The spectrofluorimetric determination of sulphides

Abstract

The spectrofluorimetric determination of trace amounts of sulphide with mercury(II)-2,2′-pyridylbenzimidazole is described. The sulphide can be determined in solutions with concentrations in the range 300 pg to 300 ng ml^–1, with a standard deviation of 0·75 per cent. for a concentration of 60 ng ml^–1. Interferences can be avoided by the use of standard distillation procedures. The main advantages, apart from the extremely high sensitivity of the method, are the high stability of the reagent and of the reacted sulphide system. The over-all time of the method after liberation of the sulphide can be as little as 2 to 5 minutes, and the time lapse between the reaction and measurement of solution is not critical as up to 48 hours' delay has no significant effect.