Use of barium chloranilate solid-phase reactor for the determination of sulfate in natural water samples exploiting long pathlength spectrophotometry and multicommutation

摘要

A flow-injection method for the spectrophotometric determination of sulfate in natural water samples using a solid-phase reactor with barium chloranilate (BaC_6Cl_2O_4) immobilized in a polyester resin is presented. This procedure is based on the formation of insoluble barium sulfate (BaSO4) in the solid-phase reactor releasing chloranilate ions (C_6Cl_2O_4~(2-)), which was monitored spectrophotometrically at a wavelength of 533 nm. The analytical curve was linear in the sulfate concentration range from 2.5 to 40.0mgL~(-1) with a detection limit of 0.1mgL~(-1) and an analytical frequency of 50 h~(-1).