주조공정에서의 벤젠 발생원 규명에 관한 연구

오도석 ( Doe Suk Oh ),이성민 ( Seong Min Lee ),이병재 ( Byoung Jae Lee ),김영주 ( Young Ju Kim ) 한국산업위생학회 2006 한국산업보건학회지 Vol.16 No.1

The aim of this study was to identify the sources of benzene detected in airborne of casting workplace where benzene was not used as raw material. We have identified benzene by GC/FID and GC/MSD. In this pilot test, small size iron chamber(diameter 30 cm, height 20 cm) was used. As the raw materials, new sand, recovered sand, and mixed casting sand(new sand + solidifying agent + organic resin + coating material) was tested, respectively. In the new sand benzene was not detected, but in the recovered sand and the mixed casting sand was detected. Xylenesulfonic acid(solidifying agent), one of the mixed casting sand ingredients was thought to product benzene by thermal decomposition above 400°…, but the other raw materials(organic resin and coating material) were thought not to product benzene. In this experiment, the most of benzene by thermal decomposition was produced within 1 hour after pouring the iron solution(1560°…) in small size iron chamber. When the mixed casting sand with coating material was used, the concentration of the produced benzene was average 2.91 ppm(range 1.98~3.72 ppm), and without coating material, benzene concentration was average 0.11 ppm(range 0.08~0.14 ppm).

GC에서 검출한계 결정을 위한 새로운 접근 방법에 대한 연구

오도석 ( Doe Suk Oh ),신경애 ( Kyoung Ae Shin ),이지아 ( Ji A Lee ),임종호 ( Jong Ho Lym ),신미선 ( Mi Sun Shin ) 한국산업위생학회 2010 한국산업보건학회지 Vol.20 No.4

The purity methods to determine LOD/LOQ using standard deviation of the residual, intercept and blank by IUPAC and ACS describe many of the pitfalls and pose significant challenges to analytical chemists. Therefore, the aim of this study is the development of the simple, easy, convenient and statistically significant method to determine LOD in quantitative analysis of organic solvents by GC. The new approaching method by linearization in the given concentration range used coefficient of variation ; σn-1/S(standard deviation, σn-1 and average, S) of sensitivity(Response/concentration). The comparison of results among the purity methods(IUPAC and ACS) and the linearization have been fulfilled the F-test for standard deviations and t-test for LOD range values. The results of F-test and t-test are satisfied within 95 % confidence level, respectably. The LOD values determined by the new procedure are n-Hexane 0.0116mg/m3, Toluene 0.0807mg/m3, and o-Xylene 0.0494mg/m3. Because the standard deviation of the residual, intercept and blank and the slope of calibration curve are not calculated and the new approaching method use the coefficient of variation of sensitivity by linearization, this new method is simple, easy, convenient and statistically significant. In future, many chemical analysts will expect to applicate and routinely use this method in the all quantitative analysis.

자동차 산업의 작업환경측정결과 분석 연구

오도석 ( Doe Suk Oh ),이용학 ( Yong Hack Lee ) 한국산업위생학회 2004 한국산업보건학회지 Vol.14 No.3

The aims of this study are to confirm the improvement by comparison with the excess-rate for exposure level of the harmful factors for working environmental measurement results of 1995~2003 year of automobile factories and to suggest direction for working environmental measurement in future. 1st, the harmful factor continuously issued at A(B; same factory) and C factories during 1995~2003 year was the noise. The total excess-rate of harmful factors for overall processes was 19.4% during 1995~1997 year, 2000~2001 year 9.4% in A(B) factory and C factory was 1.96% during 2001~2003 year. The results of improvement for harmful factors are as follows. 1. Noise; The total excess-rate for overall processes of A(B) factory was av. 24.9% during 1995~1997 and av. 19.7% during 2000~2001 and especially at 2001(13.6%) was very improved. The mainly improved process was the press-process. The excess-rate of C factory during 2001~2003 year was av. 6.1% for overall processes. 2. Manual material handling(MMH) and repeated works; The RWL excess-rate for MMH of A(B) factory was very high during 1995~1997 but during 1999~2001(61.5% → 7.1%)was very improved. The ANSI excess-rate for repeated works during 1995~1997 was 77.2%. The MMH for C factory have been automated and not issued. 3. Dusts(welding fume, Fe2O3 dust, and etc.) and heavy metals; During 1995~2003 the excess-rate for dusts and heavy metals was zero in A(B) and C factories. 4. Organic solvents; During 1995~1997 the excess-rate for organic solvents of A factory was 5.3% and during 1999~2001(zero%) was very improved. During 1995~2001 benzenes(A2) have been detected but not exceed exposure level. The excess-rate for C factory was zero% and benzenes were not detected. 5. The others(specific chemical materials, toxic gases, oil mists, asbestos, electromagnetic wave, vibration, heat, etc.) not exceed the exposure levels except the oil mist and the a few physical factors. 2nd, Until now as the chemical factors have been very improved, the direction of working environmental measurement in future will manage the chemical factors as the basis and enforce the physical factors(noise, vibration, electromagnetic wave etc. and the ergonomic factors(MMH and repeated work related with the CTDs).

주조작업장 공기 중 벤젠의 정량

오도석,이병재,이성민,김영주 한국산업위생학회 2001 한국산업보건학회지 Vol.11 No.3

This article describes identification and quantification of benzene in the casting process. Air samples around the casting process were taken by using personal air sampler attached charcoal tube and desorbed by carbon disulfide. The identification and quantitative analysis of benzene have been performed by GC-MS and GC-FID. Calibration range of standard solutions for benzene was prepared in range from 0.1 to 2 times TLVs concentrations(1.4∼28㎍/1㎖ CS2) and the limit of detection was 0.11 ±0.002㎍/1㎖ CS2, Benzene detected in airborne was ranged in 4.0ppb∼104.7ppb.

냉각증기 원자흡수분광법에 의한 뇨 및 공기중의 무기수은 정량에 관한 연구

오세민,오도석 한국산업위생학회 1991 한국산업보건학회지 Vol.1 No.2

Inorganic mercury in urine and airborne was determined by cold vapor atomic absorption spectrophotometry. Detailed sampling methods and analytical results are as follows : 1. 100∼200㎖ of urine for each person was taken in 250㎖ borosilicate bottle and K₂S₂O_8 (0.1g/100㎖ urine) was added to prevent bacterial contamination. About 1001 air of workingplace was absorbed in l0㎖ of absorbing solution. Urine samples and absorbing solution tubes were stored at 4℃. Dillution solution to prepare standard solution used deionized water (D.W) for urine and absorbing solution (A.S) for air. 2. In this procedure detection limit was l ng/㎖ and mercury contents of blank reagent solution was 1∼2 ng/㎖. 3. Calibration range was 0.02∼0.1 ㎍/㎖ and in this range r.s.d for each calibration curve in D.W and A.S and ±7.9% and ±3.7%, respectively. 4. Repeatability (n=5 times, conc. 0.05 ㎍/㎖) was ±5.8%, in D.W. and ±4.4% in A.S, respectively. 5. Recovery for urine adding spiked concentration (0.05 ㎍/㎖) was about 90%. 6. Analytical result of samples was 1∼139 ㎕/1 in urine and ∼0.127 ㎎/㎥ in airborne.

도료 제조업 근로자들의 복합유기용제 폭로농도에 관한 연구

오세민,최호춘,오도석,정규철 한국산업위생학회 1993 한국산업보건학회지 Vol.3 No.2

The exposure levels of mixed organic solvents for 66 exposed workers in six paint manufacturing plants were evaluated. In 66 exposed workers and 30 control subjects, we also determined the concentrations of toluene and xylene metabolites, hippuric acid. (o^-, m^-, and p^-)methylhippuric acid. The results were as follow ; 1. Seven organic compounds, which on averge accounted for approximately 90% of the identified mass in each painting plants air samples, were selected for quantification : methyl ethyl ketone, ethyl acetate, methyl isobutyl ketone, toluene, butyl acetate, ethyl benzene, (o^-. m^-, p^-)xylene. 2. The average mixed organic solvent exposure levels in 66 points with workplace were 3.8ppm of MEK, 12.2ppm of ethyl acetate, 4.0ppm of MIBK, 28.7ppm of toluene, 3.8ppm of butyl acetate, 10.2ppm of ethyl benzene, 14.6ppm of xylene, respectively. 3. For the total 66 points with workplace, the rate of them of which mixed solvents in air was exceeded th TLV of 1.0 were obtained for 23%(15/66 point). 4. The concentrations of hippuric acid in urine of exposed group and control were 0.94 0.65g/g of creatinine, 0.16±0.11g/g of creatinine, respectively. 5. There was a linear correlation between the end shift hippuric acid acid levels in urine and exposed toluene in air : y= 0.02079 × +494.2, r=0.6488, n=55 y: hippuric acid in urine(㎎/g of creatinine), x: toluene levels in air(ppb) Toluene levels of 100ppm in air have been caculated to hippuric acid of 2.57g/g of creatinine in urine. 6. There was a linear correlation between the end shift methylhippuric acid acid levels in urine and exposed xylene in air : y=0.01664 × +31.6, r=0.7264, n=55 y: methylhippuric acid in urine(㎎/g of crea.), x: xylene levels in air(ppb) Xylene levels of 100ppm in air have been caculated to methylhippuric acid of 1.69g/g of creatinine in urine.