Study on the determination of lead, cadmium, mercury, nickel and zinc by a rapid column high-performance liquid chromatography

Guangyu Yang, Qiufen Hu, Zhangjie Huang, Jiayuan Yin
2005 Journal of the Brazilian Chemical Society  
Um novo método para determinação simultânea de cinco íons de metais pesados em água, alimentos e cabelo, usando-se cromatografia líquida de alta eficiência foi desenvolvido. Os íons de chumbo, cádmio, mercúrio, níquel e zinco foram derivatizados (pré-coluna) com 2-(2-quinolinil-azo)-4-metil-1,3dihidroxidobenzeno (QAMDHB) para formar quelatos coloridos. A seguir, os quelatos Pb-QAMDHB, Cd-QAMDHB, Hg-QAMDHB, Ni-QAMDHB e Zn-QAMDHB foram enriquecidos pela extração em fase sólida, com cartucho de C
more » ... 8 . O fator de enriquecimento de 100 foi obtido ao eluir os quelatos retidos no cartucho, com tetrahidrofurano (THF). Esses quelatos foram separados em uma coluna de análise rápida ZORBAX Stable Bound (4,6×50 mm, 1,8 μm) com 68% de metanol (contendo 0,05 mol L -1 da solução tampão de ácido acético-pirrolidina, pH 8,5, e 0,01 mol L -1 de CTMAB) como fase móvel, fluxo de 2,0 mL min -1 , em um detector por um detector de arranjo de fotodiodos a 450 ~ 600 nm. Os quelatos Pb-QAMDHB, Cd-QAMDHB, Hg-QAMDHB, Ni-QAMDHB e Zn-QAMDHB foram separados completamente em 2,0 min. Os limites de detecção do chumbo, cádmio, mercúrio, níquel e zinco são 1,2 ng L -1 , 1,0 ng L -1 , 0,8 ng L -1 , 1,6 ng L -1 e 1,9 ng L -1 , respectivamente, nas amostras originais. Este método foi aplicado na determinação dos cinco íons desses metais pesados com bons resultados. A new method for the simultaneous determination of five heavy metal ions in water, food and human hair by a rapid column high-performance liquid chromatography was developed. The lead, cadmium, mercury, nickel and zinc ions were pre-column derivatized with 2-(2-quinolinylazo)-4methyl-1,3-dihydroxidebenzene (QAMDHB) to form colored chelates. Then the Pb-QAMDHB, Cd-QAMDHB, Hg-QAMDHB, Ni-QAMDHB and Zn-QAMDHB chelates were enriched by solid phase extraction with C 18 cartridge. The enrichment factor of 100 was achieved by eluting the retained chelates from the cartridge with tetrahydrofuran (THF). These chelates were separated on a ZORBAX Stable Bound rapid analysis column (4.6×50 mm, 1.8 μm) with 68% methanol (containing 0.05 mol L -1 of pH 8.5 pyrrolidine-acetic acid buffer solution and 0.01 mol L -1 of CTMAB) as mobile phase at a flow rate of 2.0 mL min -1 using a photodiode array detector from 450-600 nm. The Pb-QAMDHB, Cd-QAMDHB, Hg-QAMDHB, Ni-QAMDHB and Zn-QAMDHB chelates were separated completely within 2.0 min. The detection limits of lead, cadmium, mercury, nickel and zinc are 1.2 ng L -1 , 1.0 ng L -1 , 0.8 ng L -1 , 1.6 ng L -1 and 1.9 ng L -1 , respectively in the original samples. This method was applied to the determination of these five heavy metal ions with good results.
doi:10.1590/s0103-50532005000700011 fatcat:pdzowndgrrhhhbzap2ft2tyd5m