1987 Volume 36 Issue 2 Pages 77-81
Rapid and sensitive determination of chloride, sulfate and nitrate ions in river water was achieved by ion chromatography with UV photometric detector. Comparison of elution ability of eluent ions was made by using phthalate, hemimellitate, trimellitate, trimesate and pyromellitate ions at pH 7.5. Trimellitate solution (1, 2, 4-benzenetricarboxylate, 4×10-4 M) is superior to other eluent ions because of its strong light-absorption at longer wavelength beyond 250 nm, suitable ability of elution for chloride, sulfate and nitrate ions, low price, high purity and easy availability. An anion exchange column (TSK gel IC-Anion-PW, 4.6 mm i.d.×50 mm) was used. Twenty microliters of sample solution was injected and decrease in absorbance of the trimellitate eluent at 250300 nm was detected. The calibration curves were linear in the range of (0.810)×10-4 M for chloride, (0.44)×10-4 M for sulfate and (0.120)×10-4 M for nitrate. By the proposed method, chloride, sulfate and nitrate in river water were determined within four min. The relative standard deviations of ten measurements of tap water were 0.35% for chloride, 0.56% for sulfate and 1.3% for nitrate, respectively.
