• Proceedings of the PSK Conference
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• 2003.04a
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• pp.275.1-275.1
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• 2003

Because people who take more than two drugs have increases, a simple and sensitive method for the simultaneous analysis of amphetamine, methamphetamine and nalbuphine in urine was developed. After alkalinization of the urine samples with 6 N-NaOH, the analytes were extracted using ethyl acetate, derivatized with MSTFA : TSIM : TMCS (= 100 : 2 : 5) prior to gas chromatography-mass spectrometry(GC-MS) analysis with selected ion monitoring. (omitted)

• Proceedings of the PSK Conference
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• 2003.10b
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• pp.112.1-112.1
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• 2003

The qualitative and quantitative analysis of MDMA and MDA in hair samples by GC/MS were reported. Hairs were collected from subjects aged 22-37 years, who were suspected of abusing MDMA. After washing with methanol, hair samples were cut into small pieces, extracted with methanol containing 1 percent hydrochloric acid for 20th, and the solution was evaporated. MDMA or MDA in the extract were determined by GC/MS using selected ion monitoring after derivatization with trifluoroacetic anhydride. (omitted)

• Analytical Science and Technology
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• v.29 no.1
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• pp.49-55
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• 2016

A ketone body (acetoacetic acid, β-hydroxybutyric acid, and acetone) increases from blood or urine when bio-energy dependence pays more fatty acid than glucose. However, in case oxidation of fat is greater than the capacity of the citric acid cycle the fatty acid oxidation is made from acetoacetyl CoA to acetoacetate then, again form β-hydroxyburytic acid to acetone, the diffusion take place into the blood. Enzymes that oxidize ketone body in the brain and nerve tissue blood ketone dody is increased during prolonged fasting, brain used it as energy. In this study, we developed the rapid two step derivatization method for sensitive detection of the ketone body by GC-MS/SIM. The plasma was deproteinized and then the hydroxy and carboxyl groups of ketone body are subjected to extraction and drying then, keto-group were derivatized with hydoxylamine at 60℃ for 30 min for oximation. Then it was trimetyl-silylated with BSTFA at 80℃ for 30 min and analyzed using a GC-MS. The linear ranges were in between 0.001 μg/mL and 250 μg/mL for β-hydroxy butyrate, and acetoacetate. The method detection limits were below 0.1 pg over each target compound determined. The mean recoveries (%) of target compounds were ranged from 88.2 % to 92.3 % at 1 µg/mL, from 89.5 % to 94.8 % at 10 μg/mL, with RSD of 6.3-9.4 %. This method could be applied to quantification of ketone bodies which are seen in the keto-acidosis in children and adults from a variety of diseases that cause ketones in the blood and urine.

• Analytical Science and Technology
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• v.11 no.5
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• pp.374-385
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• 1998

Phytoestrogens are biologically active compounds derived from plants foods. It had been suggested that phytoestrogens, by inhibiting aromatase in peripheral and/or cancer cells and lowering estrogen levels, may play a protective role as antipromotional compounds during growth of estrogen-dependent cancers. Therefore, simultaneous analysis of estrogens and phytoestrogens is necessary to elucidate the possible involvement of phytoestrogens in estrogen metabolism. In this view, we developed a simple and reproducible procedure to quantitatively determine estrogen and phytoestrogen metabolites. The proposed method consisted of solid phase extraction using preconditioned Serdolit AD-2 resin, enzyme hydrolysis with ${\beta}$-glucuronidase/arylsulfatase from Helix pomatia, liquid-liquid extraction and TMS-ether derivatization. And the final determination was carried out by gas chromatography/mass spectrometry (GC/MS) in selected ion monitoring mode (SIM). The precision and accuracy of this method was evaluated through within-a-day and day-to-day test. Recovery range and detection limit were 71.96~105.66%, 2~4 ng/mL, respectively. Using this method, 17 estrogen and 5 phytoestrogen compositions in urine of normal subjects were analyzed. It was found that amounts and relative distribution of urinary phytoestrigens and estrogens showed different pattern in male and female subjects.

• Analytical Science and Technology
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• v.11 no.5
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• pp.353-359
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• 1998

Danazol, one of the IOC banned substances, is a synthetic steroid which stimulates the synthesis of cellular protein with multiple and diverse biologic effects. To confirm the androgenic effects of danazol, levels of eight endogenous steroids and its major metabolite in human urine were simultaneously analyzed by selected ion monitoring (SIM) of GC/MS after oral administration. The recovery range of this method was 71.59%~93.56% and the RSD values of precision and accuracy test were 1.87%~10.48% and 1.32%~11.25%, respectively. The limits of detection of most of the drugs were $0.01{\sim}0.05{\mu}g/mL$ and calibration was carried out using urine spiked with each endogenous steroid and ethisterone standard at a concentration of 0.1, 0.5, 1.0, 10, 20 and $50{\mu}g/mL$ and with $10{\mu}g/mL$ of internal standard. Correlation coefficients varied between 0.963 and 0.991. The endogenous steroid profiling is one of valuatle tool for decteation of anabolic steroids.

• Journal of Environmental Health Sciences
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• v.29 no.2
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• pp.50-55
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• 2003

3,3-dichlorobenzidine is suspected to be cancinogenic in experimental animal and human. Several studies have investigated excretion of metabolites in urine, hemoglobin adduction and cancer incidence among workers occupationally exposed to 3,3'-dichlorobenzidine. In these researches, metabolites of 3,3'-dichlorobenzidine had a very important role, and were required as highly purity. The purpose of this study was synthesis and isolation of its metabolites from 3,3'-dichlorobenzidine. 3,3'-dichlorobenzidine was partially dissolved in benzene, ether, ethanol and methanol, and completely dissolved in 70% acetic acid on mixtures of citric acid containing less than 1% DCB, pyridine, a mixture of 0.5N NaOH and toluene(1:2), and phenol saturated with 20 mM TRIZA base. DCB, monoacetyl-DCB and diacetyl-DCB were measured by using gas chromatography/mass spectrometry(GC/MS). Detection for checking them was nitrogen phosphorous detection mode(NPD), and for identifying them was selected ion monitoring mode(SIM). The base peaks were 252 m/z in DCB, 252, and 294 m/z in monoacetyl-DCB, and 252, 294 and 336 m/z in diacetyl-DCB, respectively. Diacetyl-DCB was synthesized by titrating DCB solution of pyridine with sufficient acetyl chloride. Precipitation was diacetyl-DCB, which was purity of 98.7%. And its supernatant was composed of DCB, monoacetyl-DCB and diacetyl-DCB. By using acetic acid as controller of acetylation, monoacetyl-DCB was isolated from diacetyl-DCB . And residual pyridine was removed by using acetone. The purity of monoacetyl-DCB was 98.8%.

• Journal of Dairy Science and Biotechnology
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• v.33 no.1
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• pp.27-34
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• 2015

The aim of this study was to optimize a simple, fast, and economic analytical method for the simultaneous determination of various pesticides (aldrin, p,p'-DDT, o,p'-DDT, p,p'-DDE, ${\alpha}$-endosulfan, ${\beta}$-endosulfan, dieldrin, heptachlor, permethrin, chlordane, deltamethrin, diazinon, bifenthrin, methoprene, propargite, fenpropathrin, cypermethrin, fenvalerate, and fenpropathrin) in milk by using dispersive solid phase extraction (SPE). In this study, two different extraction methods (low temperature cleanup and liquid-liquid partitioning), which were followed by a cleanup process based on dispersive-SPE, were evaluated and compared for the 19 pesticides. The results for all the pesticides were determined by gas chromatography mass spectrometry (GC/MS) with selected-ion monitoring mode, and the matrix effect of the method was evaluated. Comparison of these approaches yielded higher and more consistent recoveries of most pesticides at fortification levels of $1{\mu}g/mL$ using low-temperature fat precipitation, followed by cleanup process based on dispersive-SPE with PSA and C18 as sorbents, than other preparation process. The relative standard deviation was <20 % and the combination of this method were very effective for the cleanup.

• Journal of Environmental Health Sciences
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• v.28 no.4
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• pp.6-11
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• 2002

3.3'-Dichlorobenzidine(DCB) has be shown carcinogenic in several animals, and the development of non-invasive biomonitoring method in workers exposed with it is a very important subject. DNA adduct is a good biomarker for biomonitoring about carcinogens exposure, and lymphocytes is a good non-invasive samples. So we studied to analyze metabolites in blood lymphocytes of female Sprague-Dawley rats exposed orally with DCB(20, 30, and 40 mg/kg wt.) for 3 weeks. For analysis of them, we isolated DNA adducts from blood lymphocytes by using the enzymes method in /sup 32/P-postlabeling, and measured them by using gas chromatography/mass spectrometry-selected ion monitoring(GC/MS-SIM). 4-aminobiphenyl and phenanthrene-d/sub 10/ were added as internal standard for blank sample. Standard metabolites of DCB were synthesized with using pyridine and acetic acid which were promoter and controller in acetylation of DCB. And they were used for calibration curve. Our results showed two kinds of metabolites in DNA adducts of blood lymphocytes. They were N-acetyl 3,3'-dichlorobenzidine(acDCB) and N,N'-diacetyl 3,3'-dichiorobenzidine(di-acDCB ). They were combined with DNA at the same time as an acetyl of it was removed. So we measured DCB and acDCB for two kinds of metabolites in DNA adducts of blood lymphocytes. Our results showed the levels of DCB were 1.46∼2.26 times more than that of acDCB. And also the levels of metabolites in 20, 30 and 40 mg/kg wt. were gradually increased with going days from 1st to 3rd week. They are 1.66, 1.38 and 0.90 times in total metabolites, 1.76, 1.49 and 1.02 times in DCB, and 1.51, 1.22 and 1.28 times in acDCB. In conclusion, the results of this study showed DCB exposed to rats formed DNA adduct in blood lymphocytes after acetylated to N-acetyl 3.3'-dichloro benzidine(acDCB) and N,N'-diacetyl 3,3'-dichlorobenzidine(di-acDCB), and they could be analyzed by us ing gas chromatography/mass spectrometry-selected ion monitoring(GC/MS-SIM).

• Analytical Science and Technology
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• v.15 no.3
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• pp.196-213
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• 2002

The alkylphenols, chlorophenols and bisphenol A were determined by gas chromatography/mass spectrometry-selected ion monitoring mode followed by three work-up methods for comparison; EPA method, isoBOC derivatization method and TBDMS derivatization method. Eleven phenols in water samples were extracted with dichloromethane. Also, solid-phase extraction (SPE) with XAD-4 and subsequent conversion to isobutoxycarbonyl derivatives or tert.-butyldimethylsilyl derivatives for sensitive analysis with the selected ion-monitoring (SIM) mode. The recoveries were 85.1~109.9% (EPA method) and 90.3~126.6% (isoBOC derivatization and TBDMS derivatization), respectively. The method detection limit of bisphenol A for SIM were 0.732 ${\mu}g/{\ell}$ (EPA method), 0.002 ${\mu}g/{\ell}$ (isoBOC derivatization) and 0.021 ${\mu}g/{\ell}$ (TBDMS derivatization). The SIM responses were linear with the correlation coefficient varying 0.9755~0.9981 (isoBOC derivatization), and 0.9908~0.9996 (TBDMS derivatization). When these methods were applied to treated wastewater sample from a polyethylene plant, the concentrations of 11 phenols were below the method detection limit.

• Analytical Science and Technology
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• v.21 no.6
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• pp.518-525
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• 2008

Mandipropamid is a new mandelamide-type fungicide to control foliar Oomycete pathogens in some vegetables. An analytical method was developed to determine mandipropamid residues in agricultural commodities using high-performance liquid chromatography (HPLC) and liquid chromatography/mass spectrometry (LC/MS). Mandipropamid was extracted with methanol from grape, tomato, green pepper, Chinese cabbage and potato samples. The extract was diluted with saturated sodium chloride solution and distilled water, and dichloromethane partition was followed to recover the mandipropamid from the aqueous phase. Florisil column chromatography was employed to further remove interfering co-extractives prior to HPLC analysis. Reverse-phased HPLC was successfully applied to determine mandipropamid in sample extracts with the detection at its ${\lambda}_{max}$ (223 nm). Overall recoveries of mandipropamid from fortified samples averaged $99.8{\pm}1.7$ (n=6), $89.3{\pm}5.3$ (n=6), $98.7{\pm}2.2$ (n=6), $99.7{\pm}6.8$ (n=6) and $91.1{\pm}3.1$ (n=6) for grape, tomato, green pepper, Chinese cabbage and potato, respectively. Limit of quantification of the method was 0.02~0.04 mg/kg for all samples. A LC/mass spectrometry with selected-ion monitoring was also provided to confirm the suspected residue. The proposed method was reproducible and sensitive enough to determine the terminal residue of mandipropamid in agricultural commodities.