ELC石墨管涂锆-石墨炉原子吸收法在测定饮水中铝的应用

Determination of aluminum in drinking water by AAS graphite furnace using ELC Zirconium coated graphite tube

目的研究ELC石墨管涂锆的简易程序并用于石墨炉原子吸收测定饮水中铝的方法。方法采用每次进样20μl 4 g/L ZrOCl_2·8H_2O溶液,按仪器推荐的升温程序对ELC石墨管进行涂锆处理5次,再空烧5次即完成石墨管的涂锆处理。优化灰化、原子化温度等测试条件,在最优化测试条件下测试1%HNO_3空白溶液吸光度至低于0.005时正式开始测试。结果 ELC石墨管经涂锆处理,石墨炉原子吸收法测定饮水中铝,石墨管使用500余次未见性能显著下降(平行测定RSD<10%)。采用次灵敏线257.3 nm做测试波长,在0μg/L^200μg/L时线性关系良好,r>0.995。测定Al环境标准水样[GSB07-1375-2001,(150±15)μg/L],结果铝含量为135μg/L^163μg/L,均值为151μg/L,再现性精密度RSD为5.3%(n=16)。结论本法简便、快速、准确,可满足日常监测饮水中铝的测定。

Objective To determine aluminum in drinking water by AAS graphite furnace using ELC Zirconium coated graphite tube. Methods Each time, 20 μl solution of 4 g/L ZrOCl2 · 8H2O was injected. The temperature programming which com- plies with the specification of the instrument specified by manufacturer was employed. The process was underwent 5 times and the empty tube was cleaned 5 times to complete the coating process. The ashing and atomization temperature were optimized. Under the optimized level, 1 % HNO3 blank was determined. When the absorhance was lower than O. 005 abs, the analysis star- ted. Results By using ELC graphite tube after coated with Zirconium to carry out the analysis of A1 in drinking water, even af- ter more than 500 times using, no significant deterioration of tube was found（RSD 〈 10% ）. The less sensitive line 257.3 nm was set as the chosen wavelength, the linearity obtained is good within 0 μg/L - 200μg/L, r 〉0.995. When analyzing A1 en- vironmental water sample [ GSB07 - 1375 - 2001 （ 150 ± 15） μg/L], the average values were got within 135 μg/L - 163 μg/L, and the average value is 151 μg/L. The RSD is 5.3% （n = 16）. Conclusion This method is simple, quick and accurate. It can meet the routine determination of A1 in drinking water.