Solid-Phase Extraction of Caffeine and Catechin Compounds from Green Tea by Caffeine Molecular Imprinted Polymer

Yinzhe Jin,노경호 대한화학회 2007 Bulletin of the Korean Chemical Society Vol.28 No.2

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 MIP-based 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 m, 250 4.6 mm) with methanol/water (40/60, %v/v) as the mobile phase at a flow rate of 0.5 mL/min.

Solid-Phase Extraction of Caffeine and Catechin Compounds from Green Tea by Caffeine Molecular Imprinted Polymer

Jin, Yinzhe,Row, Kyung-Ho Korean Chemical Society 2007 Bulletin of the Korean Chemical Society Vol.28 No.2

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.

생체시료로부터 미량 $\beta$-Blockers의 동시고상추출에 사용될 흡착제들의 특성

김경례,김도정,Kim, Kyoung Rae,Kim, Do Jeong 한국분석과학회 1993 분석과학 Vol.6 No.4

생체시료 중 ${\beta}$-blockers의 동시분석을 위한 시료 전처리 과정에서 고상추출법을 사용하기 위해 4가지 흡착제의 흡착 및 탈착 효율을 조사하였다. 용출 용매로서 methanol을 사용하였을 때 Chromosorb 107이 가장 높은 회수율을 보였다. ${\beta}$-Blockers의 breakthrough 조사를 하여 Chromosorb 107 컬럼의 우수한 흡착 및 탈착 성질을 혈청 중 2~8 ppm 농도 범위의 ${\beta}$-blockers를 동시에 고상추출하는 데 Chromosorb 107/methanol의 유용성을 조사하였다. The efficiencies of four different solid absorbents were evaluated for the simultaneous solid-phase extraction of six ${\beta}$-blockers from biological sample. Chromosorb 107 using methanol as the eluting solvent gave the highest solid-phase extraction yield. From the breakthrough studies of ${\beta}$-blockers, the excellent sorption and desorption properties of the Chromosorb 107 column were verified. The usefulness of Chromosorb 107/methanol was examined for the simultaneous solid-phase extraction of the ${\beta}$-blockers from serum in the concentration range of 2~8ppm.

Solid Phase Micro Extraction을 이용한 산초의 휘발성 성분 분석

이재곤,장희진,곽재진,김옥찬,이계호 한국식품영양학회 1999 韓國食品營養學會誌 Vol.12 No.2

Solid phase micro extraction(SPME)법의 최적조건 실험 및 SPME로 추출된 산초(Zanthoxylum schinifolium)의 휘발성 성분을 GC/MSD로 확인하였다. 휘발성 성분 추출에 자주 이용되는 동시증류추출(SDE)법으로 산초의 휘발성분을 분석하여 SP-ME 법에서 확인된 휘발성 성분과 조성비를 비교하였다. SPME 최적조건 시험에서 분자량이 적고 비점이 낮은 성분은 온도가 증가할수록 화이버에 흡착되는 양은 적게 나타났으며, 분자량이 크고 비점이 높은 성분은 추출시간이 증가할수록 흡착되는 양은 증가하였다. SPME 최적조건인 추출시간 30분과 50℃에서 분리된 휘발성 성분에서는 limonene(14.65%), geranyl acetate(11.07%), β-phellandrene(7.42%), 및 phellandral(3.08%) 등의 monoterpenoids 화합물과 caproic acid(11.99%), caprylic acid(8.01%), heptanoic acid(3.49%) 등의 지방산 화합물이 주요 성분으로 확인되었고, SDE법으로 추출된 휘발성 성분에서는 geranyl acetate(13.31%), limonene(12.81%) β-phellandrene(8.86%), trans-geraniol(5.22%) 및 caprylic acid(3.03%) 등의 화합물이 주요 성분으로 확인되었다. 지방산 성분들은 SPME법에서 높게 나타난 반면에 알코올 성분들은 SDE법보다 낮았다. SPME법은 적은 양의 시료로도 매우 신속하고 간단하게 전처리 할 수 있기 때문에 기존의 휘발성분 분석시 주로 사용한 SDE법에 비해 편리하며 경제적인 것으로 생각된다. Test of optimum condition of solid phase micro extraction(SPME) was performed by use of 5 volatile components in dilute aqueous solution. Volatile components of Sancho(Zanthoxylum schinifolium) were isolated by SPME method and were analyzed by GC/MSD, and compared with volatile components isolated by simultaneous distillation extraction(SDE) method. Total 31 components were identified by comparing gas chromatography retention time and mass spectral data. The major compounds were limonene, geranyl acetate, β-phellandrene, phellandral, myrcene, linalool, rose oxide, caproic acid and caprylic acid. SPME sampling procedure was found to be a good method for qualitative analysis of the volatile components.

물리적 가공법을 이용한 강황으로부터 Curcuminoid의 고체상추출

이광진,양혜진,정상원,마진열 한국생약학회 2012 생약학회지 Vol.43 No.3

In order to extract the curcuminoid such as curcumin, demethoxycurcumin (DMC), and bisdemethoxycurcumin (BDMC) in turmeric (Curcuma longa), solvent extraction methods (dipping and ultrasonic extraction method) and solid-phase extraction (SPE) were used. RP-HPLC (reverse-phase high-performance liquid chromatography) and TLC (thin-layer chromatography)were used for identification and analysis the three curcuminoid. From the experimental results, it is evident that the percentage of curcuminoid extracted from turmeric by ultrasonic extraction method was higher than dipping method. The percentage of curcumin extracted from turmeric by pure methanol was higher than any aqueous methanolic composition. Moreover,the total peak area of three curcuminoid was above 92% in RP-HPLC using solid-phase extraction. These results will form a database for investigating the constituents of natural products and the resources of pharmaceutical, nutrition, and cosmetic products.

Solid Phase Extraction of Trace Cu(II), Mn(II), Pb(II) and Zn(II) in Water Samples with Pulverized Silica-salen(NEt₂)₂

Kim, Young-Sang,In, Gyo,Choi, Jong-Moon Korean Chemical Society 2006 Bulletin of the Korean Chemical Society Vol.27 No.10

The use of chemically modified silica-salen$(NEt_2)_2$ was studied for the separation and concentration of the metal ions from an aqueous solution by a solid phase extraction. After the salen(NEt2)2 was synthesized, it was chemically bonded to silica gel by a diazonium coupling reaction. The adsorption capacities and binding constants were obtained with respect to Cu(II), Mn(II), Pb(II) and Zn(II) by a graphical method. Some experimental conditions were optimized for the determination of the trace elements. After the silica-salen(NEt2)2 was pulverized in a sample solution of which the pH was adjusted, the solution was stirred to pre-concentrate the metal ions. The metal ions adsorbed were desorbed with nitric acid solution. And the concentrated analytes were determined by a flame AAS. The method proposed here was so rarely influenced by a sample matrix that the procedure was applied to 3 types of water samples. The reproducible results of less than 10% RSD were obtained at the concentration level of ca. 100 ng/mL and the recoveries of 95-109% were obtained in the spiked samples in which given amounts of analytes were added.

Solid-phase extraction of chlorophenols in seawater using a magnetic ionic liquid molecularly imprinted polymer with incorporated silicon dioxide as a sorbent

Ma, Wanwan,Row, Kyung Ho Elsevier 2018 Journal of chromatography Vol.1559 No.-

<P><B>Abstract</B></P> <P>A type of magnetic ionic liquid based molecularly imprinted polymer coated on SiO<SUB>2</SUB> (Fe<SUB>3</SUB>O<SUB>4</SUB>@SiO<SUB>2</SUB>@IL-MIPs) was prepared with 1-vinyl-3-ethylimidazole ionic liquid as functional monomer, and 1,4-butane-3,3′-bis-1-ethylimidazole ionic liquid as cross linker, 4-Chlorophenol as template was successfully applied as a selective adsorbent for selective extraction of 5 chlorophenols in seawater samples by using the magnetic solid-phase extraction (MSPE) method. 11 types of Fe<SUB>3</SUB>O<SUB>4</SUB>@SiO<SUB>2</SUB>@IL-MIPs were synthesized and investigated for their different compositions of functional monomer (such as [C<SUB>2</SUB>min][Br], [C<SUB>2</SUB>min][BF<SUB>4</SUB>], [C<SUB>2</SUB>min][PF<SUB>6</SUB>], acrylamide, methacrylic acid and 4-vinyl pyridine) and cross-linker (such as [C<SUB>4</SUB>min<SUB>2</SUB>][Br], [C<SUB>4</SUB>min<SUB>2</SUB>][BF<SUB>4</SUB>], [C<SUB>4</SUB>min<SUB>2</SUB>][PF<SUB>6</SUB>], divinylbenzene, and ethylene glycol dimethacrylate), respectively. The [C<SUB>2</SUB>min][BF<SUB>4</SUB>] and [C<SUB>4</SUB>min<SUB>2</SUB>][PF<SUB>6</SUB>] based Fe<SUB>3</SUB>O<SUB>4</SUB>@SiO<SUB>2</SUB>@IL-MIP with the highest extraction efficiencies was applied to the optimization experiment of MSPE process (including extraction time, adsorbent mass and desorption solvents). Good linearity was obtained with correlation coefficients (R<SUP>2</SUP>) over 0.9990 and the relative standard deviations for the intra-day and inter-day determination were less than 3.10% with the extraction recoveries ranged from 85.0% to 98.4%. The results indicated that the proposed Fe<SUB>3</SUB>O<SUB>4</SUB>@SiO<SUB>2</SUB>@IL-MIPs possesses great identification and adsorption properties, and could be used as a good sorbent for selective extraction of CPs in environment waters.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Novel magnetic ionic liquid based molecularly imprinted polymers (Fe<SUB>3</SUB>O<SUB>4</SUB>@SiO<SUB>2</SUB>@IL-MIPs) were synthesized. </LI> <LI> Ionic liquids were applied as functional monomer and cross linker. </LI> <LI> A Fe<SUB>3</SUB>O<SUB>4</SUB>@SiO<SUB>2</SUB>@IL-MIPs-MSPE method was applied to extract chlorophenols in seawater. </LI> <LI> This adsorbent was with high efficient for recognizing chlorophenols. </LI> </UL> </P>

A Solid-Phase Extraction Method for Analyzing Trace Amounts of Polychlorinated Dibenzo-p-Dioxins and Dibenzofurans in Waste Water

Park, Deok-Hie,Youn, Yeu-Young,Choi, Jae-Won,Lim, Young-Hee,Cho, Hye-Sung Korean Society for Mass Spectrometry 2011 Mass spectrometry letters Vol.2 No.1

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.

An integrated microfluidic device with solid-phase extraction and graphene oxide quantum dot array for highly sensitive and multiplex detection of trace metal ions

Park, Minsu,Seo, Tae Seok Elsevier 2019 Biosensors & bioelectronics Vol.126 No.-

<P><B>Abstract</B></P> <P>An integrated microfluidic device, consisting of a solid-phase extraction (SPE) unit for metal ion pretreatment, a micropump, a micromixer, and a detachable graphene oxide quantum dot (GOQD) array chip was constructed for selective and sensitive detection of As<SUP>3+</SUP>, Cd<SUP>2+</SUP>, and Pb<SUP>2+</SUP>. The entire process could be sequentially and automatically completed by actuating a pneumatic micropump. Effect of the pH for metal ion capture and pumping scheme for recovery efficiency were investigated on a chip. The ion As<SUP>3+</SUP>, Cd<SUP>2+</SUP>, and Pb<SUP>2+</SUP> whose concentrations ranged from 10<SUP>−2</SUP> µM to 10<SUP>2</SUP> µM were successfully recovered with high efficiency over 80%. Monoplex and multiplex detection of As<SUP>3+</SUP>, Cd<SUP>2+</SUP>, and Pb<SUP>2+</SUP> were then executed on a GOQD array chip. The target metal ions were specifically captured on the DNA aptamer linked GOQD array, which results in the fluorescence quenching of GOQD due to the electron transfer from the GOQD to metal ions under the laser irradiation. The proposed integrated SPE-GOQD array based microdevice could perform As<SUP>3+</SUP>, Cd<SUP>2+</SUP>, and Pb<SUP>2+</SUP> detection with detection limits of 5.03 nM, 41.1 nM, and 4.44 nM, respectively. Simultaneous multiplex detection for binary or ternary mixture of As<SUP>3+</SUP>, Cd<SUP>2+</SUP>, and Pb<SUP>2+</SUP> was performed, and the proposed integrated microdevice also showed high recovery values ranging from 83.52% to 128.3% from the environmental samples.</P> <P><B>Highlights</B></P> <P> <UL> <LI> We report an integrated microdevice for trace metal ion detection. </LI> <LI> We preconcentrated As<SUP>3+</SUP>, Cd<SUP>2+</SUP>, and Pb<SUP>2+</SUP> from an aqueous solution by on-chip solid-phase extraction (SPE). </LI> <LI> On-chip detection of As<SUP>3+</SUP>, Cd<SUP>2+</SUP>, and Pb<SUP>2+</SUP> was performed on the DNA aptamer linked graphene oxide quantum dot (GOQD) array sensor. </LI> <LI> Automatic operation, high selectivity, and low detection limit were achieved. </LI> <LI> Multiplex detection of As<SUP>3+</SUP>, Cd<SUP>2+</SUP>, and Pb<SUP>2+</SUP> in real environmental samples was successfully executed with high recovery yields. </LI> </UL> </P>

Rapid and simple extraction of lipids from blood plasma and urine for liquid chromatography-tandem mass spectrometry

Bang, D.Y.,Byeon, S.K.,Moon, M.H. Elsevier 2014 Journal of chromatography Vol.1331 No.-

A simple and fast lipid extraction method from human blood plasma and urine is introduced in this study. The effective lipid extraction from biological systems with a minimization of the matrix effect is important for the successful qualitative and quantitative analysis of lipids in liquid chromatography-electrospray ionization-tandem mass spectrometry (LC-ESI-MS/MS). The method described here is based on the modification of the quick, easy, cheap, effective, rugged and safe (QuEChERS) extraction method, which was originally developed for pesticide residue analysis in food, for the purpose of isolating lipids from biological fluids. Applicability of QuEChERS method for lipids was evaluated by varying organic solvents for the extraction/partitioning of lipids in MgSO<SUB>4</SUB>/CH<SUB>3</SUB>COONa for the removal of water and by varying sorbents (primary secondary amines, graphitized carbon black, silica, strong anion exchange resins and C18 particles) for the dispersive solid-phase extraction (dSPE) step. This study shows that 2:1 (v/v) CHCl<SUB>3</SUB>/CH<SUB>3</SUB>OH is effective in the extraction/partitioning step and that 50mg of C18 particles (for 0.1mL plasma and 1mL of urine) are more suitable for sample cleanup for the dSPE step of the QuEChERS method. Matrix effects were calculated by comparing the recovery values of lipid standards spiked to both plasma and urine samples after extraction with those of the same standards in a neat solution using nanoflow LC-ESI-MS/MS, resulting in improved MS signals due to the decrease of the ion suppression compared to the conventional Folch method. The modified QuEChERS method was applied to lipid extracts from both human urine and plasma samples, demonstrating that it can be powerfully utilized for high-speed (<15min) preparation of lipids compared to the Folch method, with equivalent or slightly improved results in lipid identification using nLC-ESI-MS/MS.