Determination of thiosulfate ions by the complexation of lead thiosulfate with 4-(2-pyridylazo)-resorcinol on the PANF-AV-17 solid phase

摘要

A procedure was developed for determining thiosulfate ions; the procedure involved their adsorption as a complex with lead ions at pH 4 on disks of polyacrylonitrile fiber filled with an AB-17 anion exchanger and determination by the reaction with 4-(2-pyridylazo)-resorcinol at pH 10. The analytical range was (0.2-0.8) x 10-4; the detection limit was 2 mu g/mL. The determination did not interfere with metal cations at the level of the maximum permissible concentrations for potable water, as well as 2-15-fold amounts of sulfites, sulfides, and iodides; 100-200-fold amounts of sulfates, pyrosulfates, and bromides; and 1000-fold amounts of chlorides. The developed procedure was used in the analysis of tap water by the "added-found" method (RSD < 20%).