离子色谱法同时测定水源水和饮用水中草甘膦和氨甲基膦酸

Simultaneous detection of glyphosate and aminomethylphosphonic acid in drinking water and source water by ion chromatography

目的建立离子色谱同时测定水源水和饮用水中草甘膦和氨甲基膦酸的分析方法。方法水样用0.22μm滤膜过滤后直接进样。色谱条件:Ion Pac AS19色谱柱(250 mm×2 mm)和Ion Pac AG19保护柱(50 mm×2 mm);RFIC系统的EG50淋洗液自动发生器在线产生的KOH作为淋洗液,浓度梯度淋洗,淋洗液流速:0.25 ml/min;抑制器采用外加水模式,电导检测器检测。结果草甘膦和氨甲基膦酸的浓度为0.10 mg/L^2.0 mg/L时,线性关系良好,草甘膦的线性方程为y=0.736 9x+0.003 41,r=0.999 8,检出限和定量限分别为0.004 4 mg/L和0.015 mg/L;氨甲基磷酸的线性方程为y=1.816 4x-0.092 4,r=0.999 6,检出限和定量限分别为0.017 mg/L和0.056 mg/L。在0.20 mg/L、0.60 mg/L、1.00 mg/L 3种加标水平下,草甘膦、氨甲基膦酸的回收率分别为86.3%~98.7%、94.6%~98.1%,相对标准偏差(RSD)为0.42%~5.63%。结论本方法灵敏度和回收率高,选择性好,适用于水源水和饮用水中草甘膦和氨甲基膦酸的测定。

Objective To establish an ion chromatography（ IC） method for the simultaneous determination of glyphosate（ GLY）and aminomethylphosphonic acid（ AMPA） in drinking water and source water. Methods After filtrated with 0. 22 μm micropore filtrer membrance and direct feeding,the water samples were analyzed by IC directly with the analytical column,Thermo Ion Pac AS19（ 250 mm × 2 mm） and the guard column,Ion Pac AG19（ 50 mm × 2 mm）. Gradient KOH eluent generated by an eluent generation cartridge was used at a flow rate of 0. 25 ml / min. The suppressor adopted external water mode,and conductivity detector was used in the test. Results Good linearity was obtained when the concentration of GLY and AMPA was among0. 10 mg / L- 2. 0 mg / L,with correlation coefficients（ r） greater than 0. 999 8. The linear equotion of GLY was y = 0. 736 9x ＋0. 003 41,limits of detection were 0. 004 4 mg / L for GLY and 0. 017 mg / L for AMPA,and the limits of quantitation were0. 015 mg / L for GLY and 0. 056 mg / L for AMPA. In the species spiked levels of 0. 20 mg / L,0. 60 mg / L and 1. 00 mg / L,the recovery rates of glyphosate and ammonia methyl phosphate acid were respectively among 86. 3%- 98. 7%,94. 6%- 98. 1%,and the relative standard deviation（ RSD） was among 0. 42%- 5. 63%. Conclusion The experiments verified that the method is sensitive,selective with good recovery,and it can be applied for the determination of GLY and AMPA in drinking water and source water.