Abstract
An indirect method is described for the micro-determination of primary and secondary amines in the presence of tertiary amine by means of a catalytic indicator reaction. The copper bis (dithiocarbamate) complex formed from primary or secondary amine and carbon disulfide in the presence of copper was removed by extraction into chloroform. The remaining copper in aqueous solution was determined by measuring the rate of oxidation of pyrocatechol violet by hydrogen peroxide. A simplified complementary tristimulus colorimetry (SCTS method) was used for determination of the reaction rates, since it has the advantage of permitting accurate determination of the rate constants in the presence of color impurities. Quantitative recoveries were obtained of microamounts of primary and secondary amines with good accuracy (from -2.9% to +2.9% error). The method presented is sensitive and does not require a separate calibration curve for each primary and secondary amine.
