• Korean Journal of Clinical Laboratory Science
• /
• v.40 no.2
• /
• pp.147-152
• /
• 2008

Due to the development and expansion of industries and medical standards, the number of workers who handle organic solvents within hospitals is increasing. The authors in this study intended to investigate the actual conditions of the handling of the solvents and to encourage the recognition that the exposure to such solvents may be possible because of insensitivity to safety. In order to investigate the actual conditions of exposure of workers within hospitals, the experimental group included the three sections (Pathology department, Central Supply Room, and Operating Room), which handle organic solvents most frequently. Meanwhile, university interns were selected to be the control group. This study was conducted between May 1 to May 30, 2007, and urine was taken as samples. Hippuric acid, mandelic acid, methylhippuric acid, and phenylglyoxylic acid were analyzed through gas chromatography, and a total of 52 subjects of the experimental and the control groups were performed of the analysis. As for the results of the analysis of the experimental group, the exposure to benzene was $42.27{\pm}3.70mg/g$ creatinine, that of xylene was $1.30{\pm}0.18g/g$ creatinine, and that of toluene was $2.36{\pm}0.24g/g$ creatinine. Meanwhile, the results of the analysis of the control group showed that the exposure to benzene was $15.54{\pm}2.85mg/g$ creatinine, that of xylene was $0.52{\pm}0.02g/g$ creatinine, and that of toluene was $0.85{\pm}0.20g/g$ creatinine. The amount of exposure to benzene, xylene, and toluene was shown to be under the maximum permitted level, but as for Pathology department, it was required to educate on working conditions, to educate workers on prevention management about their health, and to install fume hood and exhaust system to improve the environments.

• The Korean Journal of Nuclear Medicine
• /
• v.17 no.2
• /
• pp.71-77
• /
• 1983

Amino acids such as L-tyrosine, L-histidine, and tryptophan, which bear an aromatic ring in the molecule, could successfully be labelled by radioactive iodine through arylthallium ditrifluoroacetate intermediate. Generally, the labelling reaction could proceed in a short labelling time(ca, 20 minutes) and resulted in a high labelling yields and purity of the labelled product. This procedure has, therefore, been proved to be effective as the labelling method of short labelling time and high specific activity. Labelling proteins such as oval albumin and human albumin could also be achieved in $34\sim48%$ net labelling yield by thallating them at the low temperature $(0\sim10^{\circ}C)$, whereas the labelled products were mainly composed of various denatured products by thallating them at the high temperature$(35\sim40^{\circ}C)$, though the radioactivity was highly retained in the labelled products. Uracil and hippuric acid could also be labelled in a short labelling time though their thallation required a prolonged heating procedure. It was proved that this procedure may be effective to label these compounds by short lived radioisotopes. The labelling yields were, however, lower than 30%.

• Journal of Preventive Medicine and Public Health
• /
• v.27 no.3 s.47
• /
• pp.557-567
• /
• 1994

This study was conducted to examine the effect of chronic low dose organic solvent exposures in the industries towards then neurobehavioral functions of workers. Subjective symptoms on neurobehavioral function as well as a visual reaction time test (Flicker test) were administered to 94 exposed and 162 unexposed workers in a oil refinery and some other auto-repair shops. The results obtained were as follows : 1. Symptom complaints were higher and Flicker test values were lower in exposed workers than in unexposed workers. 2. Flicker valus were Inversely correlated with urinary Hippuric acid concentration in exposed workers(r=-0.26, p<0.05). 3. Flicker valus were inversely co..elated with Subjective symptom score(r=-0.15, p<0.05). Low Flicker value were also related with some subjetive symptoms such as 'Dimmed vision', 'Nightmare', 'Weakness on extrimity' in workers as a whole. While symptoms of 'Dimmed vision ', 'Nightmare' only observed among exposed workers.

• Journal of the Korean Chemical Society
• /
• v.54 no.4
• /
• pp.414-418
• /
• 2010

Ethyl 1-aminotetrazole-5-carboxylate (1) reacted with hydrazine hydrate to give the corresponding aminohydrazide 2. Cyclization of 2 by carbon disulfide yielded 1,3,4-oxadiazole-5-thiol structure 3. Reaction of 3 with either chloroacetone or ethyl chloroacetate furnished S-acyl 1,3,4-oxadiazole derivatives 4 and 5, respectively. Also compound 3 reacted with hydrazine hydrate afforded 4-amino-1,2,4-triazole-5-thiol derivative 6. 6-Methyl-1,3,4-triazolo[3,4-b]-1,3,4-thiadiazole structure 7 was synthesized by reaction of aminothiol 6 with glacial acetic acid. Diazotization of 1 with sodium nitrite in presence of hydrochloric acid yielding the diazonium salt which on treating with hippuric acid, oxazolone derivative 8 was obtained. Furthermore, tetrazolo[5,1-f]-1,2,4-triazine 9 was constructed via cyclization of aminoester 1 with formamide. Compound 9 reacted with carbon disulfide to furnish 8-thione derivative 10 which reacting with chloroacetone, ethyl chloroacetate, and hydrazine hydrate, the corresponding chemical structures 11, 12, and 13 were synthesized. 1,2,4-Triazolo[4,3-d]tetrazolo[5,1-f]-1,2,4-triazines 14 and 15 were resulted by treating of compound 13 with triethyl orthoformate, and glacial acetic acid, respectively. The structures of the newly synthesized products were elucidated according to elemental analyses and spectroscopic evidences. Some of the representative members of the prepared compounds were screened for antimicrobial activity.

• Nuclear Engineering and Technology
• /
• v.13 no.3
• /
• pp.145-152
• /
• 1981

Even though a lately reported method of high temperature exchange labelling of o-iodo-hippuric acid (Hippuran) in the absence of oxidizing agent was considered to be an attractive one, the exchange mechanism was somewhat unclear. In this study iodine isotope exchanges between o-iodohippuric acid (OIH) and radioiodide ($^{125}$ $I^{ }$) or between OIH and molecular radioiodine ($^{125}$ $I_2$) were carried out at two different temperatures. Rate constants and activation parameters were measured by applying a radio-paper chromatography technique. Since o-iodobenzoic acid is known as a by-product in the exchange labelling of OIH, data were also obtained for the OIB-iodide systems for comparison. The rate constant was increased in the order of OIB...$^{125}$ $I^{[-10]}$ >OIB...$^{125}$ $I_2$>OIH..$^{125}$ $I^{[-10]}$ >OIH...$^{125}$ $I_2$ and the activation parameters for OIH were generally larger than those for OIB :$\Delta$H$\neq$$_{OIH}$>$\Delta$H$\neq$$_{OIB}$, $\Delta$S$\neq$$_{OIH}$>$\Delta$S$\neq$$_{OIB}$. These results suggest that the mechanism of the high temperature exchange is predominantly nucleophilic even though some electrophilic character can also be involved depending upon reaction conditions. Such a fact may well be caused by a feasible formation of hydrogen bonding type transition state due probably to the ortho substituent effect of-CONHC $H_2$COOH. Thus, the high temperature exchange method is estimated to be quite effective for labelling Hippuran especially at a small research center where reducing agent-free $^{131}$ I is unavailable.ailable..

• Analytical Science and Technology
• /
• v.19 no.5
• /
• pp.433-440
• /
• 2006

A HPLC/UV method was developed and validated for the rapid and simultaneous determination of urinary metabolites of organic solvents, mandelic acid, hippuric acid, phenylglyoxylic acid, ortho-, meta- and para-methylhippuric acid, using a monolithic column. The mobile phase was composed of tetrabutylammonium bromide as ion-pairing reagent with a flow rate of 2.4 mL/min. The total run time was less than 2.5 min for all six analytes. Good linearities were obtained for all the metabolites with correlation coefficients above 0.9993. Intra-day precision, accuracy and inter-day precision was 0.01~7.32%, 83.9~116.3% and 0.01~7.16%, respectively. The method was validated and confirmed by quantification of the quality assurance samples of Industrial Safety and Health Research Institute, Korea Occupational Safety and Health Agency.

• The Korean Journal of Physiology
• /
• v.21 no.2
• /
• pp.291-296
• /
• 1987

There have been reports on the aberration of the control mechanisms of the blood pressure, hormone secretion, and renal functions in spontaneously hypertensive rats (SHR). However, the contribution of the renin-angiotensin system in the maintenance of high blood pressure in SHR is still controversial. Recently, it has been reported that the negative feedback short loop control mechanism of the renin-angiotensin system may be changed in SHR. In the present experiment, it was attempted to explore the possible alterations in the effect of arginine vasopressin (AVP) on the renal function in SHR. Experiments have been done in anesthetized SHR as well as in normotensive Wistar and Sprague-Dawley rats as control groups. Pharmacologic doses of AVP (10-13 mU/rat/10 min) decreased urine volume, excreted amount of creatinine and para-amino-hippuric acid. No differences in these parameters was observed between normotensive and hypertensive rats. AVP increased sodium and potassium excretion, but the responses in SHR were suppressed as compared with normotensive rats. Intravenous infusion of AVP also increased blood pressure in normotensive and hypertensive rats and a vasopressor effect of AVP was attenuated in SHR. There was a positive correlation between the changes in blood pressure and excreted amount of sodium during AVP infusion. These data suggest that the attenuated natriuretic effect of intravenous infusion of AVP may be due to a difference in renal tubular responsiveness to AVP but not due to a difference in vasopressor responsiveness.

• Journal of Korean Society of Occupational and Environmental Hygiene
• /
• v.20 no.1
• /
• pp.53-62
• /
• 2010

일샵 종사자들의 1) 공기 중 화학물질에 대한 노출정도를 파악하고 2) 공기 중 미량으로 존재하는 아세톤 및 톨루엔과 요 중 아세톤 및 마뇨산과의 연관성을 분석하여 후자들이 아직도 생물학적인 지표로 유용한지를 알아보고자 본 연구를 실시하였다. 경인 지역소재 9개의 네일숍에 근무하는 20명의 종사자들을 노출군으로 선정하였으며 이 작업과 무관한 일반 여성 20명을 대조군 선정하였다. 작업장 공기는 한 네일숍에 3개씩 총 27개의 시료를 가능한 한 작업자의 호흡영역에서 가장 가까운 곳에서 지역시료로 채취하였다. 공기 중 유기증기 13개 물질, 포름알데히드, 요 중 아세톤, 요 중 마뇨산을 가스크로마토그래프, 자외선분광광도계 그리고 GC/MS를 이용하여 분석하였다. 유기증기 13개 물질 중 아세톤과 톨루엔은 모든 네일샵에서 검출되었다. 각 네일샵 공기 중 유기증기의 노출정도를 기하평균(GM)과 복합물질간 상가작용을 이용하여 평가를 하였을 때 노동부 노출기준의 10%, ACGIH의 13% 수준에 불과하여 네일샵 종사자들의 유기증기에 대한 직업적인 노출정도는 매우 낮은 것으로 판단되었다. 요 중 아세톤과 마뇨산은 공기 중 아세톤과 툴루엔과 약한 상관성을 보였다(아세톤의 상관 계수 r=0.49, 톨루엔의 상관계수 r=0.45). 그러나 요 중 아세톤의 농도가 노출군과 대조군 간에 통계적으로 유의하지 않았으며 마뇨산은 대조군에 비해 노출군에서 약간 높은 것으로 나타났다. 따라서 저자들은 공기 중 아세톤과 톨루엔의 농도가 낮은 작업장에서 요 중 아세톤과 마뇨산을 생물학적 지표로 삼는 것은 적절하지 못한 것으로 결론지었다.

• Journal of Korean Society of Occupational and Environmental Hygiene
• /
• v.7 no.1
• /
• pp.71-85
• /
• 1997

The purpose of this study was to evaluate concentrations of organic solvent mixtures in air of rotogravure printing workplaces. Qualitative and quantitative analysis of organic solvents contained in the gravure inks used at rotogravure factories had been done. The results obtained were as follows: 1. The gravure inks mainly consist of toluene, methyl ethyl ketone(MEK), and ethyl acetate(EA), and traces of isopropyl alcohol(IPA), xylene, 2-butanol, cyclohexane, cellosolve etc were also contained in them. 2. Thinner used as a diluent consist of toluene, MEK, and EA. 3. Geometric mean concentration of toluene in ambient air were 23.81 ppm at gravure printing of packing material, 42.10 ppm at gravure printing of wallpaper, 16.95 ppm at gravure printing of plastic bottle for beverage and 4.31 ppm at gravure printing of plywood printing or floor covering. Concentrations of toluene in ambient air showed statistically significant difference between types of printing. 4. Concentrations of MEK in ambient air were 12.43 ppm at gravure printing of packing material, 5.47 ppm at gravure printing of wallpaper, 16.78 ppm at gravure printing of plastic bottle for beverage and 16.44 ppm at gravure printing of plywood printing or floor covering. MEK concentrations in ambient air showed no significant difference. 5. Conentrations of EA were 14.30 ppm at gravure printing of packing material, 1.92 ppm at gravure printing of wallpaper and 21.12 ppm at gravure printing of plywood printing or floor covering. EA concentrations in ambient air shown significant difference. 6. Percentage of the workplaces where the ambient air concentration of organic solvent mixtures exceeded the Korean Permissble Exposure Level(KPEL) amounted to 18.03%. 7. Toluene concentrations in ambient air of rotogravure printing workplaces ranged from 0.69 to 156.02 ppm and urinary hippuric acid excretion ranged from 0.10 to $1.32g/{\ell}$.

• Bulletin of the Korean Chemical Society
• /
• v.30 no.9
• /
• pp.2021-2026
• /
• 2009

Toluene, xylene and styrene are volatile organic solvents that are commonly used in mixtures in many industries. Because these solvents are metabolized and then excreted in urine, their urinary metabolites are thought to be biomarkers of occupational exposure to these solvents. Therefore, a simple, rapid, and yet reliable analytical method for determining the metabolites is required for accurate biological monitoring. In the present study, a simple and rapid HPLC-UV method was developed for the simultaneous determination of eight major metabolites of toluene, xylene and styrene: hippuric acid (HA), mandelic acid (MA), o-, m- and p-methylhippuric acids (o-, m- and p-MHAs), and o-, m- and p-cresols. A monolithic column was employed as the stationary phase and several conditions, including flow rate, composition of mobile phase and column temperature, were variables for the optimization of the chromatographic resolution. All eight metabolites were successfully resolved within 5 minutes in 10% aqueous ethanol containing 0.3% acetic acid and 1.6% $\beta$-cyclodextrin, using a flow rate gradient of 1.0 - 5.0 mL/min at 25 ${^{\circ}C}$. The performance of this method was validated by linearity, intra- and inter-day accuracy, and precision. The linearity was observed with correlation coefficients of 0.9998 for HA, 0.9999 for MA, 0.9989 for o-MHA, 0.9998 for m-MHA, 0.9991 for p-MHA, 0.9997 for o-cresol, 0.9998 for m-cresol, and 0.9986 for p-cresol. The intra- and inter-day precision of the method were less than 5.89% (CV) and the accuracy ranged from 92.95 to 106.62%. The validity was further confirmed by analysis of reference samples that were prepared by the inter-laboratory quality assurance program of the Korea Occupational Safety and Health Agency (KOSHA, Seoul, Korea). All measured concentrations of the analytes agreed with the certified values.