DIFFERENTIAL-PULSE POLAROGRAPHIC MICRODETERMINATION OF AMINO-ACIDS VIA IN-SITU GENERATION OF DITHIOCARBAMATES

Amino acids underwent in situ derivatization with carbon disulfide in the presence of triethylamine at room temperature to yield the corresp onding dithiocarbamate derivatives, which were then determined in aque ous media by differential-pulse polarography. The dithiocarbamate deri vative of an amino acid usually showed a characteristic cathodic peak in the range between -0.51 and -0.61 V (versus Ag-AgCl). Calibration g raphs obtained by plotting the measured polarographic peak current of the dithiocarbamate derivative versus the concentration of the amino a cid undergoing derivatization were rectilinear over the range 1.6-20 m umol 1-1. For the micro-determination of amino acids, the method was f ound to be precise, and the detection limit was calculated to be 1 mug .