• 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.

• Archives of Pharmacal Research
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• 제21권2호
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• pp.212-216
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• 1998

A coupled achiral-chiral high-performance liquid chromatographic system has been developed for the determination of the enantiomers of salmeterol, S-(+)-salmeterol and R-(-)-salmeterol in urine. THe salmeterol was separated from the interfering components in urine and quantified on the silica column, and the enantiomeric composition was determined on a Sumichiral OA-4700 chiral stationary phase. The two columns were connected by a switching valve equipped with a silica precolumn. The two columns wer connected by a switching valve equipped with a silica precolumn. The precolumn was used to concentrate the salmeterol in the eluent from the achiral column before backflushing onto the chiral phase. The coupled system was validated.

• Archives of Pharmacal Research
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• 제23권5호
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• pp.441-445
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• 2000

Achiral-chiral column switching HPLC assay was developed to allow the separation and quantification of the enantiomers of terbutaline in human plasma by means of fluorescence detection. Plasma samples were prepared by solid-phase extraction with sep-pak silica, followed by HPLC assay. The enantiomers of terbutaline and the internal standard were separated from the biological matrix on a silica column, and the two enantiomers were resolved and quantified on a Sumichiral OA-4900 column. The two columns were connected by a switching valve equipped with silica trap column, The trap column was used to concentrate the terbutaline in the eluent from the achiral column before back flushing onto the chiral phase. For each enantiomers, the assay was linear between 2.5-125 ng/$m\ell$ (r=0.9999) and detection limit was 1.0 ng/$m\ell$ .

• Bulletin of the Korean Chemical Society
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• 제26권4호
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• pp.569-574
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• 2005

A coupled column liquid chromatography system was applied for the separation of the burnup monitors in spent nuclear fuel sample solutions. A reversed phase column was studied for the adsorption behavior of uranyl ions using alpha-hydroxyisobutyric acid as an eluent and used for the separation of plutonium and uranium. A cation exchange column prepared by coating 1-eicosylsulfate onto the reversed phase column was used for the separation of the lanthanides. In addition, retention of Np was checked with the reversed phase column and cation exchange column, respectively, according to the oxidation states to observe the interference effect for the separation of burnup monitors. This chromatography system showed a great reduction in separation time compared to a conventional anion exchange method. A good agreement from the burnup data was obtained between for this method and a conventional anion exchange method to within 1% of a difference for the spent nuclear fuel samples of about 40 GWD/MTU.

• 분석과학
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• 제28권2호
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• pp.125-131
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• 2015

사람혈장 중 베타투 수용체 작용약 테르부탈린의 정량법을 개발하고 밸리데이션을 실시하였다. 혈장시료를 Sep-pak 실리카를 이용하여 고상추출한 후 HPLC로 측정하였다. C18 칼럼을 사용하여 혈장 중의 방해물질로부터 테르부탈린 분획을 분리하여 실리카칼럼으로 보내어 테르부탈린과 내부표준물질을 분리 정량하였다. 두 칼럼은 짧은 실리카 전칼럼이 달린 절환밸부로 연결하여 사용하였다. C18 칼럼의 이동상에 녹아있는 테르부탈린의 분획은 전칼럼에서 농축되어 실리카칼럼으로 보내지고 형광 여기파장 276 nm와 들뜸파장 306 nm로 측정하였다. 이 분석법은 여섯 명의 혈장에서 특이성이 있음을 확인하였다. 혈장 중 테르부탈린 0.4-20.0 ng/mL 농도범위에서 상관계수 0.9999로 양호한 직선성을 나타내었다. 정량한계농도는 0.4 ng/mL 농도로 정밀도가 10.1% 를 나타내었다.

• Bulletin of the Korean Chemical Society
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• 제24권12호
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• pp.1805-1808
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• 2003

The simultaneous determination of As(III), As(V), and DMA has been performed by ion chromatography (IC) coupled with inductively coupled plasma-mass spectrometry (ICP-MS). The separation of the three arsenic species was achieved by an anionic separator column (AS 7) with an isocratic elution system. The separated species were directly detected by ICP-MS as an element-selective detection method. The IC-ICP-MS technique was applied for the determination of arsenic species in a NIST SRM 1643d water sample. An As(III) only was detected in the sample. The detection limits of As(III), As(V) and DMA were 0.31, 0.45, and 2.09 ng/mL, respectively. It was also applied for the determination of arsenic species in a human urine obtained by a volunteer, and three arsenic species were identified. The determination of total As in human urines that were obtained from 25 volunteers at the different age was also carried out by ICP-MS.

• Natural Product Sciences
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• 제21권1호
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• pp.30-33
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• 2015

Anthocyanins are water soluble plant pigments which are responsible for the blue, red, pink, violet colors in several plant organs such as flowers, fruits, leaves and roots. In recent years, anthocyanin-rich foods have been favored as dietary supplements and health care products due to diverse biological activities of anthocyanins including antioxidant, anti-allergic, anti-diabetic, anti-microbial, anti-cancer and preventing cardiovascular disease. High-performance countercurrent chromatography (HPCCC) coupled with reversed-phase medium pressure liquid chromatography (RP MPLC) method was applied for the rapid and efficient isolation of cyanidin 3-glucoside (C3G) and peonidin 3-glucoside (P3G) from black rice (Oryza sativa L., Poaceae). The crude black rice extract (500 mg) was subjected to HPCCC using two-phase solvent system composed of tert-butyl methyl ether/n-butanol/ acetonitrile/0.01% trifluoroacetic acid (TBME/B/A/0.01% TFA, 1 : 3 : 1 : 5, v/v, flow rate - 4.5 mL/min, reversed phase mode) to give enriched anthocyanin extract (37.4 mg), and enriched anthocyanin extract was sequentially chromatographed on RP-MPLC to yield C3G (16.5 mg) and P3G (8.7 mg). The recovery rate and purity of isolated C3G were 76.0% and 98.2%, respectively, and those of P3G were 58.3% and 96.3%, respectively. The present study indicates that HPCCC coupled with RP-MPLC method is more rapid and efficient than multi-step conventional column chromatography for the separation of anthocyanins.

• 한국식품위생안전성학회지
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• 제8권4호
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• pp.251-254
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• 1993

Extraction and Clean-up procedures coupled with quantitation by high performance liquid chromatography(HPLC) was evaluated for the detection of 4 aflatoxins, B1, B2, G1 and G2, in peanut butter. The Sep-pak clean-up method showed poorer separation and repeatability than did the modified DeVries' and an immunoaffinity column clean-up methods. No significant difference of detected aflatoxins between the affinity column clean-up and modified DeVries' method. The coefficients of variation for the 4 aflatoxins were ranging from 6.3∼32.3 by the modified DeVries' method and 5.3∼9.8 by the affinity column clean-up.

• 분석과학
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• 제27권3호
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• pp.140-146
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• 2014

후 컬럼 동위원소 희석법(PCID, post column isotope dilution)을 HPLC-ICP/MS (high performance liquid chromatography-inductively coupled plasma/mass spectrometry)에 적용한 정량법에서 내부 표준물을 동시에 사용하여 정확도와 정밀도를 개선하였다. 전통적인 여러 정량법과 후 컬럼 동위원소 희석법을 비교하여 볼 때에 PCID의 경우에 컬럼내에서 발생하는 오차가 가장 큰 요인으로 작용하였음을 알 수 있었다. PCID에서 내부 표준물을 사용하여 컬럼내에서의 손실에 대한 오차를 효과적으로 보정하고 정확도와 정밀도를 개선할 수 있었다. 셀레늄 화학종인 SeMet을 시료로 사용하고 내부 표준물로 MeSecys 또는 $Se^{4+}$를 이용한 결과, 사용하지 않은 경우와 비교하면 상대오차는 각 각 31%와 13%에서 모두 1% 대로 낮아져 정확도가 크게 개선되었으며, 상대 표준편차는 5.1%와 6.9%에서 각각 1.5%와 0.2%로 정밀도 또한 크게 개선되었다. PCID에서 내부 표준물을 사용하였을 때의 정량분석법의 장점을 다른 분석법과 비교 토의하였다.

• Bulletin of the Korean Chemical Society
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• 제31권8호
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• pp.2322-2328
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• 2010

A multiple solid-phase extraction (SPE) method was used with liquid chromatography, coupled with mass spectrometry (LC/MS), for the analysis of heterocyclic amines (HCAs) in human urine. Separation efficiencies based on the pH of the mobile phase and the types of columns were compared. An amide column showed better baseline separation and narrower HCA peak widths at pH 5.0 for the mobile phase than a $C_8$ column. Each SPE step, HLB, MCX, and HybridSPE, was optimized by controlling the pH conditions. The combined method with the three SPEs effectively removed interfering species that cause ion-suppression during HCA detection. Validation of the method, performed with SIM and SRM detection, showed correlation coefficients above 0.991 in the range 0.3 - 16.7 ng/mL. Recovery rates were 45.4 - 97.3% on the $C_8$ column and 71.8 - 101.4% on the amide column, and method detection limits were 0.11 - 0.65 ng/mL on the $C_8$ column and 0.12 - 0.48 ng/mL on the amide column. This method using multiple SPEs offers significant benefits for high-throughput determination of HCAs in urine.