• Title, Summary, Keyword: Sep-pak $C_{18}$

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Analysis of Carbendazim and Carbaryl by Micro-HPLC (Micro-HPLC에 의한 Carbendazim과 Carbaryl의 분석)

  • Choi, Kyoung-Sook;Lee, Hoe-Yeon;Lee, Duck-Hee;Byun, Woon-Ki
    • Analytical Science and Technology
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    • v.7 no.3
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    • pp.421-425
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    • 1994
  • A micro-high performance liquid chromatography(Micro-HPLC) techniquie with solid phase extraction was reported which detected carbendazim and carbaryl at picogram levels. They were separated on microbore packed $C_{18}$ column($1.0mm\;I.\;D{\times}150mm$, $d_f=5{\mu}m$) using a 50% methanol mobile phase and detected at UV 220nm(${\alpha}=2.94$, $R_s=4.71$), while they were not resolved on analtical HPLC system(${\alpha}=1.27$, $R_s=0.76$). The detection thresholds of carbendazim and carbaryl were 0.5ng and 0.1ng on Micro-HPLC, therefore Micro-HPLC system was 20~40 told more sensitive than anayltical HPLC system. Sep-Pak $C_{18}$ catridge was found to be efficient in enriching carbendazim and carbaryl from dilute aqueous solution with 97.0% and 97.8% recoveries of them. The Sep-Pak $C_{18}$ catridge followed by the Micro-HPLC had been applied to the quantitative analysis of carbendazim and carbaryl in spiked juices and a commercial drinking water.

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Comparision of Preparation Methods for Water Soluble Vitamin Analysis in Foods by Reversed-Phase High Performance Liquid Chromatography (역상 고속 액체 크로마토그래피에 의한 식품 중 수용성 비타민 분석을 위한 전처리법의 비교)

  • Kim, Hyung-Soo;Jang, Duck-Kyu;Woo, Dong-Kyun;Woo, Kang-Lyung
    • Korean Journal of Food Science and Technology
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    • v.34 no.2
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    • pp.141-150
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    • 2002
  • Owing to a need for simple extraction and purification for analysis of water soluble vitamins in food samples by RP-HPLC with UV-detector, the methods of bromelain and protease hydrolysis and $C_{18}$ Sep-Pak solid phase extraction were employed. The recoveries of standard water soluble vitamins by the bromelain and protease hydrolysis and $C_{18}$ Sep-Pak solid phase extraction were significantly high compared to AOAC methods in most of vitamins. The contents of pyridoxal determined with protest in the pork was similar, but in the bromelain hydrolysis and AOAC method, was high compared to the results of reference. The niacinamide, thiamin and riboflavin determined with bromelain and protease hydrolysis showed similar values to the results of references. In the potato, pyridoxamine was detected in the AOAC method, which was not detected in the bromelain and protease hydrolysis methods. Pyridoxal contents in the protease hydrolysis and AOAC methods were very similar to the results of references. The recoveries of fortified standard vitamins in food samples were significantly high and accurate compared to those of AOAC methods. The extraction and purification with $C_{18}$ Sep-Pak solid extractor might be considered superior method for the determination of water soluble vitamins in food samples.

A Study on the Determination of Caffeine in Coffee, Black tea and Green Tea by high performance Liquid Chromatography (고속액체 크로마토크래피에 의한 커피, 홍차, 녹차중의 카페인 정량에 관한 연구)

  • 권익부;이윤수;우상규;이충영;서준걸
    • Journal of Food Hygiene and Safety
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    • v.5 no.4
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    • pp.213-217
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    • 1990
  • A simple and practical method for the determination of caffeine in coffee, black tea and green tea was studied. The analysis of caffeine was performed by reverse phase high perfomance liquid chromatography using a ${\mu}-Bondapak$ C18 column at isocratic condition with methanol-acetic acid-water (20: 1: 79) on UV detector at 280 nm. The extraction and clean-up of caffeine in sample is based on combing a simple pretreatment with the use of a Sep-Pak Alumina A cartridge. The average recoveries of caffeine from several samples were 95.2 -101.3%, the relative standard deviation for the whole procedure was 0.10 ~ 0.62%, and the detection limit of caffeine in sample solution was about $0.1\;\mu\textrm{g}\;per\;ml$.

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Rapid Preparation and Quality Control of $^{99m}Tc$-ECD, $MAG_3$ and MIBI using Microwave Heating and Sep-Pak Cartridges (마이크로웨이브와 Sep-Pak 카트리지를 이용한 $^{99m}Tc$-ECD, $MAG_3$, MIBI의 신속한 제조 및 정도관리)

  • Oh, Seung-Jun;Moon, Dae-Hyuk;Ryu, Jin-Sook;Lee, Hee-Kyung
    • The Korean Journal of Nuclear Medicine
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    • v.33 no.4
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    • pp.430-438
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    • 1999
  • Purpose: We evaluated a rapid preparation procedures for the labeling and quality control of $^{99m}Tc$-ECD, $MAG_3$, and MIBI using microwave heating and Sep-Pak cartridges. Materials and Methods: $^{99m}Tc$ labeling of ECD, $MAG_3$, and MIBI kit preparation was performed according to the package inserts with microwave heating modification. Heating time was 10-15 sec, and heating was performed with 3 mm plastic bottle with screw cap to prevent radiation contamination. Labeling efficiency was obtained with $C_{18}$ or Alumina N Sep-Pak cartridges. Results: The radiochemical purity of $93{\sim}96%$ for $^{99m}Tc$-ECD and $95{\sim}99%$ for $^{99m}Tc$-MIBI was obtained using Alumina N Sep-Pak cartridge. The optimum irradiation time of microwave method for 3 ml $^{99m}Tc$-labeled radiopharmaceutical solution was 10 sec for $^{99m}Tc$-ECD and $^{99m}Tc$-MIBI, and 15 sec for $^{99m}Tc-MAG_3$. The results of quality control data with Sep-Pak cartridges were well correlated with TLC method. The total preparation time of these radiopharmcaeuticals was $5{\sim}6min$ including quality control procedure. Conclusion: This study demonstrates that radiopharmaceuticals preparation by microwave heating and quality control by Sep-Pak cartridges can be efficiently utilized as an alternative to the recommended method by manufacturer's manual.

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Detection and Quantitation of Residual Antibiotics and Antibacterial Agents in Foods

  • Ryu, Jae-Chun;Seo, Ja-Won;Song, Yun-Seon;Park, Jong-Sei
    • Journal of Food Hygiene and Safety
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    • v.5 no.3
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    • pp.159-164
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    • 1990
  • To detect and quantitation residual antibiotics and antibacterial agents in meats, we performed a biological assay employing the three microorganisms Bacillus subtilis ATCC 6633, Micrococcus luteus ATCC 9341, and Bacillus cereus var. mycoides ATCC 11778 for the screening purpose and developed a Gas Chromatography-mass Spectrometry(GC/MS) analysis for the confirmation and quantiation. In the biological assay (paper disk method), three test solution are used depending on the character of the residual antibiotics and antibacterial agents, follow by a simple clean up procedure which includes homogenization with Mcilvaine buffer, defatting with includes homogenization with Mcilvaine buffer, defatting with hexane, extraction with chloroform, clean-up by Sep-Pak $C_{18}$ and Bakerbond SPE carboxylic acid column. The chloroform layer is used for the analysis of sulfa agents. macrolides antibiotics and antibacterial agents, Adsorbed materials in the Sep-Pak $C_{18}$ were also employed for th analysis of penicillins and tetracyclines. Effluents from the Sep-Pak $C_{18}$ were cleaned-up one more by Bakerbond 10 SPE COOH column and employed for the analysis of aminoglycosides. In the instrumental analysis by using the GC/MSD, residual antibiotics and antibacterial agent were quantitated by selected ion monitoring (SIM) mode after derivatization. A simultaneous analysis of six residual antibiotic and antibacterial agent such as oxytetracycline, penicillin, ampicillin, choliraphenicol and thiamphenicol was developed with simple cleanup procedures revealing good recovery and reproducibility. Also, simultaneous detection of macrolides antibiotics such as erythromycin, spiramycin, and oleandomycin was developed after acid hydrolysis due to their large molecular structures. Because of the high reproducibility and selectivity of these two methods, it is very desirable that the combination of the two methods be used in the bioassay for the screening of residual antibiotics and antibacterial agent and that GC/MSD analysis be used for the confirmation and quantitation.

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Simultaneous Determination of the Water Soluble Vitamins in Multi-Nutrient Tablets by Reversed-Phase High-Performance Liquid Chromatography

  • Kim, Hyung-Soo;Jang, Duck-Kyu;Woo, Dong-Kyun;Woo, Kang-Lyung
    • Preventive Nutrition and Food Science
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    • v.7 no.1
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    • pp.12-17
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    • 2002
  • Simultaneous determination of nine water-soluble vitamins contained in multi-nutrient tablets was carried out by reversed phase high-performance liquid chromatography (RP-HPLC) equipped with analytical $C_{18}$ column and UV (270 nm) detector. Those standard vitamins were successfully separated within 23 minutes by gradient elution with solvent A (0.5 M potassium phosphate monobasic) and solvent B (0.25 M potassium phosphate monobasic-methanol, 1:1). Calibration curves showed good linealities with correlation coefficients (> 0.92) in tested ranged respectively. The detection limits were considered to be 2.1 ng for ascorbic acids 60 ng for Vit B$_{6}$ 3 ng for p-aminobenzoic acid, 9 ng for niacinamide, 9 ng for thiamin, 5.0 ng for folic acid and 1.5 ng for riboflavin at 0.05 a.u.f.s. Solid phase extraction through Sep-Pak (C$_{18}$ ) cartridge was successfully applied for purification of water soluble vitamins in commercial multi-nutrient tablets.ts.

Determination of terbutaline in human plasma by coupled column chromatography (커플드칼럼크로마토그래피에 의한 사람 혈장 중 테르부탈린의 정량)

  • Ko, Mi Young;Jeon, Sang-Seol;Kim, Kyeong Ho
    • Analytical Science and Technology
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    • v.28 no.2
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    • pp.125-131
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    • 2015
  • A method was developed and fully validated for the determination of terbutaline, a β2-receptor agonist, in human plasma. Plasma samples were prepared by solid-phase extraction with Sep-Pak silica, followed by high-performance liquid chromatography (HPLC). The terbutaline was pre-separated from the interfering components in plasma on a Luna C18 (2) column, and terbutaline and salbutamol as an internal standard were resolved and determined on a Luna Silica column. The two columns were connected by a switching valve equipped with silica pre-column. The pre-column was used to concentrate the terbutaline in the eluent from the C18 column before back-flushing onto the silica column with fluorescence detection at an excitation/emission wavelength of 276/306 nm. The method was shown to be specific by testing six different human plasma sources. Linearity was established for a concentration range of 0.4-20.0 ng/mL with a correlation coefficient of 0.9999. The lower limit of quantitation was 0.4 ng/mL with a precision of 10.1% as C.V.%.

Purification, Bacteriolytic Action and Plasmid Isolation of Acidocin 4A Produced by Lactobacillus acidophilus GP4A (Lactobacillus acidophilus GP4A 박테리오신의 정제, Bacteriolytic 작용 및 생산 관련 Plasmid의 선별)

  • Han, Gyeong-Sik;Jeon, U-Min;Kim, Yeong-Hun;Kim, Se-Heon
    • Journal of Dairy Science and Biotechnology
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    • v.21 no.2
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    • pp.114-119
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    • 2003
  • Acidocin 4A produced by Lactobacillus acidophilus GP4A was purified to homogeneity by ammonium sulfate precipitation and sequential chromatographies containing Octyl sepharose CL-4B column, $C_{18}$ Sep-Pak Cartridge, $C_{18}$ RP HPLC and HPLC gel filtration. Tricine SDS-PACE resulted in a single band with estimated molecular mass of 4.1 kDa corresponding to the polypeptide weight marker. Electron microscopy of acidocin-treated indicator cells(L. delbrueckii subsp. lactis ATCC 4797) confirmed that acidocin 4A presented bacteriolytic effect, resulting in cell lysis. Curing trial using ethidium bromide (EtBr) was carried out to examine whether acidocin 4A determinant was encoded either by chromosome or on plasmid. The plasmid designated as pLA4A, being about 20 kb in size, was responsible for acidocin 4A production and immunity to host cells.

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Determination of Aldehydes in Tap Water by Reverse Phase Liquid Chromatography (역상 액체 크로마토그래피에 의한 수도수 중 알데하이드류의 정량)

  • Choi, Yong Wook;Choi, Yun Jung
    • Journal of the Korean Chemical Society
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    • v.43 no.4
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    • pp.438-446
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    • 1999
  • The optimum analytical method of aldehydes, ozone by-products, was established by reverse phase liquid chromatography. Six aldehydes including formaldehyde, acetaldehyde, acrolein, propionaldehyde, butylaldehyde and benzaldehyde, and one ketone including acetone were selected as aldehyde test samples through preliminary experiments. Such analytical conditions as the pH of citrate buffer solution, reaction temperature, reaction time, and concentration of DNPH, the component and composition of desorption solvent were optimized. As the result, pH 3.0 of citrate buffer solution, 40$^{\circ}C$ of reaction temperature, 15 minutes of reaction time, and 0.012% of DNPH concentration were chosen as optimum conditions. Aldehydes-DNPH derivatives in water were concentrated on $C_18$ Sep-Pak cartridge and followed by elution of their derivatives fraction with THF/ACN(70/30) mixture, and showed recoveries of the range from 87 to 107%. Separation condition on Nova-Pak $C_18$ column with low pressure gradient elution from ACN/MeOH/water(30/10/60) of an initial condition to 80% ACN of a final condition was found to give a good resolution within 20 minutes of run time. 86% to 103% of recovery for aldehydes using this method was similar to that for aldehyde using EPA Method 554 which is ranged from 84% to 103%.

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Optimization of HPLC Method and Clean-up Process for Simultaneous and Systematic Analysis of Synthetic Color Additives in Foods (식품 중 타르색소의 동시분석 및 계통분석을 위한 HPLC 분석조건 및 정제과정 확립)

  • Park, Sung-Kwan;Hong, Yeun;Jung, Yong-Hyun;Lee, Chang-Hee;Yoon, Hae-Jung;Kim, So-Hee;Lee, Jong-Ok
    • Korean Journal of Food Science and Technology
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    • v.33 no.1
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    • pp.33-39
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    • 2001
  • To develop a method for separation process using Sep-pak $C_18$, simultaneous and systematic analysis of 8 permitted and 11 non-permitted synthetic food colors in Korea, optimization of analysis conditions for reverse phase ion-pair high performance liquid chromatography was carried out. For the best result of Sep-pak $C_18$ separation the pH of color standard mixture solution was $5{\sim}6$ and 0.1% HCl-methanol solution were set as eluent. The colors eluated from Sep-pak $C_18$ cartridge were determined and confirmed by high performance liquid chromatography with a photodiode array detector at 420 nm for yellow colors type, at 520 nm for red colors type, at 600 nm for blue and green colors type and at 254 nm for mixed colors. Conditions for HPLC analysis were as follows: column, Symmetry $C_18$ (5 m, 3.9 mm $i.d.{\times}150\;mm$); mobile phase, 0.025 M ammonium acetate (containing 0.01 M tetrabutylammonium bromide) : acetonitrile : methanol (65 : 25 : 10) and 0.025 M ammonium acetate(containing 0.01 M tetrabutylammonium bromide) : acetonitrile : methanol (40 : 50 : 10); flow rate, 1 mL/min. It takes 35 minutes for simultaneaus analysis and 18 minutes for systematic analysis. The detection limits range of each colors were $0.01{\sim}0.05\;{\mu}g/g$.

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