New block-grafted anion exchanger for environmental water analysis by ion chromatography

The IonPac AS14A is a recently developed stationary phase that was produced using a new block-grafting technique, which enables the preparation of hig h-water-content anion exchangers with excellent peak shape and good chromat ographic efficiency. The performance of this column for the analysis of ino rganic anions was compared to that obtained using an IonPac AS4A column, wh ich is specified in US Environmental Protection Agency Method 300.0, in add ition to another commonly used alternative; the AS14 column. The AS14A colu mn is available in two different formats; 250 x 4 mm I.D. (7.0 mum diameter particle) and 150 x 3 mm I.D. (5.5 mum diameter particle). The IonPac AS14 A (in 4 mm I.D. format) was found to provide similar performance to the AS1 4 column with increased peak efficiency and better pH stability and is a su itable alternative for the analysis of anions in moderate- to high-ionic-st rength samples. The IonPac AS14A (in 3 mm I.D. format) provides comparable run times to the AS4A column with better overall peak selectivity and impro ved fluoride resolution, hence this column would be a suitable column to su bstitute in place of either the AS4A or AS14 columns for the analysis of in organic anions in low- to moderate-ionic-strength environmental waters. The AS14A column used with an Atlas electrolytic suppressor provides equivalen t method detection limits to those obtained when using a micromembrane supp ressor but with the operational convenience of a self-regenerating suppress or. (C) 2001 Elsevier Science BN. All rights reserved.