• Analytical Science and Technology
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• v.34 no.1
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• pp.23-35
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• 2021

In order to measure the volatile organic compounds (VOCs) of a sample which is too large to use commercially available chamber, a stainless steel vacuum chamber (VC) (with an internal diameter of 205 mm and a height of 50 mm) was manufactured and the temperature of the chamber was controlled using an oven. After concentrating the volatiles of the sample in the chamber by helium gas, it was made possible to remove residual volatile substances present in the chamber under reduced pressure ((2 ± 1) × 10-2 mmHg). The chamber was connected to a purge & trap (P&T) using a 6 port valve to concentrate the VOCs, which were analyzed by gas chromatography-mass spectrometry (GC-MS) after thermal desorption (VC-P&T-GC-MS). Using toluene, the toluene recovery rate of this device was 85 ± 2 %, reproducibility was 5 ± 2 %, and the detection limit was 0.01 ng L-1. The method of removing VOCs remaining in the chamber with helium and the method of removing those with reduced pressure was compared using Korean drinking water regulation (KDWR) VOC Mix A (5 μL of 100 ㎍ mL-1) and butylated hydroxytoluene (BHT, 2 μL of 500 ㎍ mL-1). In case of using helium, which requires a large amount of gas and time, reduced pressure ((2 ± 1) × 10-2 mmHg) only during the GC-MS running time, could remove VOCs and BHT to less than 0.1 % of the original injection concentration. As a result of analyzing volatile substances using VC-P&T-GC-MS of six types of cell phone case, BHT was detected in four types and quantitatively analyzed. Maintaining the chamber at reduced pressure during the GC-MS analysis time eliminated memory effect and did not affect the next sample analysis. The volatile substances in a cell phone case were also analyzed by dynamic headspace (HT3) and GC-MS, and the results of the analysis were compared with those of VC-P&T-GC-MS. Considering the chamber volume and sample weight, the VC-P&T configuration was able to collect volatile substances more efficiently than the HT3. The VC-P&T-GC-MS system is believed to be useful for VOCs measurement of inhomogeneous large sample or devices used inside clean rooms.

• Natural Product Sciences
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• v.21 no.2
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• pp.87-92
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• 2015

The stem barks, heartwoods, and leaves of Acer tegmentosum (Aceraceae) are widely used in Korea to treat hepatic or cerebral disorders mainly due to alcohol poisoning. This study was aimed to analyze phenolic substances in A. tegmentosum. Quantitative analysis of the three phenolic substances (salidroside, (+)-catechin and scopoletin) was performed by HPLC and the identification of volatile phenolic substances were done by GC-MS. The contents of the three compounds in the three MeOH extracts were higher in the stem bark (salidroside: 80.22 mg/g, (+)-catechin: 23.31 mg/g, and scopoletin: 9.45 mg/g) compared to the heartwoods and leaves. And GC-MS analysis of the stem bark extract demonstrated that p-tyrosol is a main substance of twenty-one compounds identified.

• Elastomers and Composites
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• v.52 no.1
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• pp.59-68
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• 2017

The effect on the hydrolysis resistance properties by the addition of maleic anhydride grafted EMDM (MA-g-EPDM) and PP (MA-g-PP) to a PA66/GF composite was investigated with respect to the mechanical properties, thermal properties, and morphology. The degree of hydrolysis of the PA66/GF composite was measured using py-GC/MS analysis. When compared to the PA66/GFcomposite in MEG/water solution, the composites where MA-g-EPDM and MA-g-PP were added to PA66/GF showed a higher degree of hydrolysis resistance, impact strength, and thermal properties, whereas their tensile strength, tensile modulus, flexural strength and flexural modulus decreased. As immersion time in the solution increases, the rate of tensile strength drop of the MA-g-PP added composite appeared lower than that of the PA66/MA-g-EPDM/GF and PA66/GF composites. The py-GC/MS analysis confirmed the formation of PA66 hydrolysis reaction by products such as carboxylic acid and alkylamine with increasing immersion time.

• Journal of the Korean Society of Food Science and Nutrition
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• v.24 no.3
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• pp.459-465
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• 1995

The ether extract of Salviae miltiorrhizae Radix(SMR) was fractioned to give five subfractions, so that two subfractions of them were recrystallized to yield each pure diterpene quinone pigment. On the basis of spectral evidence, these two compounds were identified as tanshinone II and crytotanshinone. Cryptotanshinone exhibited both of a potent platelet anti-aggregating activity in vitro and a potent antimicrobial activity. GC-MS analysis of the other extract showed that tanshinone II was contained in the largest proportion of all the diterpene quinones. In addition, GC-MS analysis gave other valuable analytical informations.

• Mass Spectrometry Letters
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• v.11 no.4
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• pp.95-102
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• 2020

In this study, we provide full descriptions of how to make a low-cost and completely open-source laboratory-made air sampler that will be used for sample adsorption for thermal desorption-gas chromatography mass spectrometry (TD-GC/MS) analysis. It is well known that harmful gases cause bad effects on human bodies, so it is necessary to identify the types and amounts of gases in industrial sites. One of the most commonly used methods for gas sampling is to utilize a sorbent tube using an air sampler. Commercially available air samplers are expensive, typically priced between $1,000 and $2,000, and their design often cannot be modified to fit the experiment. To address these shortcomings, we have developed a do-it-yourself (DIY) air sampler that is not only cheap enough, but also completely open-source. Furthermore, the performance of the fabricated air sampler was validated in conjunction with TD-GC/MS for the analysis of volatile compounds.

• Journal of the Korean Society of Tobacco Science
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• v.27 no.1 s.53
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• pp.100-106
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• 2005

To obtain the optimum condition for analysis of 10 alkaloids in tobacco leaves, such as nicotine, nornicotine, anatabine, anabasine, myosmine, cotinine, 2,3'-dipyridyl, $\beta-nicotyrine,\;\beta-nornicotyrine\;and\;\beta-formylnornicotin$, 5 types of extraction method were investigated by GC-FID and GC/MS. The optimum condition of alkaloid extraction was achieved by using methanol:dichloromethane(1:3, v/v) after NaOH treatment. The use of mass selective detector (MSD) provided unambiguous nicotine related alkaloid analysis. Alkaloids in various tobacco leaves were extracted with the optimum extraction condition and quantified by GC/MS/SIM mode. Compared with concentrations of alkaloids among the various tobacco leaves, the concentration of alkaloids was generally in the order burley > flue-cured > oriental tobacco. In flue-cured tobacco leaves, the order of concentration of alkaloids was nicotine > anatabine > nornicotine > $\beta-nicotyrine\;>\;\beta-formylnornicotine\; >\;myosmine\;>\;2,3'-dipyridyl\;>\;cotinine\;>\;anabasine\;>\;\beta-nornicotyrine$. However, in the case of burley and oriental tobacco leaves, the concentration of nornicotine was higher than that of anatabine.

• The Research Journal of the Costume Culture
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• v.12 no.4
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• pp.579-590
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• 2004

This research was aimed to investigate and compare the effectiveness of TLC and GC-MS methods in the analysis of chromophoric substances extracted from madder plant. Alizarin and purpurin 0.3% solution were used as comparative standards; madder extraction was prepared by heating the solution of powdered madder at 80℃, pH 1.5, for 90 min. Best elution solvent for TLC in silica gel plate was toluene:ethyl acetate=9:1, which resulted in red and yellow spots from madder extraction each of which showed R/sub f/ values 0.32-0.43 and 0.07-0.11. Although the red spot in particular exhibited similar characteristics as standard purpurin in color, shape, and R/sub f/ values, the result was inconsistent throughout different TLC trials. GC-MS analysis showed only small amount of alizarin and no purpurin in the madder extraction. Other chromophoric substance such as 2-furancarboxaldehyde, 5-(hydroxymethyl)-, anthralin, and danthron were also detected in small amounts. The result indicated that TLC was less sensitive to detecting and identifying the natural dyestuff which is generally constituted with a number of similar but chemically different chromophoric substances.

• Journal of Ginseng Research
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• v.20 no.3
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• pp.284-290
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• 1996

To Identify phenolic components known to exist in Korean ginseng (Panax ginseng C.A. Meyer) by GC/MS, three derivatization methods were employed for their analyses. First, phenolic components in ether soluble acidic fraction prepared from Korean red ginseng powder were taimethylsilylated. Secondly, phenolic acids in the same fraction were esterified with diazomethane followed by trlmethylsilylation. Thirdly, acidic components in ginseng powder were extracted and esterified concurrently by methanolic sulfuric acid, followed by fractionation of phenolic components with Silica Sep-Paka and trimethylsilylatlon. All phenolic components found in ginseng except gen tisic acid were identified by retention times and mass spectrums of standards. Besides, 5 phenolic components including salicyl alcohol and 1-H-indole-2-carboxylic acid were first identified from Korea an red ginseng by GC/MS.

• Proceedings of the PSK Conference
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• 2003.04a
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• pp.169.2-169.2
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• 2003

A method using EI-GC-MS is described for the determination of amphetamines in hair. The method is applied to simultaneous quantify amphetamines (methamphetamine, amphetamine, MDMA and MDA). Drugs were extracted in 1 ％ HCl in methanol from hair. After derivertization with TFAA, the resulting drugs were separated on HP-5MS column during a 16 min program and identified by mass spectrometry with the SIM mode(EI-GC-MS). (omitted)

• YAKHAK HOEJI
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• v.54 no.6
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• pp.429-440
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• 2010

HS-SPME-GC/MS was studied and optimized for the determination of 17 orgarnophosphorous pesiticides (OPPs: chlorpyrifos, chlorpyrifos-methyl, demeton-s-methyl, diazinon, dimethoate, EPN, fenitrothion, fenthion, malathion, methidathion, monocrotophos, parathion, phenthoate, phosphamidon, sulfotep, terbufos, triazophos) in blood. Optimum SPME parameters were selected: choice of SPME fiber (85 ${\mu}m$ polyacrylate), pH effect (0.5 N HCl), salt effect ($Na_2SO_4$, 0.2 g; 20%), headspace incubation temperature ($80^{\circ}C$), headspace incubation time (1 min), headspace adsorption time (30 min) and GC desorption time (2 min). These parameters were optimized using HS-SPME autosampler coupled with gas chromatography-mass spectrometry (GC-MS). Method validation was carried out in terms of linearity, limit of detection (LOD), limit of quantitation (LOQ) and recovery in blood. The assay was linear over 0.5~5.0 mg/l ($r^2$=0.955~1.000). Limit of detection (LOD) and limit of quantitation (LOQ) in blood were determined 0.03~0.3 mg/l (S/N=3) and 0.1~1.1 mg/l (S/N=10), respectively. Relative recovery with 0.5, 1 and 5 mg/l (in blood) were 90.8%, 98.5% and 94.1%, respectively. This method will be applied to the determination of the orgarnophosphorous pesticides in postmortem blood. The proposed protocol can be an attractive alternative to be used in routine toxicological analysis.