Validação do método para determinação de cotinina em urina por cromatografia líquida de alta eficiência / Validation of a high-performance liquid chromatography method for the determination of cotinine in urine

ABSTRACT

Tobacco dependence reaches nearly one third of the world population, and is the second leading cause of deth around the world. Cotinine, a major metabolite of nicotine, is conssidered the most appropriate parameter to evaluate tobacco exposure HLPC (High Performance Liquid Chromatography) was choses to analyze cotinine concentrations in urine. Aiming at validating this method of analysis, urine samples with added cotinine were submitted to liquid-liquid extractions using2-phenylimidazole as the internal standard. After evaporation, residue was injected in HLPC with ultraviolet detection and C8 column. The following parameters were stabilishe linearity, precision, detection and qualification limit, accuracy, ans stability. The calibration curve, determined ian a interval of 10ng/mL and 1000ng/mL, presented linearity (R2 = 0,09979). The method limit of detection was of 5ng/mL, and the limit of quantification was of 10ng/mL. In 50, 500, and 1000ng/mL concentrations, the precision was of 11.2; 12.3, and 8.1 per cent, accuracy found was of 107.0; 101.7, and 97.0 per cent, and loss during the stability test was of 8.1...