Flow injection dialysis for the determination of anions using ion chromatography

摘要

Flow injection dialysis (FID) coupling with ion chromatography (IC) is proposed for simultaneous determination of some anions (bromide, chloride, fluoride, nitrate, nitrite, phosphate and sulfate). A standard or sample containing the anions is injected into a donor stream of a mixture (0.022 M Na_2CO_3 and 0.028 M NaHCO_3) flowing into a dialysis cell. The bolus of the dialysate containing the anions, in the acceptor stream of water, flows to the IC injection valve where a portion of the bolus is injected into the IC and analysed under normal IC conditions, with a conductivity detector. FID provides on-line separation and dilution of the analytes from matrix especially from some species such as proteins, surfactant, particulates which amy cause damage to the IC columns. Prolongation of life-time of the IC columns is an additional advantage to others which will be discussed. On-line dialysis-IC was also investigated.