A fast and simple method for the determination of urinary 1-Hydroxypyrene
The determination of total 1-Hydroxypyrene (1-OH-Py), a pyrene metabolite, in human urine is used as a biological indicator for exposure to PAHs, which is related to the combustion of organic material. Smoking, living in urban environments and eating grilled or smoked food contribute to the levels detected in humans. In this paper, a fast method for the measurement of metabolites of pyrene in urine was improved by high performance liquid chromatography with fluorescence detector using "heart-cut" technique. This method can quantify the total amount of pyrene metabolites corresponding to glucuronic acid and sulfate conjugates as well as free 1-OH-Py. The hydrolysed biological fluid was directly injected into the chromatographic system, via a column-switching system. Pre-treatment and analysis were performed within 0.5 and 9 min, respectively. Enzymatic hydrolysis has been optimised to not exceed 2 hours. The best response function, in the 0.2-10 ng/mL range, is the linear regression, bringing simplicity, good accuracy and low quantitation limit. The intra- and inter-day precision values were less than 1 and 2%, respectively. The proposed method provided a simple, convenient and practical procedure to determine the level of the main urinary pyrene metabolites in biological samples. For one hundred samples, the handling time of this on-line method is four times less than off-line methods. Of course, these handling times are directly linked with the cost of the analysis. This method offers also the advantage that the reduction of handling operations decreases the associated risk of error, and, the requested urine sample is low, less than 1 mL, which facilitates biological sampling and transport.