• Journal of Environmental Science International
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• v.12 no.1
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• pp.81-86
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• 2003

The study was carried out to evaluate the new analytical method of phthalate esters(diethylphthalate, di-n-butylphthalate, butylbenzylphthalate, bis(2-ethylhexyl)phthalate), one of the endocrine disruptors, which were performed by GC/MS-SIM(selected ion monitoring). The phthalate esters were extracted from water samples using solid-phase extraction on $C_{18}$ columns. It investigated that the extraction recovery rate of phthalate esters with different solvents and solvent volume. The optimal solvent was dichloromethane and proper volume of dichloromethane for recovery of phthalate esters was 4 mL. There were good linearities(above $R^2$=0.9975) in the range 0.01~0.50mg/L, and the detection limits were below 0.01~0.03$\mu\textrm{g}$/L. The recovery rates, RSD and MDLs for phthalate esters were 80~114%, 5.0~8.1% and 0.03~0.11$\mu\textrm{g}$/L, respectively. This method shows a good precision of phthalate esters.

• Toxicological Research
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• v.4 no.2
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• pp.117-129
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• 1988

A sensitive method for the quantitation of oxandrolone in urine was developed using GC/MS. After oral administration of 10mg oxandrolone, oxandrolone excreted in urine as unchanged form was extracted in ether and derivatized to its O-TMS. Oxandrolone excreted in urine as glucuronide conjugated form was extracted after enzymatic hydrolysis and derivatized to its O-TMS. The amounts of oxandrolone-O-TMS was measured in GC/MS with selected ion monitoring. Calusterone, a structurally similar anabolic steroid, was employed as internal standard.

• Mass Spectrometry Letters
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• v.8 no.3
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• pp.49-52
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• 2017

Ibuprofen is one of the most popular analgesic and antipyretic drugs. An isotope dilution mass spectrometry method based on LC/MS was developed as a candidate reference method for the accurate determination of ibuprofen in pharmaceutical tablets. Isotope labelled ibuprofen, $ibuprofen-d_3$, was added as an internal standard into sample extracts. Ibuprofen and $ibuprofen-d_3$, was analysed by LC/MS in a selected ion monitoring (SIM) mode to detect ions at m/z 205 and 208, respectively. The repeatability and reproducibility of the developed ID-LC/MS method were tested for the validation and assessment of metrological quality of the method.

• Journal of Korean Society for Atmospheric Environment
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• v.18 no.6
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• pp.475-485
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• 2002

An analytical method was investigated for the meaiiurement of polychlorinated biphenyls (PCBs) and organochlorine pesticides (OCPs) concentrations in air samples. Procedures required for column chromatographic clean up. silicagel (stage I) and gel permeation chromatography (stage II), were discussed. Identification and quantification of PCBs and OCPs were performed using a combination of gas chromatography/mass spectrometry/ selected ion monitoring. Recovery tests calculated from six samples are 68∼137% for PCBs and 58∼130% for OCPs except for endrin aldehyde. Instrumental detection limits determined for the PCBs and OCPs varied from 0.05 to 0.18 pg/m3 and from 0.71 to 16.82 pg/㎥, respectively. The method has been applied to the analysis of air samples collected at Ansung city, Kyonggi province, Korea. This method may serve as a screening protocol for the simultaneous determination of PCBs and OCPs in air.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.22 no.2
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• pp.153-160
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• 1996

A novel simple method to detect vitamins in cosmetic products by gas chromatography-mass spectrometry(GC-MS) has been developed. Three vitamins(panthenol, cholecalciferol and tocopherol) were used for this study. Vitamins were prepared by dissolving in tetrahydrofuran(THF), and silylated with bis-trimethylsilyltrifluoroacetamide-trichloromethylsilane(BSTFA). Silated vitamins were separated on a fuses-silica capillary column coated with DB-5. The identification of each vitamin was accomplished by retention time and mass spectrum library search with a computer, and the quantitation was made in the selected-ion monitoring(SIM) mode of GC-MS. SIM mode had given sensitivity to determine 50pg of panthenol, 285pg of cholecalciferol and 130pg of tocopherol. Linearity was maintained over the range 0.005-0.20% for each vitamin. Each cosmetic product(i.e. hair tonic and lotion) was found to contain amounts of the vitamins. This method was sensitive and gave 77.5-99.9% recovery of each vitamin from these cosmetic products. From these results, we concluded that silylation with BSTFA followed by GC-MS analysis allows the simple, covenient and exact determination of panthenol, cholecalciferol and tocopherol.

• Bulletin of the Korean Chemical Society
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• v.29 no.5
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• pp.985-987
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• 2008

Parathion is an organophosphate pesticide being legally applied for the purpose of agriculture and is being manufactured in Korea. A gas chromatography/mass spectrometric method was developed for the determination of parathion urinary metabolite, p-nitrophenol. p-Nitrophenol was extracted from weak acidic urine, and then measured by gas chromatography-mass spectrometry (selected ion monitoring). The recovery of pnitrophenol in the overall procedure was 88.2%. The detection limit of the assay was 1.0 $\mu$ g/L based upon assayed urine of 2.0 mL. The method was applied to the determination of p-nitrophenol in urine of workers of a parathion industry. Spot urines of workers of a parathion industry were sampled at the end of shift and pnitrophenol was analyzed using above developed method. p-Nitrophenol could be detected in all of the urine samples at concentrations varying from 3.0 to 681 $\mu$ g/L.

• Archives of Pharmacal Research
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• v.8 no.4
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• pp.213-220
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• 1985

From olibanum, acetylboswellic acid (I) and boswellic acid (II) were isolated as mixed crystals of $\alpha$-and $\alpha$-forms in the ratio of 1 to 2 and 1 to 4, respectively. And acetyl-11-keto$\beta$-boswellic acid (III) and 11-keto-$\beta$-boswellic acid (IV) were also isolated and their $\alpha$-forms were not found in olibanum by GC/selected ion monitoring MS technique. Contents of four compounds were determined.

• Archives of Pharmacal Research
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• v.19 no.6
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• pp.566-569
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• 1996

A sensitivity method has been developed for the detection and determination of niflmic acid(NA) in human urine. Samples were extracted with diethylether. Flunixin (FN) was added to the sample prior to extraction as an internal standard. Niflumic acid was converted to its methyl derivative and analyzed by capillary gas chromatography/negative chemical isonization mass spectrometry. Using selected ion monitoring (SIM), the levels of NA down to 5 pg/ml could be detected in 5 ml spiked urine sample. Calibration curve was linear over the range of 0.5 ppm-50 ppm. The recovery of niflumic acid from urine at 40 pg/ml was to be $91.7{\pm}3.8(n=3)$ and the coefficient of variation was 4.1%.

• Preventive Nutrition and Food Science
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• v.4 no.4
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• pp.270-275
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• 1999

Radiation-induced hydrocarbons and 2-alkylcyclobutanones are formed from the fatty acids of irradiated fats. Peanuts were irradiated with a dose of 0.1∼10 kGy. The method consists of the extraction of fat from peanuts, separation of hydrocarbons and 2-alkylcyclobutanones with florisil column chromatography and identification of hydrocarbons by the GC/MS method and 2-alkylcyclobutanones by GC/MS/selected ion monitoring (SIM). Concentrations of hydrocarbons and 2-alkylcyclobutanones were linearly increased with the dose levels of radiation. The major hydrocarbons in the irradiated peanut samples were 8-heptadecene and 1,7-hexadecadiene from oleic acid and 6,9-heptadecadiene and 1,7,10-hexadecatriene from linoleic acid. 2-(5'-Tetradecenyl)cyclobutanone, one of 2-alkylcyclobutanones, was the highest amount in the irradiated peanuts. Radiation-induced hydrocarbons in the peanuts were detected at doses of 0.5 kGy and over, and radation-induced 2-alkylcyclobutanones were detected at doses of 1 kGy and over. These compounds were not confirmed in unirradiate peanuts.

• Proceedings of the PSK Conference
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• 2002.10a
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• pp.395.2-395.2
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• 2002

The determination method for 11 corticosteroids (betamethasone, cortisol. cortisone, cortisone acetate. dexamethasone. cortisol acetate, isoflupredone acetate, methylprednisolone. prednisone, prednisolone, and triamcinolone acetonide) in a herbal medicinal preparation (Sibjeondaibotang) by a gas chromatography-mass spectrometric (GC-MS) method with selected ion monitoring (SIM) mode is described. Samples (4 mL) were extracted by liquid-liquid extraction with diethyl ether. (omitted)