Sequential injection solvent dispersive micro solid phase extraction (SI-SD-μSPE) platform coupled with atomic absorption spectrometry for lead determination in water samples

Abstract

A novel automatic versatile sequential injection solvent dispersive micro solid phase extraction platform coupled with flame atomic absorption spectrometry is developed for the first time. The analytical procedure is based on chemical dispersion of benzophenone and ternary component systems. The full dispersion of sorbent into the aqueous phase, in the shape of micro particles, is achieved by on-line mixing of the two flows; a small flow of methanol containing the sorbent in a low concentration and a higher one of the aqueous sample solution. The resulted cloudy mixture is consisted of sorbent's fine particles, which are dispersed into the whole aqueous phase. Via this continuous process, metal chelating complexes are retained onto the sorbent particles. An integrated, easy and fast reusable syringe filter was studied for the on-line collection and dissolution of the sorbent. The potentials of this novel schema were demonstrated for trace Pb(II) determination in water samples. All the critical parameters affecting the performance of the proposed method were optimized. For a sample consumption of 11.0 mL, the working range was 5.28–400.0 μg L−1, while the enhancement factor, the detection limit and the relative standard deviation were 120, 1.59 μg L-1 and 2.4% (at 50.0 μg L−1) respectively. The developed method was evaluated by analyzing certified reference materials and applied to the analysis of environmental water samples.