Differential-pulse polarographic microdetermination of reactive organohalides via in situ generation of S-alkylisothiouronium salts

Abstract

Reactive organohalides, after in situ derivatization to the corresponding S-alkylisothiouronium salts in the presence of an excess of thiourea, were determined in aqueous solution by differential-pulse polarography. A single differential-pulse polarographic peak was obtained at pH 12.6 for all the organohalides under investigation. The calibration graphs were rectilinear over the range from 1 × 10–6 to 1 × 10–4 mol dm–3 in the sample solution. Each of the S-alkylisothiouronium derivatives has a characteristic polarographic peak potential, thus allowing the qualitative and quantitative determination of different organohalides. For the microdetermination of reactive organohalides, the method was found to be precise and the detection limit was 1 µg of halide.