Successful quantification of 4′-methyl-α-pyrrolidinohexanophenone (MPHP) in human urine using LC–TOF-MS in an autopsy case

The toxicological detection of the new synthetic cathinone 4′-methyl-α-pyrrolidinohexanophenone (MPHP) in urine samples has been impossible, because much of MPHP is metabolized before its excretion into urine. In this study, we successfully quantified unmetabolized MPHP in urine of an autopsy case using a sensitive method by liquid chromatography–time-of-flight-mass spectrometry. The quantification method showed good linearity in the range of 1.00–100 ng/mL, and the limit of detection was 0.5 ng/mL in human urine. In the autopsy case, the concentrations of MPHP in urine, plasma, and liver tissue samples were determined to be 60.1, 32.9 ng/mL, and 63.1 ng/g, respectively.