Abstract: A method constituted by molecularly imprinted solid-phase extraction (MISPE) with high-performance liquid chromatography coupled to diode array detector (HPLC-DAD) was developed for cotinine analysis in saliva samples. For this purpose, the separation was carried out with a C18 reversed-phase column at 20 °C. The mobile phase which was composed of a mixture of 09:91 (v/v) acetonitrile/phosphate buffer, pH 6.3, was delivered with isocratic flow rate at 1.4mLmin-1. Employing MISPE, the best conditions were achieved with 1.5mL of saliva plus 1.5mL of 0.1molL-1 of acetate buffer, pH5.5, which were then passed through a cartridge previously conditioned with 2mL acetonitrile, 2mL methanol, and 2mL of 0.1molL-1 sodium acetate buffer, pH5.5. The washing was carried out with 1mL deionized water, 1mL of 0.1molL-1 sodium hydroxide, and 1mL hexane; finally; the cotinine elution was carried out with 3mL methanol/water (97.5: 2.5, v/v). Linearity ranged from 30 to 500ngmL-1 with r > 0.99. Intra-assay, interassay precision, and accuracy ranged from 3.1% to 10.1%, 5.2% to 15.9%, and 99.22% to 111.17%, respectively. The detection and quantification limits were 10 and 30ngmL-1, respectively. This investigation has provided a reliable method for routine cotinine determination in saliva, and it is an important tool for monitoring cigarette smoke exposure in smokers. The method was applied in five smokers' samples who consumed around five to 20 cigarettes per day and the values of cotinine in saliva were from 66.7 to 316.16 ngmL-1
Template and target information: cotinine
Author keywords: molecularly imprinted polymer, Solid-phase extraction, Cotinine, Saliva, liquid chromatography

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