• 대한화학회지
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• 제33권1호
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• pp.46-54
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• 1989

식품 및 비타민 제제중에 존재하는 지용성 비타민의 추출 및 동시 정량법을 검토하였다. 역상 액체크로마토그래피에 의한 지용성 비타민의 동시 분리 및 정량은 메탄올 : 물 = 95 : 5 이동상으로 Novapak $C_{18}$ 컬럼하에서 이루어졌다. 비타민의 검출에는 UV검출기를 사용하였으며 검출감도를 증가시키기 위하여 분석중 UV 검출파장을 각각의 비타민 용리시간에 따라 최대흡수 파장인 330, 265, 285 및 290nm로 변경하였다. 지용성 비타민의 분리 및 분석은 40분안에 완료되었다. 시료의 전처리에는 알카리 가수분해법과 효소가수분해법을 이용하였으며, 비타민의 추출은 액체-액체추출법과 액체-고체추출법을 이용하였다. 비타민 A,D, E 분석에는 알카리 가수분해법 및 효소가수분해법이 비타민 K 분석에는 효소가수분해법만이 좋은 결과를 나타냈으며, 비타민 추출에는 액체-액체 추출시 diethyl ether, pentane 및 n-hexane이, 액체-고체 추출시 silica 카트리지가 좋은 추출효과를 나타냈다.

• 한국자기공명학회논문지
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• 제15권1호
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• pp.14-24
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• 2011

We have performed Liquid Chromatography-Solid Phase Extraction-NMR (LC-SPE-NMR) analysis for liquid crystalline mixture and elucidated the structures of selected components by NMR spectra. Combining the results of one-dimensional 1H experiments as well as homonuclear and heteronuclear two-dimensional experiments, we could analyze the molecular structure of the liquid crystal singles whose structure had not been interpretable by mass spectrometry alone.

• 분석과학
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• 제13권3호
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• pp.399-402
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• 2000

To determine the concentrations of microcystins present in lake water or in tap water using high performance liquid chromatography, it is necessary to concentrate a large volume of water samples (about 20 L) into very small volume (0.1-0.3 mL). Concentration can be conveniently done when disc type solid phase extraction (SPE) apparatus is used. Using this apparatus we have investigated the recovery rates of three kinds of microcystins, RR, YR, LR. The recovery rates were relatively low and the reproducibilities were not good either. It is expected, however, that the appropriate selection of the disc conditioning and eluting solvents and reproducible reconcentration process after SPE will improve both the recovery rates and the reproducibilities.

• 분석과학
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• 제30권1호
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• pp.20-25
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• 2017

An analytical method for determining potential endocrine disruptors (bisphenol A, 2-chlorophenol, 2,4-dichlorophenol, 2,4,6-trichlorophenol, pentachlorophenol, p-t-butylphenol, p-pentylphenol, p-hexylphenol, p-t-octylphenol, p-heptylphenol, nonylphenol) by solid-phase extraction (SPE) and High Perfomance Liquid Chromatography(HPLC) equipped with fluorescence and variable wavelength detector has been developed. The SPE process for sample concentration was performed on a commercially available Oasis HLB cartridge packed with polymeric sorbents. The effect of elution solvent and elution volume on the recoveries of the analytes were investigated with HPLC. Average recovery of >85% was achieved with 60mg sorbents using 5mL of methanol as elution solvent. Phenolic compounds in canned drinks, beverages and water samples were surveyed by this proposed method.

• Bulletin of the Korean Chemical Society
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• 제28권2호
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• pp.276-280
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• 2007

In this work, caffeine and some catechin compounds + C, EC, EGC, and EGCG were extracted from green tea by using molecular imprinted polymers (MIP) as sorbent materials in a solid-phase extraction (SPE) process known as MISPE (molecular imprinted solid-phase extraction). For synthesis of MIP, caffeine was employed as the template, MAA as the monomer, EGDMA as the crosslinker, and AIBN as the initiator. A solution of caffeine (0.2 mg/mL in methanol) was utilized in the solid extraction cartridges following loading, washing, and elution procedures with acetonitrile, methanol, and methanol-acetic acid (90/10, %v/v) as the solvents, respectively. This solid-phase extraction protocol was applied for the extraction of caffeine and some catechin compounds from green tea. A comparison was made between the results obtained with the MIP cartridges and a traditional C18 reversed-phase cartridge. It was thereupon found that the recovery of caffeine by the MIPbased sorbent used in this work was almost two and four times greater than that by a commercially available C18 material. A quantitative analysis was conducted by high performance liquid chromatography (HPLC) using a C18 column (5 μm, 250 × 4.6 mm) with methanol/water (40/60, %v/v) as the mobile phase at a flow rate of 0.5 mL/min.

• Mass Spectrometry Letters
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• 제2권1호
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• pp.12-15
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• 2011

The Korean government has regulated emission of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) in waste water of manufacturing facilities producing chlorinated compounds since 2009. As this regulation is expected to be reinforced in 2013 to 50 pg I-TEQ/L, a large sample volume is required for the analysis of trace amounts of PCDD/Fs in waste water. Liquid-liquid extraction (LLE) is used to extract PCDD/Fs from aqueous samples; however, its low efficiency makes it inadequate for analyzing large sample volumes. Herein, we present a disk-type solid-phase extraction (SPE) method for the analysis of dioxin at a part per quadrillion level in waste water. This SPE system contains airtight glass covers with a decompression pump, which enables continuous semi-automated extraction. Small (0.5 L) and large (7 L) samples were extracted using LLE and SPE methods, respectively. The method detection limits (MDLs) were 0.001.0.25 and 0.015.4.1 pg I-TEQ/L for the SPE and LLE methods, respectively. The concentrations of detected congeners with both methods were similar. However, the concentrations of several congeners that were not detected with the LLE method were quantified using the SPE method.

• Bulletin of the Korean Chemical Society
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• 제30권1호
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• pp.61-66
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• 2009

An analytical method based on solid-phase extraction and gas chromatography / mass spectrometry has been developed for measurement of acaricides (amitraz, bromopropylate, coumaphos, cymiazole, and tetradifon) in honey sample. In the stability test of acaricides in honey, amitraz underwent a rapid degradation into 2,4-dimethylaniline (DMA), 2,4-dimethylphenylformamide (DMPF), and N-(2,4-dimethylphenyl)-N'-methylformamidine (DMPMF), whileas other acaricides were found to be stable even for over three months. Extraction of five acaricides from 5g of honey sample was carried out by liquid-liquid extraction using 20mL of ethylacetate. For purification, Florisil-SPE cartridge with elution of 5mL of n-hexane/ acetone (55:45, v/v) was found to remove interferences effectively. Quantification was performed using gas chromatography / mass spectrometry in the selected ion monitoring mode. Spiking experiments were carried out to determine the recovery, precision, and limits of detection (LODs) of the method. The overall recovery values from honey spiked at 0.02 and 0.20 ${\mu}g/g$ levels, respectively, were found to be greater than 75% for all acaricides. The method detection limits for acaricides were ranged from 0.1 to 3 ppb. The developed method in this study was applied for the monitoring of acaricides in honey products collected from urban markets in Korea.

• 식품보건융합연구
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• 제10권3호
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• pp.19-22
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• 2024

The field of synthetic biology has emerged in response to the ongoing progress in the life sciences. Advances have been made in medicine, farming, eating, making materials, and more. Synthetic biology is the exploration of using living organisms to create new organisms. By manipulating specific genes to express targeted proteins, proteins can be created that are both productive and cost-effective. Solid-phase extraction (SPE) and liquid-liquid extraction (LLE) are employed for protein separation during the production process involving microorganisms. This study centers on Scanning Probe Microscopy (SPM) to showcase its utility in the food industry and food management. SPE is predominantly utilized as a pretreatment method to eliminate impurities from samples. In comparison to LLE, this method presents benefits such as decreased time and labor requirements, streamlined solvent extraction, automation capabilities, and compatibility with various other analytical instruments. Anion exchange chromatography (AEC) utilizes a similar methodology. Pharmaceutical companies utilize these technologies to improve the purity of biopharmaceuticals, thereby guaranteeing their quality. Used in the food and beverage industry to test chemical properties of raw materials and finished products. This exemplifies the potential of these technologies to enhance industrial development and broaden the scope of applications in synthetic biology.

• Journal of the Korean Wood Science and Technology
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• 제51권6호
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• pp.481-492
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• 2023

The ecofriendly lifestyle has attracted considerable support for sustainable development. Natural dyes, as sustainable products, have become a research focus and development area for many scientists. Ecofriendly processing also supports circular sustainable development. This study effectively obtained tannins as a natural dye from merbau (Intsia bijuga) sawdust using water as an ecofriendly solvent. Merbau sawdust is an underutilized industrial waste. Temperature and solid-solvent ratio variations were performed to extract tannins from merbau sawdust. Temperature and solid-solvent ratio positively affected solution yield and tannin concentration. The optimal condition was identified using response surface methodology and experimental observations. A yield of 0.2217 g tannins/g merbau was obtained under the conditions of 333.15 K and 0.125 solid-solvent ratio. Extraction was controlled by convective mass transfer at the interface of solid particles.

• 한국환경보건학회지
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• 제25권3호
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• pp.103-107
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• 1999

Even if odorous compounds remain very low concentration in water, it cause strong odor. Because Geosmin and most of odorous compound had very low vaporization, those were difficult to analyze with GC/MSD and Purge & Trap. So, we needed pre-treatment method for decreasing amounts of extracting solvents, improving recovery efficiencies and increasing analytical efficiencies. This study developed efficient technology for analyzing odorous compounds, using various adsorbents and extracting solvents. The optimum adsorbent was XAD resins. Especially, XAD-2, XAD-7 and XAD-2010 were superior, but XAD-2 of these and the optimum extraction solvent is MTBE. Other extraction solvents' efficiency is in order of MTBE>Dichloromethane>n-Hexane>Diethylether. The optimum NaCl dosage for increasing efficiency is 5 g in liquid-liquid extraction method. The shaking time(0~24hr) has no concern with adsorption efficiency. The optimum adsorbent is XAD-2 resin and extraction solvent is MTBE. Dosing NaCl, adsorption efficiency is increased in liquid-liquid extraction method, but NaCl has no effect on liquid-solid extraction method. In this experimental results, this algae toxins(Mycrocystin, Anatoxin etc.).