• Journal of the Korean Electrochemical Society
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• v.14 no.1
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• pp.44-49
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• 2011

This paper describes an electrochemical immunosensor for simple, fast and quantitative detection of a urinary hippuric acid which is one of major biological indicator in toluene-exposed humans. The feature of this electrochemical system for immunoassay of hippuric acid is based on the direct conjugation of ferrocene to a hippuric acid. With the competition between the ferrocene-hippuric acid complex and hippuric acid for binding to the anti-hippuric acid monoclonal antibody coated onto gold nanoparticles, the electrical signals are turned out to be proportional to urinary hippuric acid in the range of 0.01-10 mg/mL, which is enough to be used for the point-of-care. The proposed electrochemical method could extend its applications to detect a wide range of different small molecules of antigens in the health care area.

• Journal of Electrochemical Science and Technology
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• v.2 no.1
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• pp.57-61
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• 2011

This paper describes an electrochemical immunoassay for simple, fast and quantitative detection of a urinary hippuric acid which is one of major biological indicator in toluene-exposed humans. The electrochemical system of immunoassay was based on the directly osmium complex conjugated with hippuric acid. With the competition between free hippuric acid (HA) and the osmium-hippuric acid conjugate (Os-HA) to bind with antibody hippuric acid (Anti-HA) coated onto gold nanoparticles, the electrical signals were proportional to urinary hippuric acid (HA) in the range of 0.01-5 mg/mL which is enough range to be used for in-field or point-of-care (POC) diagnosis. The proposed electrochemical method can be extended to the applications to detect a wide range of different small molecules in the field of health care.

• Safety and Health at Work
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• v.5 no.4
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• pp.227-233
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• 2014

Background: The aims of this study were to determine hippuric acid levels in urine samples, airborne toluene levels, acute and chronic neurological symptoms, and to describe any correlation between urinary hippuric acid and airborne toluene. Methods: The hippuric acid concentration in the urine of 87 paint workers exposed to toluene at work (exposed group), and 87 nonexposed people (control group) was studied. Study participants were selected from similar factories in the same region. Urine samples were collected at the end of a shift and analyzed for hippuric acid by high performance liquid chromatography. Air samples for the estimation of toluene exposure were collected with diffusive personal samplers and the toluene quantified using gas-liquid chromatography. The two groups were also interviewed and observed about their work practices and health. Results: The median of the 87 airborne toluene levels was 55 ppm (range, 12-198 ppm). The median urinary hippuric acid level was 800 mg/g creatinine (range, 90-2547 mg/g creatinine). A statistically significant positive correlation was found between airborne toluene exposure and urine hippuric acid levels (r = 0.548, p < 0.01). Workers with acute symptoms had significantly higher hippuric acid levels than those who did not (p < 0.05). It was concluded that there was a significant correlation between toluene exposure, hippuric acid levels, and health (p < 0.001). Conclusion: There appears to be a significant correlation between workers exposure to toluene at work, their urine hippuric acid levels, and resulting symptoms of poor health. Improvements in working conditions and occupational health education are required at these workplaces. There was good correlation between urinary hippuric acid and airborne toluene levels.

• Journal of Preventive Medicine and Public Health
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• v.21 no.2 s.24
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• pp.374-379
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• 1988

In order to prepare the fundamental data for preventing the hazardous effects at toluene exposure in many kinds of industry, the authors determined the level of urinary hippuric acid on 592 toluene exposed women(exposed group) and 102 unexposed women(control group) in Pusan area, from April. 1 to October 31, 1986. Hippuric acid was measured by high performance liquid chromatography. The results were summarized as follows; 1. The mean value of urinary hippuric acid concentration of the control group was $0.44{\pm}0.21g/l$(0.11-0.89g/l). The distribution of urinary hippuric acid concentration of the control group was not fit to the normal distribution. 2. The mean value of urinary hippuric acid concentration of the exposed group was $1.56{\pm}0.95g/l$(0.44-4.57g/l). The distribution of urinary hippuric acid concentration of control group was not fit to the normal distribution. 3. The urinary hippuric acid concentration by age group was not statistically significant in the control group, but in the exposed group the urinary hippuric acid concentration was highest in women between 20-29 years old($1.71{\pm}0.95g/l$) and was statistically significant(p<0.01). 4. The urinary hippuric acid concentration by duration of working hours was not statistically significant (p>0.1).

• Journal of Preventive Medicine and Public Health
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• v.22 no.4 s.28
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• pp.480-485
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• 1989

The objective of this study was to examine the correlation between personal exposure of toluene at workplace and the concentration of hippuric acid in urine of male solvent workers. The study groups are 60 toluene exposed workers who worked at video tape factory and printing factory. The results are as follows : 1. The coefficient of correlation between toluene concentration of personal exposure and concentration of urinary hippuric acid was 0.649 (regression equation Y=0.015X+0.936, Y=urinary hippuric acid concentration, X=Toluene concentration of personal exposure). 2. Urinary hippuric acid concentration of workers with TLV 100 ppm of toluene was calculated 2.44 g/L by the regression equation (Y=0.015X+0.936).

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.3 no.2
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• pp.188-193
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• 1993

Toluene in air and blood and hippuric acid in urine were checked for the 41 female workers who are exposed to toluene and have normal liver function in shoe making factories in July, 1993. Toluene in air was sampled with charcoal by personal air sampler at least 4 times and analyzed by gas chromatography. At the end of shift, blood and spot urine were collected with a vacuum tube containing EDTA and a polyethylene bottle for detecting blood toluene and urine hippuric acid and analyzed by gas chromatography and high performance liquid chromatography. Means of air and blood toluene and urine hippuric acid concentrations were 34.35ppm, 0.360mg/L, and 1.78g/g creatinine, respectively. Toluene in air showed a good correlation with hippuric acid in urine(r=0.4503) and toluene in blood(r=0.4596). The hippuric acid in urine and toluene in blood corresponded 10 exposure of 100ppm toluene in air were 2.628g/g creatinine and 0.481mg/L. Blood toluene and urine hippuric acid expected ratio were not correlated to the obesity index and working duration, however increased with age.

• Analytical Science and Technology
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• v.13 no.1
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• pp.121-126
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• 2000

The aim of this study is to assess the interference effect of other organic acids to the values of hippuric acid analysed by UV method. We calculated the interference effect of several metabolites of styrene and xylene, i.e., methylhippuric acid, phenylglyoxylic acid, and mandelic acid to hippuric acid, respectively. The result of interlaboratory quality control program of urinary hippuric acid showed that there was no significant difference between the results by UV and HPLC if there were no other organic acids in urine. However, 0.5-2.0 g/L methylhippuric acid showed positive interference of 64-82% to 0.33 g/L urinary hippuric acid while mandelic acid or phenylglyoxylic acid did not show this positive effect. We suggest that HPLC or GC method is more acceptable than UV method to analyse urinary hippuric acid for biological monitoring when the worker was exposed to mixture of toluene and xylene.

• Journal of Environmental Science International
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• v.10 no.6
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• pp.445-450
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• 2001

This study was carried out In Investigate the correlation between toluene In air and hippuric acid In human urine, which 1.: based on the results of the health check-in and the measure of working environment, was investigated for two years. The concentration of toluene in air for the five working places in Yang-San area were ranged from 39.05±10.31 ppm to 4.04±3.38ppm and the mean value of those was 16.89±14.76ppm. The mean value was 16.89±14.76ppm which is below the permissible limit of toluene. The concentration of hippuric acid(HA) In the worker's urine were between 0.47g/ℓ and 0.76g/ℓ. There was mutual correlation (Υ=0.94) between the concentration of toluene in air and that of hippuric acid in urine. In case of male workers, the mean value of hippurlc acid In urine was 0.56g/ f and the female workers was 0.57g/ℓ that showed higher than the male's. However, there was no relationship between the workshop and the distinction of sex. From the mean value of toluene in air(T) and that of hippuric acid(H), we obtained the formula, Η=0.3logΤ+0.235.

• Journal of Environmental Science International
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• v.14 no.2
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• pp.201-207
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• 2005

This study was carried out to investigate the correlation between toluene in air and hippuric acid in human urine, which is based in the results of the health check-in and measure of working environment, was investigated for five years. Toluene in air and hippuric acid in urine were checked 116 workers who exposed to toluene in five type of industry. The Mean concentration of toluene in air by type of industry and every year and sex distinction, had positive correlation.(p<0.01) The Mean concentration of hippuric acid in urine by type of industry, every year, sex distinction, disparity of age and term of duty had positive correlation.(p<0.01).

• Journal of Environmental Science International
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• v.4 no.5
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• pp.517-526
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• 1995

The health symptoms assessment and urinary hippuric acid excretions of workers exposed to toluene occupationally in shoes workshops were investigated by the Questionnaire and the field monitoring. Based on the results, the acute health symptoms of workers exposed to toluene by questionnaire were fatigue(58.7%), irritation of the eyes, nose and throat(57.2%), and skin dryness(43.3%). And the complaints about workshop environment are odor, dust and noise. The mean values of urinary hippuric acid excretions in m식e and female were 1.08 $\pm$ 0.50 g/l, 1.59 $\pm$ 1.27 g/l in total workers, espectively.