• Journal of the Korean Society of Tobacco Science
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• v.36 no.1
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• pp.12-19
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• 2014

A matrix solid-phase dispersion (MSPD) method was developed for extracting and cleaning-up the selected agrochemicals in tobacco using gas chromatography-mass spectrometry with selected ion monitoring (GC/MS-SIM). Different parameters of the method were investigated and optimized, such as the type of solid-phase (alumina, $C_{18}$ and Florisil) and eluent (acetone, acetonitrile, ethylacetate and n-hexane). The best results were obtained using 0.5 g of tobacco sample, 1.0 g of $C_{18}$ as dispersant sorbent, 1.0 g of Florisil as clean-up sorbent and acetonitile saturated with n-hexane as eluting solvent. The method was validated using tobacco samples fortified with agrochemicals at their different concentration levels. This method gave good linearity for the selected agrochemicals of ranging from $0.01{\mu}g/mL$ to $0.1{\mu}g/mL$. Recoveries of the selected agrochemicals in tobacco were more than 80 % and reproducibilities were found to be better than 10 % RSD. Those results suggested that the analytical procedure including MSPD method in combining with GC/MS could be applicable to the rapid determination often the selected agrochemicals in tobacco.

• Analytical Science and Technology
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• v.32 no.3
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• pp.88-95
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• 2019

This study was conducted to establish the analytical method for the determination of cyanide in blood, urine, lung and skin tissues in rats. In order to detect or quantify the sodium cyanide in above biological matrixes, it was derivatized to Pentafluorobenzyl cyanide (PFB-CN) using pentafluorobenzyl bromide (PFB-Br) and then reaction substance was analyzed using gas chromatography mass spectrometer (GC/MS)-SIM (selected ion monitoring) mode. The analytical method for cyanide determination was validated with respect to parameters such as selectivity, system suitability, linearity, accuracy and precision. No interference peak was observed for the determination of cyanide in blank samples, zero samples and lower limit of quantification (LLOQ) samples. The lowest limit detection (LOD) for cyanide was $10{\mu}M$. The linear dynamic range was from 10 to $200{\mu}M$ for cyanide with correlation coefficients higher than 0.99. For quality control samples at four different concentrations including LLOQ that were analyzed in quintuplicate, on six separate occasions, the accuracy and precision range from -14.1 % to 14.5% and 2.7 % to 18.3 %, respectively. The GC/MS-based method of analysis established in this study could be applied to the toxicokinetic study of cyanide on biological matrix substrates such as blood, urine, lung and skin tissues.

• Korean Journal of Environmental Agriculture
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• v.34 no.4
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• pp.309-317
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• 2015

BACKGROUND: An analytical method was developed using GC-ECD/MS to precisely determine the residue of fipronil, a phenylpyrazole insecticide used to control a wide range of foliar and soil-borne pests.METHOD AND RESULTS: Fipronil residue was extracted with acetone from representative samples of five raw products which comprised hulled rice, soybean, Kimchi cabbage, green pepper, and apple. The extract was diluted with saline water, and fipronil was partitioned into n-hexane/dichloromethane (20/80, v/v) to remove polar co-extractives in the aqueous phase. Florisil column chromatography was additionally employed for final purification of the extract. Fipronil was separated and quantitated by GC-ECD using a DB-17 capillary column. Accuracy of the proposed method was validated by the recovery from crop samples fortified with fipronil at 3 levels per crop in each triplication.CONCLUSION: Mean recoveries ranged from 86.6% to 106.0% in five representative agricultural commodities. The coefficients of variation were less than 10%. Limit of quantitation of fipronil was 0.004 mg/kg as verified by the recovery experiment. A confirmatory technique using GC/MS with selected-ion monitoring was also provided to clearly identify the suspected residue. Therefore, this analytical method was reproducible and sensitive enough to determine the residue of fipronil in agricultural commodities.

• Proceedings of the PSK Conference
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• 2001.10a
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• pp.288.1-288.1
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• 2001

• Analytical Science and Technology
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• v.8 no.3
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• pp.237-248
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• 1995

The simultaneous analysis of 16 organic pesticides, which are listed as a part of 129 priority pollutants by EPA(Environmental Protection Agency), was performed by GC-ECD(electron capture detector) and GC/MS-SIM(selected ion monitoring). Two extraction procedures from SW-846, sonication extraction and Soxhlet extraction, were somewhat modified and compared as an extraction and concentration method for the analysis of priority pollutants in soil. Accuracy and precision of the methods were reported from the calculation of mean recovery, mean relative standard deviation, and method detection limit.

• Applied Biological Chemistry
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• v.32 no.4
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• pp.350-356
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• 1989

The determinabilities of several lignan compounds by capillary-GC (F1D) were studied. The lignan compounds used were deoxyschizandrin, gomisin N, schizandrin, wuweizisu C, gomisin A, angeloylgomisin H and tigloylgomisin H which were isolated from fruits of Schisandra chinensis BAILLON and identified with GC/MS(EI, 70eV), 1H-NMR(300MHz) and IR. The GC column used was SPB-1 fused silica capillary$(0.25mm\;ID{\times}30m,\;Supelco)$, and the column oven temperature was programmed from $200^{\circ}C$ to $300^{\circ}C$ at the rate of $4^{\circ}C$ per minute. The linearities between concentration and FID response were maintained in $2{\sim}500ppm$ of deoxyschizandrin and wuweizisu C and in $5{\sim}500ppm$ of gomisin N, schizandrin, gomisin A, angeloylgomisin H and tigloylgomisin H. The contents of lignan compounds in fruits of S. chinensis BAILLON produced at Moo-ju area were analyzed by the GC method: the values obtained of schizandrin and gomisin N were 6.5 and 5.9mg/g respectively, and those of gomisin A, wuweizisu C, angeloylgomisin H, deoxyschizandrin and tigloylgomisin H were $0.5{\sim}1.6mg/g$.

• Journal of the East Asian Society of Dietary Life
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• v.16 no.6
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• pp.724-730
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• 2006

Two types of powdered chungkookjang, were prepared by a hot air-drying process, and the freeze-drying, and composition and aroma patterns were examined. The fresh chungkookjang was composed of 53.8% moisture, while the hot air-dried and freeze-dried powdered chungkookjang contained 5.2% moisture, $39.3{\sim}39.4%$ crude protein, $18.6{\sim}18.7%$ crude lipid, $4.7{\sim}5.0%$ crude ash, and $31.7{\sim}32.2%$ carbohydrate. The pH of the each powered chungkookjang was similar, ranging from 6.5 to 6.7. The freeze-dried powdered chungkookjang showed the highest lightness (67.30), yellowness (59.37) while the highest redness (43.1) was observed in the hot air-dried chungkookjang. Each chungkookjang was analysed by an electronic nose with metal oxide 12 sensors and SPME-GC/MS. The response by the electronic nose was analysed by principal component analysis (PCA). The proportion of the first principal component was 90.47%, suggesting that each aroma pattern of the prepared chungkookjang was discriminated. SPME-GC/MS was used to identify the pyrazines. The percentage of pyrazines observed in the fresh chungkookjang, freeze-dried powdered chungkookjang, and hot air-dried powdered chungkookjang was 6.6, 3.8 and 15.9%, respectively. A higher overall preference was obtained from the hot air-dried powdered chungkookjang than with the freeze-dried powdered chungkookjang.

• Analytical Science and Technology
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• v.18 no.6
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• pp.511-519
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• 2005

A method for determination of toluene diisocyanates (TDI) in toluene diisocynate (TDI)-based polyurethane (PUR) packing material was investigated, and also the migration of TDI to food was studied. TDI was extracted using food simulants such as n-haptane and 4% aqueous acetic acid. The determinations were performed using gas chromatography/mass spectrometry (GC/MS). One of major components for polyurethane, toluene diisocyanates, were detected in ten samples among twenty six food contact materials with the concentration range of $0.51{\sim}60.88{\mu}g/ml$. However the highest extracted amount was just 0.7% of $60.88{\mu}g/ml$ if the contact surface of food packing for extracting liquid was limited to the outer layer without exposure of the cutting edge of food packing multi-layers. The result of this study and the analysis method for TDI diisocyanate will be very useful for further study about food contact material, and the monitoring result could be used for evaluating the safety of food contact material before it is to be used for food, preservation.

• 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.

• Journal of the Korean Chemical Society
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• v.41 no.4
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• pp.186-197
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• 1997

Estrogens, which play an important role in sex hormone and potential inhibitor of cancer cell proliferation were profiled for normal female and male. The nineteen endogeneous estrogens were simultaneously analyzed by selected ion monitoring method of GC/MS. Urinary estrogens were extracted by using Serdolit AD-2 resin, hydrolyzed with $\beta-glucuronidase/arylsulfatase$ from Helix pomatia, liquid-liquid extraction and quantitatively derivatized by MSTFA/TMSCl mixture in order to be detected on the GC/MS. The good quality-control data were obtained through the precision and accuracy test and the recovery range of them was 80.97∼97.81%. The Korean reference values of urinary estrogens were established and differences were found in normal female compared with normal male.