Simultaneous determination of amitraz, chlordimeform, formetanate and metabolites in human blood by liquid chromatography tandem mass spectrometry with phospholipid-removal pretreatment.

In this study, a reliable ultra-performance liquid chromatography tandem mass spectrometry (UPLC-MS/MS) method coupled with an easy, fast and effective sample pretreatment procedure was developed for simultaneous determination of amitraz, chlordimeform, formetanate and their metabolites in human blood. With the procedures of protein precipitation and a phospholipid-removal step, the endogenous compound interference was significantly reduced, and matrix effects were significantly reduced. The linear ranges of matrix-matched standard curves were from 0.5 to 1000 ng/mL with coefficients of determination >0.996. Very low limits of detection (0.05-0.12 ng/mL) and limits of quantitation (0.15-0.4 ng/mL) were achieved. Reasonable recoveries ranging from 88.1 to 103.5% were obtained. The intra-day RSDs ranging from 3.2 to 8.6% and inter-day RSDs ranging from 4.8 to 9.2% indicated good precision. With the introduction of a phospholipid-removal step, the ME ranged from 90.1 to 98.5%. The established method was successfully applied to the analysis of a blood sample from a formetanate poisoning case. This method possesses the advantages of high sensitivity, reduced matrix effects and rapidity.

Capillary gas chromatography with mass spectrometric and atomic emission detection for characterization and monitoring chlordimeform degradation in honey.

Capillary gas chromatography-mass spectrometry and capillary gas chromatography-atomic emission detection have been successfully used to identify and monitor the main degradation products of chlordimeform when this compound is initially present in honey. The analysis of laboratory-spiked honey samples over 28 weeks revealed the occurrence of two degradation products: 4-chloro-o-toluidine (I) and N-formyl-4-chloro-o-toluidine (III). During this period the concentration of chlordimeform decreased to 7.5% of its initial value; the concentration of compound I increased gradually whereas compound III was present in a larger proportion and reached a maximum around the 14th week.