Ti (IV) modified vinyl phosphate magnetic nanoparticles for simultaneous preconcentration of multiple arsenic species...

Ti (IV)-modified vinyl phosphate magnetic nanoparticles (Fe₃ O₄ @SiO₂ @KH570-PO₄ -Ti (IV)) was prepared for simultaneous extraction of multiple arsenic species, followed by high performance liquid chromatography (HPLC)- inductively coupled plasma mass spectrometry (ICP-MS) analysis. Inorganic arsenic (iAs), dimethyl arsenic acid (DMA), monomethyl arsenic acid (MMA), p-amino phenyl arsenic acid (p-ASA), 4-hdroxyphenylarsenic acid (4-OH), phenyl arsenic acid (PAA), and 3-nitro-4-hydroxyphenylarsenic acid (ROX) were investigated as interest analytes. It was found that they were quantitatively adsorbed on Fe₃ O₄ @SiO₂ @KH570-PO₄ -Ti (IV) at pH 5, and desorbed completely with 0.1 mol/L sodium hydroxide solution. Enrichment factor of 100-fold was obtained by consuming 100 mL sample solution. Under the optimal conditions, the method combining MSPE with HPLC-ICP-MS presented a linear range of 1-5000 ng/L for seven arsenic species. The limits of detection were 0.39, 0.60, 0.23, 1.85, 0.54, 0.48, and 0.84 ng/L for DMA, MMA, p-ASA, iAs, 4-OH, PAA, ROX, with the relative standard deviations (c = 10 ng/L, n = 7) of 3.6, 3.9, 5.5, 12.4, 6.1, 5.8, 5.0, respectively. The accuracy of the method was validated by analyzing BCR 627 Tuna fish. The application potential of the method was further evaluated by chicken muscle and liver samples. No target arsenic species were detected in these samples, and good recoveries (80.6-123%) were obtained for the spiked samples at low, medium, and high concentration levels.