27. November 2009 by The Cyanide Guy.

We have been working with the EPA in an effort to get the new ASTM cyanide methods approved for NPDES reporting. We have updated ASTM D2036 to include ion chromatography and FIA gas difussion amperometry as determinative steps. We have also included ASTM D7284. D7284 determines cyanide by FIA gas diffusion amperometry following small scale distillation. Of course, ASTM D7511 is included as well.

Much work has been done on the Table of approved inorganic methods to try and make it more readable, and also ofn Part 136.6. Part 136.6 is “method flexibility” and the part has been expanded to include example situations of what is allowed.

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27. November 2009 by The Cyanide Guy.

After years of existence as a instrument manufacturer method, OIA 1678 is now an ASTM International Standard. The method should be used for samples suspected to contain sulfide, thiosulfate, thiocyanate, or sulfite. These compounds interfere with distillation methods more significantly than with ASTM D7511-09. The CFR 40 Part 136 footnote 6 says that any method that overcomes these interferences can be used. EPA approval is expected next year, however, the fact that ASTM D7511-09 overcomes these specific interferents should be enough to convince you to use this method. Or would you rather continue reporting results you know are incorrect?

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