Crosslinked Carboxymethyl Starch Based Solid Phase Extraction Combined with Direct Slurry Sampling Graphite Furnace Atomic Absorption Spectrometry for the Determination of Trace Lead in Water Samples

A new method of solid phase extraction (SPE), using crosslinked carboxymethyl starch as adsorbent, combined with direct slurry sampling graphite furnace atomic absorption spectrometry (ss-GFAAS) has been developed for the high sensitive determination of lead in water samples. The SPE adsorbent loaded with the analyte was made in to slurry with the assistance of Triton X-100. The slurry was directly injected into the graphite furnace for the determination of lead. Variables such as the pH, sample volume, and amount of Crosslinked Carboxymethyl Starch (CCMS) were investigated. The detection limit (3 sigma) was 0.082 mu g L-1 and the RSD was 4.9% (n = 11, c = 1.0 mu g L-1) for Pb(II). The enrichment factor was 100 at a sample volume of 100 mL. The proposed method has been applied to the determination of lead in environmental water reference materials and two water samples with satisfied results.