Abstract: In ClCH₂COOH medium, 1,4-dithiothreitol (DTT) can shows a sensitive polarographic wave at -0. 31 V (vs. SCE). In this paper, conditions are found for the determination of 1,4-dithiothreitol with single sweeping polarography. Under the best condition the detection limit is 8×10^-8 mol/Land the linear range of 1.1×10^-7～5×10^-5 mol/Lis exhibited. The polarographic character of DTT is investigated, the polarographic wave resulted from DTT shows the properties of adsorptive catalysis wave. The electrode reaction mechanisms are discussed in the paper and the effect of Cu²⁺on the polarographic wave is also studied.

Key words: 1,4-Dithiothreitol, Polarographic adsorptive wave, Polarographic properties of mercapto compound