ASTM D5257-97

1.1 This test method covers procedures for the determination of dissolved hexavalent chromium in waste water, surface water, and drinking water.

1.2 The precision and bias of this test method has been tested in reagent water and industrial waste water and has been found suitable over the range of approximately 1 to 1000 [mu]g/L. See Table 1 for details. Higher levels can be determined by appropriate dilution.

1.3 Samples containing very high levels of anionic species (that is, chloride, sulfate, etc.) may cause column overload. Samples containing high levels of reducing species (that is, sulfides, sulfites, etc.) may cause reduction of Cr(VI) to Cr(III). This can be minimized by buffering the sample to a pH of 9 to 9.5, filtering it, storing it at 4°C and analyzing it within 24 h.

1.4 The values stated in SI units are to be regarded as the standard.

1.5 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.