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

• KSBB Journal
• /
• v.18 no.1
• /
• pp.74-77
• /
• 2003

A simple, reproducible, and rapid gas chromatographic method for putrefactive metabolite determination in feces was developed. The method involves the direct injection of fecal supernatants into the gas chromatograph, without pretreatment. The mass spectra of these metabolites were obtained using an HP 5971 mass selective detector operated in electron impact (EI) ionization mode. This method produced sharp peaks and allowed the simultaneous determination of fecal putrefactive metabolites.

• Korean Journal of Pharmacognosy
• /
• v.16 no.3
• /
• pp.136-140
• /
• 1985

Sixty-eight kinds of aliphatic and aromatic substances peaks from ether extract of Codonopsis pilosulae Radix were shown by GC-Mass. Of them, 3 kinds of compounds were identified as ethyl benzene, acetophenone and 1-phenyl-2-butanone, which are compared with authentic specimen, and one compound was assumed as an aliphatic $C_8H_{16}O\;or\;C_9H_{20}$.

• Bulletin of the Korean Chemical Society
• /
• v.26 no.4
• /
• pp.575-578
• /
• 2005

Electrospray ionization mass spectrometry (ESI MS) was used, along with gas chromatography-mass spectrometry (GC-MS), to monitor Paal-Knorr synthesis of 2,5-dimethyl-1-phenylpyrrole by condensation of aniline with 2,5-hexanedione. In addition to 2,5-dimethyl-1-phenylpyrrole observed as a single spot by TLC, unexpected dimer size compounds were observed by GC-MS. Dimers and trimers were observed by ESI MS. ESI tandem mass spectrometry was used to select plausible structures for the dimer. ESI MS with or without liquid chromatographic separation is useful for observing oligomeric byproducts with low volatility produced in organic reactions.

• Mass Spectrometry Letters
• /
• v.14 no.2
• /
• pp.25-35
• /
• 2023

Plants are a traditional source of many chemicals used as biochemical, flavors, food, color, and pharmaceuticals in various countries, especially India. Most herbal medicines and their derivatives are often made from crude extracts containing a complex mixture of various phytochemical chemical components (secondary metabolites of the plants). This study aimed to identify bioactive compounds from the different parts of the plant from the ethanolic extract of Gymnema sylvestre, Senna auriculata, and Cissus quadrangularis (leaves, flower, stem) by gas chromatography-mass spectroscopy (GC-MS). The gas chromatography - mass spectrometry analysis revealed the presence of various compounds like 3,4-dimethylcyclohexanol, hexanoic acid, D-mannose, and N-decanoic acid. Hence, the Gymnema sylvestre, Senna auriculata, and Cissus quadrangularis may have chemopreventive, anti-cancer, anti-microbial activity, antioxidant, anti-diabetic activity, anti-inflammatory, and antifungal due to the presence of secondary metabolites in the ethanolic extract. These phytochemicals are supported for traditional use in a variety of diseases.

• Mass Spectrometry Letters
• /
• v.14 no.3
• /
• pp.79-90
• /
• 2023

Natural goods, especially therapeutic plants, are abundant in the World. Because they have the ability to provide all humanity with countless advantages as a source of medicines, medicinal plants are presently receiving more attention than ever. These plants' therapeutic efficacy is based on bioactive phytochemical components that have clear physiological effects on the human body. The drying process is crucial for the preparation of plant materials prior to extraction since freshly harvested plant materials include active enzymes that create active components, intermediates, and metabolic processes. Many of the phytoconstituents may be extracted using the semi-polar solvent methanol. The goal of the current work is to use the GC-MS gas chromatography- mass spectrometry technology to identify the phytochemicals and review their biological activity. In methanol leaf extract, 5 phytocompounds were found in Ricinus communis, 5 phytocompounds in Pongamia pinnata, 12 phytocompounds in Datura metal, 7 phytocompounds in Azadirachta indica, 11 phytocompounds in Acalypha indica.

• The Korean Journal of Food And Nutrition
• /
• v.10 no.4
• /
• pp.539-543
• /
• 1997

This study was carried out to investigate the Chinese and Baek-Seok chive. We collect the volatile components of Chinese and Baek-Seok chive by dynamic head space method. Chinese chive was analyzed by Gas chromatography-Mass Spectrometry(GC-MS). 28 components including 20 sulfides, 5 alcohols, 1 benzene and 2 aldehydes compounds were identified in samples, Also Baek-Seok chive was analyzed by GC-MS. 32 components including 19 sulfides, 10 alcohols, 2 benzonoides and 1 aldehyde compounds were confirmed.

• Journal of The Korean Astronomical Society
• /
• v.43 no.4
• /
• pp.105-113
• /
• 2010

We study the dynamical evolution of the M87 globular cluster (GC) system using the most advanced and realistic Fokker-Planck (FP) model.By comparing our FP models with both mass function (MF) and radial distribution (RD) of the observed GC system, we find the best-fit initial (at M87's age of 2-3 Gyr) MF and RD for three GC groups: all GCs, blue GCs, and red GCs. We estimate the initial total mass in GCs to be $1.8^{+0.3}_{-0.2}{\times}10^{10}M_{\bigodot}$, which is about 100 times larger than that of the Milky Way GC system. We also find that the fraction of the total mass currently in GCs is 34\%. When blue and red GCs are fitted separately, blue GCs initially have a larger total mass and a shallower radial distribution than red GCs. If one assumes that most of the significant major merger events of M87 have ended by the age of 2-3 Gyr, our finding that blue (metal-poor) GCs initially had a shallower radial distribution supports the major merger scenario for the origin of metallicity bimodality.

• Mass Spectrometry Letters
• /
• v.1 no.1
• /
• pp.29-32
• /
• 2010

Cross reacting antibodies can cause an overestimation of the results of immunoassays. Therefore, alternative methods are needed for the accurate quantification of steroids. Gas chromatography combined with isotope-dilution mass spectrometry (GC-IDMS) is developed to quantify urinary active androgens, testosterone, epitestosterone and dihydrotestosterone, which are clinically relevant androgens to both hair-loss and prostate diseases. The method devised involves enzymatic hydrolysis with $\beta$-glucuronidase, solid-phase extraction, liquid-liquid extraction using methyl tert-butyl ether and subsequent conversion to pentafluorophenyldimethylsilyl-trimethylsilyl (flophemesyl-TMS) derivatives for sensitive and selective analysis in selected-ion monitoring mode. Flophemesyl-TMS derivatization not only eliminates matrix interference but also has a good peak resolution within a 6 min-run. A selective and sensitive GC technique with flophemesyl-TMS derivatives also allows accurate quantitative analysis of three active androgens when combined with IDMS. The limit of quantification of the three analytes was <50 pg/mL, and extraction recoveries ranged from 91.9 to 102.1%. The precision and accuracy were 1.2~6.5% and 89.0~106.7%, respectively. This GC-IDMS method can be useful for evaluating the drug efficacy and monitoring the biological processes responsible for male-pattern baldness and prostate diseases.

• Analytical Science and Technology
• /
• v.13 no.5
• /
• pp.666-674
• /
• 2000

The present study describes an analytical method for the determination of polybrominated biphenyls (PBBs) in biota samples by gas chromatography-mass spectrometry (GC/MS). PBBs are extracted twice from 20 g samples with mixture solvent 40mL acetone and 80mL hexane using ultrasonic agitation for 20 min. Lipids in extracts are degraded by concentrated sulfuric acid and then PBBs are purified with Florisil column. The purified extracts are analyzed by GC/MS-selected ion monitoring mode for the quantitation of PBBs in biota sample. The overall recovery yields of PBBs range between 77 and 111% under these experimental conditions.