A sensitive HPLC-ESI-MS-MS method for the determination of cotinine in urine.
A simple, sensitive, selective, and reproducible method based on high-performance liquid chromatography-electrospray ionization-tandem mass spectrometry was developed for the determination of nicotine and its major metabolite cotinine in human urine. The internal standard (acetaminophen) was separated from cotinine on a Hypersil Gold C(18) column with retention times of 9.3 and 13.0 min, respectively. The mobile phase consisted of a mixture of 10 mM acetate buffer (pH 5.4) and methanol (45:55, v/v), running through the column at a flow rate of 0.6 mL/min. The chromatographic analysis was operated at 25 degrees C. Sample preparation was prepared by liquid-liquid extraction with a mixture of methyl-t-butyl ether in dichloromethane (1:1, v/v). The precision of the method based on within-day repeatability and reproducibility (day-to-day variation) was below 15% (% coefficient of variation). Good accuracy was observed for both the intra-day or inter-day assays. Limit of quantification was accepted as 0.02 ng using 100 mL samples. The mean recoveries for cotinine and the internal standard were greater than 90%. The method has been applied to the investigation of a 2-h urinary excretion of cotinine in 154 healthy non-smoking Thai volunteers (aged 18-45 years) following the administration of a half-piece (2 mg) of nicotine gum.
Apinan
Roongnapa
R
Pharmacology and Toxicology Unit, Graduate Program in Biomedical Sciences, Faculty of Allied Health Sciences, Thammasat University (Rangsit Campus), Paholyothin Rd., Pathumthani 12121, Thailand.
Choemung
Anuruk
A
Na-Bangchang
Kesara
K
D000082:Acetaminophen / Q000032:analysis / Q000737:chemistry; D000328:Adult; D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D003367:Cotinine / Q000737:chemistry / Q000652:urine*; D004355:Drug Stability; D005260:Female; D006801:Humans; D016014:Linear Models; D008297:Male; D008875:Middle Aged; D009538:Nicotine / Q000008:administration & dosage / Q000031:analogs & derivatives / Q000737:chemistry / Q000652:urine; D011109:Polymethacrylic Acids; D011145:Polyvinyls; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D021241:Spectrometry, Mass, Electrospray Ionization / Q000379:methods*; D053719:Tandem Mass Spectrometry / Q000379:methods*; D061485:Tobacco Use Cessation Devices
D011109:Polymethacrylic Acids; D011145:Polyvinyls; D000082:Acetaminophen; D009538:Nicotine; D003367:Cotinine