• Analytical Science and Technology
• /
• v.29 no.1
• /
• pp.49-55
• /
• 2016

A ketone body (acetoacetic acid, β-hydroxybutyric acid, and acetone) increases from blood or urine when bio-energy dependence pays more fatty acid than glucose. However, in case oxidation of fat is greater than the capacity of the citric acid cycle the fatty acid oxidation is made from acetoacetyl CoA to acetoacetate then, again form β-hydroxyburytic acid to acetone, the diffusion take place into the blood. Enzymes that oxidize ketone body in the brain and nerve tissue blood ketone dody is increased during prolonged fasting, brain used it as energy. In this study, we developed the rapid two step derivatization method for sensitive detection of the ketone body by GC-MS/SIM. The plasma was deproteinized and then the hydroxy and carboxyl groups of ketone body are subjected to extraction and drying then, keto-group were derivatized with hydoxylamine at 60℃ for 30 min for oximation. Then it was trimetyl-silylated with BSTFA at 80℃ for 30 min and analyzed using a GC-MS. The linear ranges were in between 0.001 μg/mL and 250 μg/mL for β-hydroxy butyrate, and acetoacetate. The method detection limits were below 0.1 pg over each target compound determined. The mean recoveries (%) of target compounds were ranged from 88.2 % to 92.3 % at 1 µg/mL, from 89.5 % to 94.8 % at 10 μg/mL, with RSD of 6.3-9.4 %. This method could be applied to quantification of ketone bodies which are seen in the keto-acidosis in children and adults from a variety of diseases that cause ketones in the blood and urine.

• Environmental Analysis Health and Toxicology
• /
• v.17 no.1
• /
• pp.37-51
• /
• 2002

Eleven phenols including two chlorophenols, eight alkylphenols and bisphenol A were derivatized with isobutylchloroformate to form their isobutoxycarbonyl derivatives. Standard phenol mixture was concentrated for the isobutoxycarbonyl (isoBOC) derivatization and analysed by gas chromatography/mass spectrometry (GC/MS). The recoveries of the derivatization method of alkylphenols, chlorophenols, and bisphenol A were calculated by gas chromatography/mass spectrometry-selected ion monitoring mode using two work-up methods for comparison; shaking and heating method. The linear detector responses were obtained in the concentration range of 5∼400 ng, with correlation coefficients varying from 0.9755∼0.9981. Recoveries of the alkylphenols, chlorophenols, and bisphenol A were determined by gas chromatography/mass spectrometry-selected ion monitoring mode using two work-up methods for comparison ; the US-EPA method and the isoBOC derivatization method, Eleven phenols in water samples were extracted with dichloromethane and then concentrated. Also, solid-phase extraction (SPE) with XAD-4 and subsequent conversion to isobutoxycarbonyl derivatives for sensitive analysis with the selected ion-monitoring (SIM) mode. The recoveries were 85.1∼109.9％ and 90.3∼126.6％ for the US-EPA method and the isoBOC.

• Analytical Science and Technology
• /
• v.15 no.3
• /
• pp.185-189
• /
• 2002

International Olympic Committee (IOC) prohibits the use of cyclofenil for male. To prove whether cyclofenil product was taken or not, the analytical method in urine using GC/MS was established. The extraction recoveries of cyclofenil and its metabolites were higher in the range of pH 5-9. Because the parent drug (cyclofenil) was not excreted in urine, metabolites were detected and theses were used as a criteria of cyclofenil dose. Therefore the metabolites were hydrolyzed, extracted at pH 9.6, derivatized with MSTFA and analyzed by GC/MS.

• Journal of Marine Bioscience and Biotechnology
• /
• v.15 no.2
• /
• pp.96-102
• /
• 2023

Salicornia herbacea, a noted halophyte, has been widely researched for its diverse physiological activities. The continuous exploration of its compounds is essential. This study employed gas chromatography (GC) coupled with mass spectrometry (MS) for qualitative analysis. This involved pretreatment including trimethylsilyl (TMS) derivatization of the S. herbacea extract, facilitating its GC analysis. Five compounds, including various fatty acids and β-sitosterol, were identified by direct analysis of the methanol extract of S. herbacea without pretreatment by GC-MS. Conversely, the analysis of the TMS-derivatized extract revealed 28 distinct peaks. Quantitative analysis further indicated that the predominant compounds in the S. herbacea extract were sugars and sugar derivatives, notably glucose, fructose, and glucitol. The collective concentration of these sugars and its derivatives amounted to 116.45 mg/g, representing 11.6% of the dry weight of the raw S. herbacea. Following sugars and their derivatives, fatty acids constituted the next most abundant group of compounds. However, the presence of amino acids and organic acids was relatively low.

• Analytical Science and Technology
• /
• v.20 no.3
• /
• pp.198-203
• /
• 2007

The analysis method of 3-Monochloropropane-1,2-diol (3-MCPD) compound in water was developed using liquid chromatography with mass spectrometric detection. Aqueous solution was controlled in strong basic condition with sodium hydroxide, and then $25{\mu}L$ of benzoyl chloride was added to the solution for the derivatization of 3-MCPD. The derivative was extracted using pentane and analyzed by the selected ion monitoring (SIM) method of LC-MS. The results of analyses showed that the calibration curves was in the range of 1.0 to $100{\mu}g/mL$ with a good linearity (correlation coefficient of $r^2=0.992$) and limit of detection was below $0.01{\mu}g/mL$. The recoveries of this analysis method by LC-MS were 92.3-98.0 %.

• Analytical Science and Technology
• /
• v.18 no.2
• /
• pp.163-167
• /
• 2005

In this study, a novel analytical method has been developed for the rapid determination of L-carnitine in human plasma using electrospray ionization tandem mass spectrometry. Free carnitine (FC) was analyzed after extraction with 80% methanol and total carnitine (TC) was analyzed after hydrolysis and extraction. Acyl carnitine (AC) was subtracted FC from TC. Analytical methods used multiple reaction monitoring (MRM) scan modes. A correlation coefficient of linear regression ($r^2$) was 0.9995, recovery was 97%, reproducibility was less than 10%, and limit of detection (LOD) was $0.0016{\mu}mol/L$. This method reduced sample preparation time and showed high resolution and good reproducibility compared to that with liquid chromatographic methods. Normal control showed AC was lower than FC. Clinical management of patients with inborn error of metabolism showed FC was lower than AC. Thus, carnitine fraction level was very important to monitoring patients with metabolic disorder.

• Journal of Korean Society of Water and Wastewater
• /
• v.18 no.5
• /
• pp.638-648
• /
• 2004

In many drinking water treatment plants, chlorination process is one of the main techniques used for the disinfection of water. This disinfecting treatment leads to the formation of haloacetic acid (HAAs). In this study, headspace solid-phase microextraction (HS-SPME) was studied as a possible alternative to liquid-liquid extraction for the analysis of HAAs in drinking water. The method involves direct derivatization of the acids to their methyl esters without methyl tert-butyl ether (MTBE) extraction, followed by HS-SPME with a $2cm-50/30{\mu}m$ divinylbenzene/carboxen/polydimethylsiloxane fiber. The effects of experimental parameters such as selection of SPME fiber, the volume of sulphuric acid and methanol, derivatization temperature and time, the addition of salts, extraction temperature and time, and desorption time on the analysis were investigated. Analytical parameters such as linearity, repeatability and limit of detection were also evaluated. The $2cm-50/30{\mu}m$-divinylbenzene/carboxen/polydimethylsiloxane fiber, sulphuric acid of 1ml, methanol of 3ml, derivatization temperature of $50^{\circ}C$ derivatization time of 2hrs, sodium chloride salt of 10g, extraction time of 30 minutes, extraction temperature of $20^{\circ}C$ and desorption time of 1 minute at $260^{\circ}C$ were selected as the optimal experimental conditions for the analysis of HAAs. The linearities ($r^2$), relative standard deviations (%RSD) and limits of detection (LOD) for HAAs were 0.9978~0.9991, 1.1~9.8% and $0.05{\sim}0.2{\mu}g/l$, respectively.

• Analytical Science and Technology
• /
• v.7 no.1
• /
• pp.65-78
• /
• 1994

The herbicide mixture of 7 triazines and 9 phenoxyalkanoic acid esters was simultaneously separated and determinated with the selected ion monitoring by using gas chromatography/mass spectrometry. The extraction recoveries of those herbicides from the reagent water were studied for the organic solvent extraction(LLE) with methylene chloride. The calibration curves of them showed good linearity over the concentration range of 0.2~0.5ng/ml and the detection limits were 0.2~0.5ng/ml for 100ml of water. This analytical method could be applied to the drinking water and biological sample.

• Analytical Science and Technology
• /
• v.12 no.4
• /
• pp.265-272
• /
• 1999

A simultaneous profile analysis of 19 environmental estrogens, which act like estrogen and may effect the endocrine system by binding to hormone receptors or influencing cell signaling pathways, was attempted. The present method was based on the selected ion monitoring (SIM) mode of gas chromatography/mass spectrometry (GC/MS). It involves solid-liquid extraction, enzyme hydrolysis, liquid-liquid extraction and quantitative conversion into trimethylsilyl (TMS)-ether derivatives. Analytical recovery range was 47.6 ~ 99.5% and the RSD values of within-a-day and day-to-day test were 0.66 ~ 9.33%, 1.66 ~ 16.14%, respectively. The Korean reference values for the evaluation of environmental estrogen effects were established by this method.

• Journal of the Korean Chemical Society
• /
• v.41 no.4
• /
• pp.186-197
• /
• 1997

Estrogens, which play an important role in sex hormone and potential inhibitor of cancer cell proliferation were profiled for normal female and male. The nineteen endogeneous estrogens were simultaneously analyzed by selected ion monitoring method of GC/MS. Urinary estrogens were extracted by using Serdolit AD-2 resin, hydrolyzed with $\beta-glucuronidase/arylsulfatase$ from Helix pomatia, liquid-liquid extraction and quantitatively derivatized by MSTFA/TMSCl mixture in order to be detected on the GC/MS. The good quality-control data were obtained through the precision and accuracy test and the recovery range of them was 80.97∼97.81%. The Korean reference values of urinary estrogens were established and differences were found in normal female compared with normal male.