高效液相色谱-电感耦合等离子体质谱法检测净水器对无机砷的净化效果

Evaluation on the purifying efficiency of water purifier for inorganic arsenic by high performance liquid chromatography-inductively coupled plasma mass spectrometry

目的采用高效液相色谱-电感耦合等离子体质谱法初步探讨净水器对无机砷的净化效果。方法选择Dionex Ion Pac AS7(4.0 mm×250 mm,10μm)为分离色谱柱,以100 mmol/L(NH4)2CO3和1%CH3OH水溶液为流动相,梯度洗脱,在7 min内实现了5种形态砷的快速分离。通过净化加标自来水实验和重复冲洗净水器实验,研究了净水器对无机砷的净化效果。结果 5种形态砷的检出限为0.1μg/L;线性关系良好,相关系数均≥0.999。净化器在处理含低浓度无机砷的自来水时,会释放微量五价砷至水中而导致砷含量升高;而在处理含高浓度无机砷的自来水时,能达到去除部分无机砷的效果。结论该方法操作简便、快速、灵敏,满足相关检验要求。部分净化器在使用时存在释放微量五价砷至水中的风险。

Objective To develop a high performance liquid chromatography- inductively coupled plasma mass spectrometry（ HPLC/ICP- MS） method for detecting the purifying efficiency of water purifier for inorganic arsenic. Methods Dionex IonPac AS7（ 4. 0 mm × 250 mm,10 μm） was used as the separation column,100 mmol / L（ NH4）2CO3- 1% CH3 OH solution was used as mobile phase for gradient elution,and the five arsenic species could be separated within 7 min. The purifying efficiency of water purifier was studied by determination of the arsenic in purified spiked water and re- washing water. Results The detection limits of the five arsenic species were 0. 1 μg / L. Good linearity was obtained,with the correlative coefficients ≥0. 999.In the treatment of tap water containing low concentration of inorganic arsenic,purifier could release trace As（ V） to the tap water,but purifier could remove some inorganic arsenic in water containing high concentration of arsenic. Conclusion The method is simple,rapid and sensitive,and can meet the requirements of the inspection. There is the risk of releasing trace pentavalent arsenic to water with some water purifier.