Optimized syringe-assisted dispersive micro solid phase extraction coupled with microsampling flame atomic absorption spectrometry for the simple and fast determination of potentially toxic metals in fruit juice and bio-fluid samples

In this work, a novel method called Syringe-assisted dispersive micro solid phase extraction ( SA-DM-SPE ) was developed based on repeatedly withdrawing and pushing out a mixture of an aqueous sample including some chelated potentially toxic metal ions with bis-(acetylacetone) ethylenediimine and a low level of a suitable adsorbent ( 1.6 mg of multi-walled carbon nanotubes ) in a test tube using a syringe. Since maximum contact surface areas were simply provided between the chelated ions and adsorbent with no need to essentially off-line the accelerating mass transfer ( including sonication and vortex ) and centrifugation steps, maximum efficiency was achieved within a short period of time. The optimized conditions for the extraction of Pb 2+ , Cd 2+ , Co 2+ , Ni 2+ , and Cr 3+ , as target ions, were investigated by the experimental design strategy. Under the optimum conditions, limits of detection, linear dynamic ranges, consumptive indices, and repeatabilities (in terms of intra-day precisions) ranged from 0.3 to 2.0 μg L −1 , 0.9 to 980 μg L −1 , ∼0.33, and 3.4 to 4.2, respectively. The method was successfully applied to the determination of target ions in different water ( tap and wastewater ), fruit juice ( apple, pear, grape, and grapefruit ), and biological fluid ( saliva and urine ) samples using a microsampling flame atomic absorption spectrometry (MS-FAAS) technique.