纳米TiO_2微柱分离富集-分光光度法测定环境样品中的微量硒  

Nanometer TiO_2 Microcolumn Preconcentration of Trace Selenium in Environment Samples

作　　者：张蕾[1] 刘娜[1] 康平利[1] 李绮[1] 周新宇[1] 

机构地区：[1]辽宁大学化学学院,沈阳110036

出　　处：《应用化学》2010年第3期323-327,共5页Chinese Journal of Applied Chemistry

基　　金：辽宁省教育厅优秀人才支持项目(2009R30);辽宁省自然科学基金(20082049)资助项目

摘　　要：以处理过的纳米TiO2为微柱吸附材料,采用流动注射技术进行微量硒的分离富集,考察了纳米TiO2微柱对Se(Ⅳ)的吸附性能,探讨了溶液的pH值、试样流速、试样体积、洗脱液浓度和用量以及干扰离子等因素的影响。实验结果表明,pH在1～6范围内,试样流速为0.5mL/min,纳米TiO2对Se(Ⅳ)具有良好的吸附性能,吸附率可达98.3%,动态饱和吸附容量为7.92mg/g;选用1mL0.1mol/LNaOH溶液可将吸附的Se(Ⅳ)完全洗脱,富集倍数为40。本法的检出限(3σ)为0.13mg/L,相对标准偏差为1.56%。将本法应用于国家标准样品GBW07280的分析,测定值与参考值一致。A method using a microcolumn packed with nanometer TiO2 as solid-phase extractant has been developed for the preconcentration of trace amounts of Se （ Ⅳ ） prior to the measurement by ultraviolet speetrophotometry. Effects of pH, sample flow rate and volume, elution solution and interfering ions on the recovery of the analytes have been investigated. The sorption was optimized with respect to the pH, maximum sorption was achieved from the solutions of pH 1 - 6. The optimum sample flow rate to adsorb Se （ Ⅳ ） ions was 0. 5 mL/min, and the adsorption percentage was 98.3%. Sorbed Se （Ⅳ） was desorbed with 1.0 mL of 0. 1 mol/L NaOH, with an enirchment of 40. The detection limit （ 3σ ） of the method for Se （ Ⅳ ） was 0. 13 mg/L（n = 13） ; and the relative standard deviation was 1.56% （ n = 13, c = 10 mg/L）. At room temperature, dynamic saturated adsorption capacity was 7. 92 mg/g. The proposed method was applied to the determination of trace amounts of Se （ Ⅳ ） in GBW07280, the determined value was in good agreement with the certified value.

关 键 词：流动注射 微柱分离 纳米二氧化钛 硒 

分 类 号：O655[理学—分析化学]