• 한국산업보건학회지
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• 제16권3호
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• pp.211-221
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• 2006

This study was performed to compare with desorption efficiency and storage stability of CSC and CMS tubes for Ketones in workplace air. 1. The best desorbing solution for CSC tube was 1 % or 3 % dimethylformamide(DMF) in carbon disulfide($CS_2$). The desorption efficiencies were 96.40 % for cyclohexanone, 94.86 % for acetone, 96.96 % for methyl ethyl ketone(MEK), 103.44 % for methyl isobutyl ketone(MIBK), 100.17 % for methyl amyl ketone(MAK), 100.43 % for methyl butyl ketone(MBK), 97.01 % for toluene and 99.33 % for trichloroethylene(TCE). 2. The best desorbing solution for CMS tube was 1 % or 3 % DMF in $CS_2$. The desorption efficiencies were 96.42 % for cyclohexanone, 98.53 % for acetone, 99.67 % for MEK, 105.48 % for MIBK, 100.13 % for MAK, 100.13 % for MBK, 95.42 % for toluene and 98.15 % for TCE. 3. In the storage condition at room temperature($20^{\circ}C$), the recovery rates of cyclohexanone and MEK on CSC tube were rapidly decreased 30.9 % and 50.9 % after 4 weeks, respectively. The recovery rates of all of 6 ketones and 2 nonpolar solvents were shown over 80 % after 1 week in the storage condition of refrigerate temperature($-4^{\circ}C$), and were kept over 80 % after 4 weeks in the storage condition of freezer temperature($-20^{\circ}C$). 4. The recovery rates of cyclohexanone on CMS tube were 80.6 % for 1 week after and 60.5 % for 4 weeks after at room temperature($20^{\circ}C$). The recovery rates of cyclohexanone were shown 80.6 % for 1 week after and 60.5 % for 4 weeks after at $-4^{\circ}C$, and of 6 ketones and 2 non-polar solvents were kept stable over 85 % at $-4^{\circ}C$ and over 97 % at $-20^{\circ}C$ for 4 weeks after. In conclusion, the best desorbing solution was 1 % or 3 % DMF in $CS_2$ and more appropriate sorbent tube for ketones and non-polar solvents was CMS than CSC. We recommend CSC tube would be useful if the samples analyzed within 1 week because CMS tubes are more expensive than CSC tubes. However, if the storage time is needed more than 3 weeks, CMS tubes should be suitable and the storage condition should be below $-20^{\circ}C$.

• 분석과학
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• 제20권1호
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• pp.41-48
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• 2007

유리소재 중의 미량의 납 및 카드뮴을 Na-DDTC를 가하여 Pb- 및 Cd-DDTC 착물을 형성시켜 유리 matrix 원소들로 부터 분리한 다음 MIBK로 추출하여 ICP-AES로 분석하였다. 유리 기질성분인 Na, Si, Mg 그리고 Ca 화합물 등은 미량의 납 및 카드뮴 정량에 방해작용을 하므로 직접 분석할 수 없으므로 용매추출법에 의해 Pb 및 Cd를 효율적으로 분리할 수 있었다. Pb 및 Cd 화합물이 첨가된 시험기준 시료와 NIST SRM 1412에 대한 용매추출실험에서 matrix의 영향을 받지 않고 정량하였다.

• 한국산업보건학회지
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• 제5권1호
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• pp.104-118
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• 1995

This study was performed to evaluate factors affecting desorption of organic solvents collected on charcoal tube and to find out the optimum condition. Desorption efficiency for polar analytes was improved when several polar desorption solvents such as methanol, dimethylformamide(DMF), 2-(2-butoxyethoxy)ethanol were added to carbon disulfide($CS_2$). The best improvement was achieved when 10% dimethylformamide(DMF) in $CS_2$ was used as desorption solvent. During storage of polar analytes, recovery was greatly reduced. Especially, the recovery of cyclohexanone was decreased to 18.1 % after a month storage at $34^{\circ}C$. After two weeks storage, recovery of polar analytes was sharply decreased. Water adsorbed on charcoal interfered the recovery of polar analytes but didn't interfere that one of nonpolar solvent, toluene. When 10% DMF in $CS_2$ was used as desorption solvent, the effect of water on recovery was decreased, comparing with Desorption efficiency increased when analyte loading increased, and usage of 10% DMF in $CS_2$ decreased the loading effect. Increasing volume of desorption solvent was not effective to improve desorption efficiency of analytes when 10% DMF was used. Continuous shaking and sonication is not helpful to increase the desorption efficiency of analytes except cyclohexanone using 10% DMF. When silica gel used as adsorbent, methanol was better desorbent than dimethylsulfoxide. Analytes adsorbed on silica gel showed high recovery in low concentration and less affected by humidity. On the basis of this study, the following conclusions have been drawn. To improve the recovery of polar organic materials in air samples, it is necessary to analyze samples as soon as possible after they were collected. Otherwise, samples must be stored at low temperature. Using two components of desorption solvents, such as 10% DMF in $CS_2$, the effects of loading and humidity decreased for polar analytes such as methyl ethyl ketone and methyl isobutyl ketone. When work place has high humidity with low concentration of polar organic solvents, silica gel can be used as adsorbent, because it produces quantitative recovery for polar analytes at this condition. But it should be noted that high humidity makes breakthrough easy in silica gel samples.

• 청정기술
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• 제27권1호
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• pp.79-84
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• 2021

본 연구에서는 도장 공정에서 사용된 폐활성탄을 원통형 카트리지에 충진하여 저온 가스에 의한 탈착 특성을 파악하였다. 폐활성탄의 탈착유량을 결정하기 위하여 활성탄의 톨루엔 흡착 및 탈착 실험을 진행하였다. 실험결과에서 1, 2, 4 ㎥ min-1의 유량으로 탈착을 하였을 때 높은 THC 농도와 탈착시간에 의하여 2 ㎥ min-1이 적절하다고 판단하였다. 폐활성탄은 탈착시간 초기에 가스성분에서 비점이 낮은 2-butanone과 MIBK (methyl isobutyl ketone)가 높은 비율로 발생되었고, 그 이후에는 THC의 농도가 감소하면서 BTX계열이 상대적으로 높은 비율로 탈착되었다. 폐활성탄의 탈착시간 동안 발생되는 가스 성분의 총 열량은 316 kcal kg-1으로 나타났다. 폐활성탄을 이용하여 톨루엔으로 5회 반복 재생한 결과에서는 요오드가 및 비표면적이 신탄에 비하여 상대적으로 낮은 것으로 분석되었다. 원통형 카트리지 2개를 직렬로 연결한 탈착실험에서는 최대 THC농도가 약 470 ppm으로 나타났다.

• 한국대기환경학회지
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• 제25권6호
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• pp.503-511
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• 2009

VOC mixture was fed to a trickle bed air biofilter (TBAB) with step-change in influent mixture concentrations from 50 ppmv to 1,000 ppmv, corresponding to loadings of $5.7\;g/m^3/hr$ to $114.1\;g/m^3/hr$. VOC mixture was an equimolar ratio of two aromatic VOCs, i.e., toluene and styrene, and two oxygenated VOCs, i.e., methyl ethyl ketone (MEK) and methyl isobutyl ketone (MIBK). The TBAB system employed backwashing as biomass control. The experimental results showed that a critical loading rate for VOC mixture removal was determined to be about $60\;g/m^3/hr$, and critical loading rates for individual VOCs in the mixture were different. Specifically, toluene content in the mixture played a major role in the biofilter overall performance. As VOC mixture was fed beyond the critical loading rate, reacclimation of the biofilter to reach the 99% removal efficiency following backwashing was delayed, which was a critical factor in the biofilter performance. In the mass balance analysis, 63.8% of the carbon equivalent in VOCs removal was used for $CO_2$ production during the experimental runs. The 82.6% nitrogen utilized in the biofilter was contributed to microbial cell synthesis. The obtained results were compared against consistently high efficient performance of TBAB for VOC mixture by employing backwashing as biomass control.

• Korean Membrane Journal
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• 제1권1호
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• pp.81-85
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• 1999

Tributyl phyosphate(TBP) polypropylene glycol 4000(PPG-4000) and the mixture of two compounds were examined as a liquid membrane in a supported liquid membrane (SLM) to separate phenol from aqueous solution.The feed concentration of phenol was varied in a broad range from 500 mg/L to 5000 mg/L and different types of liquid membrane were prepared to elucidate their effects on separation of phenol. It was found that the modified PPG 4000 with TBP and toluene diisocyanate(TDI) might be used as a proper liquid membrane because the mass transfer rate examined with this membrane was higher than that through methyl isobutyl ketone (MIBK) which has been used as a conventional solvent in a solvent extraction process. The breakthrough pressure of the SLM is defined to be the pressure difference across the membrane at which the supported liquid membrane is not kept in the pores any more. it indicates how the SLM is stable., It was found that the breakthrough pressure of the modified PPG-4000 was much higher than those of typical organic solvents.

• 한국산업보건학회지
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• 제3권2호
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• pp.177-187
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• 1993

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 workplce 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 $0.94{\pm}0.65g/g$ of creatinine, $0.16{\pm}0.11g/g$ 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=0.02079X+494.2, r=0.6488, n=55 y:hippuric acid in urine(mg/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=0.01664X+31.6, r=0.7264, n=55 y:methylhippuric acid in urine(mg/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.