• Analytical Science and Technology
• /
• v.24 no.6
• /
• pp.421-428
• /
• 2011

In this study, headspace disk type monolithic material sorptive extraction (HS-MMSE) was developed, validated and applied to the analysis of volatile aroma compounds from vanilla perfume by gas chromatography -mass spectrometry (GC/MS). HS-MMSE uses monolithic material (MonoTrap) based on silica bonded with octadecyl silane (ODS) and activated carbon as a sorbent. Aroma compounds was adsorbed onto the MonoTrap in headspace and extracted by only 100 ${\mu}L$ of solvent. Total 12 volatile compounds from vanilla perfume were successfully analyzed using HS-MMSE. The influence of extractive parameters was investigated and optimized, using benzyl acetate, linalyl acetate, vanillin, ethyl vanillin as target compounds. Under the optimum condition, the limit of detection (S/N = 3) and the limit of quantification (S/N = 10) of proposed method for the target compounds were obtained within the range of 8.35~13.76 ng and 27.82~45.88 ng, respectively. The method showed good linearity with correlation coefficient more than 0.9888, satisfactory recovery and reproducibility. These results showed that HS-MMSE using disk type MonoTrap is a new promising technique for the analysis of volatile aroma compounds from vanilla perfume.

• Proceedings of the Korean Society of Food Hygiene and Safety Conference
• /
• 2002.05a
• /
• pp.127-131
• /
• 2002

Migration of di-(ethylhexyl)phthalate (DEHF) from PVC food packaging materials detected plasticizer into food simulanting solvents(4% Acetic acid, 8% Ethanol, 50% Ethanol, 95% Ethanol, Heptane) were studied. For executing this study ,2 PVC food packaging materials detected DEHP were used. Analysis was by GC-FID and GC-MSD(selected ion monitoring) for DEHP, and optimized for quantification of plasticizer. The recovery of DEHP into food simulanting solvents were min. 87.4${\pm}$ 3.6 ∼ max. 109.9 ${\pm}$ 10.7% respectively. Following exposure to food simulants 95% Ethanol for 24hours at 60$^{\circ}C$ the migration results of 1020.90 ${\pm}$ 10.15$\mu\textrm{g}$/g, 563.54 ${\pm}$ 5.60$\mu\textrm{g}$/dm$^2$and 73.51 ${\pm}$ 5.09$\mu\textrm{g}$/g 149.22 ${\pm}$ 10.34$\mu\textrm{g}$/dm$^2$were detected from the container for lunch and for stock fish respectively.

• Resources Recycling
• /
• v.20 no.6
• /
• pp.50-55
• /
• 2011

Using ultrasonic irradiation, the separation and recovery of PV cell, made of silicon wafer, from PV module was carried out through selective decomposition of EVA used as an interlaminated binder. The ultrasonic cleaner of bath-type (Output: 130 W, Frequency: 40 kHz) was used as an ultrasonic apparatus in this research. With the fixed distance of 2 cm, from ultrasonic generator to PV cell, the experiment of EVA decomposition was performed in various organic solvents such as Toluene, Trichloroethylene, O-dichlorobenzene, Benzene. And also their concentrations and temperature was changed to survey the optimum conditions. However EVA can be decomposed perfectly at $55^{\circ}C$ within 160 min in 5 M of all kinds of solvent, PV cell may be recovered with being damaged or broken severely. This damage may be resulted from the swelling of EVA in the process of decomposition. Whereas, at the condition of 5 M at $65^{\circ}C$, PV cell can be recovered with the state of minor damage or crack. This implies that the decomposition rate of EVA increases with an increase of temperature, thereby EVA can be decomposed before the swelling of EVA layer. Conclusively, it is possible for PV cell to be recovered within 40 min, at $65^{\circ}C$ in 5 M, with less damage.

• Journal of the Society of Cosmetic Scientists of Korea
• /
• v.38 no.1
• /
• pp.33-41
• /
• 2012

An effective, environmentally friendly analytic methods using gas chromatography with mass spectrometric detector (GC-MSD) have been developed for the quantitative analysis of trace phthalate levels in cosmetics such as nail lacquer and hair spray. Since such cosmetics are largely comprised of organic solvents, conventional clean-up methods that have been widely used for phthalate analyses are in adequate. In addition, analysis of trace phthalate levels is notorious for its sensitivity to contamination, which causes high analytical values. A direct sample dilution method using an organic solvent was adopted to the sample preparation process to determine the exact amounts of phthalates and simultaneously avoid the high risk of secondary contamination. The method has many advantages including high accuracy, sensitivity, and simplicity in sample preparation. Dibutyl phthalate (DBP) and di (2-ethylhexyl) phthalate (DEHP) were selected for analysis because they have been frequently detected in cosmetics and consistently reported as endocrine disruptors in humans and animals. Internal standard method using two deuterium substitutes (DBP-$d_4$, DEHP-$d_4$) as the internal standard was also used. The results of 'Method validation' showed the capabilities of this method for the routine analysis of phthalates at the ppm level. The recovery ranges were between 95 % and 106.1 %, and relative standards deviations (RSD) were less than 3.9 % in fortified nail lacquer and hair spray samples at the concentration of $25{\mu}g/g$.

• Korean Chemical Engineering Research
• /
• v.54 no.6
• /
• pp.806-811
• /
• 2016

Organosolv pretreatment is the process to frationation of lignocellulosic feedstocks to enhancement of enzymatic hydrolysis. This process has advantages that organic solvents are always easy to recover by distillation and recycled for pretreatment. The chemical recovery in organosolv pretreatment can isolate lignin as a solid material and carbohydrates as fermentable sugars. For the economic considerations, using of low-molecular-weight alcohols such as ethanol and methanol have been favored. When acid catalysts are added in organic solvent, the rate of delignification could be increased. Mineral acids (hydrochloric acid, sulfuric acid, and phosphoric acid) are good catalysts to accelerate delignification and xylan degradation. In this study, the biomass was pretreated using 40~50 wt% ethanol at $170{\sim}180^{\circ}C$ during 20~60 min. As a results, the enzymatic digestibility of 2-stage pretreatment of rigida using 50 wt% ethanol at $180^{\circ}C$ was 40.6% but that of 1-stage pretreatment was 55.4% on same conditions, therefore it is shown that the pretreatment using mixture of the organosolv and catalyst was effective than using them separately.

• Journal of the Korean Chemical Society
• /
• v.58 no.6
• /
• pp.535-542
• /
• 2014

A simple and efficient preconcentration method was developed using three-phase liquid phase microextraction prior to HPLC-UV for simultaneous extraction and determination of tetracycline antibiotics (tetracycline, oxytetracycline, and chlortetracycline). The tetracycline antibiotics were separated simultaneously on a column ($C_8$, $3.0{\times}150mm$, $3{\mu}m$) with high selectivity and sensitivity using gradient elution. Under optimized conditions (extraction solvent, heptanal; pH of donor, 9.0; pH of acceptor, 1.0; stirring speed, 700 rpm; NaCl salt, 0%; and extraction time, 60 min), enrichment factors (EF) were between 5.6 and 22.3. The limit of detection (LOD) and limit of quantitation (LOQ) in the spiked urine matrix were in the concentration range of $0.08{\sim}0.8{\mu}g/mL$ and $0.4{\sim}1.6{\mu}g/mL$, respectively. The calibration curves were linear within the range of $0.1{\sim}32{\mu}g/mL$ with the square of the correlation coefficient being more than 0.995. The precision (as a relative standard deviation, RSD) and accuracy (as a relative recovery) within working range were 1.3~9.1% and 84~118%, respectively.

• Journal of Korean Society of Occupational and Environmental Hygiene
• /
• v.4 no.2
• /
• pp.208-223
• /
• 1994

The purpose of this study was to evaluate the efficiency of diffusive(or passive) sampler in measuring airbone organic solvents. Diffusive samplers are generally simple in construction and do not require power for operation. The efficiency of the diffusive samplers has not sufficiently been investigated in Korea. Three types of samplers were studied in this study. The sampling and analytical results by passive samplers were compared with results by charcoal tube method recommended by NIOSH(National Institute for Occupational Safty and Health). The following characteristics are identified and studied as critical to the performance passive monitors; recovery, reverse diffusion, storage stability, accuracy and precision, face velocity and humidity, n-Hexane, TCE(trichloroethylene) and toluene were used as test vapors. A dynamic vapor exposure system consisting of organic vapor generator and sampling chamber for evaluating diffusive samplers are made. The results of the study are summarized as follows. 1. NIOSH recommands that the overall accuracy of a sampling method in the range of 0.5 to 2.0 times the occupational health standard should be ${\pm}25$ percent for 95 percent confidence level. Among three types of diffusive samplers, sampler A has permeation membrane and samplers Band C have diffusive areas, samplers A and B met the criterion that overall accuracy for 95% confidence level of the samplers were within ${\pm}25$ percent of the reference value. Sampler C had overall accuracy ${\pm}9.6%$ and ${\pm}11.8%$ in hexane and TCE, respectively. The concentration of toluene was overestimated in sampler C with overall accuracy of ${\pm}43.9%$. 2. The desorption efficiencies of diffusive samplers were 96-107%. 3. There was no significant sampe loss during four weeks of storage both with and without refrigeration. 4. There was no significant reverse diffusion, when the samplers were exposure to clean air for 2 hours after sampling for 2 hours at the level of 2 TLY. 5. In case of 8 hours sampling, relative differences(RD) of concentrations between charcoal tube method and diffusive method were 15-39%, 13-46%, and 4-35% for sampler A, B and C, respectively. The performance was poor in 8 hours sampling for multiple substance monitors. 6. At high velocity(100 cm/sec), samplers B and C overestimated the concentrations of organic vapors, and sampler A with permeation membrance gave better results. 7. At 80% relative humidity, samplers showed no siginificant effect. Low humidity also did not affect the diffusive samplers.

• Journal of Radiation Protection and Research
• /
• v.20 no.4
• /
• pp.275-283
• /
• 1995

PERALS(Photon Electron Rejecting Alpha Liquid Scintillation) spectrometry coupled with solvent extraction method has been set up for the analysis of $^{222}Rn\;and\;^{226}Ra$ in the groundwater. This analytical method offers low background, better energy resolution and lower quenching problem than the other techniques. By the analysis of NIST SRM 4966 $^{226}Ra$ standard, the analytical accuracy and precision were found to be 3% and 1%, respectively, and the relative standard deviation of the recovery of Rn extraction between pH2 and pH10 was 7%. Detection limits of $^{222}Rn$ and $^{226}Ra$ for 10 hours counting were counted to be $0.42 pCi/{\iota}\;and\;0.016 pCi/{\iota}$, respectively. For the test analysis of $^{222}Rn\;and\;^{226}Ra$ in the graundwater, hot spring water samples of 17 regions were analyzed. The concentration of $^{222}Rn$ were in the range of $90{\sim}5200pCi/{\iota}$ and average value was $1470pCi/{\iota}\;^{226}Ra$ concentration showed a peak value of $97.9pCi/{\iota}$ in a Kangwon region, but the average value was $1.14pCi/{\iota}$ except that region.

• Journal of Life Science
• /
• v.25 no.12
• /
• pp.1393-1398
• /
• 2015

In this study, we investigated the extraction condition of alginate from Laminaria japonica, the enzymatic degradation of the extracted alginate, and the inhibitory activity of the degraded alginate on the differentiation of 3T3-L1 preadipocytes. The optimal conditions for the efficient extraction, precipitation, and recovery of alginate from the brown seaweed L. japonica were 1% for Na₂CO₃ concentration, 80℃ for extraction temperature, and ethanol for precipitation solvent. In the enzymatic reaction for the production of low-molecular-weight alginate (LMWA) by using alginate lyase from Flavobacterium sp., the initial concentration of Laminaria alginate was 3%. The low-molecular-weight degree from alginate was independent with the enzyme concentration, and the optimal concentration of alginate lyase was found to be 5 unit/ml. Through the enzymatic reaction with 5 unit/ml of alginate lyase at 37℃ for 3 hr, the viscosity and molecular weight of LMWA were 4.5 cp and 307 kDa, respectively. Treatment with LMWA significantly suppressed the accumulation of lipid droplet and triglyceride in 3T3-L1 preadipocytes with a dose-dependent manner. Therefore, it seems that LMWA treatment could inhibit the differentiation of 3T3-L1 preadipocytes. These results indicate that LMWA or the degraded alginate produced by alginate lyase enzyme can be useful for the development of anti-obesity biosubstances.

• Analytical Science and Technology
• /
• v.14 no.3
• /
• pp.244-252
• /
• 2001

A comprehensive analytical method of endocrine distruptors[i.e., nonylphenol(NP), octylphenol(OP), bis(2-ethylhexyl)phthalate(BEHP)] is fish samples was developed using two internal standards. This method employed closed culture tube extraction with dichloromethane and solvent exchange to iso-hexane and SPE(2g) aminopropyl column, followed by determination on gas chromatograph linked to mass spectrometer(GC/MS) operated in the single ion monitoring(SIM) mode. The recoveries of nonylphenol and octyphenol in the range of $0.2{\sim}20{\mu}g/g$ using 1-phenyl decanol as one internal standard were over 75%, and recovery of bis(2-ethylhexyl)phthalate in the range of $0.4{\sim}40{\mu}g/g$ using bis(2-ethylbutyl)phthalate(BEBP) as the other internal standards was showed over 102%. The present method was applied to fish samples from Korea and UK. The range of concentrations for nonylphnol(NP) and bis(2-ethylhexyl)phthalate in Korean fish were $0.02{\sim}0.06{\mu}g/g$ in 2 samples and $0.18{\sim}2.03{\mu}g/g$ in 9 samples respectively, but bis(2-ethylhexyl)phthalate(BEHP) in UK samples was found $2.99{\mu}g/g$ in just 1 sample. But octylphenol(OP) was not dected in any samples by this method. This two internal standard method provides a more precise analytical tool to investigate endocrine disruptors in a biological matrices of limited quantity.