title: A reliable method of liquid chromatography for the quantification of acetaminophen and identification of its toxic metabolite N-acetyl-p-benzoquinoneimine for application in pediatric studies.
abstract: The aim of the present study was to develop a simple, selective and reliable method to quantify acetaminophen and its toxic metabolite N-acetyl-p-benzoquinoneimine (NAPQI) for pediatric studies using 100 µL plasma samples, by reverse-phase HPLC and UV detection. The assay was performed using a C₁₈ column and an isocratic elution with water-methanol-formic acid (70:30:0.15; v/v/v) as mobile phase. Linearity of the method was assayed in the range of 1-30 µg/mL for acetaminophen and 10-200 µg/mL for NAPQI, with a correlation coefficient r = 0.999 for both compounds, and inter- and intra-day coefficients of variation of less than 13%. Several commonly co-administered drugs were analyzed for selectivity and no interference with the determinations was observed. The detection and quantification limits for acetaminophen and NAPQI were 0.1 and 1 µg/mL, and 0.1 and 10 µg/mL respectively. The present method can be used to monitor acetaminophen levels using 100 µL plasma samples, which may be helpful when very small samples need to be analyzed, as in pharmacokinetics determination or drug monitoring in plasma in children. This assay is also able to detect the NAPQI for drug monitoring in patients diagnosed with acetaminophen intoxication.
authors.affiliation: Laboratorio de Farmacología, Instituto Nacional de Pediatría, México.
authors.forename: Carmen
authors.initials: C
authors.lastname: Flores-Pérez
authors.forename: Juan Luis
authors.initials: JL
authors.lastname: Chávez-Pacheco
authors.forename: Blanca
authors.initials: B
authors.lastname: Ramírez-Mendiola
authors.forename: Radamés
authors.initials: R
authors.lastname: Alemón-Medina
authors.forename: Raquel
authors.initials: R
authors.lastname: García-Álvarez
authors.forename: Hugo
authors.initials: H
authors.lastname: Juárez-Olguín
authors.forename: Janett
authors.initials: J
authors.lastname: Flores-Pérez
mesh_terms: D000082:Acetaminophen / Q000097:blood*; D000293:Adolescent; D016227:Benzoquinones / Q000097:blood*; D002648:Child; D002675:Child, Preschool; D002851:Chromatography, High Pressure Liquid; D056148:Chromatography, Reverse-Phase / Q000379:methods*; D016903:Drug Monitoring / Q000379:methods; D004355:Drug Stability; D005260:Female; D006801:Humans; D007097:Imines / Q000097:blood*; D007223:Infant; D008297:Male; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity
chemical_list: D016227:Benzoquinones; D007097:Imines; D000082:Acetaminophen; C028473:N-acetyl-4-benzoquinoneimine