• 분석과학
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• 제15권5호
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• pp.451-458
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• 2002

전국적으로 67 개소의 하수종말처리장에서 배출되는 하수슬러지 중 nonylphenol (NP), octylphenol (OP), di (2-ethylhexyl)phthalate (DEHP)를 이염화메탄용액으로 Soxhlet 추출후 GC/MS-SIM방법으로 분석하였다. 대부분의 하수슬러지에서 NP와 DEHP가 검출되었으며 OP는 검출되지 않았다. NP의 범위와 평균 농도는 각각 nd~593, $62{\mu}g/g$ dry 였고, DEHP의 범위와 평균농도는 각각 13~4773, $1176{\mu}g/g$ dry이었다. NP에 비하여 DEHP가 20 배 이상 높게 포함되어있었다. NP와 DEHP의 지역별 농도 증가는 전라남북도 (제주도) < 충청남북도 (강원도) < 경상남북도 < 광역시 < 경기도 순으로 증가하였다.

• Natural Product Sciences
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• 제24권1호
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• pp.71-78
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• 2018

The present study deals with the determination of optimal values of operating parameters such as the temperature of heating, the mass of the plant material and the volume of water leading to the best yield of electromagnetic induction (EMI) heating extraction of Algerian Thymus fontanesii essential oil. After an appropriate choice of the three critical variables, eight experiments leaded to a mathematical model as a first-degree polynomial presenting the response function (yield) in the relation to the operating parameters. From the retained model, we were able to calculate the average response, the different effects and their interactions. The maximum of essential oil recovery percentage relative to the initial mass of plant material was 1.69%, and was obtained at ($140^{\circ}C$, 250 g and 4.5 L). The chemical composition of the Algerian T. fontanesii essential oil under the obtained optimal conditions ($140^{\circ}C$, 250 g and 4.5 L), determined by GC/MS and GC/FID, reveled of the presence of major components such as: carvacrol ($70.6{\pm}0.1%$), followed by p-cymene ($8.2{\pm}0.2%$).

• 한국식품조리과학회지
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• 제8권3호
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• pp.247-253
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• 1992

The total dietary fiber (TDF) contents in cultivated dodok, wild dodok and ginseng were determined by AOAC method and Mongeau et al's method. Also, the nonstarch polysaccharide (NSP) contents of them were analyzed by Englyst et al's gas chromatographic (GC) method. The TDF values by AOAC method and Mongeau et al's method were 34.50% and 35.92% for wild dodok, 46.40% and 47.55% for cultivated dodok, and 14.93% and 14.03% for ginseng, respectively. The ratios of soluble dietary fiber (SDF) contents to TDF contents by Mongesu et al's method were 64.17% for wild dodok, 75.77% for cultivated dodok, and 53.74% for ginseng, respectively. The major sugar constituents of NSF in wild dodok, cultivated dodok and ginseng by GC were glucose, galactose and uronic acid. The Enalyst's TDF contents, i.e., NSP plus lignin contents in wild dodok, cultivated dodok, and ginseng were 20.65%, 20.03% , and 9.72%, respectively.

• 한국균학회소식:학술대회논문집
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• 한국균학회 2016년도 춘계학술대회 및 임시총회
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• pp.35-35
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• 2016

A mycotoxin is a toxic secondary metabolite produced by organisms of the fungus kingdom, commonly known as molds and has been widely contaminated in agricultural products such as grains and cereals. Many methods including high performance liquid chromatography (HPLC) and gas chromatography (GC) have already been proposed and reviewed for mycotoxins. These methods are either expensive or time-consuming due to the complication of sample preparation and pre-concentration before determination. In addition, both methods are unsuitable for the routine screening of large sample numbers. A biosensor is a fictive analytical device that combines a biological component with a physicochemical detector for the detection of an analyte. Biosensors represent a rapidly expanding field, at the present time, with an estimated 60% annual growth rate; the major impetus coming from the health-care industry but with some pressure from other areas, such as food safety and environmental monitoring. Antibodies and aptamers are bioreceptors which have been used in the development of biosensors. There are many kinds of antibodies and aptamers specific to mycotoxin, and antibody (or aptamer)-based biosensors have been successfully developed for the detection of mycotoxin. The biosensors permit the rapid, sensitive, simple, and on-site detection of a range of mycotoxins and can be an alternative method to traditional methods such as HPLC and GC. This presentation provides the development trends of biosensors to mycotoxins and their application to food and agricultural products.

• Toxicological Research
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• 제25권1호
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• pp.41-45
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• 2009

This study was conducted to monitor the level of bifenthrin residues in pear sprayed with 2% bifenthrin wettable powder (WP) at the recommended rate at four different schedules prior to harvest. The target analyte was extracted with acetone, partitioned into dichloromethane, and then purified by florisil chromatographic column. The residue determination was performed on a DB-5 capillary column using GC with electron capture detector (ECD). Linearity of this method was quite good ($r^2$ = 0.9951) in the concentration ranged from 0.2 mg/kg to 10 mg/kg. Recovery test was carried out at two concentration levels, 0.2 mg/kg and 1.0 mg/kg, in three replicates, and their rates were from 82.9% to 107.2%. No quantitative bifenthrin was detected in pear of all kinds of treatments including the treatment sprayed 4 times until 7 days before harvest. This sensitive and selective method can be used to monitor the trace residual amounts of bifenthrin in pear in a quite low concentration level.

• Mass Spectrometry Letters
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• 제12권2호
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• pp.31-40
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• 2021

Probable human carcinogenic compounds nitrosamines, have been detected as by-product impurities in sartan pharmaceuticals in recent years which has drawn worries for medication safety. To provide a sensitive and effective method for the quality control of sartan pharmaceuticals, this study established a feasible gas chromatography-tandem mass spectrometry (GC-MS/MS) method for simultaneous determination of 13 nitrosamines. The target analytes were separated on a DB-WAX Ultra Inert column (30 m × 0.25 mm; i.d., 0.25 ㎛) and were then subjected to electron impact ionization in multiple reaction monitoring mode. The established method was validated and further employed to analyze authentic samples. Limits of detection (LODs) and limits of quantification (LOQs) of the 13 nitrosamines were 15-250 ng/g and 50-250 ng/g, respectively, which also exhibited intra-day and inter-day accuracies of 91.4-104.8%, thereby satisfying validation criteria. Five nitrosamines, viz., N-nitrosodiethylamine, N-nitrosodimethylamine, N-nitrosodiphenylamine, N-nitrosomorpholine, and N-nitrosopiperidine were detected at concentrations above their LODs in 68 positive samples out of 594 authentic samples from seven sartans.

• 한국근적외분광분석학회:학술대회논문집
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• 한국근적외분광분석학회 2001년도 NIR-2001
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• pp.3114-3114
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• 2001

During the last years phytochemistry and phytopharmaceutical applications have developed rapidly and so there exists a high demand for faster and more efficient analysis techniques. Therefore we have established a near infrared transflectance spectroscopy (NIRS) method that allows a qualitative and quantitative determination of new polyphenolic pharmacological active leading compounds within a few seconds. As the NIR spectrometer has to be calibrated the compound of interest has at first to be characterized by using one or other a combination of chromatographic or electrophoretic separation techniques such as thin layer chromatography (TLC), high performance liquid chromatography (HPLC), capillary electrophoresis (CE), gas chromatography (GC) and capillary electrochromatography (CEC). Both structural elucidation and quantitative analysis of the phenolic compound is possible by direct coupling of the mentioned separation methods with a mass spectrometer (GC-MS, LC-MS/MS, CE-MS, CEC-MS) and a NMR spectrometer (LC-NMR). Furthermore the compound has to be isolated (NPLC, MPLC, prep. TLC, prep. HPLC) and its structure elucidated by spectroscopic techniques (UV, IR, HR-MS, NMR) and chemical synthesis. After that HPLC can be used to provide the reference data for the calibration step of the near infrared spectrometer. The NIRS calibration step is time consuming, which is compensated by short analysis times. After validation of the established NIRS method it is possible to determine the polyphenolic compound within seconds which allows to raise the efficiency in quality control and to reduce costs especially in the phytopharmaceutical industry.

• Journal of Biosystems Engineering
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• 제33권6호
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• pp.404-409
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• 2008

Excessive presence of heavy metals in environment affects plants and fruits grown in the contaminated area. Rapid on-site monitoring of heavy metals can provide useful information for efficiently characterizing heavy metal-contaminated sites and for minimizing the exposure of the contaminated food crops to humans. This study reports on the evaluation of gold and glassy carbon (GC) electrodes with mercury or bismuth as a coating material for simultaneous determination of cadmium (Cd) and lead (Pb) in 0.1 M $HNO_3$ solution by anodic stripping voltammetry (ASV). The use of a square-wave voltammetric potential between a working electrode and a reference electrode caused Cd and Pb ions deposited on the electrode surface to be oxidized, thereby generating electric currents at different potentials. The mercury-coated gold electrode was not sensitive enough to detect the usable range of Cd concentrations (1 to 100 ppb). The GC electrodes with mercury or bismuth displayed well-defined, sharp and separate current peaks for Cd and Pb ions when the square-wave voltammetric potentials were applied. The peak currents measured with both mercury- and bismuth- coated GC electrodes were linearly proportional to Cd and Pb concentrations in the range of 1 to 200 ppb in 0.1 M $HNO_3$ with strong linear relationships between concentration and peak current ($R^2$ > 0.95), indicating that both of Cd and Pb ions could be quantitatively measured.

• Bulletin of the Korean Chemical Society
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• 제32권5호
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• pp.1547-1553
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• 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.

• 분석과학
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• 제25권6호
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• pp.467-475
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• 2012

지표수 중에 GC-MS에 의한 페놀, 다환방향족탄화수소 및 농약류를 포함한 17 개 유해화합물을 동시에 분석하는 방법을 개발하였다. 1.0 L의 물 시료를 분액깔대기 안에 넣고 NaCl로 포화시킨 다음 40mL methylene chloride로 추출하였다. 이 방법은 1.0-10 ng/L 범위의 정량한계를 보였고 22% 이내의 정밀도를 보였다. 확립한 방법을 사용하여 35 지역의 금강 물 70 개 시료를 분석한 결과 유해화합물이 1.1-26,604 ng/L의 농도범위로 검출되었으며 측정값은 외국에서 확립한 준거치를 초과하는 값은 없었다. 이 측정방법은 지표수에서 유해화합물에 대한 국가모니터링사업에 사용할 때 효율적인 것으로 판단된다.