大孔吸附树脂结合硅胶柱层析纯化环孢菌素A

采用大孔吸附树脂层析结合硅胶柱层析,对环孢菌素A的分离纯化进行研究,确定了最佳层析条件,建立了工业化制备环孢菌素A的工艺。大孔吸附树脂层析选用D101树脂作为吸附介质,提取液丙酮含量控制在50%,最大吸附量为35 mg/g湿树脂,洗脱剂选用丙酮;硅胶柱层析选用42~64μm硅胶作为层析介质,最优层析条件为柱床高径比10∶1,流动相配比V(石油醚)∶V(丙酮)=70∶30,流速80 mL/m in,环孢菌素A上样质量浓度100 g/L,硅胶层析平均收率为84.2%,环孢菌素A纯度可达到97%以上,整个工艺总收率为65%~70%。     

大孔吸附树脂对金银花叶茎藤总黄酮的吸附性能

从金银花叶茎藤中提取总黄酮并用D-101大孔吸附树脂进行纯化,研究了D-101大孔吸附树脂对总黄酮的吸附及解吸附特性。结果表明,D-101树脂对金银花叶茎藤总黄酮分离纯化的最佳工艺参数为:上样液黄酮浓度0.538 mg/mL,静置吸附时间80 min,料液比1∶5(g∶mL),pH 2,流速为2 mL/min,以60 mL 75%的乙醇溶液洗脱,黄酮解吸率为94.5%,纯化后黄酮纯度为84.5%,是粗提液黄酮含量(16.8%)的5倍。金银花叶茎藤总黄酮在D-101树脂上的吸附等温线符合Langmuir等温吸附方程。吸附热力学参数表明吸附过程为自发、放热过程,吸附动力学可用Pseudo-second-order模型较好地拟合,30℃时其表观吸附速率常数为1.034×10-2g/mg.min。     

藤黄灰链霉菌-H103发酵液中抗真菌活性成分的分离纯化

通过大孔树脂吸附等方法对藤黄灰链霉菌H103发酵液中的抗真菌活性成分进行了分离纯化,得到了纯度较高的活性物质的结晶,并且建立了通过大孔树脂吸附-结晶的分离纯化路线以及反相高压液相色谱-蒸发光散射(HPLC-ELSD)的检测方法,为进一步的理化性状研究打下了一个良好的基础。实验表明,最佳吸附树脂为X-5树脂,洗脱剂为50%乙醇,HPLC条件为:反相色谱柱Agilent 20RBA×310SB-C18(150mm×4.6mm i.d,5μm),以乙腈(A)-水(B)为流动相,梯度洗脱,0~4.0m in,V(A):V(B)=20∶80,4.0~9.5m in,V(A)∶V(B)=45∶55,此后V(A):V(B)=80∶20,流动相流速:0.8mL/m in,柱温:30℃,ELSD条件:漂移管温度115℃,载气流速(空气)2.3L/m in。     

DM-130树脂对甘草酸的吸附性能及提纯应用研究

探讨了大孔吸附树脂DM-130对甘草酸的吸附性能及原液浓度、pH值、流速对此树脂吸附性能的影响.结果表明,DM-130树脂对甘草酸的吸附性能好,易于洗脱,分离效果好,产品纯度可达94.676%;正交试验表明,pH为5.4±,原液浓度为10 mg/ml,以2 BV/h的流速为最佳处理;洗脱液采用3 BV 10%的乙醇最经济.     

榅桲总多酚的纯化工艺及PTP1B抑制作用研究

通过采用11种大孔吸附树脂对榅桲多酚粗提物的静态吸附和解吸试验,筛选出适合分离纯化榅桲总多酚的最优树脂,并对其动态吸附特性和影响因素进行研究。结果表明:最佳纯化工艺条件为:AB-8大孔吸附树脂做吸附填料,上样液质量浓度0.04 g/m L,以2 BV/h的吸附速率进行吸附,上样量为11 BV,用3 BV蒸馏水除杂后,以50%乙醇溶液为洗脱剂,洗脱液用量为4 BV,洗脱流速控制在2 BV/h。经AB-8树脂吸附富集后,样品总多酚质量浓度达到了30.11 mg/g,是粗提物(9.55 mg/g)的3倍。对纯化前后的榅桲总多酚进行PTP1B的抑制作用研究,结果显示,榅桲总多酚对PTP1B有较强的抑制作用,即榅桲总多酚纯化前的IC50为78.14μg/m L,用AB-8树脂纯化后所得总多酚的IC50为16.12μg/m L。     

AB-8大孔树脂吸附分离红花桑寄生总黄酮的影响因子研究

AB-8大孔吸附树脂对红花桑寄生总黄酮静态吸附和动态洗脱的效果,受提取液质量浓度、pH值及环境温度、振速以及洗脱剂乙醇浓度、流速等因素影响。试验表明,提取液质量浓度和pH值对AB-8树脂的吸附效果有显著影响,其吸附分离总黄酮的工艺条件为:浓度为1.2~2.0 mg/ml、pH 3.0~4.0的红花桑寄生提取液,置于摇床上,于室温条件下振荡(振速160 r/min)吸附2~3 h,然后用5倍于树脂体积(5BV)的50%乙醇以1.5 ml/min流速进行柱上动态解吸。AB-8树脂对红花桑寄生总黄酮的饱和吸附量可达29.0 mg/g,动态洗脱率达95.0%,获得产品中黄酮纯度为46.0%,得率为5.5%。     

虎眼万年青总皂苷的纯化及抗氧化活性研究

对虎眼万年青总皂苷的纯化工艺及抗氧化活性进行研究。以比吸附量和比洗脱量为指标,筛选大孔树脂型号,进一步优化工艺条件。结果表明,AB-8型大孔树脂对虎眼万年青总皂苷具有良好的吸附和洗脱效果,最佳纯化条件为药材量与树脂用量比不超过7∶1,用水、30%乙醇除杂,70%乙醇洗脱,在此条件下得到的虎眼万年青总皂苷纯度为55.18%。对纯化后虎眼万年青总皂苷的抗氧化活性进行研究,发现虎眼万年青总皂苷对羟自由基、超氧自由基阴离子和DPPH自由基的IC_(50)分别为2.43、2.28和0.05 mg/m L,具有良好的抗氧化活性。     

大孔吸附树脂纯化亚麻木酚素

以纯化亚麻木酚素粗品为目的,比较了X-5、D101和AB-8三种大孔吸附树脂对木酚素的吸附性能,筛选出X-5大孔树脂最合适。通过动态吸附、解吸实验确定了上样浓度与上样量。在上样浓度10 mg/m L,上样量25 m L时分离效果最佳。同时,重点考察了梯度洗脱和等度洗脱两种解吸方式对木酚素产品纯度和收率的影响。等度洗脱采用30%乙醇水溶液,木酚素纯度可达85.49%,收率为57.59%;采用60%乙醇水溶液洗脱,木酚素纯度为59.30%,收率最高为75.05%。梯度洗脱可得到不同纯度产品,过程总收率为77.63%。     

大孔吸附树脂分离富集苜蓿皂甙的研究

本项工作以对苜蓿皂甙的吸附量和解吸率为指标筛选大孔吸附树脂。研究结果表明,X-5吸附树脂具有较好的吸附性能和解吸效果。研究应用正交试验方法进一步对大孔吸附树脂分离纯化苜蓿皂甙的工艺条件进行试验分析,确定苜蓿皂甙分离富集的最佳操作条件为:上样浓度8mg/mL,色谱柱的径高比1∶7,药材-树脂比例1∶3;吸附完全后,先以水洗脱,除去杂质,再以50%乙醇洗脱,可以得到纯度较好的苜蓿皂甙。     

桑椹中黄酮类物质的大孔树脂纯化工艺

以桑椹中黄酮类物质的吸附量和解吸率为指标,对比分析HZ-801、HZ-816、HZ-818等12种大孔吸附树脂对桑椹提取液的分离纯化效果,优选出最佳树脂HZ-801并通过对上样液pH、上样液质量浓度、上样量、吸附流速、洗脱剂质量浓度、洗脱剂用量、洗脱流速等影响因素的考察,确定最优工艺:吸附阶段上样液pH=4,上样液质量浓度0.45mg/mL,上样量420mL,吸附流速120mL/h,动态吸附量(干树脂)25.34mg/g,吸附率84.25%;洗脱阶段的洗脱剂体积分数为60%乙醇,洗脱剂用量270mL,洗脱流速120mL/h。此优化工艺条件下的洗脱率为85.78%,总黄酮纯度从23.64%提高到82.36%。     

Applications of magnetic surface imprinted materials for solid phase extraction of levofloxacin in serum samples

In this work, molecularly imprinted magnetic carbon nanotubes (MCNTs@MIPs) was prepared with surface imprinting technique for extraction of levofloxacin in serum samples. The preparation of molecularly imprinted polymers (MIPs) used levofloxacin as template, methacrylic acid as functional monomer, and ethylene glycol dimethacrylate as cross‐linker, and the magnetic carbon nanotubes (MCNTs) was synthesized by solvothermal method. The prepared polymers not only can be separated and collected easily by an external magnetic, but also exhibited high specific surface area and high selectivity to template molecules. Kinetic adsorption and static adsorption capacity investigations indicated that the synthesized MCNTs@MIPs had excellent recognition towards levofloxacin. Furthermore, magnetic solid phase extraction (MSPE) using the prepared MCNTs@MIPs as sorbent was then investigated, and an efficient sample cleanup was obtained with recoveries ranged from 78.7 ± 4.8 % to 83.4 ± 4.1%. In addition, several parameters, including the pH of samples, the amount of MCNTs@MIPs, the adsorption and desorption times, and the eluent, were investigated to obtain optimal extraction efficiency. Under the optimal extraction conditions, the stability of the polymer was also evaluated, and the average recovery reduced less than 7.6% after 5 cycles. MCNTs@MIPs successfully applied in the preconcentration and determination of levofloxacin in serum sample suggested that the MSPE method based on the novel polymers could be a promising alternative for selective and efficient extraction of trace amounts of pharmaceutical substances in bio‐matrix samples. Copyright © 2015 John Wiley & Sons, Ltd.     

Molecular imprinting and solid phase extraction of flavonoid compounds

Molecularly imprinted polymers (MIPs) for quercetin have been successfully prepared by a thermal polymerization method using 4-vinylpyridine (4-VP) and ethylene glycol dimethacrylate (EDMA) as functional monomer and cross-linker, respectively. The obtained molecularly imprinted polymers were evaluated by HPLC using organic eluents, with respect to their selective recognition properties for quercetin and related compounds of the flavonoid class. Two equivalent control polymers, a blank polymer and a polymer imprinted with a structural analogous template, were synthesized, in order to confirm the obtained results. Furthermore, preliminary experiments confirm the applicability of the prepared MIPs for solid phase extraction (SPE), as rapid and facile clean-up of wine samples for HPLC analysis is an envisaged field of application. The successful preparation of molecularly imprinted polymers for flavones provides an innovative opportunity for the development of advanced separation materials, with applications in the field of wine and fermentation analysis.     

Solid-phase extraction of tramadol from plasma and urine samples using a novel water-compatible molecularly imprinted polymer

In this study, a novel method is described for the determination of tramadol in biological fluids using molecularly imprinted solid-phase extraction (MISPE) as the sample clean-up technique combined with high-performance liquid chromatography (HPLC). The water-compatible molecularly imprinted polymers (MIPs) were prepared using methacrylic acid as functional monomer, ethylene glycol dimethacrylate as cross-linker, chloroform as porogen and tramadol as template molecule. The novel imprinted polymer was used as a solid-phase extraction (SPE) sorbent for the extraction of tramadol from human plasma and urine. Various parameters affecting the extraction efficiency of the polymer have been evaluated. The optimal conditions for the MIP cartridges were studied. The MIP selectivity was evaluated by checking several substances with similar molecular structures to that of tramadol. The limit of detection (LOD) and limit of quantification (LOQ) for tramadol in urine samples were 1.2 and 3.5 μg L⁻¹, respectively. These limits for tramadol in plasma samples were 3.0 and 8.5 μg L⁻¹, respectively. The recoveries for plasma and urine samples were higher than 91%.     

Magnetic molecularly imprinted polymers for improved extraction of tanshinones from herbs via integrated extraction and cleanup system

A novel separation technology at room temperature for traditional Chinese medicines was proposed in this work by adding magnetic molecularly imprinted polymers (M-MIPs) into extraction solution and sample matrix. The M-MIPs show a more adsorption capacities and higher selectivity for the template than magnetic non-molecularly imprinted polymers (M-NMIPs) without the specific binding sites. Addition of the M-MIPs to the extraction solution provides one-step extraction and cleanup, the improvement of extraction rate and extraction yields of three tanshinones (from 0.40, 0.23 and 0.12 mg g⁻¹ in 240 min by solvent extraction to 0.52, 0.27 and 0.19 mg g⁻¹ in 5 min by 200 mg sorbent), and reusability of extraction solvent. The extraction yields of three tanshinones by this technology at room temperature in 5 min were higher than those by ultrasonic extraction in 30 min, by heat reflux extraction in 45 min and by solvent extraction at room temperature in 4 h. The integrated technology has the advantages of one-step extraction and cleanup, high extraction efficiency, low solvent consumption and room temperature.     

Synthesis of a molecularly imprinted polymer for the solid‐phase extraction of betulin and betulinic acid from plane bark

Introduction – Plant extracts are usually complex mixtures of various polarity compounds and their study often includes a purification step, such as solid‐phase extraction (SPE), to isolate interest compounds prior analytical investigations. Molecularly imprinted polymers (MIPs) are a new promising type of SPE material which offer tailor‐made selectivity for the extraction of trace active components in complex matrices. Numerous specific cavities that are sterically and chemically complementary of the target molecules, are formed in imprinted polymers. A molecularly imprinted polymer (MIP) was synthesised in order to trap a specific class of triterpene, including betulin and betulinic acid from a methanolic extract of plane bark. Methodology – Imprinted polymers were synthesised by thermal polymerisation of betulin as template, methacrylic acid (MAA) or acrylamide (AA) as functional monomer, ethylene glycol dimethacrylate as crosslinking agent and chloroform as porogen. Afterwards, MAA‐ and AA‐MIPs were compared with their non‐imprinted polymers (NIPs) in order to assess the selectivity vs betulin and its derivatives. Recovered triterpenes were analysed by HPLC during MIP‐SPE protocol. Results – After SPE optimisation, the MAA‐imprinted polymer exhibited highest selectivity and recovery (better than 70%) for betulin and best affinity for its structural analogues. Thus, a selective washing step (chloroform, acetonitrile) removed unwanted matrix compounds (fatty acids) from the SPE cartridge. The elution solvent was methanol. Finally, the MAA‐MIP was applied to fractionate a plane bark methanolic extract containing betulin and betulinic acid. Conclusion – This study demonstrated the possibility of direct extraction of betulin and its structural analogues from plant extracts by MIP technology. Copyright © 2009 John Wiley & Sons, Ltd.     

Selective solid-phase extraction using molecularly imprinted polymer for analysis of methamidophos in water and soil samples

An analytical methodology for the analysis of methamidophos in water and soil samples incorporating a molecularly imprinted solid-phase extraction process using methamidophos-imprinted polymer was developed. Binding study demonstrated that the polymer exhibited excellent affinity and high selectivity to the methamidophos. Evidence was also found by FT-IR analysis that hydrogen bonding between the CO(2)H in the polymer cavities and the NH(2) and P=O of the template was the origin of methamidophos recognition. The use of molecularly imprinted solid-phase extraction improved the accuracy and precision of the GC method and lowered the limit of detection. The recovery of methamidophos extracted from a 10.0 g soil sample at the 100 ng/g spike level was 95.4%. The limit of detection was 3.8 ng/g. The recovery of methamidophos extracted from 100 mL tap and river water at 1 ng/mL spike level was 96.1% and 95.8%, and the limits of detection were 10 and 13 ng/L respectively. These molecularly imprinted solid-phase extraction procedures enabled selective extraction of polar methamidophos successfully from water and soil samples, demonstrating the potential of molecularly imprinted solid-phase extraction for rapid, selective, and cost-effective sample pretreatment.     

Spectrofluorimetric determination of atenolol from human urine using high‐affinity molecularly imprinted solid‐phase extraction sorbent

This study presents a novel, sensitive and selective molecularly imprinted solid‐phase extraction (MISPE)–spectrofluorimetric method for the removal and determination of atenolol from human urine. Molecularly imprinted and non‐imprinted polymers were synthesized thermally using a radical chain polymerization technique and used as solid‐phase extraction sorbents. Acrylic acid ethylene glycol dimethacrylate, dibenzoyl peroxide and dichloroethane were used as a functional monomer, cross‐linker, initiator and porogen, respectively. The calibration curve was in the range of 0.10–2.0 μg/ml for the developed method. Limit of detection and limit of quantification values were 0.032 and 0.099 μg/ml, respectively. Owing to the selectivity of the MISPE technique and the sensitivity of spectrofluorimetry, trace levels of atenolol have been successfully determined from both organic and aqueous media. Relatively high imprinting factor (4.18) and recovery results (74.5–75.3%) were obtained. In addition, intra‐ and interday precision values were 0.38–1.03% and 0.47–2.05%, respectively, proving the precision of the proposed method. Thus, a selective, sensitive and simple MISPE–spectrofluorimetric method has been developed and applied to the direct determination of atenolol from human urine.     

Isolation and detection of steroids from human urine by molecularly imprinted solid-phase extraction and liquid chromatography

Naturally occurring steroids such as progesterone, testosterone and 17β-estradiol were analyzed in this study. These bio-identical molecules paradoxically can be either beneficial or harmful. Unfortunately as growth promoters can be toxic and cancerogenic at elevated levels. Due to difficulty in monitoring at trace quantities of these hormones in biological matrices specific adsorption materials molecularly imprinted polymers (MIPs) were used for preconcentration and clean up in sample preparation step. A non-covalent imprinting approach was used for bulk polymerization of progesterone, testosterone and 17β-estradiol imprinted polymers. Synthesis of MIPs was achieved by thermal, UV and γ irradiation initiated polymerization whereby were used methacrylic acid (MAA), 4-vinylpyridine (4-VP) as functional monomers, ethylene glycol dimethacrylate (EDMA), trimethylolpropane trimethacrylate (TRIM) as cross-linking agents and acetonitrile, isooctane–toluene (1:99, v/v) and chloroform as porogen solvents. It was also used as initiator 2,2′-azobis(2-methylpropionitrile) (AIBN) or benzyl methyl ether (BME). The MIPs were applied as selective sorbents in solid-phase extraction (SPE). Molecularly imprinted solid-phase extraction (MISPE) considered as hyphenated technique were applied in extraction step before HPLC-DAD analysis of steroids from human urine.     

硝酸铵水凝胶分子印迹聚合物的制备

目的：目前安全问题成为世界各国的首要问题,尤其是对炸药分子的检测。硝酸铵是硝铵炸药的主要成分。研究水凝胶分子印迹法对硝铵炸药分子的检测。方法：水凝胶分子印迹方法制备硝酸铵水凝胶分子印迹聚合物,运用静态结合实验对其结合率进行了测定。结果：聚合物对硝酸铵具有良好的识别和吸附性能。印迹聚合物的解离常数为4.08g/L,最大吸附量为3.51mg/g。结论：水凝胶分子印迹法可合成水溶性炸药分子印迹聚合物,并且识别及吸附性能良好。     

Molecularly imprinted polymer cartridges coupled on-line with high performance liquid chromatography for simple and rapid analysis of dextromethorphan in human plasma samples

In this paper, a novel method is described for automated determination of dextromethorphan in biological fluids using molecularly imprinted solid-phase extraction (MISPE) as a sample clean-up technique combined with high performance liquid chromatography (HPLC). The water-compatible molecularly imprinted polymers (MIPs) were prepared using methacrylic acid as functional monomer, ethylene glycol dimethacrylate as cross-linker, chloroform as porogen and dextromethorphan as template molecule. These imprinted polymers were used as solid-phase extraction sorbent for the extraction of dextromethorphan from human plasma samples. Various parameters affecting the extraction efficiency of the MIP cartridges were evaluated. The high selectivity of the sorbent coupled to the high performance liquid chromatographic system permitted a simple and rapid analysis of this drug in plasma samples with limits of detection (LOD) and quantification (LOQ) of 0.12 ng/mL and 0.35 ng/mL, respectively. The MIP selectivity was evaluated by analyzing of the dextromethorphan in presence of several substances with similar molecular structures and properties. Results from the HPLC analyses showed that the recoveries of dextromethorphan using MIP cartridges from human plasma samples in the range of 1-50 ng/mL were higher than 87%.