水中草甘膦的柱前衍生-固相萃取-高效液相色谱荧光法测定

Determination of glyphosate in water by high- performance liquid chromatography- fluorescence detection with pre- column derivatization and solid- phase extraction

目的建立快速、准确的水中草甘膦的柱前衍生-固相萃取-高效液相色谱荧光测定方法。方法水样经衍生和固相萃取后,在XBridge RP18色谱柱上,以甲醇/水(70+30,V/V)为流动相,流速1.0 ml/min,荧光检测激发波长为265 nm,发射波长为315 nm。结果草甘膦的加标回收率在86.4%~93.0%范围,其相对标准偏差均<5.0%,在0.005 mg/L^0.5 mg/L范围呈现良好的线性,其回归系数>0.999,最低定量检出限(LOQ)为0.002 mg/L。结论本方法回收率高,净化效果好,杂质干扰少,可满足水中痕量草甘膦的残留检测要求。

Objective To develop a method for the determination of glyphosate in water by high - performance liquid chroma- tography - fluorescence detection with pre - column derivatization and solid - phase extraction. Methods After the glyphosate was derived from water samples and cleaned - up with solid - phase extraction, the separation was performed on an XBridge RP18 column using a mobile phase consisting of methanol/water （70 ＋ 30, V/V） at a flow rate of 1.0 ml/min. The fluorescence excitation and emission wavelengths were 265 nm and 315 nm, respectively. Results The addition standard recovery of glyphosate was 86.4% - 93.0% , and the RSDs were less than 5.0%. Calibration curve of glyphosate was linear within the range of0. 005 mg/L -0.50 mg/L with regression coefficient greater than 0. 999. The limit of quantification （LOQ） was 0.002 mg/L. Conclusion This method has high recovery rate and good purifing results and less Impurity interference. It is suitable for the detection of trace glyphosate residue in the environmental water.