Thiocyanate as a source of error in the ferric chloride test for lactic acid, with a method for the elimination of the thiocyanate

Abstract

Abstract It is pointed out that KCNS is a common and generally unrecognized contamination in the ferric chloride test for the presence of lactic acid in gastric contents, and may lead to incorrect conclusions especially in patients who smoke. It is shown that KCNS is secreted by the gastric glands. The addition of saturated HgCl 2 solution prior to the performance of any of the common tests for lactic acid will remove the KCNS.