Simultaneous determination of pentachlorophenol, niclosamide and fenpropathrin in fishpond water using an LC-MS/MS method for forensic investigation

Pentachlorophenol, niclosamide and fenpropathrin are agrochemicals commonly used as molluscicides or pesticides; however, criminal poisoning aquaculture products using the above three agrochemicals, by motive of illegal economical competition or ill-willing reprisal, occur in high frequency in some fishery regions. Identifying the poison is important to the forensic investigation of such cases of criminal poisoning. In this work, an LC-MS method was developed for the simultaneous determination of the three toxicants. Selective ion monitoring (SIM) was applied for the determination of pentachlorophenol, and multiple reaction monitoring (MRM) was applied for the determination of niclosamide and fenpropathrin. These methods showed excellent reliability and assay performance, and can serve as a reference method for forensic investigations of fish poisoning, So far, this method has been successfully applied in some cases of criminal poisoning.