• Korean journal of food and cookery science
• /
• v.16 no.3
• /
• pp.216-220
• /
• 2000

Volatile flavor components in the fruits of dried Zanthoxylum schinifolium were extracted by supercritical fluid extraction method using diethyl ether as solvent. Essential oils were analyzed by gas chromatography (GC) and combined gas chromatography-mass spectrometry (GC-MS). Identification of volatile flavor components was based on the RI of GC and mass spectrum of GC-MS. A total of 30 components, including 6 hydrocarbons, 4 aldehydes, 8 alcohols, 5 esters, 4 acids and 3 miscellaneous components were identified in the essential oils. Geranyl acetate, ${\beta}$-phellandrene, D-limonene and citronellal were found to be major volatile flavor components in fruits of dried Zanthoxylum schinifolium. The masking effects of Zanthoxylum schinifolium on meaty and fishy flavor were measured by sensory evaluation to investigate the usefulness of Zanthoxylum schinifolium as a natural spice. Meaty flavor was significantly reduced with the addition of 0.05% and 0.1% Zanthoxylum schinifolium. And the addition of 0.l% powdered Zanthoxylum schinifolium also reduced the fishy flavor of mackerel.

• Analytical Science and Technology
• /
• v.22 no.1
• /
• pp.44-50
• /
• 2009

In this study, the use of purge & trap GC-MS technique for determination of methylmercury in sediment samples was described. The method detection limit of the method was determined as 0.06 ng/g and the recovery of the method was $102{\pm}11.4%$, with precisions better than 11.2%. The method was validated by analysis of CRMs such as ERM CC580 (estuarine sediment) and IAEA 405 (sediment). Additionally, the performance of the method was tested on river sediment samples and the analytical results were compared with those of the GC-CVAFS, which has been widely used for methylmercury analysis.

• Journal of Environmental Health Sciences
• /
• v.32 no.1 s.88
• /
• pp.67-70
• /
• 2006

A gas chromatography/mass spectrometric method was developed for the determination of formaldehyde in hair. 0.3mg of hair was placed in 10ml headspace vial. 1.5mM pentafluorophenylhydrazine solution (pH 2) in 0.03 M phosphoric acid and $20\;{\mu}l$ of 500 mg/l $acetone-d_6$ as internal standard were added in vial and sealed tightly with cap. The solution was heated for 30 min at $90^{\circ}C$ in heating block. The extraction, the derivatization and the evaporation were performed simultaneously. After heating of the solution, 0.5 ml of headspace was taken up and analyzed by gas chromatography-mass spectrometry (GC-MS). Low limit of detection (LaD) and Low limit of quantitation (LOQ) of formaldehyde were 0.5 and 1.5 ng/g, respectively. The method was used to analyze formaldehyde in rat hair after oral exposure. The developed method may be valuable to be used to analyze formaldehyde in human hair.

• Korean Journal of Environmental Agriculture
• /
• v.14 no.1
• /
• pp.45-54
• /
• 1995

esters of the acid analytes were synthesized using $H_2SO_4$ as the catalyst. Efficiency of derivatization and instrumental molecular-response were compared with herbicides methylated with $BF_3-methanol$(14% W/V), $H_2SO_4-methanol$(33% V/V), and diazomethane. The molecular integrity of TFE-2,4-D, TFE-dicamba, and TFE-mecoprop, in the mixture, was confirmed by the GC/MSD method. The TFE-Esterification efficiency was maximized by adjusting the volume of $H_2SO_4$ the reaction time, and temperature. Optimal efficiency for the herbicide mixture was obtained by adding 1 ml of $H_2SO_4$ and 1 ml of TFE to the dried sample and allowing the reaction to proceed at $22^{\circ}C$ for 8 hr or using 0.5 ml $H_2SO_4$ and 1 ml of TFE at $60^{\circ}C$. For 120 min increasing the temperature and decreasing the reaction time were required for maximum esterification efficiency. The sensitivity of the GC/ECD to the TFE esters was about $2{\sim}20$ times greater than that to the methyl ester derivatives. The herbicides were extracted and esterified to TFE derivatives simultaneously from soil leachates previously spiked with the analytes. Herbicide recovery, peak resolution, and detector sensitivity were excellent without using column cleanup procedures.

• The Korea Journal of Herbology
• /
• v.23 no.4
• /
• pp.159-170
• /
• 2008

Objectives: This study was carried out to evaluate the quality of the peels of various Citrus species. Method: The contents of hesperidin from fruit peels used as Citri Pericarpium such as C. natsudaidai, C. grandis, C. unshiu, and C. sunki, were analyzed by HP-TLC, HPLC, and essential oils of those were analyzed by GC/MS. Results: HPLC analysis showed that the hesperidin from the peel of C. unshiu and C. reticulata was satisfied the standard of Korean Pharmacopoeia. The essential oil was analyzed by GC/MS. As a result, limonene, furfural, 5-methyl-2-furfural, linalool oxide(cis), linalool oxide(trans), terpinen-4-ol, $(-)-{\alpha}$-terpineol, germacrene D, 4-methyl-2,6-di-tert-butylphenol was detected in all 4 kinds of Citrus species. Conclusions: As a result of chemotaxonomical similarity analysis with essential oils, the peels of C. natsudaidai and C. grandis are closely related, while C. unshiu is distantly related to the others.

• Journal of Food Hygiene and Safety
• /
• v.38 no.3
• /
• pp.131-139
• /
• 2023

In this study, we investigated pesticide residue levels in 535 domestically distributed agricultural products in South Korea using multi-residue analysis. Agricultural products from 13 regions, including Seoul, were pretreated using QuEChERS and d-SPE, and subsequently analyzed using LC-MS/MS and GC-MS/MS. Residual pesticides were detected in 288 (53.8%) out of the 535 samples, including 40 of apples, 40 of peppers, 33 of mandarins, 31 of peaches, and 144 other commodities. Furthermore, one sample of Korean cabbage exceeded the permitted maximum residue limit (MRL), diniconazole (0.18 mg/kg), detected at about twice the MRL. In total, 91 types of residual pesticides were detected, including fungicides (42), insecticides (48), and a nematicide. The most frequently detected pesticides were dinotefuran (91), carbendazim (75), tebuconazole (61), and pyraclostrobin (59). Our results showed that continuous monitoring of agricultural products is necessary.

• Journal of the Society of Cosmetic Scientists of Korea
• /
• v.34 no.1
• /
• pp.51-55
• /
• 2008

Although phthalates aren't used as an cosmetic ingredient, some cosmetics especially nail lacquer, hair spray, and perfume still have phthalates. This is mainly caused by contamination and carryover during manufacturing process, so analysis of phthalates in those cosmetics has became a very important thing for quality-assurance(Q.A). The main phthalates under debate are diethyl phthalate(DEP), dibutyl phthalate(DBP), and bis(2-ethylhexyl) phthalate (DEHP) in domestic market. Gas chromatography-mass spectrometry(GC-MS) coupled with solvent extraction and concentration has been used for ppm level and sub ppm level analysis of phthalates. It requires much time and cost to use mass spectrometric detector and to prepare the test solution. Moreover analysis of phthalates at low concentrations is difficult because of contamination which results in wrong analytical results. In the present study, we showed a simple method using gas chromatography-flame ionization detector(GC-FID) which has fast analysis time, minimum use of solvent, reduced sample preparation steps for minimizing contamination and quantitative range of $2{\sim}50{\mu}g/g(ppm)$ in products. Consequently, this method will be proper for Q.A analysis in related companies.

• Applied Biological Chemistry
• /
• v.32 no.4
• /
• pp.350-356
• /
• 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 $0.5{\sim}1.6mg/g$.

• Korean Journal of Environmental Biology
• /
• v.34 no.3
• /
• pp.216-221
• /
• 2016

Level and distribution of fourteen polycyclic aromatic hydrocarbons (PAHs) in the agricultural water samples collected in the waterways located in Gyeonggi and Gangwon, Korea were determined for monitoring and risk assessment. A simplified, fast but effective extraction and clean-up methods combined with gas chromatography tandem mass spectrometry (GC-MS/MS) was employed to measure the concentration of the target compounds. The extraction of the analytes of interest in water sample (10 mL) was performed with acetonitrile (10 mL) and the salt. To purify the target PAHs, the clean-up procedure was employed with 2 mL tubes of dispersive solid phase extraction. The optimized method was validated with recoveries, method detection limit (MDL), accuracy and precision. Good recoveries for each PAHs at 10 and $25{\mu}g\;L^{-1}$ were achieved (60 to 110%, with RSD <20%) with linearity (>0.99). MDL for all the analytes was achieved with $0.2{\mu}g\;L^{-1}$. GC-MS/MS results showed that concentration of phenanthrene in the water samples from Gyeonggi (20 sites) ranged from 0.82 to $2.56{\mu}g\;L^{-1}$ and from Gangwon (15 sites) ranged from 0.83 to $1.62{\mu}g\;L^{-1}$. Other PAHs were not found in the water samples but the continuous monitoring for these areas were required.

• Journal of the Korean Wood Science and Technology
• /
• v.22 no.3
• /
• pp.59-67
• /
• 1994

The essential oils of leaves and resins from P. densiflora and P. koraiensis were analyzed to identify their components. After each retention times of 45 known terpenoids were dertermined with a fixed analytical condition by GC the essential oil compounds of leaves and resins were identified by comparing their retention times with the retention times of known standards. To confirm these results the essential oil components of leaves from P. koraiensis were analized by 2 different GC/MS. According to these results, 36 terpenoids in essential oils of leaves from P. densiflora and P. koraiensis were identified and 15 terpenoids and 22 terpenoids were identified from P. koraiensis resin and P. densiflora resin, respectively. The major components which are more than 2% of total amaunt of volatile components were as follows: 1. The major terpenoids of leaves from red pine. ${\alpha}$-pinene, camphene, ${\beta}$-pinene, D-limonene, ${\beta}$-phellandrene, myrcene, terpinolene, ${\alpha}$-terpineol. 2. The major terpenoids of leaves from korean pine. ${\alpha}$-pinene, camphene, myrcene, D-limonene, 3-carene, terpinolene, bornyl acetate, ${\beta}$-caryophyllene, ${\alpha}$-terpineol, borneol, ${\delta}$-cardinene. 3. The major terpenoids of resin from red pine. ${\alpha}$-pinene, ${\beta}$-pinene, myrcene, ${\beta}$-phellandrene, linalool, linalyl acetate. 4. The major terpenoids of resin from korean pine. ${\alpha}$-pinene, ${\beta}$-pinene, D-limonene, ${\beta}$-caryophyllene, phytol.