气相色谱-质谱法测定豆芽中6种植物生长调节剂残留

Determination of 6 plant growth regulators in bean sprouts by gas chromatography-mass spectrometry

目的建立豆芽中2,4-D、2,4-D丁酯、4-氯苯氧乙酸、吲哚乙酸、吲哚丁酸、萘乙酸的气相色谱-质谱法(GC-MS)。方法使用酸化乙腈为提取液,浓缩干燥后加入2 ml甲醇溶解,取其中1 ml经Qu ECHERS试剂盒净化后测定2,4-D丁酯;另外1 ml甲醇样液经MCS固相萃取柱净化后,用10%三氟化硼甲醇溶液甲酯化,提取后GC-MS测定其余5种植物生长调节剂。结果 6种植物生长调节剂在0.5μg/ml^5.0μg/ml质量浓度范围内呈良好的线性关系,相关系数为0.991 0~0.999 3。在空白样品中分别添加浓度为0.5μg/ml和2.0μg/ml的标准溶液,平均回收率为79.8%~89.9%,相对标准偏差(RSD)为3.9%~9.1%。结论本方法简单、快速、可靠,结合Qu ECHERS净化法可以满足豆芽中植物生长调节剂多残留检测的要求。

Objective To establish a method for the determination of 2,4- D,2,4- D butyl ester,4- chlorophenoxyaceticaid,indoleacetic acid,indole butyric acid,naphthalene acetic acid in bean sprouts by gas chromatography- mass spectrometry（ GC- MS）. Methods The analytes were firstly extracted with acidic acetonitrile,and then dried- up; the residue was redisovled in 2 ml methanol,1 milliliter of the solution was directly analyzed for 2,4- D butyl ester after purified with Qu ECHERS cartridge. Another 1 milliliter of the solution was treated by MCS solid phase extraction column and then methyl esterified with10% boron trifluoride methanol,and finally the other 5 analytes were determined by GC- MS. Results Good linearity was obtained when the concentrations of the 6 plant growth regulator were within 0. 5 μg/ml- 5. 0 μg/ml,with the correlation coefficient（ r） within 0. 991 0- 0. 999 3. Adding 0. 5 μg/ml and 2. 0 μg/ml of standard solution in blank samples respectively,the average recovery of the method was within 79. 8%- 89. 9%,and relative standard deviation（ RSD） was within 3. 9%- 9. 1%.Conclusion The method was simple,rapid and reliable. It can meet the detection requirements of plant growth regulator residue in bean sprouts with Qu ECHERS cartridge.