Rapid identification of pesticides in human oral fluid for emergency management by thermal desorption electrospray ionization/mass spectrometry

Self‐poisoning with pesticides accounts for approximately one‐third of all suicides worldwide. To expedite rescue in the emergency department, it is essential to develop a point‐of‐care analytical method for rapid identification of ingested pesticides. In this study, five of the most common pesticides ingested by self‐poisoning patients in Taiwan were analyzed from oral fluid samples. Pesticide‐oral fluid mixtures were applied on a cotton swab and then transferred into methanol. A metallic probe was used to sample the methanol solution for subsequent thermal desorption‐electrospray ionization mass spectrometry analysis. Altogether, pesticide sampling, transfer, desorption, ionization, and detection took less than 1 min. The reproducibility of this method (n = 6) was shown in the observed low‐relative standard deviation (