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An analytical method was established for simultaneous determination of chlorantraniliprole, cyantraniliprole and its metabolite J9Z38 in litchi by high performance liquid chromatography coupled to tandem mass spectrometry (HPLC-MS/MS) combined with a modified QuEChERS procedure. The target compounds were extracted from the samples with acetonitrile and then cleaned up with primary secondary amine (PSA) and octadecylsilane (C18). The analytes were separated on a C18 column using V (formic acid aqueous solution) : V (acetonitrile)=15 : 85 as mobile phase and analyzed in multiple reaction monitoring (MRM) mode with positive electrospray ionization (ESI+ ). Quantitative analysis was performed by external standard method using matrix-matched calibration curves. The results showed that the linearity of the target compounds was good (r >0.99) in the range of 0.005-1 mg/L. The limits of quantification (LOQs) were 0.000 5-0.01 mg/kg. The average recoveries of the three pesticides in litchi (whole fruit and pulp) ranged from 76% to 98% at the spiked levels of 0.000 5-0.5 mg/kg, with the relative standard deviations of 2.5% to 9.6%. The method was applied for the detection of twenty commercial litchi samples in Guangzhou City. The results showed that the residues of chlorantraniliprole were 0.001-0.01 mg/kg, and neither cyantraniliprole nor its metabolite J9Z38 were found. The proposed method is convenient, effective and rapid, and is suitable for the simultaneous determination of chlorantraniliprole, cyantraniliprole and its metabolite in litchi. [ABSTRACT FROM AUTHOR]

A sensitive method for determination of spirotetramat and its metabolites and chlorantraniliprole in longan（Dimocarpus longan Lour.） were developed based on high performance liquid chromatography-tandem mass spectrometry（HPLC-MS/MS） technique. The terminal residues of spirotetramat and chlorantraniliprole in longan under field conditions were studied in 6 experimental sites in 2018. The samples were extracted with acetonitrile, cleaned up with PSA, detected by HPLCMS/MS, and quantified by external standard method. The mean recoveries of spirotetramat and its four metabolites and chlorantraniliprole in longan whole fruit and longan pulp were 83%-103%, and 87%-92%, respectively, at the three spiking levels from 0.01 to 1 mg/kg with relative standard deviations（RSDs） of 2.3%-8.7%, and 3.3%-6.3%. The limits of quantitation（LOQs） of spirotetramat and its four metabolites and chlorantraniliprole was 0.01 mg/kg. In the field trials, 22.4% spirotetramat SC and 5%chlorantraniliprole SC were applied at the dosage of 60 and 50 mg/kg for two times with the interval 7-10 d, respectively. The results showed that terminal residues of spirotetramat and chlorantraniliprole in longan whole fruit were 0.30-1.14 and 0.06-0.29 mg/kg, respectively, at 14 d after application, and were <0.05 and < 0.01 mg/kg, respectively in longan pulp. This study would be helpful to guide scientific and efficient utilization of these pesticides. Because of the absence of maximum residue limits（MRLs） value of spirotetramat and chlorantraniliprole in longan, these results could provide data to facilitate the setting of longan MRL. [ABSTRACT FROM AUTHOR]

Copyright of Chinese Journal of Pesticide Science / Nongyaoxue Xuebao is the property of Chinese Journal of Pesticide Science and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Chinese Journal of Pesticide Science / Nongyaoxue Xuebao is the property of Chinese Journal of Pesticide Science and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Chinese Journal of Pesticide Science / Nongyaoxue Xuebao is the property of Chinese Journal of Pesticide Science and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)