摘要
当前，离子选择性电极已广泛用于海洋化学领域，对于海水中微量硫化物的测定，与碘量法和比色法相比较，电极法不仅灵敏、简便，而且能够实现对环境或体系中硫化物的连续自动监测。特别对于海洋底质间隙水中硫化物的现场测定，电极法更有独到之处。已往报导使用硫离子选择性电极测定天然水中硫化物的方法中，
A method is described for the determination of sulfide in sea water by ion selectivee electrode in which the electroactive membrane is made out of Ag2S formed by electrochemical technique. The backgroud electrolyte solution is 1 M NaOH containing 5mg/ml ascorbic acid as antioxidant reagent. A linear near Nernst response with the slope of 29.8±0.2 mv/logCsr is obtained over the total sulfide concentration range from 10-3Mto 10-7M for the sea water having different salinity ( 5-35% ). The average standard deviation of the odserved potentials is 0.6mv, and the relative standard deviation of the sulfide concentration is 5 %. The experimental recovery of sulfide is 101±5%. The detection limit of sulfide is about 6 ×10-8M. The interferences of some heavy metals on the electrode rea-pone were tested, the obvious interferences of Cd, Pb and Cu can be eliminated by addition of Na2H2EDTA and NaDDTC respectivily. Data obtaiued for the sea water samples by calibration curve, standard addition and graphical method are in good agreement.
