• Korean Journal of Environment and Ecology
• /
• v.29 no.4
• /
• pp.564-569
• /
• 2015

In order to discover materials that can be used for OLED, extractions of marine microalgae was screened for photoluminescence(PL) properties and analyzed using gas chromatography-mass spectrometry(GC-MS). The extractions of Nitzschia denticula, Navicula cancellata and Nannochloropsis salina showed PL spectroscopy among fourteen marine microalgae species. The selected three fractions from three microalgae were analyzed by GC-MS. According to the results, it was found that the identified organic light-emitting materials can be subdivided into three functional groups based on imidazole, purine and quinoline. These chemicals are considered to have a strong relationship with PL spectroscopy for OLED materials.

• Bulletin of the Korean Chemical Society
• /
• v.19 no.2
• /
• pp.164-169
• /
• 1998

Vulcanized rubber containing three kinds of oligomeric resins such as cashew resin, t-octylphenol formaldehyde resin and terpene modified wood rosin has been characterized by simultaneous pyrolysis methylation-gas chromatography/mass spectrometry (SPM-GC/MS). After methylation by the SPM method using tetramethylammonium hydroxide, the methylated pyrolyzates of the corresponding resins were detected with higher sensitivity than underivatized pyrolyzates without any interferences from other ingredients of vulcanized rubber.

• Proceedings of the PSK Conference
• /
• 2003.04a
• /
• pp.314.1-314.1
• /
• 2003

Examination was made of the urinary metabolite(s) of CKD-712, which is a chiral compound, named S-YS49 derived from higenamine (one component of Aconite spp.) derivatives. First of all. to analyze the metabolite(s) of CKD-712, a simple and sensitive detection method for CKD-712 was developed by using gas chromatography-mass spectrometry(GC/MS). (omitted)

• Journal of Nutrition and Health
• /
• v.18 no.4
• /
• pp.293-300
• /
• 1985

Volatile components of Korean horseradish roots harvested at different dates were prepared by steam distillation. Samples were examined by gas chromatography (GC) and combined gas chromatography-mass spectrometry (GC-MS). The major pungent constituent, allyl isothiocyanate was confirmed add tended to increase with delayed harvest time. Pungent principles also included allyl thiocyanate, 2-phenethyl, 2-butyl, 4- pentenyl, benzyl and 3-methylthiopropyl isothiocyanates. Infrared (IR) spectroscopy study showed that allyl isothiocyanate - thiocyanate interconversion did not occur under the condition of this study.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.19 no.4
• /
• pp.311-314
• /
• 1990

The volatile fraction of Oenanthe stolonifera DC. was extracted by a steam distillation under the atmospheric pressure and analyzed by gas chromatography(GC) and gas chromatogra-phy/mass spectrometry(Gc-MS) The experimental results revealed the presence of 63 volatile components. Among them 39 components identified were composed of 20 hydrocarbonss(61.94%) 9 alcohols(8.76%) 3 ketones(11.5%) 1 ester(1.34%) 1 aldehyde (2.29%) and 5 miscellaneous \ulcorner92.35%) The major volatile components of Oenanthe stolonifera DC. were limo-nene(12.12%) pulegone(94.8%) germacrene D(8.34%) and $\beta$-pinene(7.68%)

• Korean Journal of Environmental Agriculture
• /
• v.36 no.4
• /
• pp.269-278
• /
• 2017

BACKGROUND: The objective of this study was to evaluate screening method of residual multi pesticides in dead birds by Orbitrap high resolution mass spectrometry (HRMS) to identify the cause of death for birds. METHODS AND RESULTS: Extraction and clean-up method of residual pesticides in liver of dead birds was used QuEChERS (Quick Easy Cheap Effective Rugged and Safe) and method validations was conducted using liquid chromatography and gas chroamtography with triple-quadrupole mass spectrometer (LC/MS/MS and GC/MS/MS) Also, we were evaluated screening method for the determination of residual pesticides in liver of dead birds by LC and GC Orbitrap Mass Spectrometry. Results of method validations, Correlation coefficients of the matrix matched calibration curves were >0.978, and the method detection limits (MDLs) and limits of quantitation (LOQ) were 2.8~72.1 ng/g (18.4 ng/g on average) and 9.0~230 ng/g (58.5 ng/g on average). The accuracy ranged from 69.1%to 130% (103% on average), and the precision values were less than 14.8%(3.8%on average). The screening of residual pesticides in liver of dead birds by LC and GC Orbitrap HRMS was detected monocrotophos, carbofuran, carbosulfan, deltametrin, benfuracarb, carbofuran, phosphamidon, prochloraz in investigated samples. CONCLUSION: This results showed that accurate mass were extraction of residual pesticides in dead birds by Orbitrap HRMS. It suggested that this screening method is applicable to the residual pesticide analysis for the cause of death as a main tool.

• Analytical Science and Technology
• /
• v.22 no.5
• /
• pp.407-414
• /
• 2009

A simultaneous determination method for cholesterol, lanosterol and desmosterol was developed using gas chromatography/mass spectrometry. Urine was enzymatically hydrolyzed with ${\beta}$-glucuronidase/arylsulfatase. Samples were prepared using extractions with a mixture of ethyl acetate-hexane (2:3, v/v), followed by derivatization with a mixture of MSTFA/TMSI/TMCS (100:2:5 v/v/v). All analyses were performed using GC/MS in selective ion monitoring mode. Good linearities ($r^2=0.998{\sim}0.999$) in calibration curve and a satisfactory recovery (80.0%~113%) were achieved. Accuracy and precision values within ${\pm}15%$ in the concentration range of 5 to 200 ng/mL were also observed for all compounds. The developed method was applied to pravastatin-treated (70 and 250 mg/kg/day for 7 days, oral) hyperlipidemia rats. Those sterols were significantly lower in drug-treated rats compared to the controls, which justifies the drug efficacy. Therefore, these results indicate that the developed method was successfully applied to examine statin drug efficacy with urine sample.

• Korean Journal of Food Science and Technology
• /
• v.48 no.5
• /
• pp.430-436
• /
• 2016

Solid phase microextraction and gas chromatography-mass spectrometry (SPME/GC-MS), electronic nose, and electronic tongue were used to characterize the sensory profiles of cider vinegars from Korea (K1-2), China (C1-2), Japan (J1-2), and US (U1-2). SPME-GC/MS detected acetic acid as the common volatile compound in all vinegars, in addition to isovaleric acid, octanoic acid, and phenethyl acetate. Acids and acetic esters were the major components of Korean and US vinegar samples, respectively. Chinese vinegars had high ethyl acetate content, while Japanese samples were characterized by a low content of acetic acid. Principal component analysis (PCA) pattern provided a clear categorical discrimination of Chinese vinegars by E-nose and E-tongue analyses. The instrumental sensory scores and the taste attributes for flavor ($r^2=0.9431$), sourness ($r^2=0.9515$), and sweetness ($r^2=0.8325$) were highly correlated. Therefore, SPME/GC-MS, E-nose, and E-tongue analyses may be useful tools to discriminate the sensory profiles of cider vinegars of different origins.

• Journal of Food Hygiene and Safety
• /
• v.29 no.4
• /
• pp.312-315
• /
• 2014

The present study demonstrated the development and validation of the method for the quantification of phenol in food using gas chromatography coupled with mass spectrometry (GC-MS). After spiking of internal standard (Phenol-$d_5$) to food, those samples were extracted with organic solvent mixture (acetone : dichloromethane = 1 : 1, v/v) using ultra sonic extractor and cleaned by gel permeation chromatography (GPC) technique. The amount of phenol was determined by GC/MS. To validate the developed method, we evaluated parameters were the selectivity, linearity, accuracy, precision, and recovery. To demonstrate the selectivity of the method, blank samples of rice, corn, and fish(mackerel) were prepared and subjected to GC-MS analysis. To verify the linearity of the method, six different standard concentrations of phenol at 0.01, 0.05, 0.1, 0.5, 1 and 2.5 mg/kg were evaluated. The correlation coefficient ($r^2$) of calibration curve was 0.9999. The recovery rate for phenol standard calculated by internal standard method were 82.2~101.5% for samples fortified with 0.25, 0.50, and 1.0 mg/kg, respectively. Also the repeatability and reproducibility for validation of precision were 0.2~5.5%. According to the result of the validation, this established method was suitable for AOAC guideline. The limit of detection (LOD) for phenol analysis were 0.03~0.1 mg/kg, and the limit of quantification (LOQ) were 0.1~0.3 mg/kg. Therefore, we established the optimal analysis method for determination of phenol in food using GPC and GC/MS.

• Bulletin of the Korean Chemical Society
• /
• v.29 no.12
• /
• pp.2482-2486
• /
• 2008