Flow-injection/pervaporation coupling for the determination of sulphide in Kraft liquors

A dynamic manifold has been coupled with a pervaporation module for the determination of sulphide ion in complex matrices such as Kraft liquors. The method is based on ethylene blue formation and features detection limits of 0.68 and 0.42 gmL^-1 of S^2- for injection and continuous introduction of the sample, respectively, with linear ranges of 1–15 and 1–10 gmL^-1. The method is highly selective as the interferences from other sulphur species are avoided in the pervaporation process; thus, it has been applied successfully to the determination of the analyte in white and green bleaching liquors.