Rapid and sensitive determination of formamidines and metabolites with HPLC-MS/MS using core-shell columns

A number of poisoning and suicide cases involving formamidine pesticides have been reported, thus developing a rapid and low cost determination method is crucial. In this work, a rapid, sensitive and low-cost method for the simultaneous determination of formamidine pesticides (amitraz, chlordimeform, formetanate) and their main metabolites, N-(2,4-dimethylphenyl)-N-methyl-formamidine, 2,4-dimethylformamidine, 2,4-dimethylaniline, 4-chloro-2-methylaniline and 3-hydroxyacetanilide in human blood by high-performance liquid chromatography with tandem mass spectrometry is developed. The application of columns with core-shell particles significantly reduced the analysis time. Very low LODs (0.01-0.04 μg L^-1) were obtained for formamidine pesticides and their metabolites. The method was successfully applied to the analysis of human blood samples from a real forensic case. The significantly reduced analysis time, high sensitivity and low cost are the primary advantages of the developed method. This methodology provides important value for sensitive and rapid determination of residue pesticides and metabolites, study of residue pesticides behavior in human body, as well as application in real forensic cases.