Chromium VI

The purpose of this section is to identify online analytical methods that can be used for detecting, measuring, and/or monitoring chromium. The intent is not to provide an exhaustive list, but to identify well-established methods that are used as standards for analysis, particularly those used for environmental samples and approved by EPA and the National Institute for Occupational Safety and Health (NIOSH).More innovative methods are also included if their components are commercially available.

Detection

Adding Method 6800 to the Hexavalent Chromium Analysis Toolbox
Mark Bruce, Albert Vicinie III, and William Reinheimer

Brief explanation of using SW-846 Method 6800 (Elemental and Speciated Isotope Dilution Mass Spectrometry) for analyzing hexavalent chromium in difficult matrices.

Chromate Sampling Methods and Data Analysis
David Carpenter, Karta Technology, Inc., San Antonio, TX.
NTIS: ADA397830, 21 pp, Sep 2001

The OSHA Ceiling Standard is found in 29 CFR 1910. 1000 Table Z-2, for chromic acid and chromate. The ACGIH Standard is more complex; based upon epidemiological studies, it considers chromates confirmed human carcinogens. Two analytical methods commonly used when quantifying chromate exposures are 1) a general metals screen, NIOSH Method 7300 and 2) a specific analysis for hexavalent chromium, NIOSH Method 7600. There are three different calculations depending upon the analytical method used.

Comparison of Three Sampling and Analytical Methods for the Determination of Airborne Hexavalent Chromium
James M. Boiano, Marjorie E. Wallace, W. Karl Sieber, Jensen H. Groff, Jin Wang, and Kevin Ashley.
Journal of Environmental Monitoring, 2:329-333, 2000

A field study was conducted to compare the performance of two laboratory-based procedures (OSHA Method ID-215 and NIOSH Method 7605) and a field-portable method (NIOSH Method 7703). Based on analysis of variance (ANOVA) results, no statistically significant differences were observed between mean values measured using each of the three methods. Small but statistically significant differences were noted between results obtained from performance evaluation samples for the NIOSH field method and the OSHA laboratory method.

Demonstration/Validation of the Snap Sampler Passive Ground Water Sampling Device for Sampling Inorganic Analytes at the Former Pease Air Force Base
L. Parker, N. Mulherin, G. Gooch, W. Major, R. Willey, T. Imbrigiotta, J. Gibs, and D. Gronstal. ESTCP Project ER-0630, ERDC/CRREL TR-09-12, 116 pp, 2009

Lab studies and a field demonstration were conducted to determine the ability of the Snap Sampler to recover representative concentrations of several types of inorganic analytes (including perchlorate, arsenic, and chromium) from groundwater. Samples taken using a Snap Sampler were compared with samples collected using conventional low-flow purging and sampling and a regenerated cellulose passive diffusion sampler, and analyte concentrations were found to be equivalent to those in the low-flow samples with the exception of unfiltered iron, where concentrations were significantly higher in the Snap Sampler samples.

Environmental Forensics: Contaminant-Specific Guide
Robert D. Morrison and Brian Murphy.
Elsevier Academic Press, Boston. ISBN: 0125077513, 576 pp, 2006

Environmental forensics is the application of scientific techniques for the purpose of identifying the source and age of a contaminant. This book discusses the following contaminants and contaminant groups: mercury, asbestos, lead, chromium, methane, radioactive compounds, pesticides, perchlorate, polychlorinated biphenyls, arsenic, chlorinated solvents, polyaromatic hydrocarbons, crude oil, gasoline, microbes, and compounds found in sewage.

Environmental Technology Verification Report: Field Portable X-Ray Fluorescence Analyzer-Niton XL Spectrum Analyzer
U.S. Environmental Protection Agency, Office of Research and Development.
EPA 600-R-97-150, 93 pp, 1998
Contact: Teresa Harten, harten.teresa@epa.gov

Using the demonstration-derived precision RSD results and the coefficient of determination as the primary qualifiers to screen a suite of metals, the XL Spectrum Analyzer produced data of qualitative screening level for total chromium. Since a precision RSD value was not determined for chromium, no data quality level can be assigned.

Environmental Technology Verification Report: Field Portable X-Ray Fluorescence Analyzer-Spectrace TN 9000 and TN Pb Field Portable X-Ray Fluorescence Analyzers
U.S. Environmental Protection Agency, Office of Research and Development.
EPA 600-R-97-145, 119 pp, 1998
Contact: Teresa Harten, harten.teresa@epa.gov

Using the demonstration-derived precision RSD results and the coefficient of determination as the primary qualifiers to screen a suite of metals, the TN 9000 produced data of qualitative screening level for total chromium. In the operation of these instruments, the user must be aware that FPXRF analyzers do not respond well to chromium and that detection limits may be 5 to 10 times greater than conventional laboratory methods.

ESTCP Cost and Performance Report: Site Characterization and Analysis Penetrometer System (SCAPS) Heavy Metal Sensors
Environmental Security Technology Certification Program, U.S. Department of Defense, CU-9716, 45 pp, 2003

This report describes the cost and performance of X-Ray Fluorescence and Fiber Optic - Laser-Induced Breakdown Spectroscopy probes that can be driven into the subsurface by a cone penetrometer rig or direct push rig. The instruments detect a number of heavy metals including total chromium.

European Virtual Institute for Speciation Analysis (EVISA)

EVISA: All About Chromium

Offers wide ranging information on chemical speciation issues including analytical methods and has 113 specific links for chromium.

Evaluation of Methods for Quantifying Cr(VI) and Cr(III) in Soils and Wastes
Buckley, B. and R. Stiles.
SR06-051, 33 pp, 2009

Chromium speciation is a two-step process and involves complicated chemistry to perform the extraction without interconversion of the two predominant species, followed by multiple analytical methods that are precise, sensitive, and quantitative. An interlaboratory study comparing the three EPA quantitation methods--7196A, 7199, and 6800--demonstrated a statistically significant and consistent 31.6% difference between method 6800 and the results from the other two quantification methods (7196A and 7199) using the same extraction protocol (3060A). While it is primarily the analytical methods that are examined in this study, it is the development of a reproducible and repeatable extraction protocol that ultimately will determine whether the analytical methodologies are effective at quantifying the actual Cr(VI) content in a soil or waste matrix.

Field Evaluation of 1.75 Groundwater Profiler and Field Screening Device for On-Site Contamination Profiling of Chromium(Vi) in Groundwater (Abstract)
Dutta, S., T.M. Christy, W. McCall, and P. Kurup. | Environmental Earth Sciences 80:241(2021)

A direct push 1.75-inch groundwater profiler (GWP) and portable field screening device were developed to facilitate rapid, cost-effective, on-site detection of heavy metals in groundwater, surface water, and sediment pore water. The GWP obtains groundwater samples from multiple depths in a single push, and the portable field screening device uses novel disposable sensors. Extensive fieldwork was performed at a Cr(VI)-contaminated site to evaluate and validate these two technologies for Cr(VI) contamination profiling in groundwater. A preliminary investigation was performed with an Optical Imaging Profiler Hydraulic profiling tool to determine formation lithology and relative permeability to identify potential groundwater sampling intervals and contaminant migration pathways in the subsurface. Groundwater samples from selected depth intervals were collected and analyzed by lab analysis for total chromium and hexavalent chromium using EPA standards 6020 (SW) and 7196. Comparing the field results with lab results confirmed the potential of these technologies to obtain high-resolution site characterization data to improve the management of heavy metal contamination at hazardous sites.

Guidance: UCMR Monitoring, Chemical Vulnerability, Cr(VI) Sample Collection and Preservation, and Screening for Cr(VI) with Total Chromium
California Dept. of Health Services. 4 pp., Jan 2001

Hexavalent Chromium (CrVI) Field Analytical Method for Bioenvironmental Engineers
G.N. Carlton, L. Chaloux, J.M. Reichert, E.C. England, K. Greebon, Inst. for Environment Safety and Occupational Health Risk Analysis, Brooks AFB, TX.
IERA-RS-BR-TR-1999-0007, NTIS: ADA366806, 39 pp., 1999
Contact: Gary N. Carlton, Gary.Carlton@Tinker.AF.Mil

The Industrial Hygiene Branch, in a collaborative effort with the National Institute for Occupational Safety and Health (NIOSH), developed a field analytical method to measure hexavalent chromium (Cr(VI), chromate) levels in air. The method uses ultrasonic extraction of sampling filters, solid-phase extraction of chromates from the extracted solution, and a determination of chromate concentrations by spectrophotometry. It is an alternative to NIOSH methods 7300 and 7600 and overcomes some of the disadvantages of these methods. The chromate field method is relatively easy to use, specific for CrVI, has a lower detection limit than NIOSH 7600, and allows analysis before there is a chance for significant sample degradation.

Mass Flux Toolkit to Evaluate Groundwater Impacts, Attenuation, and Remediation Alternatives
Environmental Security Technology Certification Program (ESTCP), 2006

To help site managers and site consultants estimate mass flux and understand the uncertainty in those estimates, ESTCP has funded the development of a computerized Mass Flux Toolkit, free software that gives site personnel the capability to compare different mass flux approaches, calculate mass flux from transect data, and apply mass flux to manage ground-water plumes. The toolkit spreadsheet and associated documentation are available on the ESTCP contractor's website in a zipped file.

Method 218.7: Determination of Hexavalent Chromium in Drinking Water by Ion Chromatography with Post-Column Derivatization and UV-Visable Spectroscopic Detection
U.S. Environmental Protection Agency, Office of Water.
EPA 815-R-11-005, 31 pp, 2011

A New Cation-Exchange Method for Accurate Field Speciation of Hexavalent Chromium
U.S. Geological Survey
Water-Resources Investigations Report 03-4018
Contact: James W. Ball, jwball@usgs.gov

This presentation discusses joint efforts on the part of several state and federal agencies to produce a speciated Standard Reference Material from a natural source for chromium.

NIOSH Manual of Analytical Methods (NMAM), 4th Edition
National Institute for Occupational Safety and Health, DHHS (NIOSH) Publication 94-113, 1994

Method 7024: Chromium and Compounds, as Cr
Contact: Mark Millson, mbm1@CDC.GOV
Method 7300: Elements by ICP
Contact: Mark Millson, mbm1@CDC.GOV
Method 7600: Hexavalent Chromium
Method 7703: Hexavalent Chromium by Field-Portable Spectrophotometry [2003 supplement]
Contact: Kevin Ashley, kea0@CDC.GOV

Method 1636: Determination of Hexavalent Chromium by Ion Chromatography
U.S. Environmental Protection Agency, Office of Water.
EPA 821-R-96-003, 30 pp, 1996
Contact: William A. Telliard, telliard.william@epa.gov

Review of Techniques to Characterize the Distribution of Chromate Contamination in the Vadose Zone of the 100 Areas at the Hanford Site
P.E. Dresel, M.J. Truex, and M.D. Sweeney.
PNNL-16760, 61 pp, 2007

Although the reviewers identified no fully developed methods in current use for vadose zone chromate characterization, the following technologies were recommended for additional evaluation and testing: laser-induced breakdown spectroscopy, Raman spectroscopy, laser-induced fluorescence, x-ray fluorescence, in situ specific conductance, high-resolution resistivity, partitioning tracers, and neutron moisture logging.

Revised Assessment of Detection and Quantitation Approaches
U.S. Environmental Protection Agency, Office of Water
EPA-821-B-04-005, October 2004

Simultaneous Measurement of Specific Discharge and Cr(VI) Mass Flux in Porous Media Using Permeable Adsorbent Device
Timothy J. Campbell, K. Hatfield, M.D. Annable (Florida Univ., Gainesville); P.S.C. Rao (Purdue Univ., West Lafayette, IN).
Report No: AFRL-ML-TY-TR-2994-4527, NTIS: ADA423922, 32 pp, Aug 2001

The authors propose a method for simultaneous measurement of local groundwater-specific discharge and Cr(VI) mass flux using a permeable adsorbent device.

Test Methods for Evaluating Solid Wastes: Physical/Chemical Methods, 3rd Edition
U.S. Environmental Protection Agency, SW-846

3060A, Alkaline Digestion for Hexavalent Chromium
6800, Elemental and Speciated Isotope Dilution Mass Spectrometry
7195, Chromium, Hexavalent (Coprecipitation)
7196A, Chromium, Hexavalent (Colorimetric)
7197, Chromium, Hexavalent (Chelation/Extraction)
7198, Chromium, Hexavalent (Differential Pulse Polarography)
7199, Determination of Hexavalent Chromium in Drinking Water, Groundwater and Industrial Wastewater Effluents by Ion Chromatography

Literature References

Measurement and Monitoring Technologies for the 21st Century Initiative (21M²) Literature Search
Through the Measurement and Monitoring Technologies for the 21st Century initiative, EPA's Office of Solid Waste and Emergency Response (OSWER) will identify and deploy promising measurement and monitoring technologies in response to waste management and site cleanup program needs by matching existing and emerging technologies with OSWER program and client needs.