猫血浆中氟雷拉纳液相色谱-串联质谱检测方法的建立OA

Fluralaner(Flur)is an isoxazoline insecticide and acaricide characterized by rapid absorption,safety,high efficacy,long-lasting effects,and good tolerability.To investigate the pharmacokinetics of com-pound Flur drops in cats,a liquid chromatography—tandem quadrupole mass spectrometry(LC-MS/MS)method for the detection of Flur in feline plasma was established using Flur-D4 as an internal standard.Acetonitrile was used as the extraction solvent,with water-bath ultrasonic-assisted extraction followed by vacuum evaporation and redissolution prior to LC-MS/MS analysis and quantification via the internal standard method.The results showed that the feline plasma matrix did not interfere with the quantitative detection of Flur,and the method exhibited good specificity;The method exhibited high sensitivity,with a limit of detection(LOD)of 5 ng/mL and a limit of quantification(LOQ)of 10 ng/mL;matrix effects were insignificant.A standard curve was prepared using solvent-based standard solutions,and Flur exhibited a good linear relationship(R2＞0.99)in the concentration range of 10 ng/mL to 6 000 ng/mL.The spiked samples with different concentration levels,the mean accuracy ranged from 92.60％to 116.70％,with both intra-and inter-batch coefficients of variation below 10％,meeting methodological requirements.Spiked samples with different concentration remained stable when stored frozen at-18℃ or below for 6 months or after repeated freeze-thaw cycles;and the processed solution of spiked samples remained stable when stored at 4℃ for 72 hours.The standard stock solution and intermediate standard solution were stable for 9 months,while the working standard solution was stable for 2 months.The results indicate that the estab-lished method exhibits good specificity,high sensitivity,and is stable and reliable,making it suitable for pharmacokinetic studies of Flur drops in cats.