• Archives of Pharmacal Research
• /
• v.19 no.6
• /
• pp.566-569
• /
• 1996

A sensitivity method has been developed for the detection and determination of niflmic acid(NA) in human urine. Samples were extracted with diethylether. Flunixin (FN) was added to the sample prior to extraction as an internal standard. Niflumic acid was converted to its methyl derivative and analyzed by capillary gas chromatography/negative chemical isonization mass spectrometry. Using selected ion monitoring (SIM), the levels of NA down to 5 pg/ml could be detected in 5 ml spiked urine sample. Calibration curve was linear over the range of 0.5 ppm-50 ppm. The recovery of niflumic acid from urine at 40 pg/ml was to be $91.7{\pm}3.8(n=3)$ and the coefficient of variation was 4.1%.

• Bulletin of the Korean Chemical Society
• /
• v.19 no.1
• /
• pp.45-50
• /
• 1998

Most organophosphorus pesticides may be metabolized to yield some common phosphates in human or in animals, and these metabolites may be used as the exposure biomarkers to pesticides. In this study, we developed the extraction method of four phosphate metabolites from the spiked human urine in high recovery by the solid phase extraction with a reverse-phase cartridge (cyclohexyl silica) followed by the elution with methanol. The extracted urinary metabolites were derivatized with hexamethyldisilazane/trimethyl-chlorosilane/pyridine (2 : 1 : 10, v/v/v) and identified by gas chromatography/mass spectrometry. Calibration curve obtained from each metabolite standard using by GC/MS/SIM has shown good linearity and detection limits of metabolites were the range of 0.05-0.1 ㎍/㎖ in urine. Phenthoate, one of the organophosphorus pesticides, was orally administrated to rats. Four metabolites were detected in the rat urine. The results of this study may be applied to development of exposure biomarkers for monitoring of environmental pollutants.

• Analytical Science and Technology
• /
• v.13 no.4
• /
• pp.484-493
• /
• 2000

The simultaneous analysis of alkylphenols, chlorophenols and bisphenol A in biota samples was performed by gas chromatography-mass spectrometry-selected ion monitoring mode. The phenols were extracted from sample with organic solvent and Forisil and Silica columns for clean-up procedure were compared. Recovery studies were performed at 1-ppm level of phenols added to each biota sample. Their recoveries ranged between 83 and 116% with coefficient of variations of 2.4-11.9%. To improve the detection limits of phenols, trimethylsilyl (TMS) derivatization was applied. The gas chromatographic properties of free phenols and TMS derivatized phenols were also investigated.

• Bulletin of the Korean Chemical Society
• /
• v.33 no.5
• /
• pp.1693-1698
• /
• 2012

A headspace gas chromatographic mass spectrometric (GC-MS) assay method was developed for the simultaneous determination of methyl tertiary butyl ether (MTBE), $tert$-butyl alcohol (TBA) and benzene, toluene, ethyl benzene and xylene (BTEX) in soil contaminated with gasoline. 2 g of soil sample were placed in a 10 mL headspace vial filled with 5 mL of phosphoric acid solution (pH 3) saturated with NaCl, and the solution was spiked with fluorobenzene as an internal standard and sealed with a cap. The vial was heated in a heating block for 40 min at $80^{\circ}C$. The detection limits of the assay were 0.08-0.12 ${\mu}g$/kg for the analytes. For five independent determinations at 10 and 50 ${\mu}g$/kg, the relative standard deviations were less than 10%. The method was used to analyze fifty six soil samples collected from various regions contaminated with gasoline in Korea. The developed method may be valuable for the monitoring of the analytes in soil.

• Microbiology and Biotechnology Letters
• /
• v.41 no.3
• /
• pp.272-277
• /
• 2013

In this study, the tar compounds derived from the plant cell cultures of Taxus chinensis were first identified and then quantified via gas chromatography/mass spectrometry (GC/MS) and gas chromatography (GC). 2-Picoline, 2,5-xylenol, acenaphthene, 1-methylnaphthalene and o-xylene were found to be the major tar compounds by biomass. These compounds were identified and confirmed by comparing their retention times with those of authentic compounds. Each compound also spiked with the pure standard. The contents of 2-picoline, 2,5-xylenol, acenaphthene, 1-methylnaphthalene, and o-xylene in biomass were 0.2512, 0.1586, 0.1240, 0.0942 and 0.0525 wt%, respectively. Liquid-liquid extraction and adsorbent treatment were able to remove 42% and 94% of the tars from biomass, respectivly. After hexane precipitation, all of the tars were perfectly removed.

• Journal of the Korean Chemical Society
• /
• v.38 no.10
• /
• pp.726-733
• /
• 1994

Supercritical fluid extraction (SFE) followed by gas chromatographic separation and mass spectrometric (MS) detection were used in rapid analysis of polycyclic aromatic hydrocarbons (PAH's) in air particulate material extracted for 30 min with 10 ml of supercritical $N_2O$ without another sample preparation step. Two samples, urban dust in Seoul area and a certified air particulate reference material 1649 supplied by the NBS (National Bureau of Standards), were processed for the purpose of evaluating extraction and analysis methods. As a result, the quantitative recovery of PAH's in the SFE method was relatively lower than conventional organic solvent extraction methods, but reproducibility was resonable, and analysis time was reduced remarkably. The method has proved to be suitable for monitoring of PAH's in air particulate material.

• Journal of Life Science
• /
• v.10 no.2
• /
• pp.115-124
• /
• 2000

The present study was undertaken to separate the available components effectively, such as tetrodotoxin(TTX), docosahexaenoic acid(DHA, C22:6,ω-3) and eicosapentaenoic acid (EPA, C20:5,ω -3) from pufferfish liver waste, which are known to have high values as bioactive materials. By using ultrafiltration, it was possible to separate high contents of 68mg TTX from pufferfish liver waste. In contrast, by activated charcoal column, it was to obtain about 54mg TTX. The recovering ratios were 65.3% and 45.0% in the two different methods of ultrafiltration and activated charcoal column, respectively. From the results of HPLC and gas chromatography-mass spectrometry(GC-MS), the obtained toxins were identified to be TTX and its derivatives. In addition, it was also possible to obtain 72.3g DHA and 11.4g EPA from 1kg of pufferfish liver by high performance liquid chromatography (HPLC). These amounts of DHA and EPA were also 17.70% and 1.04% in the total lipid of pufferfish liver oil from analysis of gas chromatography(GC), respectively.

• Bulletin of the Korean Chemical Society
• /
• v.30 no.7
• /
• pp.1489-1496
• /
• 2009

This study was done for the determination and excretion profile of adrenosterone and its metabolites in human urine using both liquid chromatography with atmospheric pressure chemical ionization mass spectrometry and gas chromatography with mass spectrometry. Adrenosterone and its two metabolites were detected in human urine after administration a healthy volunteer with 75 mg of adrenosterone. We found that adrenosterone-M1 ($C_{19}H_{26}O_3$) was a reduction and adrenosterone-M2 ($C_{19}H_{26}O_4$) was a hydroxylation at C-ring, which did not know the exact position of the C-ring. The adrenosterone parent was detected by GC/TOF-MS, but not detected by LC/APCI/MS because of low intensity. Adrenosterone and its two metabolites were excreted as their glucuronided fractions. The recovery of this method ranged from 100.7 to 118.4% and the reproducibility and accuracy test were 85.5 to 112.0% and 1.1 to 8.4%, respectively. The excretion studies showed that adrenosterone and its metabolites were detectable in human urine during a 48 h period after oral administration, with maximum level of excretion at 4.1 h. The glucuro-/sulfaconjugated ratio of adrenosterone, M1 and M2 was 0.73 ${\pm}$ 0.03, 0.96 ${\pm}$ 0.06 and 0.89 ${\pm}$ 0.03 (n = 6), respectively. The amounts of adrenosterone excreted in urine were 14.75 ng for 48 h. Also, the maximum level of androsterone and 11$\beta$-hydroxy androsterone, which were endogenous steroids, were reached 4.1 h after the oral administration of adrenosterone.

• Bulletin of the Korean Chemical Society
• /
• v.32 no.5
• /
• pp.1547-1553
• /
• 2011

An effective analytical method of gas chromatography/mass spectrometry (GC/MS) was developed for the rapid determination of essential oils in the crude extract of Acorus species (Acorus gramineus, Acorus tatarinowii, and Acorus calamus). Major phenypropanoids (${\beta}$,${\alpha}$-asarone isomers, euasarone, and methyleugenol) and ${\beta}$-caryophyllene in Acorus species were used as marker compounds and determined for the quality control of herbal medicines. To extract marker compounds, various extraction techniques such as solvent immersion, mechanical shaking, and sonication were compared, and the greatest efficiency was observed with sonication extraction using petroleum ether. The dynamic range of the GC/MS method depended on the specific analyte; acceptable quantification was obtained between 10 and 2000 ${\mu}g/mL$ for ${\beta}$-asarone, 10 and 500 ${\mu}g/mL$ for ${\alpha}$-asarone, 10 and 200 ${\mu}g/mL$ for methyleugenol, and between 5 and 100 ${\mu}g/mL$ for ${\beta}$-caryophyllene. The method was deemed satisfactory by inter- and intra-day validation and exhibited both high accuracy and precision, with a relative standard deviation < 10%. Overall limits of detection were approximately 0.34-0.83 ${\mu}g/mL$, with a standard deviation (${\sigma}$)-to-calibration slope (s) ratio (${\sigma}$/s) of 3. The limit of quantitation in our experiments was approximately 1.13-3.20 ${\mu}g/mL$ at a ${\sigma}$/s of 10. On the basement of method validation, 20 samples of Acorus species collected from markets in Korea were monitored for the quality control. In addition, principal component analysis (PCA) and hierarchical cluster analysis (HCA) were performed on the analytical data of 20 different Acorus species samples in order to classify samples that were collected from different regions.

• Archives of Pharmacal Research
• /
• v.28 no.9
• /
• pp.1086-1091
• /
• 2005

An analytical method was developed for evaluating the cannabidiol (CBO), cannabinol (CBN), ${\Delta}^9-tetrahydrocannabinol$ $({\Delta}^9-THC)$ level in human hair using gas chromatography-mass spectrometry (GC-MS). Hair samples (50mg) were washed with isopropyl alcohol and cut into small fragments (< 1mm). After adding a deuterated internal standard, the hair samples were incubated in 1.0M NaOH for 10 min at $95^{\circ}C$. The analytes from the resulting hydrolyzed samples were extracted using a mixture of n-hexane-ethyl acetate (75:25, v/v). The extracts were then evaporated, derivatized, and injected into the GC-MS. The recovery ranges of CBD, CBN, and ${\Delta}^9-THC$ at three concentration levels were $37.9-94.5\%$ with good correlation coefficients $(r^2>0.9989)$. The intra-day precision and accuracy ranged from $-9.4\%\;to\;17.7\%$, and the inter-day precision and accuracy ranged from $-15.5\%\;to\;14.5\%$, respectively. The limits of detection (LOD) for CBD, CBN, and ${\Delta}^9-THC$ were 0.005, 0.002, and 0.006 ng/mg, respectively. The applicability of this method of analyzing the hair samples from cannabis abusers was demonstrated.