SPE和QuEChERS前处理方法结合LC-Q-TOF/MS检测苹果和番茄中282种农药残留对比研究

Comparison of SPE and QuE ChE RS combined with LC- Q- TOF / MS for determination of 282 pesticide residues in apple and tomato

利用液相色谱-四极杆/飞行时间质谱（LC-Q-TOF/MS）对比研究了固相萃取（SPE）和Qu ECh ERS两种前处理方法在282种农药残留检测上的效果。以苹果和番茄为基质,分别从基质效应、回收率、重复性、线性关系、检出限和定量限等方面进行了考察与比较。SPE法和Qu ECh ERS法在苹果中呈现出弱基质效应的农药占比分别为87.2%和57.1%,在番茄中为65.6%和42.2%。与SPE相比,Qu ECh ERS法干扰物较多,基质效应较强;在5.0μg/kg添加水平下（n=5）,SPE和Qu ECh ERS在苹果中平均回收率在70%~120%的农药占比分别为99.3%和86.9%,在番茄中为92.9%和87.9%;在5.0μg/kg添加水平下（n=5）,SPE和Qu ECh ERS在苹果中重复性相对标准偏差（RSD）〈20%（n=5）农药占比分别为98.9%和86.5%,在番茄中为92.9%和87.6%;SPE和Qu ECh ERS两种方法在苹果中定量限≤10μg/kg的农药占比为100.0%和96.1%,在番茄中为100.0%和98.9%。两种前处理方法均能与高分辨质谱技术相结合并应用于果蔬农药残留的日常检测中,其中SPE净化效果较优,定量更为准确,但步骤稍显繁琐费时,而Qu ECh ERS方法简单快速,故在检测时可根据不同需要进行选择。

By using liquid chromatography / quadrupole time-of-flight mass spectrometry（ LC-Q-TOF / MS）,The application effects of solid phase extraction（ SPE） and Qu ECh ERS in dealing with 282 pesticide residues were compared and analyzed in this paper. Taking apples and tomatoes as the research matrices,the two methods are compared from the matrix effect,recovery,repeatability,linear range,limit of detection and quantification,etc.The results show that： the pesticide proportions in apples under soft matrix effects of SPE and Qu ECh ERS are87. 2% and 57. 1%,respectively,while those in tomatoes are 65. 6% and 42. 2%,respectively. Compared with the SPE,a stronger matrix was presented for Qu ECh ERS. With the spiked level of 5. 0 μg / kg（ n = 5）,99. 3%and 86. 9% of pesticides in apple of SPE and Qu ECh ERS,can reach the recovery of 70% ~ 120%,while the corresponding rates in tomatoes are 92. 9% and 87. 9%. With the spiked level of 5. 0 μg / kg（ n = 5）,98. 9%and 86. 5% of pesticides in apple of SPE and Qu ECh ERS,will have the repeatability with relative standard deviation（ RSD） of 〈20%,while the corresponding rates in tomatoes are 92. 9% and 87. 6%. 100. 0% and96. 1% of pesticides in apple of SPE and Qu ECh ERS,respectively,can reach the limit of quantification of ≤10μg / kg,while the rates in tomatoes are 100. 0% and 98. 9%,respectively. In conclusion,the above test results indicate that the two pre-treatment methods can both be combined with the high resolution mass spectrometry and applied into the daily examination of pesticide residues in fruits and vegetables. Compared with Qu ECh ERS,SPE has a better effect on purification and quantification, except its complex and time-consuming, however Qu ECh ERS is simple and fast,so a suitable method can be selected in practical detection according to different needs.