RESUMO
This paper reports the development of a fast separation method employing capillary zone electrophoresis for the simultaneous determination of hippuric acid, mandelic acid, and creatinine in samples of urine using a coated capillary. The background electrolyte was composed of 10 mmol L-1 tris(hydroxymethyl)aminomethane and 30 mmol L-1 2-hydroxy-isobutyric acid at pH 3.6. The internal standard was 3,5-dihydroxybenzoic acid. Separations were performed in a fused silica capillary (32 cm total length, 8.5 cm effective length, and 50 µm internal diameter) coated with crosslinked hydroxypropyltrimethyl ammonium chloride chitosan and κ-carrageenan. Direct UV detection was performed at a wavelength of 200 nm. Samples and standards were injected hydrodynamically (-50 mbar, 3 s) using the short-end injection procedure. The electrophoretic system was operated under constant voltage of 30 kV with positive polarity on the injection side. The separation time for hippuric acid, mandelic acid, and creatinine was less than 70 s. The evaluation of some analytical parameters of the method for the three analytes showed good linearity (R 2 > 0.99), limit of detections of 0.21 to 0.63 mg L-1, inter-day precision better than 3.0% (peak area), and recovery in the range of 98 to 106%. The method developed was applied in the analysis of the three analytes in urine samples. Graphical Abstract New method using capillary zone electrophoresis for analysis of creatinine, hippuric acid and mandelic acid in urine.
Assuntos
Creatinina/urina , Eletroforese Capilar/métodos , Hipuratos/urina , Ácidos Mandélicos/urina , Polímeros/químicaRESUMO
We present a method that permits the simultaneous analysis of mandelic acid (MA) and phenylglyoxylic acid (PGA) in the urine of workers occupationally exposed to styrene. The method consists of urine extraction in acid medium with chloroform and the subsequent formation of the respective methyl esters. The samples were submitted to gas chromatography using a glass column packed with 10% SP-1000. Recoveries of 66.7% and 95.4% were obtained for MA and PGA, respectively, with limits of quantitation of 0.03 g/L for MA and 0.02 g/L for PGA. The method proved to be precise in terms of both intra-assay and interassay analysis, with coefficients of variation less than 10%.
Assuntos
Glioxilatos/urina , Ácidos Mandélicos/urina , Exposição Ocupacional/análise , Estirenos , Cromatografia Gasosa/métodos , Humanos , Indicadores e ReagentesRESUMO
O estireno é uma importante matéria-prima extensamente empregada na fabricaçäo de plásticos e elastômeros. Durante a sua utilizaçäo, a emissäo dos vapores para o ambiente de trabalho pode ser significativa. Considerada uma substância quìmica reconhecidamente tóxica, a monitorizaçäo biológica da exposiçäo ocupacional constitui-se em procedimento indispensável para uma avaliaçäo do risco, através da quantificaçäo do ácido mandélico urinário, seu principal produto de biotransformaçäo, e posterior comparaçäo a valores de referência. Foi padronizado o método analítico de Poggi et al que se utiliza da cromatografia em fase de alto desempenho (HPLC), obtendo-se resultados de boa precisäo (coeficientes de varaçäo intra-ensaio e interesaio menores que 2%) e recuperaçäo média de 98 +- 5%. Foi determinada a concentraçäo deste ácido presente em amostras de urina de indivíduos ocupacionalmente expostos (Grupo Exposto) e näo expostos (Grupo Controle) de uma indústria de produçäo do monômero de estireno. No Grupo Exposto foi realizada uma estimativa de exposiçäo com o uso de amostradores por difusäo passiva, e foram encontradas concentraçöes inferiores a 1,2 mg/m3 (0,3 ppm) de estireno. A concentaçäo média de ácido mandélico encontrada no Grupo Exposto foi de 0,0239 +- 0,0037 g/L (0,0136 +- 0,0019 g/g de creatinina); e a encontrada no Grupo Controle, de 0,0133 +- 0,0024 g/L (0,0073 +- 0,0011 g/g de creatinina).
Assuntos
Ácidos Mandélicos/urina , Cromatografia Líquida de Alta Pressão , Exposição Ocupacional , Estirenos/urina , ToxicologiaAssuntos
Sistema Cromafim , Glomos Para-Aórticos , Feocromocitoma/patologia , Adulto , Neoplasias Ósseas/secundário , Catecolaminas/urina , Sistema Cromafim/patologia , Feminino , Humanos , Ácidos Mandélicos/urina , Glomos Para-Aórticos/patologia , Feocromocitoma/secundário , Feocromocitoma/terapia , Feocromocitoma/urina , PrognósticoAssuntos
Doenças das Glândulas Suprarrenais/urina , Hemorragia/urina , Hidroxibenzoatos/urina , Hipertensão/urina , Ácidos Mandélicos/urina , Ácido Vanílico/urina , Doenças das Glândulas Suprarrenais/patologia , Diagnóstico Diferencial , Hemorragia/patologia , Humanos , Hipertensão/patologia , Recém-Nascido , MasculinoRESUMO
Quantitation of the urinary metabolites of catecholamines, including VMA, HVA, and metanephrines, from six normal preschool children was performed during a normal diet, a restricted diet, and a diet with increased amounts of vanilla, vanillin, and phenolic acids. Ingestion of these substances has been suspected of producing elevated values of urinary catecholamines and their metabolites. Urine was collected on the fourth day of each diet in two consecutive 12-hour aliquots, beginning at 8:00 AM. Statistically significant diurnal variation in excretion of all three metabolites and total free catecholamines (epinephrine, norepinephrine, and dopamine) was demonstrated. Diet did not alter exceretion of total free catecholamines or any of the three metabolites. This study suggests that a three-day restricted diet is not necessary prior to screening children for neuroblastoma when using quantitative assay methods and that all screening tests should be performed on a 24-hour urine sample.