An automatic stirring-assisted liquid-liquid microextraction system based on lab-in-syringe platform for on-line atomic spectrometric determination of trace metals.

A novel simple fully automatic on-line magnetic stirring-assisted liquid-liquid microextraction method, based on the lab-in-syringe (LIS) concept, has been developed as an alternative approach for sample pretreatment and atomic spectrometric assays. The analytical process includes the in-syringe reaction of the metal ion with the chelating reagent, the analyte micro-extraction and the subsequent transportation of the extractant to the detection system for electrothermal atomic absorption spectrometric (ETAAS) quantification. This novel platform has been demonstrated for trace silver determination in various types of water samples. The method is linear from 19 to 450ngL using a small volume of extraction solvent of 120μL. The entire procedure is accomplished within 240s resulting in a sampling frequency of 15h. The enhancement factor is 80, while the detection limit and the precision are 5.7ngL and 3.3%, respectively. The developed method was evaluated by analyzing standard reference materials and spiked water samples with satisfactory recoveries.