Collect. Czech. Chem. Commun. 1982, 47, 2876-2881

Extraction of dithiocarbamic acids from solutions of their salts

Drahomír Oktaveca, Bohumil Sílešb, Ján Remeňa, Václav Konečnýc and Ján Garajb

a Slovnaft, 842 12 Bratislava
b Department of Analytical Chemistry, Slovak Institute of Technology, 812 37 Bratislava
c Research Institute of Agrochemical Technology, 836 07 Bratislava


The extraction of dithiocarbamic acids with chloroform from aqueous phase containing their alkali salts has been investigated with regard to the fact that absorbing strongly in the 200-310 nm range, the acids interfere with the spectrophotometric determination of metals whose dithiocarbamate ligands exhibit their analytical absorption bands in that region. The amount of the dithiocarbamic acids formed depends on the kinetics of their formation and decomposition reactions and on the pH of the aqueous phase. The stability of the acids in chloroform extracts is highly time dependent. The maximum extraction of the acids (R2NCS2H) is attained at the following pH (R, pH): CH3 5.0, C2H5 5.9, C3H8 6.3, C4H9 6.8, C5H11 6.9, C6H13 6.9, iso-C3H7 7.2, iso-C4H9 6.9; for (CH3, iso-C3H7)NCS2H 7.3, C5H10NCS2H 7.2, C4H8ONCS2H 5.2.