纳米TiO2富集分离石墨炉原子吸收法测定食品中的铅

以石墨炉原子吸收为检测手段，研究了纳米TiO2对金属Pb的吸附性能，考察了吸附和洗脱的主要影响因素．结果表明：在pH4～5范围内，纳米TiO2对金属Pb具有良好的吸附性，吸附率达到96．5％，0．1mol／L的盐酸即可将纳米TiO2吸附的铅完全洗脱．在优化的实验条件下，静态吸附量为15．9mg／g．其检出限为（3σ）2．02×10^-13g，RSD为3．18％～5．21％，富集倍数为75倍，加标回收率在96．0％～100．5％之间．该方法对标准样品的测定与参考值相吻合，用于实际食品中Pb的测定，结果令人满意．

Determination of Pb in Food Sample by Nano-titanium Dioxide Preconcentration and Separation-furnace Atomic Absorption Spectroscopy

Through furnace atomic absorption spectroscopy, the adsorption and desorption behavior of nanometer TiO2 to Pb were investigated. It was found that the adsorption fraction of Pb was 96.5 % at pH 4-5 and the elution with 0.1 mol/L HCl was sufficient for Pb. The static adsorption capacity was 15.9 mg/g under optimized experimental condition. The detection limit （3σ） was 2.02× 10^-13g, and RSD was 3.18 %-5.21%, with the enrichment multiple as 75 times and recovery of standard addition was between 96.0%-100.5%. Practical application proves that the method is effective in determining the Pb in food.