ASTM D1687-92(1996)

1.1 These test methods cover the determination of hexavalent and total chromium in water. Three test methods are included.

Concentration Sections Range Test Method A---Photometric Diphenyl- 0.01 to 0.5 7 to 15 carbohydrazide mg/L Test Method B---Atomic Absorption, Di- 0.1 to 10 16 to 24 rect mg/L Test Method C---Atomic Absorption, 5 to 100 25 to 33 Graphite Furnace [mu]g/L

1.2 Test Method A is a photometric method that measures dissolved hexavalent chromium only. Test Methods B and C are atomic absorption methods that are generally applicable to the determination of dissolved or total recoverable chromium in water without regard to valence state.

1.3 Test Method A has been used successfully with reagent grade water Types I, II, and III, tap water, 10% NaCl solution, treated water from a synthetic organic industrial plant that meets NPDES permit requirements, and EPA-extraction procedure leachate water, process water, lake water, effluent treatment, that is, lime neutralization and precipitation of spent pickle liquor and associated rinse water from stainless steel pickling. Test Method C has been used successfully with reagent water, stock scrubber water, lake water, filtered tap water, river water, well water, production plant water, and a condensate from a medium BTU coal gasification process. Matrices used, except for reagent water, are not available for Test Method B. It is the user's responsibility to ensure the validity of these test methods for waters of untested matrices.

1.4 This standard does not purport to address all of the safety problems, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use. >For specific precautionary statements, see 4.2 and Note 5.