Aminopropyltriethoxysilane-silica hybrid monolithic capillary microextraction combined with inductively coupled plasma mass spectrometry for the determination of trace elements in biological samples.

A simple and sensitive method based on aminopropyltriethoxysilane (APTES)-silica hybrid monolithic capillary microextraction (CME) combined with inductively coupled plasma mass spectrometry (ICP-MS) was developed for the determination of trace elements in biological samples. Under the optimized conditions, the adsorption capacities of APTES-silica hybrid monolithic capillary were 42.5, 55, 57.5, 82.5, 52.5, and 40 μg/m for Mn(II), Co(II), Ni(II), Cu(II), Cd(II), and Pb(II), respectively. The LODs were in the range of 1.2 (Cd)-14 (Pb) ng/L with the relative standard deviations (RSDs) of <5.1% (c=1 μg/L, n=7). The reproducibility of APTES-silica hybrid monolithic preparation ranged from 1.6 to 5.6% in one batch, and from 2.3 to 6.2% in batch-to-batch, respectively. To validate the developed method, two certified reference materials of NIES No. 10-b rice flour and GBW 07601 (GSH-1) human hair were analyzed and the determined values were in good agreement with the certified values. The proposed method has also been applied for the analysis of human hair and urine samples with the recoveries for the spiked samples in the range of 89-106%.