Determinação da 2,5-hexanodiona em amostras de urina submetidas à hidrólise ácida: importância da coluna cromatográfica e do pH do meio

Abstract

Recebido em 1/2/02; aceito em 14/2/03 2,5-HEXANODIONE DETERMINATION IN URINE SAMPLES SUBJECTED TO ACID HYDROLYSIS: RELEVANCE OF THE CHROMATOGRAPHIC COLUMN AND THE pH. Acidic hydrolysis of samples is frequent in urinary 2,5-hexanodione determination. This hydrolysis should be performed under proper conditions, in order to avoid interference, such as the presence of 2,5-dimethylfurane and 2-acetylfurane. The results of the present work, as well as data from the literature, show that the use of non-polar or slightly polar chromatographic columns of 30 m length is an essential condition for 2,5-HD determination in an acid hydrolysed urine sample. In the same way the pH should be kept between 0.3 and 0.5. The mean concentrations of 2,5-HD in samples submitted to hydrolysis (0.50 ± 0.28 mg/g of creatinine) was about 3 times higher than those found in the samples without acid hydrolysis (0.19 ± 0.3 mg/g of creatinine).