单 位：
农业部农药残留检测重点实验室·浙江省有害生物防控重点实验室-省部共建国家重点实验室培育基地·浙江省农业科学院农产品质量标准研究所
摘 要：
【目的】评价啶氧菌酯在葡萄上使用的安全性。【方法】采用超高效液相色谱-串联质谱法建立了葡萄果实和园地土壤中啶氧菌酯的残留检测方法,研究了啶氧菌酯在葡萄果实和园地土壤中的消解动态。样品中啶氧菌酯经乙腈提取,HLB小柱净化,超高效液相色谱-串联质谱(UPLC-MS/MS)检测。【结果】啶氧菌酯在葡萄果实和园地土壤中的最低检测质量分数均为0.01 mg·kg~(-1),最小检出量均为4.0×10-13g。当添加质量分数为0.01~5.0 mg·kg-1时,添加回收率为85%~100%,相对标准偏差为2.1%~4.4%。啶氧菌酯在葡萄果实和园地土壤中的降解动态曲线符合一级动力学方程,半衰期分别为5.9~12.6 d和2.2~10.7 d。【结论】该方法能用于检测啶氧菌酯在葡萄果实和园地土壤中的残留。啶氧菌酯在葡萄果实和园地土壤中降解较快。
译 名：
Degradation of picoxystrobin in grape fruit and grapery soil by UPLC-MS/MS
作 者：
HU Xiuqing;ZHU Yahong;ZHANG Changpeng;ZHANG Chunrong;ZHAO Hua;MOA Key Lab for Pesticide Residue Detection·Supported by State Key Laboratory Breeding Base for Zhejiang Sustainable Pest and Disease Control·Institute of Quality and Standard for Agro-products, Zhejiang Academy of Agricultural Sciences;
关键词：
Grape fruit;;Picoxystrobin;;Grapery soil;;Dissipation
摘 要：
【Objective】In this work, a simple ultra- performance liquid chromatography- tandem mass spectrometry(UPLC-MS/MS) method was established to detect picoxystrobin in grape fruit and vineyard soil. The dissipation of picoxystrobin in fruit and soil was also studied. These results would provide guidance for the proper and safe use of this pesticide. This work would also provide scientific evidence for environmental fate of picoxystrobin.【Methods】Twenty gram vineyard soil or 5 g grape fruit was weighed into250 m L conical flask. 50 m L or 25 m L(grape fruit) acetonitrile was added and shook vigorously for 60 min for soil and 30 min for fruit. After filtration by a vacuum pump, the sample was washed with 20 m L acetonitrile. The solution was collected and diluted to 80 m L for soil and 50 m L for fruit with deionized water. 1m L extract solution was transfered and diluted to 15 m L with ultrapure water. A HLB cartridge was conditioned with 2 m L acetonitrile and 2 m L of ultrapure water. The obtained solution(15 m L) was loaded to the cartridge and discard. The analytes were eluted with 3 m L acetonitrile, and the eluate was collected.The eluate was evaporated to 1.0 m L with a moderate nitrogen flow. The eluate was fixed to 2 m L with acetonitrile and filtered with 0.22 μm syringe filter for UPLC-MS/MS analysis. The field trials were conducted in Zhejiang and Beijing. The kinetic study was carried out in six field plots, each with an area of 30 m~2.Picoxystrobin formulations(250 g·L~(-1) SC, 1 000 times dilution) were sprayed to grape fruit(the half of themature individuals) and soil, respectively. The untreated plots were sprayed with water as control. Each experiment was conducted in triplicate. The representative samples were collected at 2 h 3 d, 7 d, 14 d, 21 d, 28 d, and 35 d(fruit and soil) after application. Soil samples from the top(0 cm) to 10 cm were collected and mixed fully in each treatment. The samples were placed in a freezer at-20 ℃ until analysis.【Results】In this study, calibration was performed with external standards. Linear regression analysis was performed. The calibration range was linear from 0.000 2 to 0.1 mg·L- 1, and the equations of the standard curves was as follows: y= 2 883.8x + 2 179.3(r=0.999 6). The limits of quantification(LOQ) and the limit of detection(LOD) were estimated from the chromatogram corresponding to the lowest concentration of picoxystrobin used in the calibration. The LOQs of picoxystrobin in grape fruit and soil were 0.01 mg·kg~(-1).The LODs was 4.0×10-13 g for picoxystrobin. The average recoveries of picoxystrobin in grape fruit and soil were found at the three spiking levels from 0.01 to 5.0 mg·kg~(-1). The mean recoveries of picoxystrobin were in the acceptable ranges of 85%-88% for grape fruit, and 94%-100% for soil, respectively. The RSDs of the method ranged from 2.1%-4.4% and 2.9%-4.3%, respectively. The effectiveness of the method in measuring trace levels of picoxystrobin was monitored by analyzing the samples collected from the field trials. The average levels of picoxystrobin degradation rate 35 days after treatment were over 87.5% in grape fruit in Zhejiang and Beijing. The average levels of picoxystrobin degradation rate 35 days after treatment were over 73.8% in grapery soil in Zhejiang and Beijing. The dissipation of picoxystrobin residue with time was described mathematically by a pseudo-first rate equation. The half-lives of picoxystrobin in grape fruit from Zhejiang were 8.1 and 12.6 days, which were 9.9 and 5.9 days from Beijing. The halflives of picoxystrobin in soil from Zhejiang were 2.2 and 6.3 days, which were 9.5 and 10.7 days from Beijing.【Conclusion】The method was reliable to determine the picoxystrobin in grape fruit and grapery soil.The proposed analytical method could be used to determine picoxystrobin dissipation in grape fruit and grapery soil. The half-lives of picoxystrobin were 5.9-12.6 days in grape fruit, and 2.2-10.7 days in grapery soil. Picoxystrobin is easily degraded in grape fruit and grapery soil.
