An assay for identification and determination of toxic rodenticide valone in serum by ion chromatography–electrospray ionization tandem mass spectrometry with ion trap detector

Valone has a chronic and toxic anticoagulant rodenticide that has widely used in China and has resulted in some accidental and intentional intoxication in recent years. The literature reported so far lacks sensitive and selective method for the confirmation of valone. The purpose of this study was to establish a novel assay for the identification and quantification of valone in serum by ion chromatography–electrospray ionization tandem mass spectrometry (IC–MS/MS). After serum sample was extracted with methanol/acetonitrile (10:90, v/v) and cleaned by Oasis® HLB solid-phase extraction cartridge, chromatographic separation was performed on an Ionpac® AS11 column with an eluent of methanol/30 mmol/L KOH (10:90, v/v). The overall extraction efficiency was >81.0%, and the limit of quantification was 0.5 ng/mL for valone. Regression analysis of the calibration data revealed good correlation (r2 > 0.99) for valone. Intra- and inter-day precisions for quality-control samples were less than 8.0 and 13.7%, respectively. The proposed method enables the identification and quantification of valone in both clinical and forensic specimens.