• 분석과학
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• 제34권2호
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• pp.46-55
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• 2021

Evaluation of drug-excipient compatibility is one of the basic steps in the preformulation of pharmaceutical dosage forms. Some reactive excipients have been known so far which may cause stability problems for drug molecules in pharmaceutical dosage forms. The aim of this study was to evaluate drugexcipient compatibility of gliclazide with some common pharmaceutical excipients, known for their ability to incorporate in drug-excipient interactions. Binary mixtures were prepared using lactose, magnesium stearate, polyvinylpyrrolidone, sodium starch glycolate, polyethylene glycol 2000 and dicalcium phosphate. Based on the results; gliclazide was incompatible with all tested excipients; but not with dicalcium phosphate. DSC (Differential Scanning Calorimetry) results were in accordance with HPLC (High Pressure liquid chromatography) data and were more predictive than FTIR (Fourier Transform Infrared Spectroscopy). Drug and reactive excipients incompatibility was fully discussed and documented. It is advisable to avoid incompatible excipients or carefully monitor the drug stability when incorporating such excipients in final formulation designs.

• Elastomers and Composites
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• 제57권4호
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• pp.188-196
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• 2022

Styrene-butadiene rubber(SBR) is a copolymer of styrene and butadiene. It is composed of 1,2-unit, 1,4-unit, and styrene, and its properties are dependent on its microstructure. In general, rubber composites contain a single rubber or a blended rubber. Similarly, SBR is used by mixing with natural rubber(NR) and butadiene rubber(BR). The composition of a rubber article affects its physical and chemical properties. Herein, an analytical method for determining the microstructure of SBR using via pyrolysis is introduced. Pyrolysis-gas chromatography/mass spectrometry is widely used to analyze the microstructure of polymeric materials. The microstructure of SBR can be determined by analyzing the principal pyrolysis products formed from SBR, such as 4-vinylcyclohexene, styrene, 2-phenylpropene, 3-phenylcyclopentene, and 4-phenylcyclohexene. An analytical method for determining the composition of SBR/NR, SBR/BR, and SBR/NR/BR blends via pyrolysis is introduced. The composition of blended rubber can be determined by analyzing the principal pyrolysis products formed from each rubber component.

• 한국식품위생안전성학회지
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• 제32권5호
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• pp.404-410
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• 2017

HPLC-size-exclusion chromatography에 의해 가공식품에서 알긴산프로필렌글리콜의 함량을 분석하는 방법이 개발되었다. 알긴산프로필렌글리콜을 분석하기 위해 GF-7M HQ column과 LT-ELSD detector가 선정되었다. 알긴산프로필렌글리콜 분석을 위한 전처리 조건으로는 $20^{\circ}C$에서 150 rpm으로 3시간 동안 추출하는 방법이 선정되었다. 알긴산프로필렌글리콜을 5 농도(300, 500, 700, 1,000, and 1,500 mg/kg) 범위에서 검량선을 작성한 결과 직선성($R^2$)은 0.9873으로 측정되었다. HPLC system에 의한 알긴산프로필렌글리콜 분석시 검출한계(LOD) 및 정량한계(LOQ)는 각각 171.43 mg/kg 및 519.50 mg/kg이었다. Size-exclusion chromatography에 의해 얻은 회수율 및 변동 계수(coefficient of variation)는 각각 86.1~110.4% 및 4.1~13.5%이었다. 본 연구에서 개발된 HPLC-size-exclusion chromatography system을 적용하여 134 품목의 가공식품에서 알긴산프로필렌글리콜 함량을 분석하였다. 이 결과들은 이 방법이 가공식품에서 알긴산프로필렌글리콜 함량을 분석하는데 적용할 수 있는 방법이라는 것을 나타낸다.

• 분석과학
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• 제12권1호
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• pp.84-88
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• 1999

A method to analyze additives in a polyester resin has been studied by utilizing a centrifuge and a thin layer chromatography. Identification of the separated organic and inorganic compounds were carried out by spectrophotometers, such as NMR, UV-VIS, IR and XRD. For the polyester resin studied in this research contained organic and inorganic compounds which were found to be a dimer form of 2-phenylbenzoazole and an anatase form of $TiO_2$, respectively.

• Biotechnology and Bioprocess Engineering:BBE
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• 제6권6호
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• pp.363-375
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• 2001

Chromatography has been method of choice for the separation complex biologi-cal mixtures fro analytical purpose, particularly for the last fifty years. Its use has recently been extended to preparative separation where the productivity relative to the amount of resin and sol-vent used is a matter of concern. To overcome the inherent thermodynamic inefficiency of batch chromatography, as exemplified by the partial temporal usage of the resin and dilution of the product with the solvent, chromatography has been continually modified by separation engineers. Column switching and recycling represnet some of the process modifications that have brought high productivity to chromatography. Recently, the simulated moving bed (SMB) method, which claims a high separation efficiency based on counter-current moving bed chromatography. has be-come the mainstay of preparative separation, especially in chiral separation. Accordingly, this pa-per reviews the current status of SMB along with several chromatographic modification, which may be helpful in routine laboratory and industrial chromatographic practices.

• 한국환경과학회지
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• 제5권5호
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• pp.561-567
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• 1996

31 종류의 유기 염소계 잔류 농약을 동시에 분석하는 기체 크로마토그래피 방법을 개발하기 위하여 본 연구를 수행하였다. 준비된 분석 시료를 ECD (electron capture detector)로 Ultra-2 column의 GC (gas chromatography)에 주입하였다. Column 충진 물질을 florisil과 alumina N으로 변화시키면서 잔류 용액을 column에 loading하고 용출 용매로는 ether . benzene(2 : 8) solution, hexane . benzene(1 . 1) solution, dichloromethane, acetone 및 methanol을 사용하였다. 분석 결과 column 충진 물질로 florisil을 사용하였을때 (첫째 조건) 6종류의 유기 염소(dichlorfluanid, captan, chlorofenvinfos, folpet, captafol과 dicofol)가 검출되지 않았다. 이 조건에서 dichloromethane과 methanol을 용출 용매로 첨가하였을때는 (둘째 조건) 첫째 분석 조건하에서 검출되지 않았던 6종류의 유기 염소가 검출되었고 thrin계 pesticides, 특히 captan과 captafol의 recovery가 증가하였다(첫째 조건에서와 마찬가지로 충진 물질로 florisil을 사용). 그러나 BHC(benzene hexachloride) 화합물의 recovery는 감 소하였다. 한편 alumina N을 column 충진 물질로 사용하였을 경우에는 dichlorfluanid, chlorofenvinfos, folpet 및 dicofol의 recovery가 증가하였으며 aldrin도 그러하였다. 하지만 captan과 captafol은 그렇지 못하였다. Thrin계 pesticides, captan 및 captafol을 동시에 검출하기 위하여 florisil과 alumina N을 충진 물질로 동시에 사용하고 n-hexane을 충진시켜 용출시킨 결과, captan과 captafol이 검출되지 않았는데 이는 column이 충분히 활성화되지 않았기 때문이라고 생각된다. Column(florisil과 alumina N을 충진 물질로 동시 사용)을 충분히 활성화시키고 여러가지 용출 용매를 사용하여 불순물을 제거하였을때 분석 결과가 가장 우수하였다(31 종류의 유기 염소계 잔류 농약이 sharp하게 검출되었고 높은 감도를 나타내었다).

• 분석과학
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• 제37권2호
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• pp.123-129
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• 2024

We present a rapid method for the determination of Cs, Sr, and Ba, heat generators found in highly active liquid wastes, by gas-pressurized extraction chromatography (GPEC) using a column containing a cation-exchange resin. GPEC is a microscale column chromatographic technique that uses a constant flow rate of solvent (0.07 mL/min) with pressurized nitrogen gas supplied through a valve. In particular, because this method uses a small sample volume (a few hundred microliters), it produces less chemical waste and allows for faster separation compared to traditional column chromatography. In this study, we evaluated the separation of Cs, Sr, and Ba using GPEC. The eluate from the column (GPEC or conventional column chromatography) was quantitatively analyzed using inductively coupled plasma-mass spectrometry to measure the column recovery and precision. The column reproducibility of the proposed GPEC system (RSDs of recoveries) ranged from 2.7 to 4.1 %, and the column recoveries for the three elements ranged from 72 to 98% when aqueous HCl was used as the eluent. The GPEC results are slightly different in efficiency and separation resolution compared to those of conventional column chromatography because of the differences in the eluent flow rate as well as the internal diameter and length of the column. However, the two methods had similar recoveries for Cs and Sr, and the precision of GPEC was improved by two-fold. Remarkably, the solvent volume required for GPEC analysis was five times lower than that of the conventional method, and the total analysis time was 11 times shorter.

• 분석과학
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• 제15권5호
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• pp.445-450
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• 2002

해수에 함유되어 있는 요오드화합물의 총량을 휘발성 유기물로 유도체화 후 측정하는 방법을 확립하였다. 이 방법은 요오드 음이온은 요오드로 산화시킨 후 2,6-dimethylphenol과 반응하여 4-iodo-2,6-dimethylphenol로 전환시켜 ethylether로 1단계 추출 후 gas chromatography-mass spectrometry (selected ion monitoring)로 측정하는 것으로 구성되어 있다. Iodate는 ascorbic acid 와 acetic acid로 요오드 음이온으로 환원시킨 후 요오드 음이온 측정법과 동일하게 수행하였다. 이 방법은 검출한계가 해수에서 0.1 ng/ml이었으며 검량선은 0.9997의 좋은 상관계수값을 보였다. 이 방법은 또한 재현성이 우수하고 간단하여 해수에 인체의 필수원소인 요오드를 낮은 농도까지 분석하는데 유용하게 사용될 수 있다고 사료된다.

• KSBB Journal
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• 제30권4호
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• pp.141-147
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• 2015

The convenient determination of methylsulfonylmethane (MSM) for a commercially available dietary supplement was developed using gas chromatography (GC)-flame ionization detector (FID). Chromatography was performed on a capillary column ($0.32mm\;I.D{\times}30m$, $0.25{\mu}m$) coated with dimethylpolysiloxane using diethylene glycol methyl ether as an internal standard. The performance characteristics of GC were evaluated in terms of selectivity, linearity, precision, accuracy, recovery, limit of detection (LOD) and limit of quantification (LOQ). The calibration curve was highly linear (the coefficient of determination: 0.9979) within the concentration range of $10.0{\sim}800.0{\mu}g/mL$ for MSM. The recoveries for three fortified concentrations were 96.7~97.1%, 96.6~97.3% and 96.8~97.2%, respectively. The LOD and LOQ of the method were $0.29{\mu}g/mL$ and $0.97{\mu}g/mL$, respectively. All obtained results were acceptable according to the guidelines of the Association of Official Analytical Chemists for dietary supplements. Thus, the validated analytical method using the GC-FID system is suitable for the determination of MSM in dietary supplement formulations for quality control.

• 분석과학
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• 제10권2호
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• pp.131-138
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• 1997

초임계 유체 크로마토그래피(Supercritical Fluid Chromatography, SFC)는 종래의 크로마토그래피 방법으로 분석하기 어려운 물질을 분석해 내는 기술로서 발전이 되어 왔다. 그러나 SFC에서 이동상으로 많이 사용되고 있는 초임계 유치 $CO_2$는 용매로서 특성이 n-hexane과 매우 비슷하여 극성이 큰 시료들을 용출(elution)시키기가 어렵다. 이러한 점을 해결하기 위하여 초임계 $CO_2$에 극성을 지닌 물질, 즉 변형제(modifier)를 섞어서 이동상으로 사용할 수 있다. 본 연구에서는 초임계 $CO_2$에 첨가된 수분($H_2O$)의 양을 perfluorosulfonate ionomer(PFSI) film을 이용하여 만든 amperometric microsensor로서 측정하였다. 이와 같은 방법을 사용함으로써 포화 column보다 상당히 긴 시간 동안 일정하게 수분을 첨가할 수 있었고, 실제로 이 방법을 사용하여 순수한 $CO_2$ 이동상만으로는 분리하기 어려운 비타민류의 분석에 적용한 결과 좋은 크로마토그램을 얻었다.