• Analytical Science and Technology
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• v.23 no.2
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• pp.128-137
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• 2010

The purpose of this study is to set up the analytical method of new persistent organic pollutants (POPs) such as chlordecone, endosulfan, ${\alpha}$-HCH, ${\beta}$-HCH, ${\gamma}$-HCH. The analytical methods for these compounds listed as new POPs by the Stockholm Convention need to be newly established. Therefore, we proposed the analytical method for 5 organic chlorinated pesticides (OCPs) and then applied the analytical method to environmental samples. To do this, the pre-treatment such as florisil and activated carbon cleanup process in the Korean official method for classic POPs had been reviewed. All of compounds except chlordecone were pre-treated simultaneously with reviewed cleanup process and detected by GC/MS and HRGC/HRMS respectively. There is a problem that chlordecone could not get a high sensitivity by GC analysis, but in this study GC/MS method was proposed.

• Journal of the Society of Disaster Information
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• v.9 no.3
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• pp.249-258
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• 2013

Recieved Mar. 06, 2013 Revised Mar. 29, 2013 Accepted Sep. 11, 2013In this study, we evaluated the method performance and the optimum sample injection method of the portable GC/MS(HAPSITE) which were designed to operate on scene of chemical accidents. Chemicals used for performance test were vinyl chloride(VC), methyl chloride(MC), benzene(Bz), toluene(Tol). CRM(Certified Reference Material) Manufactured by KRISS(Korea Research Institute of Standards and Science) was used as the standard gas. The results showed that 1) Among three sample injection methods(Cylinder, Silico canister, and Bag), bag was identified as the most appropriate sample injection method. Bag material and capacity did not significantly affect the results. The most ideal reproducibility occurred at the 2-minute point of the purge time in the loop and tenax methods. 2) Performance evaluation of HAPSITE was conducted. Evaluation items were reproducibility, linearity, method detection limit, etc. Tenax concentration method was appropriate for larger molecules and Carbopack concentration method was suitable for smaller molecules.

• Analytical Science and Technology
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• v.15 no.6
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• pp.534-539
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• 2002

We established an analytical method for the measurement of trace amounts of earthy/musty odorous geosmin (GSM) and 2-methylisoborneol (2-MIB) in water using GC/MS. Water samples were extracted with n-hexane (liquid-liquid extraction, LLE) and the extracts were measured by GC/MS. The extraction yields of the two compounds were tested to be ($87{\pm}8$)% and ($78{\pm}8$)%, respectively. The limits of quantitation (LOQs) of the two compounds by this method were greatly improved to ~0.3 ng/L. The analytical methods were applied to analyze water samples from several rivers in Korea and waters after water treatment processes. The highest levels of geosmin and 2-methylisoborneol in raw water from a river were measured to be ($4.2{\pm}0.4$) ng/L and ($44{\pm}4$) ng/L, respectively. The levels only slightly decreased to ($1.3{\pm}0.1$) ng/L and ($18{\pm}2$) ng/L even after water treatment, indicating that the odorous compounds were not properly removed by the treatment processes.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.67 no.4
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• pp.335-341
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• 2022

Proso millet (Pacnicum miliaceum L.) has a various of functional substances, so the demand is increasing as interest in human health benefits. In particular, miliacin, a triterpenoid in proso millet, is known to be effective in hair loss due to its promoting metabolism and proliferation of keratinocytes and showing protective effects from apoptosis. In this study, proso millet oil was extracted and analyzed by GC/MS using the extraction method of unsaponifiable substances after saponification reaction. The components of proso millet oil were confirmed through qualitative analysis by GC/MS. The miliacin content of 5 varieties of proso millet and 2 varieties of foxtail for comparison was analyzed. In the result, components of pentacyclic triterpenes such as β-amyrine and lupeol were detected in proso millet, and the content of miliacin was highest in Hallachal at 370.38±0.04 ㎍/100 mg oil. In addition, the content of miliacin was not detected in Samdachal and Samdamae, which are varieties of foxtail millet.

• Analytical Science and Technology
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• v.19 no.5
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• pp.441-448
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• 2006

11-nor-9-carboxy-${\Delta}^9$-tetrahydrocannabinol (THCCOOH) is the major metabolite of tetrahydrocannabinol (THC) which is the primary psychoactive component of marijuana. It is also the target analyte for the discrimination marijuana use. A method using solid-phase extraction (SPE) and gas chromatography/mass spectrometry (GC/MS) was developed for the determination of THCCOOH in human urine. Urine samples (3 mL) were extracted by SPE column with a cation exchange cartridge after basic hydrolysis. The eluents were then evaporated, derivatized, and injected into the GC/MS. The limits of detection (LOD) and quantitation (LOQ) were 0.4 and 1.2 ng/mL, respectively. The response was linear with a correlation coefficient of 0.999 within the concentration range of 1.2 (LLE 1.3)~50.0 ng/mL. The precision and accuracy were stable within 1.20% and the recovery was 83.6~90.7%. The recovery of SPE method was lower than that of liquid-liquid extraction (LLE), but there were no apparent differences in LOD, LOQ, precision and accuracy between the two methods. While SPE method is used as a very effective and rapid procedure for sample pretreatment, and clean extracts, LLE method was not suitable for the extraction procedure of THCCOOH in urine. The applicability of the method was proven by analyzing a urine samples from a marijuana abusers.

• Analytical Science and Technology
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• v.22 no.3
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• pp.219-227
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• 2009

The steroid compounds in Rhodiola sachalinensis were determined with adsorption column chromatographic purification and GC/MS. Sterols were extracted by sonication and Soxhlet with ethanol and dichloromethane, respectively. The extract was partitioned with chloroform and water using liquid-liquid extraction, and purified with a silica column after the sterols had been converted to the corresponding silyl derivatives with BSTFA. Eighteen free sterols, including $\beta$-sitosterol, stigmasterol and cycloartenol, and nine sterol conjugates were found from Rhodiola sachalinensis by GC/MS. Among them, cholest-5-ene-3-ol, cholesterol, stigmasterol, $\beta$-sitosterol were confirmed and quantified with sterol standards. Most sterols were presented in the chloroform part, with $C_{29}$ being the most abundant group in this sterol group. $\beta$-sitosterol was the most abundant compound with a relative content of 45.94% followed by ergost-7-ene-3-ol (11.33%), 4,14-dimethyl-ergosta-8,24(28)-diene-3-ol (7.07%), stigmasterol (6.09%), cycloartenol (5.43%) and 4-methyl-cholest-5-ene-3-ol (5.39%).

• Bulletin of the Korean Chemical Society
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• v.25 no.2
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• pp.271-279
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• 2004

The aroma component of Hallabong peel has been characterized by GC-MS with two different extraction techniques: solid-phase trapping solvent extraction (SPTE) and headspace solid-phase microextraction (HSSPME). Aroma components emitted from Hallabong peel were compared with those of other citrus varieties: lemon, orange and grapefruit by SPTE and GC-MS. d-Limonene (96.98%) in Hallabong was the main component, and relatively higher peaks of cis- ${\beta}$-ocimene, valencene and -farnesene were observed. Other volatile aromas, such as sabinene, isothujol and ${\delta}$-elemene were observed as small peaks. Also, principal components analysis was employed to distinguish citrus aromas based on their chromatographic data. For HSSPME, the fiber efficiency was evaluated by comparing the partition coefficient ($K_{gs}$Kgs) between the HS gaseous phase and HS-SPME fiber coating, and the relative concentration factors (CF) of the five characteristic compounds of the four citrus varieties. 50/30 ${\mu}$m DVB/CAR/PDMS fiber was verified as the best choice among the four fibers evaluated for all the samples.

• Journal of the Korean Chemical Society
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• v.44 no.1
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• pp.24-29
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• 2000

Yoqurt products are known to be effective for enhancing health and preventing diseases such as cancers. Such effects are generally believed to be due to actions of polysacchmides in yoqurt products. In this study we have determined compositions of monosaccharides in hydrolysates of commercial yoqrtrt products as the first step of understanding structures of polysaccharides. The yoqtrrt products were ttltracentrifuged, filtered, hydrolyzed in 1M sulfuric acid and neutralized. A portion of the solution was taken and evaporated to dryness, denvatized with TMSI (trimethly- silylimidazole) and analyzed by GC/MS. We found that the monosaccharides were fructose, glucose, and galactose. Their compositions were variant among several yoqtrrt products.

• Analytical Science and Technology
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• v.15 no.1
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• pp.26-30
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• 2002

In order to determine the contents of ethyl carbamate in Korean traditional alcoholic beverages and general beverages, GC/MS-SIM method was used after extraction of beverages with dichloromethane. The contents of ethyl carbamate in Korean traditional alcoholic beverages, non-distilled alcohol, and whisky were detected in the range of $4.6-50.2{\mu}g/L$, $27.8-45.4{\mu}g/L$, and $24.8-55.1{\mu}g/L$, respectively. The recoveries were ranged from 83.3 to 104.8 %. The values of relative standard deviation were ranged from 1.8 to 14.8 % and the detection limit was $0.3{\mu}g/L$.

• Journal of the Korean Society of Tobacco Science
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• v.36 no.1
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• pp.12-19
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• 2014

A matrix solid-phase dispersion (MSPD) method was developed for extracting and cleaning-up the selected agrochemicals in tobacco using gas chromatography-mass spectrometry with selected ion monitoring (GC/MS-SIM). Different parameters of the method were investigated and optimized, such as the type of solid-phase (alumina, $C_{18}$ and Florisil) and eluent (acetone, acetonitrile, ethylacetate and n-hexane). The best results were obtained using 0.5 g of tobacco sample, 1.0 g of $C_{18}$ as dispersant sorbent, 1.0 g of Florisil as clean-up sorbent and acetonitile saturated with n-hexane as eluting solvent. The method was validated using tobacco samples fortified with agrochemicals at their different concentration levels. This method gave good linearity for the selected agrochemicals of ranging from $0.01{\mu}g/mL$ to $0.1{\mu}g/mL$. Recoveries of the selected agrochemicals in tobacco were more than 80 % and reproducibilities were found to be better than 10 % RSD. Those results suggested that the analytical procedure including MSPD method in combining with GC/MS could be applicable to the rapid determination often the selected agrochemicals in tobacco.