• YAKHAK HOEJI
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• v.29 no.5
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• pp.227-233
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• 1985

A new method of determination of fatty acid using gas chromatography-flame photometric detector (GC-FPD) is described. Fatty acid was methylthiomethyl-esterified with methylthiomethy chloride in 1,8-diazabicyclo [5,4,0]-undec-7-ene catalyst and its concentration measured by GC-FPD with 3%OV-1 or 3% FS-1 column. The FPD responses of thirteen fatty acid methylthiomethyl esters were examined and were proportional to the concentration of the esters without regard to their chemical structures. Consequently it was possible to determine various fatty acid using one standard calibration curve by GC-FPD. We could rapidly and conveniently determine varous fatty acids using one standard calibration curve by GC-FPD. We could rapidly and conveniently determine 13 fatty acids in Ginseng Radix alba by this method.

• Journal of the Korean Chemical Society
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• v.43 no.6
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• pp.663-669
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• 1999

For determination of separated pesticides by using GC and HPLC, liquid-liquid extraction(LLE) and solid phase extraction(SPE) have been carried out to separate and concentrate the organophophorous pesticides such as Diazinon, Fenitrothion, Phosmet, Phosalon and EPN in environmental water samples. ln determination of pesticides by HPLC/UV, SPE has resulted in higher recovery and more precision than LLE, while in determination of pesticides by GC/FPD, vice versa. HPLC/UV after the pretreatment process of sample by solid phase extraction (SPE-HPLC/UV) has suggested the possibility of determination of pesticides ppb level. ln comparison of detection limit, both SPE-HPLC/UV and LLE-GC/FPD are reasonably suitable for analysis of residue pesticides. ln the respect of the rapidity and the solvent required, SPE-HPLC/UV method has proven to be superior to LLE-GC/FPD.

• YAKHAK HOEJI
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• v.28 no.1
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• pp.25-27
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• 1984

Some $\betha$-lactam antibiotics-penicillins and cephalosporins-were determined by gas chromatography (GC) with flame photometric detector (FPD) which was selective and sensitive to sulfur-containing compounds. Methyl ester derivatives of carboxyl group in $\betha$-lactam antibiotics were prepared using 0.5Mmethyl iodide in methylene chloride and were taken for gas chromatography with 0.9% or 0.6% QF-1 on Chromosorb WAW-DMCS. We have found that it is possible to determine methyl esters of $\betha$-lactam antibiotics by GC/FPD.

• YAKHAK HOEJI
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• v.30 no.4
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• pp.180-184
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• 1986

Such carboxyl drugs as mefenamic acid, alclofenac, ketoprofen, cicloxilic acid and tolfenainic acid in rat plasma were determined by the gas chromatography flame photometric detector (GC-FPD). After methylthiomethyl (MTM) esterification with MTM-chloride in 1, 8-diazabicyclo [5.4.0] undec-7-ene (DBU) catalyst, determination of these drugs by this method was tried and compared with that by the GC-flame ionization detector (FID) method in respect to sensitivity and effect of inteferences. The results showed it was possible to analyze with accuracy by this method because of specificity of the FPD, although these drugs were not separated from interferences in plasma on GC column. The GC-FPD method was more sensitive than GC-FID method and the minimum detectable amount of monocarboxylic drugs on 3%, QF-1 column was about 15fmol/injection.

• Analytical Science and Technology
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• v.14 no.3
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• pp.274-285
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• 2001

In this study, the thermal desorption-cryofocusing-gas chromatographic(TD-C-GC) method was developed for determination of volatile organic compounds(VOCs) in ambient air and was applied at the municipal solid waste landfill sites. On-column cryofocusing was possible only with a 100 ml dewars bottle in TD-C-GC method with a stainless steel column. However, high operating pressure was needed for purging VOCs from the absorbent trap, which was able to solve by pressure programming with a electric pressure controller. By using both pressure and temperature programming brought increasing of resolution power in on-column cryofocusing method, but the high pressure caused a leakage of sample tube with repeated use. A loop cryofocusing devise was also developed and compared with the direct on-column method. In loop cryofocusing method, VOCs were concentrated on a 0.8mm i.d. loop which is located between the injector and separation column by using liquid nitrogen. In order to purge VOCs from the absorbent trap, only 0.4 psi of pressure was need in the loop cryofocusing method. Dual detection system was applied for the analysis of VOCs; a FID was used for hydrocarbons and a FPD was used for sulfur-containing compounds. Qualitative analysis was done by on-column cryofocusing GC-MS system. Among the large number of VOCs, toluene was the most abundant. Hydrogen sulfide, dimethyl sulfide, carbon disulfide, dimethyl disulfide and methyl propyl disulfide were detected at landfill site by FPD.

• Journal of the Korean GEO-environmental Society
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• v.10 no.2
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• pp.37-43
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• 2009

With the economic development of Korea, sewage treatment facilities and waste food treatment facilities have been steadily increased. These facilities have positive effects such as the conservation of the water resources quality and waste food recycling while they also affect the neighborhood life with severe odor problems. Therefore, it was first collected sludge samples from 5 sewage treatment facilities and 5 waste food treatment facilities where the amounts of waste produced from above sites are relatively immense in Busan and estimate the $H_2S$ emission rates. Then it was selected 1 sample which has the highest emission rate of $H_2S$. Using flux chamber and GC/FPD analyses, it was tried to quantify the emitted amount of sulfonic gas concentration under anoxic condition. The sludge sample obtained from Noksan sewage treatment facility has the highest emission rate of $H_2S$. This sample contained 156.18 mg/kg $H_2S$. The odor compounds were analyzed using GC/FPD and the concentrations were converted to odor quotient. Among odor compounds the ratio of $CH_3SH$ (methylmercaptan) for the total odor quotient was 47.3% and considered to be the main odor compound in the sample.

• Journal of Korean Society for Atmospheric Environment
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• v.13 no.5
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• pp.355-360
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• 1997

The atmospheric concentration of dimethylsulfide (DMS), known as the predominant volatile organic. sulfur compound, is determined at subnanogram level by a combined application of non-cryogenic preconcentration method and gas chromatography with flame photometric detection (GC/FPD). The volatile DMS in air is preconcentrated using a trapping tube containing adsorbent like Molecular Sieve 5A (or gold-coated sands). The tube is then connected to the GC/FPD system via a six-way rotary valve, thermally desorbed at 40$0^{\circ}C$, separated on OV101 column, and detected by a flame photometric detector. The DMS peak elutes at about 2.5 mins and is integrated electronically. The analytical precision, if expressed in terms of relative standard error, is around 5%. The detection limit of our GC/FPD system is ca 1 ng of DMS. Details of our analytical system are presented.

• YAKHAK HOEJI
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• v.30 no.5
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• pp.214-219
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• 1986

A gas chromatographic procedure is described for the quantitative analysis of ephedrine hydrochloride, pseudoephediiiie hydrochloride and norephedrine hydrochloride in pharmaceutical preparations. The procedure was based upon the determination of thioureas formed from amines and phenylisothiocyanate. The recoveries of ephedrine, pseudoephedrine and norephedrine from pharmaceutical preparations were 100.7(S.E. 0.9), 99.5(0.8), 99.1(0.8) and 99.1%(O.9), respectively. The high accuracy and precision of this assay were inherent in the flame photometric detectors normally used in gas chromatography.

• Analytical Science and Technology
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• v.16 no.3
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• pp.240-248
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• 2003

Sulfur compounds which are well-known odor-active compounds in industrial area have very low detection threshold values. Trace amounts of volatile sulfur compounds in enviroment air around several odor sources were concentrated in liquid argon bath and determined by gas chromatograph with flame photometric detector (FPD) which exhibits very good selectivity and sensitivity. 25% ${\beta}$,${\beta}$-Oxydipropionitrile on 60/80 Chromosorb W was used as adsorbent for the preconcentration of sulfur compounds in air sample and also as packing material for a packed glass column. Concentration volume of air sample was different from place to place in the range of 0.1~3.0L. Atmospheric concentrations of sulfur compounds in air of residential districts and boundaries of business establishments, and also those in the exhausted gases of emission points such as a sewage disposal plant in industrial area were measured.

• Analytical Science and Technology
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• v.7 no.3
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• pp.349-359
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• 1994

A gas chromatographic method for analyzing the gas odorants concentration in natural gas was studied. Eight odorants involving TBM and THT were completely separated by using OV-10 column. The optimization of several interrelated key parameters affecting the response of FPD such as hydrogen flow rate, air flow rate and detector temperature were accomplished. A permeation device was used to obtain calibration curves of TBM and THT. This analytical method has applied to measure TBM and THT used as a natural gas odorant blend in natural gas pipeline. In order to elucidate the relationship between odor level and odorant level feasibility test of fragrance meter was demonstrated.