Edna Maria Alvarez Leite

Avaliação do ácido trans, trans-mucônico urinário como biomarcador de exposição ao benzeno

OBJECTIVE To assess the use of trans, trans-muconic acid as a biomarker of occupational exposure to benzene. METHODS Trans, trans-muconic acid in urine samples of exposed (exposed group, n=36) and non-exposed (non-exposed group, n=116) workers to benzene. Urinary levels of trans, trans-muconic acid were quantified by high-performance liquid chromatography. The study sample consisted of subjects exposed to benzene in an oil refinery in Belo Horizonte, Brazil. Non-parametric statistical analysis was carried out using Kruskall-Wallis test, Mann-Whitney test and Spearman correlation at p<0.05. RESULTS Workers were exposed on average to benzene levels of 0.15 +/- 0.05 mg/m3 (0.05 ppm) and they showed a urinary trans, trans-muconic acid mean value of 0.19 +/- 0.04 mg/g of creatinine. The reference value range of trans, trans-muconic acid in non-exposed subjects was 0.03 to 0.26 mg/g of creatinine (mean 0.10 +/- 0.08 mg/g of creatinine). There was seen a statistical difference between trans, trans-muconic acid levels in urine samples from exposed and non-exposed groups. There was no correlation between urinary trans, trans-muconic acid and air benzene levels. There was no correlation between urinary trans, trans-muconic acid levels in the exposed group and smoking. Alcohol consumption up to 48 hours before sampling procedure showed no effect on trans, trans-muconic acid levels in both exposed and non-exposed groups. There was however a correlation between age (range 18 to 25 years) and urinary metabolite levels in the latter group. CONCLUSIONS The results show that it is important to evaluate the effect of age and smoking habits on urinary trans, trans-muconic acid levels.OBJETIVO: Avaliar o uso do acido trans, trans-muconico urinario como biomarcador na monitorizacao da exposicao ocupacional ao benzeno. METODOS: Foi estudado o comportamento do acido trans, trans-muconico em amostras de urina de individuos expostos (N=36) e nao expostos (N=116) ocupacionalmente ao solvente. A concentracao urinaria do acido foi determinada por Cromatografia Liquida de Alta Eficiencia. A amostra foi constituida de individuos expostos ao benzeno em uma refinaria de petroleo localizada em Belo Horizonte, MG. Foram empregados os testes estatisticos nao-parametricos de Kruskall-Wallis, Mann Witney e de correlacao de Spearman, ao nivel de significância de 0,05%. RESULTADOS: A exposicao media ao benzeno dos trabalhadores selecionados foi de 0,15±0,05 mg/m³ (0,05 ppm) o que resultou em um valor medio do metabolito urinario de 0,19±0,04 mg/g de creatinina. A faixa de referencia do acido trans, trans-muconico no grupo nao exposto variou de 0,03 a 0,26 mg/g de creatinina (media de 0,10±0,08 mg/g de creatinina). Foi encontrada uma diferenca significativa entre os niveis de acido trans, trans-muconico do grupo exposto e nao exposto. Entretanto, nao houve correlacao entre os niveis do metabolito urinario e do benzeno no ar. Foi observada a correlacao entre acido trans, trans-muconico e habito de fumar no grupo de individuos expostos. A ingestao de alcool num periodo de ate 48 horas antes da coleta das amostras nao mostrou interferir nos niveis do metabolito nos dois grupos estudados. Foi observada a correlacao entre acido trans, trans-muconico e idade (faixa etaria de 18 a 25 anos) no grupo de nao expostos. CONCLUSOES: Os resultados obtidos evidenciaram a importância de ser mais bem avaliada a influencia do habito de fumar e da faixa etaria do trabalhador nos niveis urinarios do acido trans, trans-muconico.

Determination of 3,4-Methylenedioxymethamphetamine (MDMA) and 3,4-Methylenedioxyamphetamine (MDA) in Urine by High Performance Liquid Chromatography

Abstract The present study proposes a simple, inexpensive method for the identification and quantification of 3,4-methylenedioxymethamphetamine (MDMA) and its principal metabolite 3,4-methylenedioxyamphetamine (MDA) in samples of human urine utilizing high performance liquid chromatography with a UV detector. The optimized method presented adequate linearity, sensitivity, precision, selectivity, and robustness, thereby demonstrating its feasibility for adoption as a laboratorial option for the confirmation of the presence of the drug in urine samples from users.