ABSTRACT
Mercaptans (organic thiols) are collected by aspirating a measured volume of air through an aqueous solution of mercuric acetate-acetic acid. The collected mercaptans are subsequently determined by spectrophotometric measurement of the red complex produced by the reaction between mercaptans and a strongly acid solution of N,N-dimethyl-p-phenylenediamine and ferric chloride (1–3). The method determines total mercaptans and does not differentiate among individual mercaptans. Although the sensitivity for various mercaptans on a weight basis decreases with increasing molecular weight of the mercaptan, on a molar basis the sensitivity has been reported to be approximately the same (2). All concentration units in this description refer to methyl mercaptan, unless otherwise specified.
