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以石墨炉原子吸收为检测手段,分别研究了纳米TiO2对金属Pb、Cd和Cr的吸附性能,并考察了吸附和洗脱的主要影响因素。结果表明:在pH值6～8范围内,纳米TiO2对金属Pb、Cd和Cr具有良好的吸附性,吸附率达到90%以上,0.5mol/L硝酸即可将纳米TiO2吸附的Pb、Cd和Cr完全洗脱。在优化的试验条件下,静态吸附量分别为Pb 15.9mg/g、Cd 36.7mg/g和Cr 65.4mg/g。其检出限(3σ)分别为6.24 x10-14g、2.02x10-13g和1.47 x10-13g,RSD分别为3.18%～5.10%、1.55%～4.04%和2.72%～3.46%,富集倍数分别为75、50和25倍,加标回收率分别在96.1%～105.6%、97.7%～99.9%和92.5%～97.8%。用于实际食品中Pb、Cd和Cr的测定,证明该方法是十分有效的。
Graphite furnace atomic absorption as a detection means, respectively, the adsorption of nano-TiO2 on the metal Pb, Cd and Cr, and investigated the main factors of adsorption and elution. The results showed that the adsorption of Pb, Cd and Cr on the nanosized TiO2 was more than 90% at pH 6 ~ 8. The adsorption of Pb, Cd and Cd on TiO2 by 0.5 mol / L nitric acid Cr completely eluted. Under the optimized experimental conditions, the static adsorption capacities were Pb 15.9mg / g, Cd 36.7mg / g and Cr 65.4mg / g, respectively. The detection limits (3σ) were 6.24 × 10-14g, 2.02 × 10-13g and 1.47 × 10-13g, respectively. The RSDs were 3.18% -5.10%, 1.55% ~ 4.04% and 2.72% ~ 3.46% 75, 50 and 25 times respectively. The recoveries of standard addition were 96.1% ~ 105.6%, 97.7% ~ 99.9% and 92.5% ~ 97.8%, respectively. The determination of Pb, Cd and Cr in real food proves that the method is very effective.