• Journal of Food Hygiene and Safety
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• v.21 no.2
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• pp.47-51
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• 2006

The formed acrylamide in many fried and baked starchy foods is in consequence of its formation during frying and preparation methods. Being acrylamide established to be a toxic substance, the implications to public health from amounts found in food are not clear. So this study was carried out to investigate the contents of acrylamide of French fries and snacks in addition to acrylamide formation in relation to water and lipid in foods. The raw materials of foods used in the experiments were wheat, potato, com and rice. The preparation of foods was modified in a little to raise the recovery ratio and contents of water and lipid were analyzed to the public food method. The contents of acrylamide were measured by the liquid chromatography tandem mass spectrometry. The average level of acrylamide produced in snacks is $236{\pm}322$ ppb and potato snacks came out the highest value at $521{\pm}403$ ppb in 104 snacks. The formation of acrylamide in fried food was found to depends on the composition of raw material not on water and lipid contents in food and not on storage period and temperature.

• Journal of Environmental Health Sciences
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• v.40 no.2
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• pp.114-126
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• 2014

Objectives: We aimed to develop a measurement method of five metabolites of trichloroethylene (TCE) in a concurrent biological sample, e.g., trichloroacetic acid (TCA), dichloroacetic acid (DCA), S-(1,2-dichlorovinyl) glutathione (DCVG), S-(1,2-dichlorovinyl)-L-cysteine (DCVC), and N-Acetyl-S-(1,2-dichlorovinyl)-L-cysteine (NAcDCVC) and to validate the method before application to pharmacokinetic study. Methods: TCE metabolites were simultaneously analyzed using high performance liquid chromatography coupled with electrospray ionization mass spectrometry (HPLC-ESI-MS/MS) with as little as 50 ${\mu}L$ of serum and urine. DCA, TCA and NAcDCVC were extracted with diethyl ether, while DCVC and DCVG were extracted by solid phase extraction. This method was validated according to the guidelines for bioanalytical method validation of the Korean National Institute of Toxicological Research. Then, we determined the five metabolites in five strains of mice at 24 hr after exposure to 1 g TCE /kg body weight. Results: The limits of detection for the five metabolites in biological samples ranged from 0.001 to 0.076 nmol/mL, which is comparable to or better than those previously reported. Most calibration curves showed good linearity ($R^2=0.99$), and between-batch variation was less than 20% expressing acceptable robustness and reproducibility. Using this method, we found TCA and DCA were detected in all test mice at 24 hr after the oral administration while NAcDCVC and DCVC were detected in some strains, which showed strain-dependent metabolism of TCE. Conclusions: The present method could provide robust and accurate measurements of major key metabolites of TCE in biological media, which allowed concurrent analysis of TCE metabolism for limited amounts of biospecimens.

• Korean Journal of Food Science and Technology
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• v.43 no.6
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• pp.675-682
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• 2011

This study was conducted to monitor the concentrations of 24 anti-impotence drugs and their analogues in various foods and dietary supplements, with the aim of ensuring the safety of the foods and supplements. The measurements were done in 226 samples using high performance liquid chromatography/photodiode array detector (HPLC/PDA) and liquid chromatography-electrospray ionization tandem mass spectrometry (LC-ESI-MS/MS). Five male sexual function enhancing products have been detected as follows: acethylvardenafil (21,476 mg/kg; 15 mg/capsule from one sample), sildenafil (52,778 mg/kg, 29 mg/capsule in one sample; 71,535 mg/kg, 48 mg/capsule in one sample), and tadalafil (9,772-55,545 mg/kg, 6-33 mg/capsule in four samples). A sustainable monitoring of anti-impotence drugs and their analogues in various foods and dietary supplement is recommended.

• Food Science and Preservation
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• v.12 no.4
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• pp.350-354
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• 2005

It was carried out for development of natural antimicrobial on Scutellariae Radix by measuring the general nutritional composition and mineral contents. This study analyzed it with LC-MS to identify antimicrobial activity substance in the Scutellariae Radix extract, its content was analyzed using HPLC. The searching substance was examined antimicrobial activity by disk method. The approximate composition of Scutellariae Radix was $8.93\%$ of moisture, $4.13\%$ of crude ash, $15.30\%$ of crude protein, $3.71\%$ of crude fat, $67.93\%$ of carbohydrate, respectively. Scutellariae Radix was contained high contents of minerals such as K(12,050 mg/kg),. Mg(4,295 mg/kg), remarkably. It was identified that molecular weight 445' peak was baicalin, molecular weight 283' peak was wogonin and molecular weight 269' peak was baicalein on Scutellariae Radix extract Baicalin showed remarkable antimicrobial activity against V. parahaemolyticus and L monocytogenes when examined by disk method, which was estimated antimicrobial activity substance in the Scutellariae Radix extract. The content of baicalin was $0.75\%$(with D.W.) and $0.82\%$(with methanol) in the Scutellariae Radix extract using HPLC.

• Journal of the Korean Chemical Society
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• v.54 no.5
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• pp.523-532
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• 2010

The proposed method is simple, sensitive and specific Liquid chromatography-tandem mass spectrometry (LCESI-MS/MS) method for the quantification of Entacapone (EA) in human plasma using Entacapone-d10 (EAD10) as an internal standard (IS). Chromatographic separation was performed on Zorbax SB-C18, $2.1{\times}50\;mm$, $5\;{\mu}m$ column, mobile phase composed of 10 mM Ammonium formate (pH 3.0): Acetonitrile (60:40 v/v), with a flow-rate of 0.7 mL/min, followed by Liquid-liquid extraction. EA and EAD10 were detected with proton adducts at m/z $306.1{\rightarrow}233.1$ and $316.3{\rightarrow}233.0$ in multiple reaction monitoring (MRM) positive mode respectively. The method was validated over a linear concentration range of 1.00 - 2000.00 ng/mL with correlation coefficient ($r^2$) $\geq$ 0.9993. Intra and inter-day Precision within 3.60 to 7.30 and 4.20 to 5.50% and Accuracy within 97.30 to 104.20 and 98.30 to 105.80% proved for EA. This method is successfully applied in the bioequivalence study of healthy Indian human volunteers.

• Journal of Microbiology and Biotechnology
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• v.21 no.4
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• pp.421-429
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• 2011

For precise identification of a Lactobacillus K1 isolate, LC-MS/MS analysis of the putative surface layer protein was performed. The results obtained from LTQ-FT-ICR mass spectrometry confirmed that the analyzed protein spot is the surface layer protein originating from Lb. helveticus species. Moreover, the identified protein has the highest similarity with the surface layer protein from Lb. helveticus R0052. To evaluate the proteomic study, multilocus sequence analysis of selected housekeeping gene sequences was performed. Combination of 16S rRNA sequencing with partial sequences for the genes encoding the RNA polymerase alpha subunit (rpoA), phenylalanyl-tRNA synthase alpha subunit (pheS), translational elongation factor Tu (tuf), and Hsp60 chaperonins (groEL) also allowed to classify the analyzed isolate as Lb. helveticus. Further classification at the strain level was achieved by sequencing of the slp gene. This gene showed 99.8% identity with the corresponding slp gene of Lb. helveticus R0052, which is in good agreement with data obtained by nano-HPLC coupled to an LTQ-FT-ICR mass spectrometer. Finally, LC-MS/MS analysis of surface layer proteins extracted from three other Lactobacillus strains proved that the proposed method is the appropriate molecular tool for the identification of S-layer-possessing lactobacilli at the species and even strain levels.

• Analytical Science and Technology
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• v.23 no.4
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• pp.405-413
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• 2010

A new method for the simultaneous determination of six glucocorticoids (betamethasone, dexamethasone, prednisone, prednisolone, methylprednisolone, and flumethasone) in meats (bovine muscle, bovine liver) were established. Samples were effectively extracted using C18 cartridge with ethylacetate. Chromatographic separation was achieved using C18 column and negative electrospray ionization mass spectrometry was performed in the Multiple Reaction Monitoring mode for the effective quantitation and qualification of glucocorticoids. Acetonitrile and water (0.1% formic acid) were used as mobile phase and additive for effective electrospray ionization, and gave good chromatographic separation and mass spectrometric sensitivity. The limit of detection (LODs) and the limit of quantitation (LOQs) in spiked blank samples depending on types of matrix and pharmaceuticals were ranged from 0.2 to $1.0\;{\mu}g$/kg and 0.8 to $3.4\;{\mu}g$/kg, respectively. And the recoveries were between 89.5 to 119.6%. The established method showed good recoveries, accuracies, precisions and fast sample preparation and it will be applied to assay of glucocorticoids residues in meat.

• YAKHAK HOEJI
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• v.60 no.3
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• pp.112-117
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• 2016

A liquid chromatography-tandem mass spectrometry (LC-MS/MS) method was developed and validated for the determination of caffeine in forensic aqueous sample. The centrifuged sample ($100{\mu}l$) was diluted 50-fold with distilled water. The diluted sample ($400{\mu}l$) was then diluted further with $200{\mu}l$ of 0.1% formic acid solution and $400{\mu}l$ of acetonitrile containing 500 ng of caffeine-(3-methyl-$^{13}C_3$) prior to LC-MS/MS analysis. The mobile phase was composed of 0.1% formic acid in distilled water (A) and acetonitrile (B). Chromatographic separation was performed by using a Zorbax SB-C18 ($100mm{\times}2.1mm$ i.d., $3.5{\mu}m$) column and caffeine was eluted within 1.1 min. Linear least-squares regression with a 1/x weighting factor was used to generate a calibration curve with the coefficients of determination ($r^2=0.9983$). The lower limit of quantification was $25ng/ml$ for the analyte. The process efficiency was 98.6~100.1%. Intra- and inter-day precisions were not more than 2.1% and 1.7%, while intra- and inter-day accuracies were ranged from -6.8 to 4.5%, respectively. The suitability of the method was examined by analyzing unknown forensic aqueous samples.

• Analytical Science and Technology
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• v.22 no.1
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• pp.65-74
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• 2009

Active components of lacquer tree referred to as urushiol congeners, which are catechol derivatives with various alkyl or alkenyl substituents. The olefin side chains typically have one, two or three double bonds. In this study, the each congener's ratio analysis of extracts from korean lacquer tree are compared to the one from other asian lacquer tree. Extraction was performed using liquid-liquid extraction (LLE) method with soxhlet system from tree's bark and sap. Extracts were analyzed by reverse phase liquid chromatography and on-line electro spray ionization mass spectrometry (LC-MS/MS).

• Herbal Formula Science
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• v.32 no.3
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• pp.223-233
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• 2024

Objectives : Natural products containing bioactive compounds with high antioxidant activity are potentially important sources that can contribute to the improvement of various diseases. Therefore, the aim of this study was to investigate phenolic compounds of Cinnamomum cassia (C. cassia) ethanolic extract (CCEE). And then we evaluated the antioxidant effect. Methods : We used liquid chromatography with tandem mass spectrometry (LC-MS/MS) to identify the compounds in CCEE. LC-MS/MS was performed in positive ion mode using Shimadzu, Nexera HPLC system and IDA TOF mass system. Solvent A was distilled water and solvent B was acetonitrile as mobile phase. The analysis was performed at a flow rate of 0.5 ml/min, column temperature of 35 ℃ and wavelength of 284 nm. The antioxidant effect of CCEE was analyzed using DPPH (2,2-diphenyl-2-picrylhydrazyl free radical) and ABTS (2,2'-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid)). In addition, total phenolics and total flavonoids contents were measured to determine antioxidant effects. Results : Analysis using LC-MS/MS identified four compounds: Coumarin, Trans-cinnamaldehyde, Trans-cinnamic acid, and 2-Methoxycinnamaldehyde. Free radicals decreased in a concentration-dependent manner starting from 10 ㎍/ml of CCEE, and decreased to a level similar to Ascorbic acid (AA) from a concentration of 60 ㎍/ml onwards. Conclusions : Based on the findings, CCEE exhibits strong antioxidant activity as evidenced by the presence of Coumarin, Trans-cinnamaldehyde, Trans-cinnamic acid, and 2-Methoxycinnamaldehyde. Consequently, this study suggests that CCEE can serve as an important source of natural antioxidants and can be efficiently used in the management of oxidative stress diseases.