Table Notes:

¹ “Methods for Chemical Analysis of Water and Wastes,” Environmental Protection Agency, Environmental Monitoring Systems Laboratory—Cincinnati (EMSL-CI), EPA-600/4-79-020, Revised March 1983 and 1979 where applicable.

² Fishman, M.J., et al. “Methods for Analysis of Inorganic Substances in Water and Fluvial Sediments,” U.S. Department of the Interior, Techniques of Water—Resource Investigations of the U.S. Geological Survey, Denver, CO, Revised 1989.

³ “Official Methods of Analysis of the Association of Official Analytical Chemists,” methods manual, 15th ed. (1990).

⁴ For the determination of total metals the sample is not filtered before processing. A digestion procedure is required to solubilize suspended material and to destroy possible organic-metal complexes. Two digestion procedures are given in “Methods for Chemical Analysis of Water and Wastes, 1979 and 1983”. One (Section 4.1.3), is a vigorous digestion using nitric acid. A less vigorous digestion using nitric and hydrochloric acids (Section 4.1.4) is preferred; however, the analyst should be cautioned that this mild digestion may not suffice for all samples types. Particularly, if a colorimetric procedure is to be employed, it is necessary to ensure that all organo-metallic bonds be broken so that the metal is in a reactive state. In those situations, the vigorous digestion is to be preferred making certain that at no time does the sample go to dryness. Samples containing large amounts of organic materials may also benefit by this vigorous digestion, however, vigorous digestion with concentrated nitric acid will convert antimony and tin to insoluble oxides and render them unavailable for analysis. Use of ICP/AES as well as determinations for certain elements such as antimony, arsenic, the noble metals, mercury, selenium, silver, tin, and titanium require a modified sample digestion procedure and in all cases the method write-up should be consulted for specific instructions and/or cautions. Note.—If the digestion procedure for direct aspiration AA included in one of the other approved references is different than the above, the EPA procedure must be used.

Dissolved metals are defined as those constituents which will pass through a 0.45 micron membrane filter. Following filtration of the sample, the referenced procedure for total metals must be followed. Sample digestion of the filtrate for dissolved metals (or digestion of the original sample solution for total metals) may be omitted for AA (direct aspiration or graphite furnace) and ICP analyses, provided the sample solution to be analyzed meets the following criteria:

a. Has a low COD (<20)

b. Is visibly transparent with a turbidity measurement of 1 NTU or less

c. Is colorless with no perceptible odor, and

d. Is of one liquid phase and free of particulate or suspended matter following acidification.

⁵ EPA Method 200.7, “Inductively Coupled Plasma Atomic Emission Spectrometric Method for Trace Element Analysis of Water and Wastes,” from “Methods for Determination of Metals in Environmental Samples—Supplement I,” EPA-600/R-94-111, May 1994.

⁶ “Standard Methods for the Examination of Water and Wastewater,” 18th Edition (1992).

⁷ EPA Method 200.8, “Determination of Trace Elements in Waters and Wastes by Inductively Coupled Plasma-Mass Spectrometry,” from “Methods for Determination of Metals in Environmental Samples—Supplement I,” EPA-600/R-94-111, May 1994.

⁸ American National Standard on Photographic Processing Effluents, Apr. 2, 1975. Available from ANSI, 1430 Broadway, New York, NY 10018.

⁹ The use of normal and differential pulse voltage ramps to increase sensitivity and resolution is acceptable.

¹⁰ Copper, Biocinchoinate Method, Method 8506, Hach Handbook of Water Analysis, 1979, Hach Chemical Company, PO Box 389, Loveland, CO 80537.

¹¹ Hydrogen ion (pH) Automated Electrode Method, Industrial Method Number 378—75WA, October 1976, Bran & Luebbe (Technicon) Autoanalyzer II. Bran & Luebbe Analyzing Technologies, Inc., Elmsford, NY 10523.

¹² Approved methods for the analysis of silver in industrial wastewaters at concentrations of 1 mg/L and above are inadequate where silver exists as an inorganic halide. Silver halides such as the bromide and chloride are relatively insoluble in reagents such as nitric acid but are readily soluble in an aqueous buffer of sodium thiosulfate and sodium hydroxide to pH of 12. Therefore, for levels of silver above 1 mg/L, 20 mL of sample should be diluted to 100 mL by adding 40 mL each of 2 M Na2S2O3 and NaOH. Standards should be prepared in the same manner. For levels of silver below 1 mg/L the approved method is satisfactory.

¹³ Zinc, Zincon Method, Method 8009, Hach Handbook of Water Analysis, 1979, pages 2-231 and 2-333, Hach Chemical Company, Loveland, CO 80537.

¹⁴ “Direct Current Plasma (DCP) Optical Emission Spectrometric Method for Trace Elemental Analysis of Water and Wastes, Method AES0029,” 1986—Revised 1991, Thermo Jarrell Ash Corporation, 27 Forge Parkway, Franklin, MA 02038.

¹⁵ “Closed Vessel Microwave Digestion of Wastewater Samples for Determination of Metals,” CEM Corporation, PO. Box 200, Matthews, NC 28106-0200, April 16, 1992. Available from the CEM Corporation.

¹⁶ Precision and recovery statements for the atomic absorption direct aspiration and graphite furnace methods, and for the spectrophotometric SDDC method for arsenic are provided in appendix D of 40 CFR part 136 and titled, “Precision and Recovery Statements for Methods for Measuring Metals.”

¹⁷ This method does not include the digestion for solids given in Method 200.8. Not using the solids digestion procedure could affect the determined concentrations. Therefore, this method may not be used for analysis of aqueous samples with suspended solids greater than 1%.