• Food Science and Biotechnology
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• 제18권6호
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• pp.1515-1518
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• 2009

The objective of this study was to compare 3 extraction methods including, solid phase extraction (SPE), acetonitrile extraction, and methanol extraction, for their usefulness as extraction methods to determine capsaicinoids. The determination of capsaicinoids in the extracts was carried out on a reverse-phased high performance liquid chromatography (HPLC) using a fluorescence detector. Three extraction methods, i.e., SPE, acetonitrile extraction, and methanol extraction were compared for the quantification of capsaicinoids using raw peppers and pepper powder. The highest analytical values were observed using methanol extraction and the lowest values using SPE. Also, the analytical method validation parameters such as accuracy, precision, limit of detection, limit of quantitation, and specificity were calculated to ensure the method's validity. This method provides a fast and accurate approach for the determination of capsaicinoids in peppers.

• 한국지하수토양환경학회지:지하수토양환경
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• 제17권1호
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• pp.42-46
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• 2012

The ISO document of ISO/TC/190/SC3/WG11/N11 is a working draft of international standard (WD) dealing with analytical method for the determination of explosives and related compounds using high performance liquid chromatography. The scope of this WD covers the storage of samples, preparing test portion, extraction and instrumentation. The main purpose of this study was to improve the extraction conditions which were already adopted in the WD. For this purpose, mechanical shaking method could be corresponded up to 18 hours of ultrasonic bath extraction in the WD was tested. Methanol was also tested with the intention of being added as an extracting solvent other than acetonitrile in the WD. According to the results, 16 hours of mechanical shaking method showed statistically the same effectiveness as that of 18 hours of ultrasonic bath extraction. In case of extracting solvent, methanol also showed statistically the same extraction capability as acetonitrile for DNB, TNT, 2-A-DNT and 2,4-DNT. However, the recovery rate of TNB with methanol extraction was 40% higher than that of acetonitrile extraction. Through adding mechanical shaking method into committee draft (cf. the next stage draft of the WD during the process for making international standard), ISO standard of analyzing explosives and related compounds in soil would become more useful in dealing with huge number of field samples in the laboratory. In other aspect, adopting methanol as an alternative extracting solvent would be very effective in the terms of exchangeability with GC-ECD/MS method which is being developed by German experts.

• Asian-Australasian Journal of Animal Sciences
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• 제14권10호
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• pp.1465-1469
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• 2001

A sensitive high-performance liquid chromatographic method was developed to determine the content of cholesterol in milk and dairy products. To optimize separation of cholesterol, mobile phases including acetonitrile:2-propanol (8:1, v/v), acetonitrile:methanol (3:1, v/v), and acetonitrile:methanoI:2-propanol (7:3: I, v/v/v) were compared. Acetonitrile/methanol/2-propanol was superior to the other mobile phase systems for separating cholesterol. Liquid-liquid extraction (LLE) of cholesterol was simplified using a non-polar solvent, hexane, to remove interfering compounds, and had an excellent recovery $(100{\pm}1.0%)$ of cholesterol. A solid phase extraction (SPE) method using Sep-pak $C_{18}$ was developed and compared with LLE. The SPE method was rapid and highly reproducible. Both extraction methods were useful when used in combination with saponification of esterified cholesterol to facilitate total cholesterol determination. The detection limit of cholesterol was $0.01{\mu}g$. The newly developed HPLC method was rapid, simple, and accurate, and has advantages over the many methods commonly used.

• 분석과학
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• 제8권4호
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• pp.511-517
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• 1995

A cationic water soluble porphyrin (5,10,15,20-tetrakis (l-methyl-pyridinium-4-yl)porphyrin, $H_2tmpyp^{4+}$) and its metalloporphyrins (MP) were easily extracted into acetonitrile separated by addition of sodium chloride ($4mol\;dm^{-3}$) in the presence of sodium perchlorate, where M denotes $Zn^{2+}$, $Cu^{2+}$, $Co^{3+}$, $Fe^{3+}$, and $Mn^{3+}$ and $P^{2-}$ is porphyrinate ion. The extracted ion-pair complexes were completely dissociated to $[MP(ClO_4)_3]^+$, and $[MP(ClO_4)_2]^{2+}$. The extraction and the dissociation constants were determined by taking into account of the partition constant of sodium perchlorate ($K_D=1.82{\pm}0.01$). The chemical properties of the separated acetonitrile phase as $E_{T(30)}$ and $D_{II,I}$ were determined and compared with other water miscible solvents (acetone, actonitrile, 1,4-dioxane, tetrahydrofuran, 1-propanol and 2-propanol). Furthermore, a sensitive and selective method was proposed for the determination of a subnanogram amount of copper(II) in natural water samples by using the present salting-out method and the porphyrins.

• 한국축산식품학회지
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• 제21권1호
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• pp.64-70
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• 2001

The extraction procedure and HPLC condition were modified to analyze the residues of oxytetracycline, sulfamethoxazole and chloramphenicol in pork, simultaneously. The antibacterial agents in pork were extracted with 0.02M EDTA-Mcilivine buffer:ethanol:acetonitrile (5:3:2). After the removal of fat with n-hexane, the extracts were evaporated and purified with Sep-pak $C_{18}$ cartridge column using 0.01M oxalic acid 0.1% (v/v) triethylamine (TEA) in acetonitrile. The peak of antibacterial agents was detected with $\mu$ Bondapak C18 column, UV detector (280nm) and 0.01M oxalic acid: methanol: acetonitrile (7.5:2.0:0.5). Detection limits for three antibacterial standards were 0.03 ppm. Calibration curves were linear between 0.03 and 2.0 ppm (R$^2$>0.999). When spiked the level of 1.0 ppm of oxytetracycline, sulfamethoxazole and chloramphenicol into meats, the recoveries from meats were 77.3%, 79.7% and 59.3%, respectively. These results showed that the modified extraction method provided good analytical resolution and the recoveries of the above antibacterial agents in meats.

• 공업화학
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• 제5권6호
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• pp.1016-1023
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• 1994

Acrylonitrile 제조시 부산물로 생성되는 acetonitrile-water 공비혼합물에서 용매추출하여 acetonitrile을 회수하기 위하여 benzene, toluene, o-xylene, ethylacetate 및 monochlorobenzene을 용매로 선택하여 $25^{\circ}C$ 에서 solvent(1)-water(2)-acetonitrile(3)계의 액-액 평형데이타를 구하였으며, 그 실험데이타의 건전성을 조사하였고, tie line과 plait point조성을 결정하였다. 또한 NRTL, UNIQUAC 및 modified UNIQUAC모델식에 적용하여 parameter를 추산하고 각 용매에 대한 분배계수와 선택도를 결정하였다.

• 한국산업보건학회지
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• 제26권3호
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• pp.307-316
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• 2016

Objectives: In general, NIOSH method 5506 is most widely used for the occupational exposure measurement of PAHs, but 2-4 ring PAHs have poor desorption efficiency, especially for a filter. The purpose of this study was to determine a method to increase the desorption efficiency of 16-PAHs using an ultrasonic extraction procedure. Methods: Test samples prepared spiked XAD-2 tubes and PTFE filters in the range of $0.01-1.0{\mu}g/mL$ for desorption efficiency study. Four different extraction solvents, acetonitrile, acetone, tetrahydrofuran and dichloromethane, were tested in order to select the most suitable solvent for the extraction of the 16 PAHs. The addition of dimethyl sulfoxide and sonication time were considered in order to determine the method with the highest extraction efficiency. All samples were made in three sets and analysis was replicated seven times by HPLC. Results: Acetonitrile and acetone were the optimized as an extraction solvent and desorption efficiency of 2-ring PAHs such as naphthalene, acenaphthylene were increased 3~19% with dimethyl sulfoxide for XAD-2. Acetone was the best extraction solvent for PTFE filter and the desorption efficiency was increased 3~13% for 2- to 4-ring PAHs. The optimum sonication time was 60 minutes and desorption efficiency increased with extraction time. Conclusions: As a result, the best extraction solvent was acetone with dimethyl sulfoxide for ultrasonic extraction procedure and the desorption efficiency of this method was better than NIOSH 5506's. This study could be applied as a method for occupational exposure measurement of PAHs.

• KSBB Journal
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• 제16권4호
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• pp.327-331
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• 2001

전라남도 보성산 녹차로부터 유용성분인 카테킨 화합물을 초임계 이산화 탄소와 첨가제를 사용하여 추출하고 역상 고성능 액체 크로마토그래피(RP-HPLC)를 사용하여 분석하였다. LiChrospher 100RP-18(15 $\mu$m)로 충진된 column을 이용하여 0.05% phosphoric acid가 포함된 물과 acetonitrile을 이동상으로 사용하였으며 구배용매 조성법을 적용하였다. 이동상의 조성에 따른 체류인자의 조절을 통해 EGCG를 분리하였다. 각각의 초임계 추출법에 따른 EGCG의 추출량을 비교한 결과, 초임계 유체에 극성물질을 포함하는 경우가 녹차의 유용 성분인 EGCG의 추출량이 가장 많았다. 그러나 ethanol에 의한 용매 추출법은 초임계 유체에 의한 추출법보다 EGCG에 대해 많은 추출양과 선택적인 고순도 분리가 가능하였다.

• Journal of Ginseng Research
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• 제13권2호
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• pp.198-201
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• 1989

백삼의 주요 polyacetylene 성분인 panaxynol과 panaxydol을 capillary-GC(FID)로 정량하고 몇 가지 추출용매(석유 ether, dichloromethane, ether, ethyl acetate, acetone, acetonitrile and methanol) 및 추출방법(진탕추출, Soxhlet 추출 또는 환류추출)에 따른 이들 성분의 추출율을 비교하였다. 이 때, GC column은 SPB-1 fused silica capillary (0.25 mm id $\times$30 m, Supelco)를 사용하였고, column oven 의 온도는 $200^{\circ}C$에서 $300^{\circ}C$까지 분단 $4^{\circ}C$씩 승온하였다. 추출용매에 따른 panaxynol과 panaxydol의 추출율은 methanol 에 의하여 환류추출하는 방법이 백삼 중 polyacetylene 성분을 최대로 추출하는 조건인 것으로 사료되었는데, 이 추출방법에 의하여 얻어진 4년근 백삼시료의 panaxynol과 panaxydol의 함량분석값은 각각 4.2mg/g과 6.4mg/g이었다.

• 분석과학
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• 제17권4호
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• pp.289-294
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• 2004

고성능 액체 크로마토그래피를 이용하여 고삼 중의 oxymatrine을 분석하였다. acetonitrile을 포함하는 완충용액과 $C_{18}$컬럼을 이용한 역상 크로마토그래피를 수행하였다. Oxymatrine의 분리는 215 nm에서 UV흡수가 관측되었다. 고삼 중의 oxymatrine의 추출은 다양한 용매와 다양한 추출방법을 사용한 결과, 마쇄한 고삼의 최적의 추출 효율은 $80^{\circ}C$에서 50% ethanol로 5시간 동안 환류가열 하였을 때 가장 높은 효율을 보였다. 대부분의 추출 방법은 복잡한 전처리를 필요로 하지만, 본 연구에서는 승화 추출법으로 복잡한 전처리를 제외시킨 추출법을 고안하였다. 승화 추출은 높은 진공 ($1{\times}10^{-3}$ torr) 과 높은 온도 ($200^{\circ}C$)에서 수행되었다. 승화 추출법을 사용한 추출 효율은 다른 추출 방법들과 비교해서 전처리 과정을 거치지 않은 장점은 있었으나 추출 효율이 좀 낮았다.