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@#Objective - To optimize the extraction and quantification methods for the determination of S phenylmercapturic acid - Methods (SPMA) in urine with performance liquid chromatography mass spectrometry. The urine was hydrolyzed with 50.0% sulfuric acid. The hydrolysate was purified by solid phase extraction column. Purified samples were separated by C18 chromatographic column and detected by tandem mass spectrometry. The isotope labeled SPMA was used as the internal Results - standard. The internal standard curve was used for quantification. The linear range of SPMA was 0.50 50.00 μg/L with the correlation coefficient of 0.999 8. The detection limit and the lower limit of quantification were 0.05 and 0.17 μg/L, - - - - respectively. The recovery rate was 97.0% 102.0%. The within run and between run relative standard deviation were 0.6% 1.0% - and 1.7% 6.5%, respectively. The mass concentration of urinary SPMA in the occupational benzene exposure group was - vs P higher than the non occupational benzene exposure group by this method (median: 2.81 0.28 μg/g creatinine, <0.05). Conclusion Compared to the national standard method, this optimized method of solid phase extraction and internal standard for quantification eliminates the matrix effect. This method is accurate and precise, and is suitable for the determination of SPMA acid in urine.
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Objective@#To establish a method for determination the S-phenylmercapturic acid in urine by dispersive solid-phase extraction using Humic Acid/Fe3O4 magnetic nanocomposite as adsorbent.@*Methods@#The 5 ml of urine samples were adjusted to pH 1.0 and extracted by Fe3O4@HA. Then the analytes were separated on EC-C18 capillary column and detected by HPLC-VWD. The S-phenylmercapturic acid was characterized by the retention time and quantified by peak area and external standard method.@*Results@#The standard curves of SPMA showed significant linearity between 0.04~1.00 mg/L (r=0.999 7) . The average recovery was 94.2%~102.4%. The intra-day and inter-day precisions (RSD) were 2.9~6.7% (n=6) and 3.1~7.5% (n=6) respectively. The detect limit of SPMA was 0.012 g/L (S/N=3) .@*Conclusion@#This method is simple, rapid, sensitive and accurate. It is applicable for determination of SPMA in the urine of works who were exposed to benzene.
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Resumo Introdução: o benzeno é uma substância de reconhecida toxicidade e sua biomonitorização torna-se fundamental para a prevenção de danos à saúde humana, principalmente em situações de exposição ocupacional. Dentre os biomarcadores de exposição, o ácido S-fenilmercaptúrico é considerado o único específico, mas, devido a suas baixas concentrações na urina, é requerido o uso de técnicas analíticas sensíveis capazes de quantificar traços. Objetivo: revisar metodologias baseadas na cromatografia e na espectrometria de massas para a determinação do ácido S-fenilmercaptúrico. Método: revisão da literatura sobre a determinação do ácido S-fenilmercaptúrico urinário por técnicas de cromatografia e espectrometria de massas, nas principais bases de dados científicas, considerando o período entre 1951 e 2015. Resultados: 120 documentos serviram como base teórica para a construção desta revisão. A técnica analítica mais empregada foi o acoplamento da cromatografia a líquido com a espectrometria de massas. Contudo, os métodos diferem quanto ao preparo das amostras. Conclusão: o alto custo de aquisição e a manutenção de equipamentos são fatores limitantes para a difusão dos sistemas de cromatografia e espectrometria de massas. No entanto, sua elevada sensibilidade e seletividade faz com que essas técnicas, acopladas, possibilitem elucidar situações de exposição ocupacional e ambiental a poluentes, como o benzeno.
Abstract Introduction: benzene is a substance of recognized toxicity and its biomonitoring of exposure becomes critical for preventing health damages, especially in occupational exposure situations. Among all the biomarkers of exposure, S-phenylmercapturic acid is considered the only specific one, but due to its low concentrations in urine, acute analytical techniques capable of quantifying traces must be used. Objective: to review methodologies based on chromatography and mass spectrometry for determination of S-phenylmercapturic acid. Method: literature review on the determination of urinary S-phenylmercapturic acid by chromatographic techniques and mass spectrometry in the main scientific databases, considering the period between 1951 and 2015. Results: 120 documents served as theoretical basis for the construction of this review. The analytical technique that was most applied was the coupling of liquid chromatography with mass spectrometry. However, the methods differ according to the preparation of samples. Conclusion: the high cost of equipment acquisition and maintenance are limiting factors for the diffusion of chromatography systems and mass spectrometry. Nevertheless, its high sensitivity and selectivity enable these coupled techniques to elucidate situations of occupational and environmental exposure to pollutants, such as benzene.
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OBJECTIVES: This study was conducted to provide accurate exposure evaluation of workers in a biologicallymonitored state who were simultaneously exposed to benzene and toluene. For the purpose of this study, an animal experiment was conducted. METHODS: The following concentrations of solvents were administered orally to Sprague-Dawley rats : benzene at 2.26 mg/kg body weight (equivalent concentration to the 2.5 ppm, Threshold Limit Value-ShortTerm Exposure Limit, in the USA) and 9.02 mg/kg body weight (equivalent concentration to the 10 ppm, Threshold Limit Value-TimeWeighted Average in Korea), simultaneously with toluene at 106.42 mg/kg body weight (equivalent concentration to the 100 ppm, Threshold Limit Value-TimeWeighted RESULTS: The following results were obtained from the analysis of reading taken at 3hour intervals of S-phenylmercapturic acid (SPMA) and phenol concentration in urine metabolites of benzene after oral administration for 30 hours. 1. The concentrations of phenol and SPMA in urine were markedly decreased in the initial phase of the mixed group (both benzene and toluene administered group) as compared with the benzeneonly administered group, and the concentrations were slightly elevated. 2. The total excreted amounts of phenol and SPMA in urine decreased in the mixed group compared with the benzene-only group, and these decreases were more remarkable at the benzene administration concentration of 9.02 mg/kg than at 2.26 mg/kg. 3. The urinary excretions of phenol and SPMA were delayed in the case of the mixed group, and the extent of the delay was dependent on the amount of benzene administrat CONCLUSIONS: Benzene metabolism was suppressed by toluene, and hence the excretion of phenol and SPMA as urinary metabolites of benzene was delayed. This result will have applications in the interpretation of results from future biological monitoring of workers exposed to mixed solvents. We should not underestimate the importance of carefully interpreting the results of biological monitoring data when workers are exposed to mixed solvents. We should not underestimate the importance of carefully interpreting the results of biological monitoring data when workers are exposed to mixed benzene and toluene.