• Korean Journal of Food Science and Technology
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• v.30 no.4
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• pp.721-727
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• 1998

An analytical method for simultaneous and rapid determination of organophosphorus, organochlorine, carbamate, and pyrethroid pesticides in polished rice was developed. The analysis is performed by gas chromatograph with mass selective detector (GC/MSD) in selected ion monitoring (SIM) mode. Pesticides were extracted from samples with acetone by automated Soxhlet apparatus and this extract was evaporated to dryness for the analysis. The residue was dissolved in hexane, followed by a treatment with a Sep-Pak florisil catridge. Pesticides were positively confirmed by GC/MS, retention times, and ion ratios. This analytical method allows a rapid, reliable, and a good recovery of hydrophilic pesticides. Except far captafol, captan, dichlofluanid and dichlorvos, recoveries of 42 pesticides were over 70%.

• Environmental Analysis Health and Toxicology
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• v.16 no.3
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• pp.121-126
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• 2001

Analytical method of benzophenone (BP) in sediment and soil was developed by gas chromatography/mass selective detector/selected ion monitoring (GC/MSD/SIM). The ultrasonic extraction of US EPA (method 3550B) method and liquid-liquid extraction for sediment and soil samples were used for the analysis of BP from sediment and soil. BP was extracted with n-hexane. Organic layer was washed with 5% sodium chloride solution. 1∼2 l of the concentrated solution of organic layer was applied to GC/MSD. The retention time of BP peak was 11.10 min. Recovery (％) of BP by ultrasonication from sediment and soil samples was 96.0∼100.6％ and 40.0∼83.0％, respectively. Recovery of BP by liquid-liquid extraction was 51∼59％ in soil samples. The detection limit of BP in sediment and soil samples were determined to 0.1 ng/g.

• Applied Chemistry for Engineering
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• v.8 no.1
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• pp.8-15
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• 1997

This study was carried out to present a analysis of pyrolytic degradation of 4-hydroxy-3-methoxybenzal dehyde(vanillin) pyrolyzed at $330^{\circ}C{\sim}920^{\circ}C$ by Curie-point pyrolyzer connected with GC/MSD by on-line system. Identified by GC/MSD were 100 pyrolytic products of vanillin. The pyrolysis of the compound gave benzene, phenol, 1,3-cyclopentadiene, methyl benzene, benzaldehyde, benzofuran, and cresol as major products, which were produced by pyrolytic degradation and synthesis of vanillin radicals.

• Korean Journal of Pharmacognosy
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• v.29 no.2
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• pp.129-135
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• 1998

Higenamine is known as a cardiotonic principle of Aconiti tuber. The analytical procedures were established for the detection of higenamine in plants. The amounts of higenamine in several Aconiti tubers and the embryo of Nelumbo nucifera, another plant species known to contain higenamine, were determined. The $H_2O$ soluble fraction prepared from MeOH extract was first treated with AD-2 resin and then applied to either HPLC or GC/MSD systems. With HPLC, $6.4{\sim}19.2\;{\mu}g/g$ of higenamine were detected from various Aconiti tubers and $182.3\;{\mu}g/g$ of higenamine from the embryo of Nelumbo nucifera. The results obtained with GC/MSD also provided comparable data with those obtained with HPLC.

• Korean Journal of Food Science and Technology
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• v.31 no.2
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• pp.342-347
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• 1999

Kiwifruit pulp was separated into insoluble pulp and serum by centrifugation at 14,000 rpm for 10 min. The serum portion was concentrated at $30{\sim}50mmHg\;and\;50{\sim}55^{\circ}C$ with aroma recovery. Vapor generated at the early stage of vacuum evaporation was condensed and taken as aroma fractions: $E-I\;(0{\sim}10%),\;E-II,\;(10{\sim}20%)$. The volatile flavor compounds in kiwifruit pulp were collected by dynamic headspace technique and analyzed by GC and GC/MSD. The yield of serum separated from kiwifruit pulp was 70.1% and insoluble pulp fraction contained aroma compounds more than that of the serum. Twenty-six aroma compounds, including (E)-2-hexanal and ethyl butanoate were detected. The efficiency of the aroma recovery was reduced as the recovery time was extended, as indicated by the less peak numbers and kiwifruit areas of aroma fractions.

• Food Science of Animal Resources
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• v.29 no.4
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• pp.482-486
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• 2009

The aim of this study was to optimize a simple, fast, and economical analysis procedure for the determination of 16 different pesticides in raw milk via GC/MSD. Analyses were performed via gas chromatography with electron impact mass spectrometric detection in the selected ion monitoring mode (GC/MSD-SIM) using Pentachloronitrobenzene as the internal standard. The modified sample preparation methodology was based on the Pesticide Analytical Manual (PAM) of the FDA concerning fat extraction, ACN-ether partitioning, and clean-up of the Sep-Pak florisil cartridge. The modified methodology for the determination of the 16 pesticides was validated. The range of LOQs of the 16 pesticides was likely three times lower than their Maximum Residence Levels (MRLs). The recoveries of most of the pesticides were acceptable at the fortification levels of 0.5 and 1.0 ${\mu}g/mL$ and their RSD (%) level was less than 20%. None of the 16 pesticides were detected in the selected raw milk samples.

• Journal of the Korean Society of Clothing and Textiles
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• v.33 no.6
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• pp.980-989
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• 2009

Amur cork tree was extracted in methanol with the purpose of investigating the most effective extraction procedure for detecting the chromophore using the GC-MS analysis. Different procedures of waterbath and hotplate extractions were carried out and five different GC-MS instrument parameters including the operating temperatures in the GC capillary column and the MSD scan range were tested for their efficiencies. Berberine was determined by the detection of dihydroberberine at 15.0 min r.t. Hotplate was a better device for extracting amur cork tree than waterbath shaker either with or without presoaking in the room temperature. Water was not an adequate extraction medium for the berberine detection. The most effective GC-MS parameter was Method 4; the initial temperature at $50^{\circ}C$ followed by the temperature increase of $23^{\circ}C$/min until $210^{\circ}C$, then increase of $30^{\circ}C$/min until the final temperature reach at $305^{\circ}C$, then hold for 14 minutes to maintain the total run time 24.12 minutes. The MSD scan range for Method 4 was $35\sim400$m/z.

• Korean Journal of Pharmacognosy
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• v.32 no.3 s.126
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• pp.200-211
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• 2001

This study was carried out to determine the 11 organochlorine, 7 organophosphorus residual pesticides in 251 crude drugs. These residual pesticides in herbal drugs were extracted with acetonitrile and the extracts were cleaned up via LC-florisil solid phase extraction column. The prepared samples were assayed for pesticide residues using GC-ECD, NPD with capillary column and identified by GC-MSD. Recoveries were $63.9{\sim}111.5%$ in the organochlorine pesticides and $69.8{\sim}92.4%$ in the organophosphorus pesticides, and detection limits were $0.001{\sim}0.65\;ppm$ in the organochlorine pesticides and $0.0009{\sim}0.0074\;ppm$ in the organophosphorus pesticides. Pesticide residues were detected in 9 cases.

• The Korean Journal of Pesticide Science
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• v.8 no.2
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• pp.129-136
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• 2004

In order to determine the amounts of impurities and to identify the chemical structures of the impurities in the technical product of the plant growth regulator Atonic, the extracts of diethyl ether and dichloromethane were analyzed with GC-FID and GC-MSD. resulting in detection of five impurities and identification of their chemical structures. The amount of the active ingredient atonic in the technical product was about 84% and those of the impurities ranged from 0.24 to 10.74%. The identified impurities in this technical product are 2-methoxyphenol (guaiacol, m/z 124), 2-chloro-6-methoxyphenol and/or 4-chloro-6-methoxyphenol (m/z 158), 1,2-dimethoxy-4-nitrobenzene (m/z 183), and 2,6-bis(1,1-dimethylethyl)-4-methylphenol (m/z 220), suggesting that they are not hazardous impurities.

• The Korean Journal of Pesticide Science
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• v.2 no.1
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• pp.65-69
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• 1998

To determine the amount of total bromide as 2-bromoethanol, the domestic agricultural products such as rice, barley, carrot, cucumber, apple, tomato, squash, green pepper, melon, strawberry, grape, peach, potato and celery were analyzed by GC/MSD as well as GC/ECD. The bromide was detected in most of the domestic samples and the highest bromide residue determined was 13.2 ppm in barley. The imported agricultural products including melon, kiwi, lemon, pineapple, banana, orange and grape were also analyzed for the bromide. The bromide was also detected in most of the imported ones and the highest bromide residue determined was 12.3 ppm in pineapple. In addition, the bromide residue in instant noodle spices was monitored for 4 years, recently. As results, in 1994, the bromide content was in the range of non-detection to 2.4 ppm (average 1.1 ppm) from 22 out of 24 samples; in 1995, the bromide content was 1.0 and 2.2 ppm from 2 out of 37 samples; in 1996, the bromide content was in the range of 0.7 to 37 ppm (average 12.4 ppm) from all 11 samples; and in 1997, the bromide content was in the range of 0.2 to 4.6 ppm (average 1.2 ppm) from all 59 samples. However, none of sample analyzed for the bromide was exceeded Maximum Residue Limit(s) of Korea and Codex in these survey.