高效液相色谱法测定苹果汁中8种酚类化合物

提出了高效液相色谱法同时测定苹果汁中儿茶素、绿原酸、咖啡酸、表儿茶素、香豆酸、阿魏酸、槲皮素和根皮素等8种酚类化合物的方法,并考察了光照、保存时间等因素对酚类化合物的稳定性的影响.选用Eclipse XDB C18色谱柱(150 mm×4.6mm,5μm),以甲醇和乙酸-水(1+99)溶液作为流动相进行梯度洗脱,利用二极管阵列检测器,在各种酚类物质的最大吸收波长下进行紫外光度检测.对各化合物工作曲线的线性范围作了试验,并推导得到相应的线性回归方程,其相关系数均为0.999 9,在苹果汁样品的基础上用标准加入法各进行7次测定,测得平均回收率均在96.0%～100.8%之间,相对标准偏差(n=7)小于等于3.0%,8种化合物的检出限(3S/N)分别为20,10,4,20,5,8,30和7μg·L-1.     

Ionic Organic Film Sensor for Determination of Phenolic Compounds

This paper describes the development of a new sensor based on an ionic organic film. The amphiphilic molecule, 4‐[(4‐decyloxyphenyl)‐ethynyl]‐1‐methylpyridinium iodide (10PyI), which has liquid‐crystalline properties, was synthesized and applied in the construction of a GCE/10PyI sensor. Analytical parameters for caffeic acid, repeatability (4.8 %), reproducibility (2.8 %), linearity (two ranges: 9.9×10^?7 to 3.8×10^?5 mol L^?1 and 4.7×10^?5 to 9.9×10^?5 mol L^?1) and detection limits (9.0×10^?7 mol L^?1 and 8.7×10^?6 mol L^?1), were determined. The method was successfully applied in the determination of total phenolic compounds (TPC) in mate herb extracts.     

酪氨酸酶在硼掺杂金刚石薄膜电极上的固定及酚类化合物的检测

以硼掺杂金刚石(boron-doped d iamond,BDD)薄膜作基底,利用光化学反应将含有碳碳双键的烯丙胺化合物修饰在BDD表面,形成氨基单分子层,再经过酰胺键的连接使酪氨酸酶固定在氨基化的金刚石表面,从而制得酪氨酸酶修饰的电极.应用循环伏安法研究该电极用于酚类化合物(包括苯酚、对甲基苯酚和对苯二酚等)检测的灵敏度、线性范围及其稳定性.     

中国不同产区赤霞珠干红葡萄酒香气成分数据的可视化分析

可视化技术被引入葡萄酒香气成分数据的分析,以达到鉴别区分不同产区葡萄酒的目的。葡萄酒分析样品是2005年赤霞珠干红葡萄酒产品。5个产区是河北昌黎、新疆玛纳斯、云南弥勒、宁夏贺兰山东麓和河北沙城。香气成分用二氯甲烷连续萃取,有机相真空浓缩之后进行GC-MS分析检测。共鉴定并半定量分析出5个产区赤霞珠干红葡萄酒中68种香气成分,对原始色谱分析数据进行标准归一化处理,将信息映射到[0,1]之间的灰度图空间,然后根据数据可视化原理,用Vc 构建含多种香气成分信息的二维灰度图,直观表征不同产地赤霞珠干红葡萄酒的香气成分信息。研究结果是一种反映葡萄酒化学信息的条形码技术,该技术转换葡萄酒香气成分色谱数据之后得到二维灰度图,能够良好区分不同产区的赤霞珠干红葡萄酒。     

A Fast Electrochemical Technique for Characterization of Phenolic Content in Wine

In this study, the development of a fast electrochemical method for the characterization of wines through the evaluation of their phenolic compounds content was reported. Cyclic voltammetry experiments were carried out on wines using graphite-based screen-printed electrodes as transducers. Voltammograms were elaborated with software by obtaining resolved oxidation peaks that can be attributed to different groups of phenolic compounds. Results were presented as diagrams of peaks heights plotted vs. their oxidation potential, giving a “spectral distribution” of the phenolic content, which characterize each wine. The method was applied to the characterization of different samples of red and white wines.     

Characterization of Wines by Trans-Resveratrol Concentration: A Case Study of Romanian Varieties

The goal of this study was to determine the trans-resveratrol concentration in wine. A set of 70 wine samples from Romania, produced according to the appellation of origin system, were analyzed by reverse-phase high performance liquid chromatography. White wines were found to have markedly lower concentrations of trans-resveratrol in comparison with red wines. The values were between 0.025 to 10.23 mg/L for red wine and from 0.074 to 2.572 mg/L for white wine. Red wine is a good dietary source of resveratrol.     

Determination of anthocyanins in wine based on flow-injection, liquid--solid extraction, continuous evaporation and high-performance liquid chromatography--photometric detection

A continuous method, easy to automate, for the determination of anthocyanins in wine based on the coupling of continuous liquid–solid extraction, evaporation, HPLC individual separation and photometric detection is proposed. The target analytes are removed from the wine in a continuous fashion using a C₁₈ minicolumn and eluted with an aqueous solution (pH 2) with 16% acetonitrile. The eluted fraction is concentrated by solvent evaporation assisted by heat and dragging off the vapour using a flow of N₂. For in-line preconcentration, a continuous evaporation module was designed and located in the manifold between the solid-phase minicolumn and the injection valve of the chromatograph. In this way, injection of the sample into the dynamic system leads the plug through it for liquid–solid extraction of the anthocyanins, partial evaporation of the eluent (with a preconcentration factor as required) and transport to the high-pressure injection valve of the chromatograph, where individual separation and subsequent photometric detection take place. The method thus developed for the determination of malvidin-3-glucoside, cyanidin-3-glucoside and peonidin-3-glucoside anthocyanins in Spanish red wines is more sensitive than the batch manual method based on the same steps, has better linearity of the calibrations curves with lower detection limits and much wider determination range for the most abundant anthocyanins in wine. In addition, the method can be fully automated with low acquisition and maintenance costs.     

Two New Phenolic Compounds from the Rhizomes of Gastrodia elata Blume

Phytochemical investigation of the rhizomes of Gastrodia elata Blume (Orchidaceae) led to the isolation and identification of twelve compounds, including two new phenolic compounds, 4‐hydroxybenzyl vanillyl ether (=4‐{[(4‐hydroxyphenyl)methoxy]methyl}‐2‐methoxyphenol; 1 ) and 4‐{{4‐[4‐(methoxymethyl)phenoxy]benzyl}oxy}benzyl methyl ether (=1‐[4‐(methoxymethyl)phenoxy]‐4‐{[4‐(methoxymethyl)phenoxy]methyl}benzene; 2 ). The structures of 1 and 2 were elucidated by spectroscopic data analysis including 1D‐ and 2D‐NMR experiments.     

Diterpenoid and Phenolic Compounds from Juncus effusus L.

A novel diterpene, named effusenone A ( 1a ), which is the first reported rosane‐type diterpene from a Juncaceae plant, and three novel phenolic compounds, 5‐(hydroxymethyl)‐1‐methylphenanthrene‐2,7‐diol ( 4 ), 1‐methylpyrene‐2,7‐diol ( 5 ), and 7‐methoxy‐8‐methylpyren‐2‐ol ( 6 ) were isolated from the stem of Juncus effusus L. by normal‐phase and reversed‐phase silica gel column chromatography. Their structures were identified by spectroscopic methods, especially 2D‐NMR techniques.     

重油催化裂化汽油中酚类化合物的分离分析

利用100g/L NaOH作萃取剂，二氯甲烷为反萃取剂，油剂比为5：1（体积比）时浓缩分离石家庄炼油厂和燕山石油化工公司的重油催化裂化（RFCC）稳定汽油和预碱洗后汽油中的酚类化合物；多面手利用色谱-质谱联用法对浓缩分离出的酚类化合物进行了检测，结果发现RFCC汽油中的酚类化合物主要是C0-C3苯酚，还有少量C4苯酚；所用稳定汽油和预碱洗后汽油的酚类组成相似，但碱洗后苯酚含量减少。     

Comparative Study of Nanostructured Matrices Employed in the Development of Biosensors Based on HRP Enzyme for Determination of Phenolic Compounds

This paper made a comparative study of new matrices of nanostructured materials (multiwall carbon nanotube, fullerene and hydroxylated fullerene) aiming to compare them when employed in the process of immobilization of enzyme horseradish peroxidase (HRP) on the development of amperometric biosensors for the determination phenolic compounds. The results confirm that all the three nanostructured matrices used in the preparation of the biosensor show improvements when acting as a transducer stabilizer and immobilization matrix, comparing to the electrode of carbon paste. Regarding the performance of these matrices it is verified that the developed biosensor employed the multiwall carbon nanotube as matrix immobilized enzyme HRP has shown the best sensitivity for the molecule of phenol (33 nA cm^?2 µmol^?1 L), however, regarding the range of linear response, the elaborated biosensor containing the hydroxylated fullerene has shown the best response (5–200 µmol L^?1). In terms of operational stability, the biosensors maintained their responses around 95 % after more than 200 analyzes. It is also important to mention that in all the cases, the association with the graphite powder improves the answers of the biosensors around 10 to 15 %.     

中心切割GC-MS法分析煤液化油中的酚类化合物

使用碱洗提酚法提取煤液化油中的酚类化合物,然后结合Deans Switch装置和LTM色谱柱模块,采用中心切割气相色谱(GC)-质谱(MS)法对提取的酚类化合物进行定性。采用GC建立标准曲线,对煤液化油中主要酚类化合物的质量分数进行测定,并测定了煤液化油中邻甲基苯酚、2-乙基苯酚、4-丙基苯酚和5-茚酚4种酚类化合物的加标回收率。结果表明,在煤液化油中共定性出51种酚类化合物,测定了其中的35种酚类化合物的质量分数,其量占煤液化油总量的2.54(wt)%,苯酚和烷基苯酚占35种酚类化合物的88.2(wt)%。煤液化油中4种酚类化合物的加标回收率高,重复性好。     

Composite Multienzyme Amperometric Biosensors for an Improved Detection of Phenolic Compounds

A biosensor design, in which glucose oxidase and peroxidase are coimmobilized by simple physical inclusion into the bulk of graphite‐Teflon pellets, is reported for the detection of phenolic compounds. This design allows the “in situ” generation of the H₂O₂ needed for the enzyme reaction with the phenolic compounds, which avoids several problems detected in the performance of single peroxidase biosensors as a consequence of the presence of a high H₂O₂ concentration. So, a much lower surface fouling was found at the GOD‐HRP biosensor in comparison with a graphite‐Teflon‐HRP electrode, suggesting that the controlled generation of H₂O₂ makes more difficult the formation of polymers from the enzyme reaction products. The construction of trienzyme biosensors, in which GOD, HRP and tyrosinase were coimmobilized into the graphite‐Teflon matrix is also reported, and their performance was compared with that of GOD‐HRP bienzyme electrodes. The practical applicability of the composite multienzyme amperometric biosensors was evaluated by the estimation of the phenolic compounds content in waste waters from a refinery, and the results were compared with those obtained by using a colorimetric official method based on the reaction with 4‐aminoantipyrine.     

A Comment on the Use of Colorimetric Determinations of Phenolic Compounds in Surface Water

Abstract

Total phenolic compound values were determined in samples of river water by means of the Folin-Ciocalteu colorimetric method, while HPLC with UV detection was used to identify individual phenols. Preconcentration was needed in all cases to meet the required detection limits. Given the absorption coefficients of the components, the error incurred when a curve calibrated against phenol only is used to evaluate a mixture was calculated.     

Simultaneous Determination of Four Phenolic Compounds and Tanshinone IIA in Guanxintong Tablets by LC Using Combined Electrochemical Detection and DAD

A rapid, sensitive and accurate method for the simultaneous separation and determination of four phenolic compounds, including protocatechuic acid, protocatechuic aldehyde, caffeic acid and ferulic acid, and tanshinone IIA in Guanxintong tablets by high performance liquid chromatography using combined electrochemical detection with diode array detection (HPLC-ECD-DAD) has been established. The detection and quantification limits of four phenolic compounds with ECD were 7–28 fold greater than those obtained with DAD. High sensitivity was achieved using DAD for the detection of tanshinone IIA, which is an electrochemically inactive compound. All calibration curves showed good linearity (r ≥ 0.9996) within the test ranges. The recoveries ranged from 96.5% to 101.7%. Combining ECD with DAD can not only exert their respective advantages, but also widen its applications to detect various analytes in low level directly. This approach can be used to control the quality of Guanxintong tablets.     

Rapid Determination of Phenolic Compounds in Water Samples: Development of a Paper‐based Nanobiosensor Modified with Functionalized Silica Nanoparticles and Potato Tissue

In this study, we present a fast, simple, low‐cost and disposable method for determination of phenolic content in water samples, using a paper based polyphenol oxidase biosensor. The propylamine functionalized silica nanoparticles was dropped onto a paper sheet. After drying at room temperature, the potato tissue extract including polyphenol oxidase was immobilized on the paper via physical and chemical adsorption. The modified paper was placed on the top of the graphite screen printed electrode. To construct of an electrochemical nanobiosensor, the electrochemical behavior of the modified electrode in different steps was investigated by cyclic voltammetry and electrochemical impedance spectroscopy methods. After being optimized the effective parameters, the changes in the biosensor electrochemical response vs. to the different concentrations of the substrate (phenol solution) were monitored by differential pulse voltammetry and amperometry methods. The linear relationships for phenol detection were obtained in the concentration ranges of 0.01–160 μM and 0.1–300 μM with a detection limit of 0.007 μM and 0.042 μM with DPV and amperometry methods, respectively. This method was successfully used in the voltammetric determination of the phenol content in the real samples, like the river water and the wastewater of wood factory.     

Determination of Phenolic Compounds Based on Co‐Immobilization of Methylene Blue and HRP on Multi‐Wall Carbon Nanotubes

This work evaluated an amperometric biosensor based on multi‐wall carbon nanotubes (MWCNT), chemically modified with methylene blue (Met) and horseradish peroxidase (HRP), for detection of phenolic compounds. The dependences of the biosensor response due to the enzyme immobilization procedure, HRP amounts, pH and working potential were investigated. The amperometric response for catechol using the proposed biosensor showed a very wide linear response range (1 to 150 μmol L^?1), good sensitivity (50 nA cm^?2 μmol^?1 L), excellent operational stability (after 300 determinations the response remained at 97%) and very good storage stability (lifetime>3 months). Based on all these characteristics, it is possible to affirm that the material is promising for phenol detection due to its good electrochemical response and enzyme stabilization. The biosensor response for various phenolic compounds was investigated.     

葡萄酒中7种酚酸的色谱电化学分析

建立了同时测定葡萄酒中没食子酸、原儿茶酸、丁香酸、p-香豆酸、咖啡酸、绿原酸和阿魏酸等7种生物活性酚酸的反相高效液相色谱电化学分析新方法,并测定了5种国产不同品牌的葡萄酒.采用HypersilODS色谱柱(250mm×4.0mm,5.0μm),流动相为甲醇-4%醋酸,梯度洗脱,流速为0.8mL/min,工作电压为0.7V,柱温为30℃.实验结果表明,电化学法的检出限比紫外法的检出限低4～600倍.     

Comprehensive two-dimensional liquid chromatography in the analysis of antioxidant phenolic compounds in wines and juices

A novel comprehensive two-dimensional liquid chromatographic (LC×LC) system was developed for the quantification of antioxidant phenolic compounds in wine and juice. The system allows parts of the sample that are well separated in the first column to pass directly to the detector after the first column, while the rest of the sample proceeds to the second column. The optimised LC×LC system employed a combination of two C18 columns, the latter column with an ion-pair reagent (tetrapentylammonium bromide). The relative standard deviations (RSD) for the retention times were better than 0.01% in the first dimension and on average 6.3% in the second. The RSD values of the peak volumes varied from 3% (protocatechuic acid) to 13% (caffeic acid, n = 3, 10 μg/ml).