• Journal of the Korean Chemical Society
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• v.21 no.4
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• pp.293-303
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• 1977

Cellulosic organic solid wastes such as bark and sawdust, and filter papers as a pure cellulose were pyrolyzed at $300^{\circ}C$ under nitrogen current and mixed current of nitrogen and air. Amounts of condensates collected in air, water, and dry ice-acetone cooling traps, noncondensable gases, and carbonized residues were surveyed. The components of volatile liquids condensed in dry ice-acetone trap were separated by means of gas chromatograph and identified by retention times and syringe reactions. Pyrolysis under nitrogen current produced 13.4∼29.6${\%}$ of tar, 0.01∼0.12${\%}$ of aqueous liquids, 0.24∼1.43${\%}$ of volatile liquids, 9.84∼42.41${\%}$ of noncondensable gases, and 44.0∼65.81${\%}$ of carbonized residues. Pyrolysis under mixed current decreased tar and condensable liquids, but increased noncondensable gases.Volatile liquids collected under nitrogen current separated into the same 19 components by Porapak Q column regardless of the materials and only difference among materials was relative amounts of components. Volatile liquids collected under mixed current separated into six components and mainly lower molecular weight compounds such as methanol and formaldehyde were produced. According to the retention times and syringe reactions, methanol, formaldehyde, acetone, acetaldehyde, acetic acid, and three other compounds presumably containing hydroxyl group in the molecular structure were identified out of 19 compounds.

• Journal of The Korean Society of Inherited Metabolic disease
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• v.16 no.1
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• pp.47-51
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• 2016

Propionic acidemia (PA) is an autosomal recessively inherited disorder of the organic acid metabolism. It is caused by a deficiency of propionyl-CoA carboxylase (PCC). PCC is a heteropolymeric enzyme composed of ${\alpha}$- and ${\beta}$-subunits. The clinical symptoms of PA are heterogeneous and present vomiting, dehydration, hypotonia, and lethargy, and it can result in death. The typical presentations of neonatal onset PA are life-threatening metabolic acidosis and hyperammonemia. Here, we described a case of neonatal onset PA with mild clinical presentations. She was born to a healthy mother without complications. No significant illness was observed until nine days after birth. She started exhibiting poor oral feeding, vomiting, lethargy, and hypotonia at ten days old. Her laboratory results showed mild hyperammonemia and acidosis. The initial diagnosis was neonatal sepsis and she was treated with antibiotics. However, her clinical symptoms didn't improve. So we considered a metabolic disease. She was given nothing by mouth and intravenous hydration and nutrition support was performed. Propionylglycine and 3-hydroxypropionic acid were showed high concentrations in urine by gas chromatograph mass spectrometry (GC-MS). C3 level of acylcarnitine analysis elevated 10.4 uM/L (range, 0.200-5.00) in plasma. We took gene analysis for PA to be based on the symptoms and laboratory results. We detected PCCB gene mutation and diagnosed PA. She survived without severe neurologic defects and complications and was hospitalized only three times with upper respiratory tract infections for 7 years. We report a case of a ten days old neonate with PA presenting without severe metabolic acidosis and hyperammonemia who was effectively treated with early aggressive care and conventional methods.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.19 no.4
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• pp.321-327
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• 2009

1,3-butadiene is classified as suspected human carcinogen, group A2(American Conference of Governmental Industrial Hygienists, ACGIH). In Korea, 1,3-butadiene has been used as a raw material; monomer, homopolymer, polybutadiene latex, acrylonitrile-butadiene-styrene(ABS) and styrene-butadiene rubber(SBR), in the petrochemistry and precision chemistry industry. As petrochemistry industry in Korea has been developed, the potential exposure possibility of 1,3-butadiene to workers can be increased. Therefore the purpose of this study is to evaluate airborne 1,3-butadiene concentration and workers' exposure levels in the workplace using 1,3-butadiene. Air samples were collected with 4-tert-butyl catechol(TBC) charcoal tube(100 mg/50 mg) and were analyzed by gas chromatograph/flame ionization detector(GC/FID) according to the Choi's method(2002). Geometric mean (GM) and arithmetic mean (AM) of total 59 workers' exposure concentrations to airborne 1.3-butadiene were 0.042 ppm and 1.51 ppm, respectively. Although most samples were lower than 1ppm, 2 samples(21.5ppm and 33.1ppm as 8hr-TWA) were exceeded the Korean standard(2ppm) over 10 times at the repair process in synthetic rubber and resin manufacture industry. 14 samples(41%) of total 34 short-term air samples were exceeded the Korean standard(10ppm as STEL) of Ministry Labor. 1,3-butadiene concentration(GM) in the synthetic rubber and resin manufacture industry(7.87ppm) was significantly higher than that in the monomer manufacure industry (0.35ppm)(p<0.05). Also in the sampling and repair process, each GM(range) was 1.39ppm(N.D.-469.6ppm) and 7.85ppm(N.D.-410.2ppm). In conclusion, it depends on the industry and process, 1,3-butadiene can be exposed to workers as high concentration for short-term.

• Journal of the Korean Wood Science and Technology
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• v.42 no.6
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• pp.747-757
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• 2014

Since the air contamination by air pollutants from indoor construction materials and daily supplies has been increased in recent decades, the public interest of using environmentally friendly products and improving indoor air quality also attracted much attention. As known as effects of phytoncide, it has been used in construction materials and daily supplies with various method. In this study, hinoki cypress (Chamaecyparis obtusa) was used because of its high contents of phytoncide. The leaves of hinoki cypress (C. obtusa), which generated by pruning, were extracted by steam distillation, and then used as humidification water source. Volatile organic compound (VOC) from C. obtusa were characterized by GC-MS (Gas chromatograph-Mass spectrophotometry) in order to evaluate effects and risks of using C. obtusa extracts. Total 86 types and 116 types of VOC were detected from distilled water (DI water) and C. obtusa extracts, respectively. Aromatic compounds (DI water: 13 types, 53%; C. obtusa extracts: 13 types, 38%) and terpenoids (DI water: 16 types, 23%; C. obtusa extracts: 23 types, 33%) were detected more diverse types and higher amount than other compound categories. No additional aromatic compounds were found from C. obtusa extracts, so C. obtusa extracts did not affect on aromatic compounds emission. However, in terpenoids, total amount of emission from C. obtusa extracts increased to 33% from 23% (DI water) and 7 more types of compounds were found from C. obtusa extracts. Especially, from C. obtusa extracts, terpinen-4-ol was emitted 71 times higher than DI water. During the humidification with C. obtusa extracts, emitted terpenoid compounds were well known for higher anti-bacterial, anti-insect, and anti-septic functions, but also these had anti-hypertensive and anti-cancer activities. Therefore, terpenoids from C. obtusa extracts can help to improve public health by using humidifier.

• Journal of Food Hygiene and Safety
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• v.24 no.4
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• pp.332-337
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• 2009

Most propionic acid is added to food (especially breads) as preservatives and its form is sodium or calcium salt. Most countries admitted propionic acid as food preservatives but a tolerance limit is somewhat different according to countries. Recoveries of the official method for propionates reported as 50.0~60.0%. Accordingly new rapid determination method for propionates was developed using formic acid added sodium chloride (5 g) and ether (formic acid : ether = 1 : 2) as the extraction solvent to improve the official method with the complex processes. Propionate was dissolved from the samples with formic acid omitting steam distillation and ion exchange procedure. Then propionate in formic acid was extracted with ether and sodium chloride again. A $1\;{\mu}l$ aliquot of the filtrate of ether was analyzed by gas chromatograph. Recoveries from sample A and B fortified with propionic acid sodium salt were 85.0 % and 90.0 %, respectively.

• Applied Biological Chemistry
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• v.42 no.2
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• pp.111-115
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• 1999

This study was attempted to develop technique of masking the pungent odor of chonggugjang using two-stage fermentation method with mixed pure cultures. Cooked soybeans were fermented with Lactobacilli or Aspergillus oryzae at $38^{\circ}C$ for 36 hrs, and then re-fermented with Bacillus subtilis for 12 hrs. The volatile compounds of chonggugjang were obtained with a SDE(Simultaneous steam Distillation and solvent Extraction) system and the extracts were identified by GC and GC-MS. The experimental results revealed the presence of 35 volatile compounds in control chonggugjang(only Bacillus subtilis inoculation). Among them, the major volatile compounds were 2,5-dimethyl pyrazine, 2,3,5-trimethyl pyrazine and 2-methyl pyrazine. Twenty-nine kinds of volatile compounds were in chonggugjang prepared by two-stage fermentation method with Lactobacilli and Bacillus subtilis(II), and major volatile compounds were identified to be 2,3,5-trimethyl pyrazine and 2,5-dimethyl Pyrazine. In chonggugjang(Asp. oryzae and then Bacillus subtilis inoculation(III)), the contents of hexadecanoic acid and 2-methyl pyrazine were patricularly high and the main components of chonggugjang fermented with rice straw(IV) were 2,5-dimethyl pyrazine, 2,3,5-trimethyl pyrazine etc. In conclusion, the flavor compounds such as 2, 5-dimethyl pyrazine, 2,3,5-trimethyl pyrazine and 2-methyl pyrazine were increased by the inoculation of Lactobacilli or Asp. oryzae, where as unpleasant odor components-butyric acid and valeric acid were decreased. Compared with volatile compounds of chonggugjang made from different soybean cultivars, the flavor compounds (2-methyl pyrazine 2,5-dimethyl pyrazine 2,6-dimethyl pyrazine 2,3-dimethyl pyrazine 2-acetyl pyrazine 2,3,5-trimethyl pyrazine 2-ethyl-3,5-dimethyl pyrazine) of chonggugiang prepared with Sinpaldalkong were high.

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

• Applied Chemistry for Engineering
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• v.17 no.6
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• pp.638-643
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• 2006

Pyrolytic reaction study of dichloromethane ($CH_{2}Cl_{2}$) in excess hydrogen was performed to investigate pyrolytic reaction pathways at a pressure of 1 atm with residence times of 0.3~2.0 sec in the temperature range of $525{\sim}900^{\circ}C$. A constant feed molar ratio $CH_{2}Cl_{2}$:$H_{2}$ of 4:96 was maintained through the experiment. Reagent loss and product formation were monitored by using an on-line gas chromatograph, where batch samples were analyzed by GC/MS. Complete destruction(99%) of the parent reagent was observed at temperature near $780^{\circ}C$ with residence time over 1 sec. Major products observed were $CH_{3}Cl$, $CH_{4}$, $C_{2}H_{4}$, $C_{2}H_{6}$, and HCl. Minor products included $CHClCCl_{2}$, CHClCHCl, $CH_{2}CHCl$, and $C_{2}H_{2}$. The pyrolytic reaction pathways to describe the important features of intermediate product distributions and reagent loss, based upon thermodynamic and kinetic principles, were suggested. The results of this work provided a better understanding of pyrolytic decomposition processes which occur during the pyrolysis of $CH_{2}Cl_{2}$ and similar chlorinated methanes.

• Korean Journal of Food Science and Technology
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• v.21 no.6
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• pp.795-799
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• 1989

This study was carried out to hydrolyze lactose in commercial milk by ${\beta}-galactosidase$ from Kluyveromyces fragilis and to compare some physicochemical properties of yoghurts made from control and lactase-treated commercial milks. Quantitative analysis of sugars was performed by gas liquid chromatograph (GLC) on trimethylsilyl (TMS) derivatives. In commercial milk, 94.6% of lactose was hydrolyzed after 2 hours incubation at $40^{\circ}C$ with 6.0 units/ml of ${\beta}-galactosidase$. pH, titratable acidity and viable cell number of yoghurt made from lactase-hydrolyzed (LH) commercial milk were 4.1, 1.04% and $6.5{\times}10^8/ml$ of Str. thermophilus, $8.9{\times}10^8/ml$ of L. bulgaricus after 8 hours incubation at $40^{\circ}C$, respectively, The total contents of amino acid were 2.63% in control and 2.19%. in LH yoghurt. The total contents of free amino acid were 26.95 mg% in control and 17.55mg% in LH yoghurt. Analysis of free fatty acids resulted in that the contents of short chain fatty acids in LH yoghurt were a little higher than those in control. Both in control and LH yoghurt, the palmitic acid content was highest and that was followed by oleic and myristic acid.

• Korean Journal of Plant Resources
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• v.26 no.5
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• pp.539-547
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• 2013

This study investigates the change of chemical components, antioxidant and antimutagenic activity in Glycyrrhiza uralensis Fischer stems and leaves (GU) by the various processing methods, as follows: fresh (GU-1), dried under the shade (GU-2), blanched (GU-3), roasted 3 times (GU-4), roasted 4 times (GU-5). The components have been identified and quantified through the use of gas chromatograph-mass spectrometry (GC-MS). At results, cis-1,3-dimethyl-2-methylenecyclohexaneat at 19.7 min and n-hexadecanoic acid at 21.5 min were detected in five kinds of extract. 3-O-Methyl-D-fructose at 17.8 min was observed in four extracts except in GU-1 and aminopyrazine at 19.8min was observed in four extracts except in GU-4. The total phenolics contents was high in GU-4(3.38 g/100 g). ABTS radical scavenging was high in GU-5($EC_{50}$, 0.57 ug) and DPPH radical scavenging was high in GU-4($EC_{50}$, 2.66 ug). The extracts of GU-3, GU-4, and GU-2 were most potent in anti-mutagenicity activity against 1-NP, Trip-P-1, and Trip-P-2, respectively. GU-3 and GU-4 also showed most potent effect of anti-mutagenicity on 2-AA and AFB1, respectively.