Optimization and validation of analytical methodology for determination of 1-hydroxypyrene in urine of sugar cane workers

Abstract

This study aimed to optimize and validate an analytical methodology for determination of 1- hydroxypyrene in urine of workers involved in harvesting sugar cane. The method used for determining 1- hydroxypyrene in human urine is the enzymatic hydrolysis, extraction and clean-up by solid phase extraction (SPE) and quantified by high performance liquid chromatography with fluorescence detection (HPLC / Flu). Four types of cartridges were tested to verify the percentage of recovery. Urine of sugar-cane workers (nonsmokers and of both sexes) were collected during the harvest (n = 39) and non-harvest season (n = 34) of cane sugar. The best recovery results were attributed to the C18 cartridges. They presented recovery between 79% and 108%, with a coefficient of variation between 5% and 10%. The limit of quantification was 74 ng of 1- hydroxypyrene per liter of urine. The optimized and validated methodology was used for determination of real samples. The results found in the urine of workers at harvest period ranged from 0.026 to 2.3 mol of 1- hydroxypyrene per mol creatinine. During the non-harvesting season the results ranged from 0.0023 to 0.38 mol of 1-hydroxypyrene per mol creatinine. The validated methodology proved suitable for determination of 1-hydroxypyrene in human urine. The data indicate that there is strong correlation between excretion of 1- hydroxypyrene and the periods during and between harvests of sugar cane.