PMID- 28494350 OWN - NLM STAT- MEDLINE DCOM- 20170619 LR - 20191210 IS - 1873-376X (Electronic) IS - 1570-0232 (Linking) VI - 1055-1056 DP - 2017 Jun 15 TI - Liquid chromatography-tandem mass spectrometry quantification of acetamiprid and thiacloprid residues in butterbur grown under regulated conditions. PG - 172-177 LID - S1570-0232(17)30221-0 [pii] LID - 10.1016/j.jchromb.2017.04.021 [doi] AB - An analytical method was developed to quantify the residual levels of the neonicotinoid insecticides, acetamiprid and thiacloprid, in field-incurred butterbur samples using liquid chromatography-tandem mass spectrometry (LC-MS/MS). Samples were extracted with acetonitrile and partitioned with dichloromethane. After partitioning, purification was conducted using a Florisil((R)) cartridge. Linearity of a matrix-matched calibration curve of the two compounds over a concentration range of 0.004-0.4mug/g was excellent, with determination coefficients (R(2))>/=0.9998. The limits of detection (LOD) and quantitation (LOQ) for both acetamiprid and thiacloprid were 0.0006 and 0.002mg/kg, respectively. The average recoveries for acetamiprid and thiacloprid at two spiking levels (0.02 and 0.1mg/kg, i.e., 10xLOQ and 50xLOQ) were between 78.23 to 82.17%, with relative standard deviations (RSDs)