DETERMINATION OF TRACE ANIONS IN HEAVY MATRICES WITH NON-SUPPRESSED ION CHROMATOGRAPHY AFTER MATRIX ELIMINATION

Abstract

Determination of traces of anions in real samples having thousands fold excess matrix ions of nitrate, sulphate, and lead in samples is described. For the elimination of these matrix ions, simple and conventional procedures are applied. The nitrate matrix was eliminated by simple evaporation by heating of HNO₃ sample; sulphate ion of cupracid sample was removed by precipitation with barium hydroxide solution and matrix of lead in lead peroxide sample was removed by loading of lead on commercially available AG 50WX 16 cation exchange resin. The anions of interest were separated by Hamilton PRP × 100 anion column and detected by single-column conductivity detection using high performance liquid chromatography (HPLC). Recovery experiments were employed to verify the accuracy of the proposed methods using standard solution of matrix components for spiking of analyte anions. Application of these methods to determine trace levels of common anions using ion chromatography is demonstrated in real samples.

Keywords:

• AG 50WX16 cation exchange resin
• conductivity detection
• lead peroxide
• PRP X 100 anion column
• single column