title: Quantitative Method for Simultaneous Analysis of Acetaminophen and 6 Metabolites.
abstract: Hepatotoxicity after ingestion of high-dose acetaminophen [N-acetyl-para-aminophenol (APAP)] is caused by the metabolites of the drug. To gain more insight into factors influencing susceptibility to APAP hepatotoxicity, quantification of APAP and metabolites is important. A few methods have been developed to simultaneously quantify APAP and its most important metabolites. However, these methods require a comprehensive sample preparation and long run times. The aim of this study was to develop and validate a simplified, but sensitive method for the simultaneous quantification of acetaminophen, the main metabolites acetaminophen glucuronide and acetaminophen sulfate, and 4 Cytochrome P450-mediated metabolites by using liquid chromatography with mass spectrometric (LC-MS) detection.
  
  
  
  The method was developed and validated for the human plasma, and it entailed a single method for sample preparation, enabling quick processing of the samples followed by an LC-MS method with a chromatographic run time of 9 minutes. The method was validated for selectivity, linearity, accuracy, imprecision, dilution integrity, recovery, process efficiency, ionization efficiency, and carryover effect.
  
  
  
  The method showed good selectivity without matrix interferences. For all analytes, the mean process efficiency was >86%, and the mean ionization efficiency was >94%. Furthermore, the accuracy was between 90.3% and 112% for all analytes, and the within- and between-run imprecision were <20% for the lower limit of quantification and <14.3% for the middle level and upper limit of quantification.
  
  
  
  The method presented here enables the simultaneous quantification of APAP and 6 of its metabolites. It is less time consuming than previously reported methods because it requires only a single and simple method for the sample preparation followed by an LC-MS method with a short run time. Therefore, this analytical method provides a useful method for both clinical and research purposes.
authors.affiliation: Departments of *Hospital Pharmacy and †Medicine, Academic Medical Center, Amsterdam, the Netherlands.
authors.forename: Laureen A
authors.initials: LA
authors.lastname: Lammers
authors.forename: Roos
authors.initials: R
authors.lastname: Achterbergh
authors.forename: Marcel C M
authors.initials: MC
authors.lastname: Pistorius
authors.forename: Johannes A
authors.initials: JA
authors.lastname: Romijn
authors.forename: Ron A A
authors.initials: RA
authors.lastname: Mathôt
mesh_terms: D000082:Acetaminophen / Q000031:analogs & derivatives* / Q000097:blood*; D000627:Aminophenols / Q000097:blood*; D002138:Calibration; D002851:Chromatography, High Pressure Liquid / Q000379:methods; D006801:Humans; D057230:Limit of Detection; D010949:Plasma / Q000737:chemistry; D015203:Reproducibility of Results; D053719:Tandem Mass Spectrometry / Q000379:methods
chemical_list: D000627:Aminophenols; D000082:Acetaminophen; C037386:acetaminophen glucuronide; C026729:4-aminophenol; C045667:acetaminophen sulfate ester