Determination of the reduced sulfur species in the anoxic zone of the Black Sea: A comparison of the spectrophotometry and iodometry techniques

Abstract

The report presents the results of the studies of the reduced sulfur species in the water of the anoxic zone of the Black Sea. The content of hydrogen sulfide was determined by means of spectrophotometry using dilution with oxygen-free distilled water. The detection limit of the H2S amounted to 0.3 μM with the method’s precision below 3%. The accuracy of the spectrophotometric determination was verified by iodometry after the fixation of the hydrogen sulfide in zinc acetate under the distillation with argon from the acidified seawater sample.