• Korean Journal of Agricultural Science
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• v.38 no.4
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• pp.723-730
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• 2011

To search for the new development of industrial application of woody plants, the chemical composition of the volatile constituents from woody plants (Evodia daniellii, Clerodendron trichotomum, Prunus padus, and Zanthoxylum ailanthoides) was determined by GC and GC/MS spectrometric analysis with the aid of NBS, Wiley Library and RI indice searches. The major constituents were t-ocimene from the leaves of E. daniellii, linalool from the leaves of C. trichotomum, benzaldehyde from the leaves and twigs of P. padus, ${\beta}$-thujene from the leaves of Z. ailanthoides, and 2-undecanone from the stems of Z. ailanthoides. These results suggested that the major volatile constituents of woody plants could be a useful lead compound in the development of functional materials for industrial application.

• Elastomers and Composites
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• v.54 no.3
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• pp.188-200
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• 2019

Rubber articles contain various organic additives such as antidegradants, curing agents, and processing aids. It is important to extract and analyze these organic additives. In this paper, various extraction methods of organic additives present in rubber composites were introduced (solvent extraction, Soxhlet extraction, headspace extraction, and solid-phase microextraction), and the extracts were characterized using gas chromatography/mass spectrometry (GC/MS). Solvent and Soxhlet extractions are easy-to-perform and commonly used methods. Efficiency of solvent extraction varies according to the type of solvent used and the extraction conditions. Soxhlet extraction requires a large volume of solvent. Headspace sampling is suitable for extracting volatile organic compounds, while solid-phase extraction is suitable for extracting specific chemicals. GC/MS is generally used for characterizing the extract of a rubber composite because most components of the extract are volatile and have low molecular weights. Identification methods of chemical structures of the components separated by GC column were also introduced.

• Elastomers and Composites
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• v.55 no.4
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• pp.281-288
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• 2020

A calibration curve is needed to determine the SBR and BR blend ratio of SBR/BR blend rubber compounds using pyrolysis-gas chromatography/mass chromatography (Py-GC/MS) or Py-GC. In general, a calibration curve is obtained using reference SBR/BR vulcanizates with various blend ratios. In this study, the calibration curves were obtained using reference samples made of rubber solutions and were compared to those plotted using the reference SBR/BR vulcanizates. Calibration curves using variations of 1,3-butadiene/styrene, 4-vinylcyclohexene (VCH)/styrene, 2-phenylpropene (PhP)/butadiene, PhP/VCH, 4-phenylcyclohexene (PhCH)/butadiene, and PhCH/VCH ratios with the BR content were examined for the suitability. We found that the calibration curves obtained using the mixed rubber solution references (1,3-butadiene/styrene and PhP/butadiene) could replace those constructed using the reference SBR/BR vulcanizates. The calibration curves of 1,3-butadiene/styrene and PhP/butadiene obtained using the raw references can be used for the determination of the SBR/BR blend ratios by applying some correction factors.

• The Korean Journal of Pesticide Science
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• v.19 no.4
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• pp.345-353
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• 2015

The aim of this study is to develop residue analysis method for fenoxanil, a MBI (melanin biosynthesis inhibitor) propionamide fungicide, had mainly been used to control rice blast, and disease of other crops, fruits, and vegetables by using GLC/NPD and GC/MS. Extraction with acetone and partition with n-hexane/dichloromethane (80/20, v/v) were performed from hulled rice, soybean, Kimchi cabbage, green pepper, and apple, then column clean-up with florisil was applied. Mean recoveries were 82.2%-109.1% with less than 7.2% of coefficients of variation and limit of quantitation was set at the concentration of 0.04 mg/kg from the five agricultural products through the determination by GLC/NPD equipped with DB-5 capillary column and single laboratory validation. As a confirmatory method, GC/MS selected ion monitoring (SIM) was set from m/z 125.0, 188.9, and 293.0. Developed method is expected to apply the single residue analysis of fenoxanil in agricultural products.

• Korean Journal of Food Science and Technology
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• v.28 no.2
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• pp.226-231
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• 1996

A serum-pulp method was applied to concentrate peach pulp with aroma recovery. The serum portion was concentrated to five-fold at $50{\sim}55^{\circ}C$ and $30{\sim}50$ mmHg with aroma recovery. The concentrated serum, insoluble pulp and aroma fraction were recombined to make a two-fold concentrated peach pulp. The results of GC and GC/MS analysis for volatile compounds and sensory evaluation of concentrated peach pulp indicated that flavor quality was significantly improved by addition of aroma fractions. A 10% aroma recovery appeared to be appropriate for peach pulp.

• Korean journal of applied entomology
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• v.44 no.2
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• pp.161-164
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• 2005

Essential oils of three plants (caraway oil, hyssop oil and lime oil) were screened for repellency against Tetranychus urticae female adults in the lab condition. Among them, caraway oil (Carum carvi) showed $92.2\%$ repellency against female adults at 1,000 ppm concentration. Through the constituent analysis using GC and GC/MS, we confirmed that the two main constituents were carvone $(73.3\%)$ and limonene (26.7). Limonene showed 87.8 and $83.1\%$ repellency against adult females at 1,000 and 100 ppm concentrations, respectively.

• Journal of Food Hygiene and Safety
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• v.28 no.3
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• pp.222-226
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• 2013

A simple and sensitive analytical method was developed using gas chromatograph with electron capture detector (GC-ECD) and gas chromatograph-mass spectrometer (GC-MS) for determination and identification of chloropicrin. Because of small molecular weight and high volatile properties of chloropicrin, analytical method was developed utilizing headspace extraction and direct injection to the GC. The developed method was validated using hulled rice sample spiked with chloropicrin at different concentration levels, 0.1 and 0.5 mg/kg. Average recoveries of chloropicrin (using each concentration three replicates) ranged 77.7~79.3% with relative standard deviations less than 10% and calibration solutions concentration in the range $0.005{\sim}0.5{\mu}g/mL$, and limit of detection (LOD) and limit of quantification (LOQ) were 0.004 and 0.01 mg/kg, respectively. The result showed that developed analytical methods was successfully applied to detect a small amount of chloropicrin in hulled rice.

• Journal of Environmental Science International
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• v.23 no.6
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• pp.1037-1047
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• 2014

A highly sensitive analytical method based on stir bar sorptive extraction (SBSE) technique and gas chromatography/tandem mass spectrometry (GC/MS-MS) has been developed, allowing the simultaneous multi-analyte determination of seven UV filters in water samples. The stir bar coated with polydimethylsiloxane (PDMS) was added to 40 mL of water sample at pH 3 and stirred at 1,100 rpm for 120 min. Other SBSE parameters (salt effect and presence of organic solvent) were optimised. The method shows good linearity (coefficients > 0.990) and reproducibility (RSD < 12.9%). The extraction efficiencies were above 84% for all the compounds. The limits of detections (LOD) and limits of quantification (LOQ) were 2.1~8.6 ng/L and 6.8~27.5 ng/L, respectively. The developed method offers the ability to detect 8 UV filters at ultra-low concentration levels with only 40 mL of sample volume. Matrix effects in tap water, river water, wastewater treatment plant (WWTP) final effluent water and seawater were investigated and it was shown that the method is suitable for the analysis of trace level of 7 UV filters except of benzophenone (BP). The method developed in the present study has the advantage of being rapid, simple, high-sensitive and both user and environmentally friendly.

• Korean Journal of Environmental Agriculture
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• v.23 no.4
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• pp.197-202
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• 2004

The persistence of pendimethalin in soil and ground water has an injurious effect on ecosystem. Pendimethalin-degrading bacterium was isolated from Masan, Gyeongnam province and temporarily identified as Bacillus sp. MS202 by the analysis of API CHB50, kit, FAME, and 16S rDNA sequence. from the analysis of pnedimethalin metabolite using TLC, GC, and GC-MS, we found that the degradation of pendimethalin by Bacillus sp. MS202 did not result in the dealkylated form, but the formation of the reduced compound, 6-amino-2-nitro-N(1-ethylpropyl)-3,4-xylidine or 2- amino-6-nitro-N(1-ethylpropyl)-3,4-xylidine.

• YAKHAK HOEJI
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• v.37 no.4
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• pp.356-361
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• 1993

A sensitive method for the determination of methamphetamine(MA) and amphetamine(AM) in hair was developed by gas chromatography/mass spectrometry using stable isotope-labeled internal standards, amphetamine-d$_{5}$ and methamphetamine-d$_{5}$. Hair sample was washed with MeOH, incubated with MeOH(I% HCI) overnight at $37^{\circ}C$ while stirring and extracted using solid phase extraction column on a vacuum manifold. The extract obtained was pentafluoropropionated, and applied to GC/MS. The calibration curves of MA and AM were linear from 2.5 to 250 ng (r>0.99 for both). The limit of detection was 0.1 ng/mg in hair and cut-off level was set at 0.25 ng/mg for both. Hair samples of 27 MA abusers showed positive results in the range 0.7 to 106.8 ng/mg. AM, its metabolite, was detected in 20 out of 27 samples. The ratio of MA versus AM was 4.6~38.3 in specimens. Hair analysis for methamphetamine by GC/MS is an effective method for identifying long-term drug abusers.