Simultaneous determination of ethylbenzene, indan, indene and acenaphthene in air by capillary gas chromatography.

An attempt was made to establish a method for the simultaneous determination of ethylbenzene, indan, indene and acenaphthene by capillary gas chromatography with flame ionization detection. The air was sampled on charcoal tubes and extracted with carbon disulfide-methanol (60:1, v/v). The four analytes were separated by gas chromatography using a capillary column of cross-linked 5% phenylmethylsilicone. Under the applied conditions the method showed detection limits of 1.8 microg/m3 for ethylbenzene, 2.1 microg/m3 for indan, 2.8 microg/m3 for indene and 3.4 microg/m3 for acenaphthene. Relative standard deviations were as follows: ethylbenzene, 6.2%; indan, 9.9%; indene, 13.6%; and acenaphthene, 14.4%. The recoveries for these compounds were 98.6, 97.9, 55.7 and 52.1%, and the accuracies were 2.5, 3.0, 44.3 and 47.8%, a working range of 1.5-30 ng/microl for ethylbenzene and 0.75-15 ng/microl for indan, indene and acenaphthene. The method was found to be suitable for the determination of environmental and occupational analysed ethylbenzene, indan, indene and acenaphthene exposure.

Aromatic and polycyclic hydrocarbons in air and their urinary metabolites in coke plant workers.

This study describes the exposure of coke plant workers to hydrocarbons. Aromatic hydrocarbons (AHs) and polycyclic aromatic hydrocarbons (PAHs) in the breathing zone air and their oxygenated metabolites in the urine of coke plant workers are qualitatively and quantitatively determined. Concentrations of benzene, toluene, naphthalene, m + p-xylene, o-xylene and 14 different PAHs were measured at the different workplaces by personal air sampling. O-cresol, 1- and 2-naphthol, methylhippuric acid, and 1-hydroxypyrene were determined in hydrolyzed urine of workers collected after the work shift. The gas chromatography-mass spectrometry (GC/MS) method was applied to identify AHs in air and in urine samples. Time-weighted values of exposure to aromatic hydrocarbons at a coke plant were: benzene (0.06-9.82 mg/m3), toluene (0.05-4.71 mg/m3), naphthalene (0.01-3.28 mg/m3), o-xylene (0.01-1.76 mg/m3) and m + p-xylene (0.01-2.62 mg/m3). At the coke batteries, the total concentration of PAHs ranged from 7.27 to 21.92 micrograms/m3. At the sorting department, the total concentration of PAHs were about half this value. Concentration of the urinary metabolites (naphthols and methylhippuric acid) detected in workers at the tar distillation department are three times higher than those for the coke batteries and sorting department workers. A correlation between inhaled toluene, naphthalene, xylene, and urinary excretion of metabolites has been found. Time-weighted average concentrations of AHs in the breathing zone air show that exposure levels of the workers are rather low in comparison to exposure limits. The 1-hydroxypyrene concentration is below 24.75 mumol/mol creatinine. The GC/MS analysis reveals the presence of AHs, mainly benzene and naphthalene homologues. It has been found that coke plant workers are simultaneously exposed to the mixture of aromatic and polycyclic hydrocarbons present in the breathing zone air of a coke plant. Exposure levels are significantly influenced by job categories. Compounds identified in the urine appear to be the products of the hydroxylation of AHs present in the air as well as unmetabolized hydrocarbons.

Urinary excretion of phenols as an indicator of occupational exposure in the coke-plant industry.

OBJECTIVE: In the present study the relationship between the level of exposure to o-cresol and of 2,4- +2,5-, 3,4-, and 3,5-xylenols and the urinary excretion of their metabolites was examined. The mixed exposure to phenolic derivatives of exposed workers during their work shift was monitored by personal air sampling of the breathing-zone air and by measurements of phenol, o-cresol, and xylenol isomer concentrations in shift-end urine. METHODS: The study subjects were 76 men working at a coke plant who were 22-58 years old and 34 nonexposed subjects. Concentrations of phenolic compounds were determined in the breathing-zone air during the work shift, whereas concentrations of phenol, cresol, and xylenol isomers were measured in urine collected after the work shift. Concentrations of phenols in air and urine were determined by gas chromatography with flame-ionization detection. Urine samples were extracted after acid hydrolysis of glucuronides and sulfates by solid-phase extraction. The gas chromatography-mass spectrometry method was applied to identify metabolites in urine samples. RESULTS: The time-weighted average concentrations of phenol, cresol, and xylenol isomers detected in breathing-zone air showed that the exposure level of the workers was relatively low. The geometric mean values were as follows: 0.26 mg/m3 for phenol, 0.09 mg/m3 for o-cresol, 0.13 mg/m3 for p- and m-cresol, and 0.02-0.04 mg/m3 for xylenols at the tar-distillation process. Corresponding urinary concentrations were 10.39, 0.53, and 0.25-0.88 mg/g creatinine for phenol, o-cresol, and xylenol isomers, respectively. The correlation coefficients between the o-cresol and 2,4-, 2,5-, 3,4-, and 3,5-xylenol concentrations measured in urine and in the breathing-zone air were statistically significant, varying in the range of 0.54-0.74 for xylenol isomers and being 0.69 for o-cresol. CONCLUSION: We have found that the presence of o-cresol and xylenol isomers in urine can be used as a biomarker for phenol exposure. Analysis performed on workers at the tar-distillation process showed that they were exposed to relatively low concentrations of phenolic compounds.

Urinary naphthols as an indicator of exposure to naphthalene.

OBJECTIVE: The relationship between exposure to naphthalene and urinary excretion of naphthols was examined. METHODS: Concentrations of naphthalene and naphthols in breathing-zone air during a workshift and 1-naphthol and 2-naphthol in urine collected after the workshift were determined for 102 male workers. Gas chromatography with a flame ionization detector (GC-FID) was used to determine the air concentration. Urine naphthols were extracted after acid hydrolysis by solid-phase extraction and separated by the GC-FID method. Naphthalene homologues in air and their metabolites in urine samples were identified by gas chromatography-mass spectrometry. RESULTS: 1-Naphthol, 2-naphthol and 1,4-naphthoquinone were identified in the urine samples. The time-weighted average concentrations of naphthalene and naphthols in the breathing-zone air showed that the exposure level of the workers was rather low. The geometric mean values were as follows: 0.77 and 0.87 mg/m3 for naphthalene, 0.016 and 0.034 mg/m3 for 1-naphthol, 0.012 and 0.067 mg/m3 for 2-naphthol during tar distillation and naphthalene oil distillation, respectively. The corresponding urinary concentrations of 1- and 2-naphthols were 693.1 and 264.4 micromol/mol and 264.4 and 297.7 micromol/mol creatinine, respectively. The correlation coefficients between the naphthol concentrations in urine and the breathing-zone air concentrations of naphthalene were statistically significant, varying in the range of 0.64--0.75 for 1-naphthol and 0.70--0.82 for 2-naphthol. There was linear dependence (r = 0.76) between the summary concentration of naphthols in urine and the naphthalene concentration in air. CONCLUSIONS: Workers in tar distillation and naphthalene distillation are exposed to rather low concentrations of naphthalene and methylated naphthalenes and naphthols. Naphthols and 1,4-naphthoquinone identified in the urine appear to be the products of the hydroxylation of naphthalene present in the breathing-zone air. These findings suggest that the summary concentration of naphthols in urine can be used as a biomarker for naphthalene exposure.

Simultaneous determination of phenol, cresol, xylenol isomers and naphthols in urine by capillary gas chromatography.

An attempt was made to establish a method for the simultaneous determination of urinary concentrations of phenol, o-, p- and m-cresols, 1- and 2-naphthol and xylenol isomers by capillary gas chromatography. Urine samples were extracted after acid hydrolysis of glucuronides and sulfates by solid-phase extraction. The ten substances were separated gas chromatographically using a capillary column (Ultra 2) of cross-linked 5% phenylmethyl silicone. Calibration graphs were linear for 5-100 micrograms/ml of all the phenols determined. The corresponding detection limits for phenolic compounds varied from 0.1 to 0.2 microgram/ml. The relative standard deviations for samples in urine were in the range 2.6 - 16.6% and the accuracy was in the range 1.4-25%. Recoveries were generally over 80%.

Concentrations of phenol, o-cresol, and 2,5-xylenol in the urine of workers employed in the distillation of the phenolic fraction of tar.

Phenol (87.3 mg/l), p-cresol (58.6 mg/l), o-cresol (76.9 mg/l), and 2,5-xylenol (36.7 mg/l) were detected in the urine of workers employed in the distillation of the high temperature phenolic fraction of tar (carbolic oil). The concentrations of these compounds in the urine of non-exposed male workers was 11.7 mg/l, 25.7 mg/l, 68.1 micrograms/l, and 69 micrograms/l respectively. The excretion rates were 4.20 mg/h for phenol, 2.4 mg/h for p-cresol, 3.3 mg/h for o-cresol; and 1.5 mg/h for 2,5-xylenol. The highest concentrations of the mentioned compounds were detected in urine collected between eight and 10 hours from the beginning of exposure. The kinetics of excretion are considered.

The presence of 1-naphthol in the urine of industrial workers exposed to naphthalene.

1-Naphthol at concentrations ranging from 0.4 to 34.6 mg/l was found in urine collected directly after the end of the work shift from a group of industrial workers employed in distillation of naphthalene oil. The maximum excretion was found one hour after the end of the shift and the mean excretion rate was 0.57 mg/h. Coke plant workers exposed to naphthalene and other aromatic and polycyclic hydrocarbons also had 1-naphthol in their urine. Mean values were 0.89 mg/l (working with new technology) and 4.86 mg/l (working with old technology) and the excretion rates were 0.19 and 0.31 mg/h respectively. The maximum excretion was shifted to two to three hours after the end of the exposure. For non-exposed subjects the mean urinary 1-naphthol concentration was 120 micrograms/l and the excretion rate was 7.0 micrograms/h.

[Evaluation of exposure to benzene and naphthalene in coke plant workers]. / Ocena narazenia na benzen i naftalen pracowników koksowni.

Sixty two workers of a coke-chemical plant exposed to benzene, naphthalene, toluene, o-xylene, p-xylene, phenol and pyridine were examined. In urine samples collected before and after occupational exposure significant differences in concentration values of phenol (21.1-97.6 mg/l), 1--naphthol (0.1-9.38 mg/l), hippuric acid (95.5-873.9 mg/l) and m-methylhippuric acid (29.0-93.5 mg/l) were found. There was correlation between benzene and naphthalene in the breathing zone air and phenol and 1-naphthol in the urine of coke plant workers.

[Levels of metabolites of selected chemical compounds in the urine of workers in pitch coke plant]. / Poziom metabolitów wybranych zwiazków chemicznych w moczu pracowników koksowni pakowej.

In urine samples collected from pitch coke plant workers just before and after occupational exposure, differentiated concentrations of phenol (20.8-692.8 mg/dm3), p-cresol (51.8-590 mg/dm3), I-naphtol (4.9-63.7 mg/dm3) and benzo(a)pyrene (0.3-18.9 ug/dm3) have been found. The occurrence of enhanced concentrations of phenol in 10.1%, p-cresol in 31.9%, I-naphthol in 13.5% and benzo(a)pyrene in 72.8% of the test urine specimens collected prior to exposure points to a slow excretion of these metabolites of chemical compounds inherent in the work environment. Furthermore, the urinary level of the metabolites in particular coke plant workers points to different individual exposure.

Thin layer chromatography of p-aminophenol in urine after mixed exposure to aniline and toluene.

A simple method of evaluating p-aminophenol in the urine of people exposed simultaneously to aniline and toluene relies on separating p-aminophenol from hippuric acid and other physiological components of the urine by thin layer chromatography. The adsorbents and developing system have been thus fixed to make possible the separation of p-aminophenol from hippuric acid, urea, and creatinine and their quantitative determination. This method also makes possible the determination of p-aminophenol in urine in the presence of hippuric acid. Hippuric acid is a physiological component of urine and also the metabolite of toluene, so the determination of p-aminophenol is possible also after simultaneous exposure to both compounds: aniline and toluene. At the same time the concentrations of urea and creatinine as additional factors may be determined. The limit of detection of the method is: 5 micrograms/ml for p-aminophenol, 9 micrograms/ml for hippuric acid, 8 micrograms/ml for urea, and 6 micrograms/ml for creatinine.

TLC separation of hippuric, mandelic, and phenylglyoxylic acids from urine after mixed exposure to toluene and styrene.

A method using thin-layer chromatography is described to determine the concentration of hippuric acid, mandelic acid, and phenylglyoxylic acid present in the urine after occupational mixed exposure to toluene and styrene. These substances are known metabolites of toluene and styrene, and therefore the evaluation to mixed exposure to toluene and styrene may be carried out separating these metabolites beforehand. Procedures are proposed to separate the metabolites as follows: (1) separation of hippuric acid from mandelic acid, (2) separation of mandelic acid from phenylglyoxylic acid, and (3) separation of hippuric acid and mandelic acid from phenylglyoxylic acid. The developing reagent p-dimethylaminobenzaldehyde in acetic acid anhydride was used after separation on Kieselgel and Silicagel. The sensitivity of the method was 6 microgram of hippuric acid, 10 microgram of mandelic acid, and 7 microgram of phenylglyoxylic acid with an average recovery of 94%.

Thin-layer chromatography of hippuric and m-methylhippuric acid in urine after mixed exposure to toluene and xylene.

The separation of hippuric and m-methylhippuric acid as toluene and m-xylene metabolites present in urine of people exposed simultaneously to toluene and xylene is described. Chloroform was used for hippuric and m-methylhippuric acid extraction. Satisfactory separation of these metabolites was obtained on TLC plates covered with silica gels and developed in chloroform acetic acid-water (4:1:1);p-dimethylaminobenzaldehyde in acetic acid anhydride was applied to develop the colour. The sensitivity of the method was 6 micrograms hippuric acid per 1 ml urine and recovery was 100% (+/- 1).

Urinary hippuric acid concentration after occupational exposure to toluene.

The results of industrial investigations have shown a correlation between the rate of hippuric acid excretion in a single urine sample collected after daily occupational exposure and the amount of toluene absorbed. The rate of hippuric acid excretion and the average concentration of toluene vapour during exposure time were also related. The quantitative range of the test has been limited to amounts exceeding 425 mg of toluene and concentrations exceeding 69 ppm of toluene in the air because of the physiological presence of hippuric acid in urine. The rate of hippuric acid excretion in urine depends on diuresis and is constant for urinary fractions with diuresis of 30 ml/h. The physiological excretion rate was 20 mg/h with a standard deviation +/- 4.3 mg/h, maximal physiological level 33 mg/h.

[Effect of organic solvents on the state of the periodontium and oral cavity in workers employed in pigment and paint industries]. / Wplyw par rozpuszczalników organicznych na stan przyzebia i jamy ustnej u pracowników zatrudnionych w przemysle farb i lakierów.

Stomatological examinations were conducted among 270 workers employed at pigment and paint industry, exposed to organic solvents and other gaseous substances developed during the thermal conversion of oils. In the control group of one hundred persons employed in whom the detrimental action of chemical compounds does not exist, stomatological examination did not show any special variations from the normal average. Comparing the two groups it was evident that the hygiene of the oral cavity was significantly worse in the group of workers exposed to organic solvents and other chemical compounds than in the control one. Statistical analysis of the obtained results pointed out that the average index of intensity of changes in paradontium and the susceptibility to changes evaluated according to DMF index also shows higher values in the examined group as compared with the control. The frequency of occurrence of various pathological changes including leukoplakia of the mucosa was presented in detail. All collected data were divided into five groups of different exposure to the chemicals.