 1685-1704, 1996

A carbon paste electrode chemically modified with the liquid anion exchanger Amberlite LA2 was used for the voltammetric determination of nitrate and perchlorate in aqueous solutions, based on the catalytic effect of both species on the voltammetric current responses of thallium. Thallium (III) can be accumulated as TlCl4 externally under open circuit conditions from an acidic solution onto the surface of the modified carbon paste electrode, giving a reduction signal at -0.88 V vs. SCE, and reoxidation signal at -0.7 V vs. SCE in cyclic voltammetry. Both signals are enhanced catalytically upon addition of nitrate or perchlorate to the preconcentration solution. The peak increase of the re-oxidation signal was exploited for quantitative purposes with differential pulse voltammetry. A procedure for the quantitative determination of both analytes is described. The influence of various parameters affecting the results, such as pH value of the measurement and analyte solution is discussed. The dependence of the peak increase on accumulation time and concentration of nitrate or perchlorate is shown. The detection limits were found to be 0.5 mg/L for nitrate and 0.05 mg/L for perchlorate respectively. The applicability of the method for the determination of the analyte species in various samples was studied.

³⁵Cl and ³⁷Cl Magic-Angle Spinning NMR Spectroscopy in the Characterization of Inorganic Perchlorates
Skibsted, Jrgen; Hans J. Jakobsen, Instrument Centre for Solid-State NMR Spectroscopy, Dept. of Chemistry, Univ. of Aarhus, Aarhus, Denmark
Inorganic Chemistry, Vol 38 No 8, p 1806-1813, 1999

³⁵Cl quadrupole coupling constants (CQ), asymmetry parameters (Q), and isotropic chemical shifts (iso) have been determined for a series of inorganic perchlorates from ³⁵Cl magic-angle spinning (MAS) NMR spectra at 14.1 T. Illustrative ³⁷Cl MAS NMR spectra are obtained and analyzed for some of the samples. For perchlorate anions with quadrupolar couplings less than about 1 MHz, the ³⁵Cl/³⁷Cl NMR parameters are most precisely determined from the full manifold of spinning sidebands observed for the satellite transitions while line-shape analysis of the central transition is employed for the somewhat larger quadrupolar couplings. The environments for the individual perchlorate anions are best characterized by the quadrupole coupling parameters (e.g., CQ ranges from 0.3 to 3.0 MHz), while the dispersion in the isotropic ³⁵Cl chemical shifts is small (1029 ppm < iso < 1049 ppm) for the perchlorates studied. Due to the variation in quadrupole coupling parameters, ³⁵Cl MAS NMR may conveniently be employed for identification of anhydrous and hydrated phases of perchlorates, in studies of phase transitions, hydration reactions, and the composition of mixed phases. The perchlorates studied include the anhydrous and the anhydrous and/or hydrated forms.

Construction and Evaluation of Ion Selective Electrodes for Perchlorate with a Summing Operational Amplifier: Application to Pyrotechnics Mixtures Analysis
Pérez-Olmos, Ricardo; Ainoa Rios; María P. Martín; Rui A.S. Lapa; José L.F.C. Lima
The Analyst, Vol 124 No 1, p 97-100, Jan 1999

An ion selective-electrode (ISE) for perchlorate was fabricated by applying four separate but identical membranes on to a conductive graphite/epoxy support. The membranes were prepared from PVC, o-nitrophenyl octyl ether, dibutyl phthalate, and tetra-octylammonium chloride. When the use of the ISE for the direct potentiometric determination of perchlorate was evaluated, the lower linear response limit was 5.1 µM perchlorate and the detection limit was 1.2 µM, with a response time of 13-15 seconds. The sensor was applied to propellants and pyrotechnic mixtures and had a life of more than 10 months.

Determination of Nanomolar Levels of Perchlorate in Water by ESI-FAIMS-MS
Handy, Russell; David A. Barnett; Randy W. Purves; Gary Horlick; Roger Guevremont
Journal of Analytical Atomic Spectrometry, Vol 15 No 8, p 907-911, Aug 2000

Electrospray ionization (ESI) was used to generate gas-phase anions that were subsequently separated by high-field asymmetric waveform ion mobility spectrometry (FAIMS) and detected by quadrupole mass spectrometry (MS). ESI-FAIMS-MS provided selective and sensitive determination of perchlorate at low nanomolar levels, relatively free from the interferences commonly observed for this analysis using conventional ESI-MS. For instance, the gas-phase separation of ions in FAIMS eliminated isobaric overlaps of bisulfate and dihydrogen phosphate with perchlorate. Using the FAIMS interface, analysis yielded a signal-to-background ratio (S/B) improvement of over four orders of magnitude compared with ESI-MS. The detection limit for perchlorate was 1 nM (~ 0.1 ppb).

Determination of Perchlorate at Parts-Per-Billion Levels in Plants by Ion Chromatography
Ellington, J.J.; J.J. Evans
Journal of Chromatography--A, Vol 898 No 2, p 193-199, 17 Nov 2000

Abstract not available.

Determination of Perchlorate at Trace Levels in Drinking Water by Ion-Pair Extraction with Electrospray Ionization Mass Spectrometry
Magnuson, Matthew L. (U.S. EPA, Cincinnati, OH); Edward T. Urbansky; Catherine A. Kelty
Analytical Chemistry, Vol 72 No 1, p 25-29, 2000

This paper describes the analysis of perchlorate in water by liquid-liquid extraction followed by flow injection electrospray mass spectrometry (ESI/MS). Alkyltrimethylammonium salts and other cationic surfactants were used to ion-pair aqueous perchlorate, forming extractable ion pairs. The cationic surfactant associates with the perchlorate ion to form a complex detectable by ESI/MS. The selectivity of the extraction and the mass spectrometric detection increases confidence in the identification of perchlorate. The method detection limit for perchlorate determined after seven replicate injections was 100 ng L^-1 (parts per trillion). Perchlorate has been added to the U.S. EPA's Drinking Water Contaminant Candidate List.

Determination of Trace Level Perchlorate in Drinking Water and Ground Water by Ion Chromatography
Jackson, P. E.; M. Laikhtman; J.S. Rohrer, Dionex Corp., Sunnyvale, CA
Presented at the International Ion Chromatography Symposium, held in Osaka, Japan, 28 Sep-1 Oct 1998
Journal of Chromatography--A, Vol 850, No 1/2, p 131-135, 30 Jul 1999

Samples were analyzed on an IonPac AG11 guard column and an IonPac AS11 analytical column with a mobile phase of 0.1M-NaOH and suppressed conductivity detection, with use of an ASRS-ULTRA suppressor at 0.3 A. Calibration graphs were linear for 2.5-100 µg/ml of perchlorate, with a detection limit of 0.3 µg/l. When seven replicates of a 2.5 µg/l standard were injected, the retention time RSD was 0.5% and the peak area RSD was 2.4%. There was no interference from 22 common anions. Tests were also carried out on a new column, the IonPac AS16, with its IonPac AG16 guard column. The AS16 was specifically developed for polarizable anions, such as perchlorate, iodide, thiosulfate and thiocyanate. The new column is more hydrophilic than the AS11, has higher capacity (allowing the analysis of samples with higher salt contents) and higher peak efficiency. An example of analysis of 5 µg/l of perchlorate in ground water is illustrated.

Electrochemiluminescent Determination of Perchlorate by Solvent Extraction in the Presence of Ru(bpy)32+
Xu, G.; S. Dong, Lab. Electroanal. Chem., Changchun Inst. Applied Chem., Chinese Acad. Sci., Changchun, China
Electrochemistry Communications, Vol 1 No 10, p 463-466, Oct 1999

For the highly sensitive determination of perchlorate, the authors propose a method based on solvent extraction in the presence of Ru(bpy)32+ and followed by Ru(bpy)32+ electro-chemiluminescent determination. The detection limit was 50nM perchlorate and the RSD (n = 10) was 1.6%. Interference studies suggest that this method is selective for the determination of perchlorate.

An Improved Ion Chromatographic Method for Low Level Perchlorate Analysis
Jackson, Peter E., Dionex Corp., Sunnyvale, CA
[PowerPoint presentation] 33 pp, 2000

The author used these presentation pages to discuss the optimized Dionex perchlorate method. He states in his conclusion that the method is an optimized, interference free method for analysis of low µg/L perchlorate in ground and tap water that is based on 1000 uL injection, AS11 column, 100 mM NaOH eluent and suppressed conductivity detection using ASRS. It has an MDL of 0.25 µg/L, MRL of ~ 1.0 µg/L, a linear calibration range of 2 to 100 µg/L, and recovery of 98-99% at 2.5 µg/L level.

http://www.epa.gov/ogwdw000/ccl/perchlor/jackson.pdf

Improved Method for the Determination of Trace Perchlorate in Ground and Drinking Waters by Ion Chromatography
Jackson, P.E.; S. Gokhale; T. Streib; J.S. Rohrer; C.A. Pohl, Dionex Corp., Sunnyvale, CA
Journal of Chromatography--A, Vol 888 No 1/2, p 151-158, 4 Aug 2000

An improved ion chromatographic method has been developed for the determination of low µg/l levels of perchlorate in ground and drinking waters based on a Dionex IonPac AS16 column, a hydroxide eluent generated using an EG40 automated eluent generator, large loop (1 ml) injection, and suppressed conductivity detection. The method is free of interferences from common inorganic anions, linear over the range of 2-100 µg/l perchlorate, and quantitative recoveries are obtained for low µg/l levels of perchlorate in spiked ground- and drinking-water samples. The method has a detection limit of 0.15 µg/l.

Method 314.0--Determination of Perchlorate in Drinking Water Using Ion Chromatography
Hautman, Daniel P. (U.S. EPA, Office of Ground Water and Drinking Water); David J. Munch; Andrew D. Eaton (Montgomery Watson Laboratories); Ali W. Haghani
Method 314.0, Rev 1.0, Nov 1999

This method covers the determination of perchlorate in reagent water, surface water, ground water, and finished drinking water using ion chromatography. It is recommended for use only by or under the supervision of analysts experienced in the use of ion chromatography and in the interpretation of the resulting ion chromatograms. The method calls for a 1.0 mL volume of sample to be introduced into an ion chromatograph (IC). Perchlorate is separated and measured, using a system comprised of an ion chromatographic pump, sample injection valve, guard column, analytical column, suppressor device, and conductivity detector.

http://www.epa.gov/OGWDW/methods/met314.html

Microscale Extraction of Perchlorate in Drinking Water with Low Level Detection by Electrospray Mass Spectrometry
Magnuson, M.L.; E.T. Urbansky; C.A. Kelty, U.S. EPA, Water Supply and Resources Div., Cincinnati, OH
Talanta, Vol 52 No 2, p 285-291, 21 Jun 2000

Perchlorate in drinking water has been determined at sub-microgram/l levels by extraction of the ion-pair formed between the perchlorate ion and a cationic surfactant with electrospray mass spectrometry detection, a technique that compared favorably with results determined by ion chromatography. Confidence in the selective quantification of the perchlorate ion is increased through both the use of the mass based detection as well as the selectivity of the ion pair. This study investigates several extraction solvents and experimental work-up procedures in order to achieve high sample throughput. The method detection limit for perchlorate was 300 ng/l (parts-per-trillion) for methylene chloride extraction and 270 ng/l for IBMK extraction. Extraction with methylene chloride produces linear calibration curves, enabling standard addition to be used to quantify perchlorate in drinking water.

Miniaturized Reference Electrode Based on Perchlorate-Sensitive Field Effect Transistor
Pöötter, W.; C. Dumschat; K. Cammann
Analytical Chemistry, Vol 67 No 24, 4586-4588, 1995

Abstract not available.

Monitoring the Solid Phase Synthesis Using Ion-Selective Electrode
Pátek, Marcel (Selectide Corp., Tucson, AZ); Sylvia Bildstein; Zuzana Flegelová (Biopharm, Research Inst. of Biopharmacy and Veterinary Drugs, Jílové, Czech Republic)
Tetrahedron Letters, Vol 39 No 8, p 753-756, 1998

Ion-selective electrodes (ISEs) offer another noninvasive method for monitoring and quantitative determination of basic functionalities on solid support. The ISE method is based on complete protonation of basic functionalities after treatment of the resin with a large excess of 1% HClO4. After thorough washing with water, the bound anion is eluted with a suitable base providing an easily detectable perchlorate anion that can be quantified potentiomentrically with a perchlorate ion-selective electrode. Limitations of this technique include the requisite use of water-compatible solid supports and basic functionalities possessing a pKHB+ > 7.

http://www.5z.com/divinfo/procedures/ise.html

The New Analytical Method and Related Issues
Donnelly, Joseph
Perchlorate Issue Group Presentations, AWWA website

The California Department of Health Services (CDHS) has developed an interim analytical method protocol for perchlorate. The method detection limit of 0.7 µg/l in reagent water addresses the desired 4 µg/l detection limit in aqueous environmental matrices, and an 18 ppb action level. This ion chromatographic (IC) method has been used to detect perchlorate in water supplies in California, Arizona, and Nevada. Goals for an analytical method include that it be simple, rugged, use widely-available equipment and expertise, be cost-effective, reliable, and produce data of known and adequate quality. The CDHS method uses a strong base eluent. Strong acid is used to regenerate the column after analysis. The column is an anion-exchange type, from which perchlorate elutes relatively late (about 7.5 minutes retention time). A general conductivity detector is used. The potential for false positives and negatives should be studied. Potential analytical interferences could include iodide, bromate, iodate, thiocyanate, sulfate, and nitrate anions. The ion chromatographic retention time of perchlorate shifts with concentration. For example, one research group reported a retention time of 35 minutes for a 50 ppm solution. This time was shortened to 20 minutes for a 2 parts-per-thousand solution. Confirmatory analytical techniques would be desirable, both qualitative (identity) and quantitative (precision and accuracy). Other methods for perchlorate analysis are available, but either are not suitable or have not been optimized for trace-level environmental analysis. Capillary electrophoresis has been applied to perchlorate analysis in the ppm concentration level, with general detectors, such as ultraviolet, and with specific detectors such as Raman or mass spectrometric. Electrospray mass spectrometry has also been used to detect perchlorates. The following capabilities of the CDHS method should be defined: confirmation of analyte identity, and absence of interference (false positives, false negatives); single and multiple laboratory precision and accuracy; matrix effects such as dissolved solids/conductivity. Sample holding times and sample preservation should also be investigated. One goal for future research is to determine the stability of perchlorate in the environment, particularly aqueous ecosystems. The thermodynamics of perchlorate decomposition are favorable; it is potentially a powerful oxidizer. The kinetics are slow at ambient temperatures and in the absence of catalysis. Whether biological systems provide biochemical catalysts has not been found to date in the literature search. This question is key to answering concerns about the relative toxicity of the perchlorate anion in drinking water. In summary, several laboratory-based studies of the Cal-DHS method would be worthwhile.

http://www.awwarf.com/newprojects/percsum.html

Perchlorate Identification in Fertilizers
Susarla, S.; T.W. Collette; A.W. Garrison; N.L. Wolfe; S.C. McCutcheon, U.S. EPA,Natl. Exposure Res. Lab., Athens, GA
Environmental Science & Technology, Vol 33 No 19, p 3469-3472, 1 Oct 1999

After fertilizer samples were dispersed in H2O, centrifuged, and further diluted before analysis, ion chromatography was performed using a Dionex 500 ion chromatograph. The detection limit was 10 µg/l. Capillary electrophoresis was used as confirmation. The limit of detection was 10 mg/l perchlorate and the average RSD was 1.1%. Further confirmation was provided by Raman spectrometry. The types and configurations of the analytical instruments are detailed. Results are presented and discussed with reference to the possible action of fertilizers as sources of perchlorate in the food chain.

Perchlorate in the Environment [Papers presented at the 218th American Chemical Society symposium in the Division of Environmental Chemistry, 22-24 August 1999, New Orleans, Louisiana]
Urbansky, E.T. (ed.)
Plenum Publishers, New York. ISBN: 030646389X. Environmental Science Research, V. 57, c2000

These collected papers comprise the first comprehensive book to address perchlorate as a potable water contaminant. The two main topics are analytical chemistry (focusing on ion chromatography and electrospray ionization mass spectrometry), and treatment or remediation. Also included are topics such as ion exchange, phytoremediation, bacterial reduction of perchlorate, bioreactors, and in situ bioremediation. To provide complete coverage, background chapters on fundamental chemistry, toxicology, and regulatory issues are also included. The authors are environmental consultants, government researchers, industry experts, and university professors from a wide array of disciplines.

Perchlorate-Selective MEMFETs and ISEs Based on a New Phosphadithiamacrocycle
Errachid, A.; C. Perez-Jimenez; J. Casabo; L. Escriche; J.A. Munoz; A. Bratov; J. Bausells
Centre Nacional de Microelectronica, CSIC, Barcelona, Spain
Sensors and Actuators B (Chemical), Vol B43 No 1-3, p 206-210, Sep 1997

A new phosphadithiamacrocycle has been synthesized and used as a neutral carrier in ion-selective PVC membranes that have been applied to the development of perchlorate-selective MEMFETs and ISEs. Both devices have shown a wide working pH range and better response and selectivity for perchlorate ions than conventional ClO₄ ^- electrodes based on hydrophobic cations as electroactive species.

Potentiometry with Perchlorate and Fluoroborate Ion-Selective Carbon Paste Electrodes
Jezkova, J.; J. Musilova; K. Vytras, Dept. Anal. Chem., Fac. Chem. Technol., Univ. Pardubice, Pardubice, Czech Republic
Electroanalysis, Vol 9 No 18, p 1433-1436, Dec 1997

The electrodes were used for both direct potentiometric measurements and potentiometric titration with 0.1M-cetylpyridinium chloride. The electrodes had a rapid response, low resistance and limits of detection and selectivity similar to the limits of commercial membrane electrodes.

Quantitation of Perchlorate Ion by Electrospray Ionization Mass Spectrometry (ESI-MS) Using Stable Association Complexes with Organic Cations and Bases to Enhance Selectivity
Urbansky, Edward T.; Matthew L. Magnuson; David Freeman; Christopher Jelks, U.S. EPA, Cincinnati, OH
Journal of Analytical Atomic Spectrometry, Vol 14 No 12, p 1861-1866, 01 Dec 1999

Although ion chromatographic methods presently offer the lowest limit of detection for quantitation of trace levels of perchlorate ion in water (~40 nM (4 ng ml^-1)), chromatographic retention times are not considered to be unique identifiers and often cannot be used in legal proceedings without confirmatory testing. Mass spectrometry can provide such confirmation; however, detection capabilities can impose a practical limitation on its use. Moreover, quadrupole mass spectrometers cannot provide sufficient accuracy and precision in m/z to identify conclusively an ion as perchlorate when samples are run directly without prior chromatographic or electrophoretic separation. The authors report on the abilities of tetralkylammonium cations and minimally nucleophilic, sterically hindered organic bases to increase selectivity in the electrospray ionization mass spectrometric (ESI-MS) determination of perchlorate ion without concomitant loss of sensitivity. The chlorhexidine-perchlorate complex (m/z equals 605) can be observed even in the presence of equiformal nitrate, nitrite, hydrogen sulfate, chloride, bromide, bromate, and chlorate (all together) down to approximately 1 µM; thus, the method is rugged enough to find application to systems containing multiple inorganic anions.

Quantitative Determination of Perchlorate Ion Concentrations in Urine
Richman, K., American Pacific Corp., Cedar City, UT
1999 American Industrial Hygiene Conference & Exposition, Toronto, Ontario, Canada
American Industrial Hygiene Association, Fairfax, VA

Perchlorate (ClO4) concentration in water can be quantitatively analyzed using ion chromatography, and the technique has been adapted for the analysis of urine samples. Instrument parameters included a Dionex Ionpac AS11, AG11 column, elution with 100 mM NaOH, a flow rate of 1.00 mL/min, and an injection volume of 1000 mL. Suppressed conductivity was used for detection (Dionex ASRS-II, autosuppression external water mode) at a column temperature of 30 degrees C. Perchlorate ions eluted from the chromatography column in less than 10 minutes, and all urine components eluted from the column in less than 20 minutes. A practical lower limit for quantifying the perchlorate level was determined to be 0.5 parts per million (ppm).

Rapid Normal Raman Spectroscopy of Sub-ppm Oxy-Anion Solutions: The Role of Electrophoretic Preconcentration
Kowalchyk, Will K.; Patrick A. Walker III; Michael D. Morris
Applied Spectroscopy, Vol 49 No 8, Aug 1995

Normal Raman spectroscopy is used as an on-line detector for capillary electrophoresis to detect sub-ppm mixtures of nitrate and perchlorate in water. Field-amplified injection, a form of sample stacking, into a running electrolyte of 0.1 M KCl increases the analyte concentration at the detection window by up to 1800 times its starting value. Raman bands of nitrate (1047 cm^-1) and perchlorate (934 cm^-1) are measured in a total separation time of less than 3 minutes, using only 1 second integration times. The authors demonstrate the Raman spectroscopy of solutions originally 1 x 10^-5 M nitrate (620 ppb) and perchlorate (1 ppm).

Recent Developments in the Analysis of Perchlorate Using Ion Chromatography
Jackson, P.E.; S. Gokhale; J.S. Rohrer, Dionex Corporation, Sunnyvale, CA
Abstracts of Papers - American Chemical Society, Division of Environmental Chemistry, 218^th National Meeting, 22-26 August 1999, New Orleans, LA. [Session title: Perchlorate in the Environment--Toxicological, Ecological, Analytical, Water Treatment and Site Remediation Developments in Pure and Applied Science]
Plenum Pub., New York. ISBN: 9-8412-3685-2. Vol 218 Pt 1, 1999

Abstract not available.

Response Characteristics of Anion-Selective Polymer Membrane Electrodes Based on Gallium(III), Indium(III) and Thallium(III) Porphyrins
Steinle, Erich D.; Ulrich Schaller; Mark E. Meyerhoff *
Dept. of Chemistry, Univ. of Michigan, Ann Arbor, MI
Analytical Sciences (Japan Society for Analytical Chemistry), Vol 14 No 1, Feb 1998

The researchers examined the potentiometric anion responses of ion-selective electrodes prepared with polymeric membranes doped with gallium(III), indium(III) and thallium(III) metalloporphyrins. When inserted into either octaethyl- or tetraphenyl-porphyrin derivatives and subsequently incorporated into plasticized polyvinylchloride membranes, these group XIII metals serve as anion ionophores with selectivity patterns that deviate significantly from the classical Hofmeister series for anions. The gallium(III) porphyrin-based electrodes exhibit significantly enhanced response toward fluoride, whereas the indium(III) and thallium(III) porphyrins display some preference for chloride and also effectively discriminate less hydrated anions such as perchlorate and nitrate. All of the metalloporphyrins investigated have been determined to function via a charged carrier response mechanism. This mechanism is elucidated by correlating the effect of adding lipophilic ionic sites, either cationic (quaternary ammonium) or anionic (tetraphenylborate) salts, to the observed anion selectivity and response patterns of the metalloporphyrin-based liquid /polymer membrane electrodes.

http://wwwsoc.nacsis.ac.jp/jsac/analsci/pdfs/a14_0079.pdf

Selective Determination of Perchlorate at Sub-ppb Levels Using a Unique Stationary Phase
Bogren, Karin
Pittcon 2000: Pittsburgh Conference on Analytical Chemistry and Applied Spectroscopy [50th], 12-17 March 2000, New Orleans, LA

Abstract not available.

System Toggles Between IC and FIA
Water Technology News, Vol 7 No 11, Feb 2000

Lachat Instruments has developed an Ion Chromatography (IC) method for the isolation of perchlorate. Lachat's IC method for separating perchlorate detects the ion at concentrations as low as 4 ppb in ground water. Contact: Lachat Instruments, 6645 W. Mill Rd. Milwaukee, WI 53218. (414) 358-4200, Fax: (414) 358-4206.

Thermo Orion Ion Selective Electrodes

The Plastic Membrane Half-Cell is a Thermo Orion Half-Cell ISE that is useful for ammonium, calcium, chloride, fluoroborate, nitrate, perchlorate, potassium, and water hardness. The design of the sensing element determines the sensitivity and selectivity for the ion of interest. This electrode has a range that permits the sensing of perchlorate at 1.0 to 7 x 10^-6 M, 99,500 to 0.7 ppm, at 0-40 degrees C.
Contact: Thermo Orion, 500 Cummings Center, Beverly, MA 01915, (978) 232-6000 or (800) 225-1480.

Trace Level Determination of Perchlorate in Water Matrices and Human Urine Using ESI-FAIMS-MS
Ells, Barbara; David A. Barnett; Randy W. Purves; Roger Guevremont
Journal of Environmental Monitoring, Vol 2 No 5, p 393-397, Oct 2000

Abstract not available.

Using Ion Chromatography to Detect Perchlorate
Okamoto, Howard S.; Dharmendra K. Rishi,Frank J. Baumann, S. Kusum Perera, William R. Steeber
California Dept. of Health Services, Berkeley, CA
Journal AWWA, Vol 91 No 10, p 73-84, Oct 1999

Preliminary studies by the U.S. EPA established 4-18 µg/L as a "safe" concentration for perchlorate in drinking water; however, until recently no available method could detect this toxic substance at such low concentrations. Researchers at the California Department of Health Services initiated a study to develop and validate a new method to analyze trace amounts of perchlorate in water. The "California DHS Method" relies on ion chromatography with suppressed conductivity. It was found to provide reliable and reproducible results in detecting perchlorate at concentrations >4 µg/L in ground water and surface water. It has also been successfully used to test California drinking water wells considered vulnerable to perchlorate contamination. The method can provide quality results that should be acceptable to regulatory and health agencies.

The World of Separation Science: IICS '99--A Solid Year of Progress in Ion Analysis [editorial]
Stevenson, Robert
American Laboratory News, Apr 2000

Ion chromatography (IC) is not on every radar screen, but a small group of researchers are making consistent progress in improving ease of use and detection limits. Economic impact is huge, since IC is employed to monitor water used in the production of semiconductors, electrical power generation, drinking water disinfection, and numerous environmental sites. In the area of column selection in IC, Jeff Rohrer of Dionex compared several columns for the analysis of polarizable anions with a special emphasis on perchlorate. Perchlorate is cropping up in many unexpected places, primarily as a result of propellants in space and military activities. Perchlorate is suspected of affecting thyroid function as well as causing Reye's syndrome. Last year, Mr. Rohrer described the use of the AS-16 column with the EG 40 eluent generator. This provided better peak shape than the AS-11. However, there was a need to determine traces of perchlorate in groundwater with high chloride or sulfate. Although there are sample preparation techniques that can reduce the background, such as chloride precipitation with silver ion, these techniques are extra steps and may also occlude part of the sample. Thus, the Dionex column developers devised a high-capacity version called the AS-16 HC. The column, combined with the eluent generator, provides an LOD of less than 0.2 ppb with a linear range extending up to 10 ppb in the presence of high ppm levels of sulfate or chloride. A study for thiosulfate showed similar results.