Ordered mesoporous silicon doped with HPMo‐SiO ₂ solid phase extraction of trace Pb prior to flame atomic absorption spectrometry determination

Abstract

A new selective and sensitivity method for lead (Pb) determination by flame atomic absorption spectrometry has been established using an ordered mesoporous silicon doped with phosphomolybdic acid (HPMo-SiO 2) material as an adsorbent. The possible adsorptive mechanism was speculated, and factors affecting its adsorptive behaviours of Pb were investigated in detail. At potassium hydrogen phthalate media, Pb can be quantitatively adsorbed at pH 3.0-6.0, and HPMo-SiO 2 exhibited good selectivity toward it. With an enrichment factor of 50, the detection limit and relative standard deviation of Pb are 0.78 ng ml −1 and 0.76 % (n = 9 and C = 2.0 ng ml −1), respectively. The proposed method has been applied to the determination of Pb in human serum, waste water, pond water, soil and whitening cosmetics with recoveries of 93.9-108.5%. To validate the accuracy verification, a GSB-07-1183-2000 certified reference was analysed, and the result is in good agreement with the certified value.