Sulfide measurements by flow injection analysis and ion chromatography with electrochemical detection

Dissolved sulfide ions are separated and detected by using ion chromatography (IC) and electrochemical detection with a glassy carbon electrode modified by electrochemical deposition of palladium particles. The influence of various experimental factors such as pH, loading of palladium, applied potential and flow rate of mobile phase is evaluated. The effect of some common organic and inorganic compounds on the amperometric signal is also evaluated. Under optimal chromatographic conditions, the detection limit for sulfide (S/N = 3) was 0.3 mu M (15 pmol injected) and the calibration plot was linear for 0.5-350 mu M sulfide (r=0.9964, n=16). The separation and detection of sulfides in human blood serum is presented as an example of an application to real specimens. (C) 2000 Elsevier Science B.V. All rights reserved.