QuEChERS提取-气相色谱-质谱法测定豆芽中的7种植物生长调节剂残留量

Determination of 7 plant growth regulators residues in bean sprouts by QuEChERS-gas chromatography-mass spectrometry

目的建立气相色谱-质谱法测定豆芽中的7种植物生长调节剂残留量的方法。方法样品经组织捣碎、乙腈提取、甲醇定容后,采用GC-MS检测2,4-D-乙酯和2,4-D-丁酯;另取甲醇定容液1 ml,经QuEChERS净化、MCS柱过滤、三氟化硼甲醇进行衍生后,采用GC-MS检测4-氯苯氧乙酸、2,4-二氯苯氧乙酸(2,4-D)、α-萘乙酸、吲哚乙酸和吲哚丁酸。结果 7种植物生长调节剂在0.5μg/ml^10μg/ml时具有良好的线性关系,相关系数(r)均≥0.991 5。7种植物生长调节剂的LOD为0.01 mg/kg,LOQ为0.03 mg/kg,平均加标回收率为92.2%~97.4%,相对标准偏差(RSD)为4.8%~10.1%。276份豆芽样品中,4-氯苯氧乙酸检出93份,吲哚乙酸检出70份,吲哚丁酸检出26份;2,4-D、2,4-D-乙酯、α-萘乙酸和2,4-D-丁酯4个指标在所有豆芽样品中均未检出。结论该方法灵敏度高,回收率高,检测限低,符合分析要求,适合豆芽中7种植物生长调节剂残留检测的要求。

Objective To establish the QuEChERS-gas chromatography-mass spectrometry（ GC-MS） method for the determination of 7 plant growth regulators residues in bean sprouts. Methods The samples were mashed,extracted with acetonitrile,constanted volume with methanol,then 2,4-D-ethyl ester and 2,4-D-butyl ester were detected by GC-MS. Methanol constanted volume 1 ml was extracted,purified by QuEChERS,filtrated with MCS column,derived by three boron fluoride methanol for the detection of 4-chlorophenoxyacetic acid,2,4-D,α-NAA,IAA and IBA by GC-MS. Results Good linearity was obtained when the concentrations of 7 plant growth regulators were within 0. 5 μg/ml-10 μg/ml,with the correlation coeffectients（ r）〉 0. 991 5. The limit of detection（ LOD） of the 7 plant growth regulators was 0. 01 mg/kg and the limit of quantification（ LOQ） was 0. 03 mg/kg,respectively. The average spiked recoveries were within 92. 2%-97. 4%,and the relative standard deviation（ RSD） was within 4. 8%-10. 1%. Among the 276 samples of bean sprouts,4-chlorophenoxyacetic acid in93 samples,IAA in 70 samples,and IBA in 26 samples were detected; 2,4-D,2,4-D-ethyl ester,α-NAA and2,4-D-butyl ester in 276 samples of bean sprouts were not detected. Conclusion The method had a high sensitivity,high recovery rate,low detection limit,which could meet the requirement of the detection of 7 plant growth regulators residues in bean sprouts.