Quantitation of urinary metabolites of toluene, xylene, styrene, ethylbenzene, benzene and phenol by automated high performance liquid chromatography

Abstract

An automated high performance liquid chromatographic method (HPLC) for the direct determination of urinary concentrations of hippuric acid (HA), and o-, m- and p-methyl hippuric acids (MHAs), metabolites of toluene and o-, m-, and p-xylenes, and of urinary phenyl glyoxylic acid (PGA) and mandelic acid (MA), metabolites of styrene or ethylbenzene, is described. Methanol was added to urine, the mixture was centrifuged and the supernatant was injected into HPLC. A stainless-steel column packed with octadecyl silanized silicate was used and the mobile phase was a mixed solution of 5 mM potassium phosphate monobasic/acetonitrile (90/10). The method is simple and specific. Urine can be analyzed without solvent extraction. Analysis can be performed satisfactorily within 45 min for samples containing HA, MHAs, PGA and MA, and within 15 min for those containing HA, PGA and MA. Another automated HPLC method for the determination of urinary concentrations of phenylsulfate (PhS) and phenylglucuronide (PhG), metabolites of benzene and phenol, is also described. Urine was centrifuged and the supernatant was injected into HPLC. A column packed with octadecyl silicate and a mobile phase of 50 mM of potassium phosphate monobasic/acetonitrile (85/15) were used. The whole analyses and quantitative determination can be performed within 15 min for samples containing PhS and PhG in the worker's urine with a simple mobile phase. The accuracy and precision in the present methods by the use of automated HPLC were satisfactory.

Impairment of Neurobehavioral Function and Color Vision Loss among Workers Exposed to Low Concentration of Styrene. A Review of Literatures.

“…Color vision test performance was then assessed categorically and quantitatively. Color vision categories were; (a) normal color vision (no errors, single sequential error or paired reversal), and (b) two or more errors (with subcategorisation according to the relative predominance of errors in red-green or blueyellow) [20][21][22] . Quantitative evaluation was performed by calculating the sum of the color differences of the caps placed next to one another (total color difference score: TCDS), with the formula proposed by Bowman [21][22][23] .…”

Análise simultânea dos indicadores biológicos de exposição aos solventes etilbenzeno, estireno, tolueno e xileno na urina por CLAE-UV

“…Vários métodos para analisar AFG, AM, AH, o-AMH, m-AMH e p-AMH na urina foram descritos na literatura, porém poucos são capazes de analisar todos os metabólitos simultaneamente. 4,6,[12][13][14] Os métodos que utilizam cromatografia gasosa acoplada à espectrometria de massas têm sido amplamente utilizados. Entretanto, tais métodos exigem um processo de derivatização durante o preparo da amostra.…”

“…Entretanto, tais métodos exigem um processo de derivatização durante o preparo da amostra. 4,13 Entre os métodos que utilizam a cromatografia líquida para a análise simultânea dos mesmos analitos, há aquele em que a separação dos analitos foi observada apenas após 50 minutos, 12 aquele que utiliza grande volume de amostra (2 mL) e solventes orgânicos ou não utilizam padrão interno. 1A).…”

“…12,21 Nos cromatogramas apresentados na Figura 2 é possível observar a diferença na resposta do AFG quando analisado a 225 nm (Figura 2A) e a 254 nm (Figura 2B). Portanto, o presente método propõe a análise do AFG a 254 nm e os demais metabólitos a 225 nm.…”

Validation of Urine Density Correction in Cases of Hippuric Acid and Un-metabolized Toluene in Urine of Workers Exposed to Toluene

“…Urine samples were collected at the end of shift with due care to minimize possible loss of toluene in sampling procedures 23) , and analyzed for hippuric acid (HA-U, U standing for urine) and un-metabolized toluene (Tol-U) by high-performance liquid chromatography 24) and by head-space gas-chromatography 25) , respectively. CR concentration was measured by colorimetry, and SG by refractometry.…”