Simultaneous Determination of Phenolic Acids in Water Caltrop by HPLC-DAD

Trapa natans L., or the water caltrop, a native plant of Romania, has not been researched in our country until recently. It has, however, been used for the treatment of the several diseases since ancient times. The objective of this work is to validate the HPLC method to detect and quantify the phenolic acids from Trapa natans L. specie. The HPLC-DAD method was validated for the analysis of 3-O-methylgallic, chlorogenic, caffeic, and ferulic acids in water caltrop roots, leaves, pulp, and hulls. The analysis was conducted on a Zorbax XDB-C18 column with gradient elution of acetonitrile-orthophosphoric acid. The method was validated in terms of linearity, accuracy, precision, limit of detection, quantification, and recovery, and found to be satisfactory. We verified the performance parameters after experimental studies, and we established that the HPLC method can be applied for the determination of phenolic acids in plant materials.     

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.     

Determination of phenolic acids by capillary zone electrophoresis and HPLC

Selected phenolic acids are determined by capillary zone electrophoresis and HPLC, each using UV detection. The optimised CZE background electrolyte contained 50 mM acetic acid, 95 mM 6-aminocaproic acid, 0.1% polyacrylamide, 1% polyvinylpyrrolidone, and 10% methanol. Twelve phenolic acids (gallic, p-hydroxybenzoic, 3,4-dihydroxybenzoic, vanillic, syringic, o-coumaric, p-coumaric, caffeic, sinapic, ferulic, salicylic and chlorogenic) were separated within 10 minutes. Chromatographic separation of these phenolic acids was carried out on an Eclipse XBD C8 column using a mobile phase gradient (acetonitrile / methanol / water / 0.1% phosphoric acid); all were separated within 25 minutes. Electrophoretic and chromatographic determinations of ferulic and chlorogenic acids were compared on barley, malt, and potato samples. The methods’ characteristics were: linearity (1–20 mg ml and 0.2–4 mg ml⁻¹), accuracy (recovery 94 ± 5% and 96 ± 4%), intra-assay repeatability (4.1% and 3.5%), and detection limit (0.2 and 0.02 mg ml⁻¹).      

Electroanalytical Determination of Some Phenolic Acids by High‐Performance Liquid Chromatography at Gold Electrodes

The electrochemical and amperometric behavior of a gold electrode was investigated towards the oxidation of several common phenolic acids in neutral phosphate solutions. Au electrodes show an appreciable stability and reproducibility of the amperometric signals by using a constant applied potential of 1.0 V vs. Ag/AgCl. Separations of selected phenolic acids using a reverse phase C₁₈ analytical column with a mobile phase containing 10 mM NaH₂PO₄ plus 10 mM Na₂HPO₄ (pH 7) and methanol as organic modifier, are achieved isocratically in less than 30 min. The detection limits at the level of nmol/L and linear ranges of four‐five orders of magnitude are generally achieved. The proposed chromatographic strategy coupled with the electrochemical detection at the Au electrode was successful tested for the quantitative determination of phenolic acids in beer, red wine and brandy with good sensitivity and recovery.     

Determination of Phenolic Acids in Herba Epilobi by ITP–CE in the Column-Coupling Configuration

The combination of capillary isotachophoresis (ITP) and capillary zone electrophoresis (CZE) in the column-coupling configuration has been optimized in a mode in which the background electrolyte employed in the CZE step was different from the leading and terminating electrolytes of the ITP step. The optimum composition of the electrolyte system was 0.01 M HCl, 0.02 M IMI, 0.2% HEC, pH 7.2 (leading electrolyte), 0.01 M HEPES, pH 8.2 (terminating electrolyte), and 25 mM MES, 50 mM TRIS, 30 mM boric acid, 0.2% HEC, pH 8.3 (background electrolyte). All solutions contained 20% methanol. The timing of the transfer of isotachophoretically stacked analyte zones into the CZE column was also optimized. An ITP–CZE method with UV detection at 270 nm was developed for separation of nine phenolic acids (protocatechuic, syringic, vanillic, cinnamic, ferulic, caffeic, ρ-coumaric, chlorogenic, and gentisic acids) in a model mixture and used for assay of some of these acids in a methanolic extract of herba epilobi. Application of ITP–CZE resulted in 100-fold better sensitivity than conventional CZE; limits of detection ranged between 10 and 60 ng mL⁻¹. When MES–TRIS–borate-based buffer, pH 8.3, was used in the CZE separation step the linearity of the ITP–CZE response was satisfactory (correlation coefficients were from 0.9937 to 0.9777). Repeatability was also satisfactory (RSD values ranged between 0.77% and 1.28% for migration times and between 1.65% and 13.69% for peak area). Revised: 23 March and 27 April 2006     

高效液相色谱法测定烟草中有机酸

提出了高效液相色谱法测定烟草中有机酸含量的方法。烟草样品经0.1 mol.L-1氢氧化钠溶液高速匀浆提取,提取液通过装有MCI-GEL反相树脂固相萃取小柱净化,以ZORBAXStable Bound色谱柱(4.6 mm×150 mm,1.8μm)为固定相,0.01 mol.L-1磷酸二氢钠溶液(pH2.98)和乙腈(98+2)溶液为流动相梯度洗脱,用二极管阵列检测器于210 nm波长处检测。烟草中主要的有机酸均在12 min内达到基线分离,方法加标回收率在95.0%~103.0%之间,相对标准偏差(n=7)在1.8%~2.8%之间。     

Determination of Phenolic Acids and Flavones in Lonicera japonica Thumb. by Capillary Electrophoresis with Electrochemical Detection

Capillary electrophoresis with electrochemical detection (CE‐ED) was employed to analyze active ingredients of Lonicera japonica Thumb., an important crude herb frequently used in Chinese medicines. Hyperoside, chlorogenic acid, luteolin and caffeic acid are the major important active ingredients. Operating in a wall‐jet configuration, a 300 μm diameter carbon‐disk electrode was used as the working electrode, which exhibits a good response at +0.90 V (vs. saturated calomel electrode) for four analytes. Under the optimum conditions, the analytes were baseline separated within 20 min in a 50 mmol L^?1 borax buffer (pH 8.7). Notably, excellent linearity was obtained over two orders of magnitude with detection limits (S/N=3) ranging from 0.1 to 0.5 mg L^?1 for all the analytes. This method was successfully used in the analysis of Lonicera japonica Thumb. with relative simple extraction procedures, and the assay results were satisfactory.     

密闭微波辅助提取-HPLC法测定还亮草中硬飞燕草碱和巴比翠雀碱的含量

采用密闭微波辅助法(PMAE)提取还亮草中的硬飞燕草碱和巴比翠雀碱。采用单因素试验结合正交试验方法对微波实验条件进行优化。得到硬飞燕草碱和巴比翠雀碱的最佳提取方案:药物颗粒度100目,固液比1∶60,微波温度80℃,微波功率560 W,微波时间10 min。以甲醇-0.2%三乙胺(45∶55)为流动相,建立了高效液相色谱(HPLC)测定硬飞燕草碱和巴比翠雀碱含量的方法。硬飞燕草碱和巴比翠雀碱分别在0.50~50.0,0.30~30.0 mg/L范围内呈良好的线性关系,回收率为98.3%~104.5%,相对标准偏差(RSD)分别为2.0%和2.2%。与传统溶剂回流法(SRE)进行比较,该方法简单、提取率更高。     

Determination of Phenolic Acids in Root Exudates of Allelopathic Rice by Solid Phase Extraction-Ion Chromatography with Conductivity Detection

A simple, effective, and green ion chromatography method with conductivity detection was developed for the determination of benzoic acid, cinnamic acid, syringic acid, and p-hydroxybenzoic acid in the root exudates of allelopathic rice. The analytes were well separated within 25 min in an anion exchange column (150 mm × 4.0 mm i.d., 5 µm particle size) with mixtures of 6.4 m mol L^?1 Na₂CO₃ and 2.0 m mol L^?1 NaHCO₃ as the mobile phase at a flow-rate of 0.7 mL min^?1. Detection limits of benzoic acid, cinnamic acid, syringic acid, and p-hydroxybenzoic acid were 0.05, 0.20, 0.50, and 0.05 µg mL^?1, respectively. Intra- and inter-day precision was ≤4.0% and 3.2%, respectively, and the intra- and inter-day accuracy, indicated by relative error, ranged from ?8.0% to 9.0%. The developed method was successfully used to determine phenolic acids in the root exudates of allelopathic rice. The average recoveries of the analytes were between 90.7% and 103.0%.     

高效液相色谱法测定盐酸甲氯芬酯胶囊的含量

建立了用高效液相色谱测定盐酸甲氯芬酯胶囊含量的方法.采用Hypersil C18柱(5 μm,4.6 mm i.d.×200 mm),流动相为V(乙腈)∶V(0.12% NH4HCO3-0.50%三乙胺)溶液＝33∶67 (甲基磺酸调pH至3.0),流速: 1.0 mL/min,检测波长为225 nm.盐酸甲氯芬酯的线性范围为1.632～163.2 μg/mL,平均回收率为99.67%,RSD=1.8% (n=9).     

HPLC测定食品包装用胶黏剂中5种树脂酸含量

建立高效液相色谱测定食品包装用胶黏剂中枞酸、新枞酸、去氢枞酸、长叶松酸和左旋海松酸的分析方法。对样品前处理和色谱分析条件进行了优化,以乙酸乙酯为溶剂,甲醇沉淀高聚物离心后微孔滤膜过滤,乙腈-0.4%乙酸水(80∶20)为流动相,流速为1.0 m L/min,等度洗脱,采用Venusil MP C18(2)色谱柱,二极管阵列检测器(DAD),高效液相色谱法测定,枞酸和新枞酸的检测波长为240 nm,长叶松酸和左旋海松酸为270 nm,去氢枞酸为208 nm,以外标法定量。结果表明,5种树脂酸的定量下限为2.5~10.0 mg/kg,线性范围跨越两个数量级以上,连续6次进样的相对标准偏差(RSD)不大于3.4%,加标回收率为92.2%~103.6%。该方法操作简单、干扰因素少、分析速度快,满足食品包装用胶黏剂中5种树脂酸的检测要求。     

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.     

高效液相色谱法同时测定款冬花中四种酚酸

建立了同时测定款冬花中没食子酸、绿原酸、咖啡酸和阿魏酸的高效液相色谱方法。采用Sepax Gp-C18色谱柱(250×4.6mm,5μm),以甲醇-0.5%乙酸溶液为流动相梯度洗脱,流速1.0mL/min,柱温30℃,检测波长280nm,20min内4种酚酸可实现基线分离。结果表明,各组分在一定浓度范围内呈良好线性关系,相关系数均大于0.9990,检测限为0.05~0.14mg/L,平均回收率在92.3%~102.0%之间,相对标准偏差为0.27%~2.70%,且不同来源的款冬花中4种酚酸的含量有明显差异。该方法简便、快速、准确、重复性好,可作为款冬花药材质量控制的方法。     

香丹注射液中丹酚酸B的HPLC法测定

建立了1种测定香丹注射液中丹酚酸B含量的反相高效液相色谱法;色谱分析柱为Hypersil ODS(4.6mm×250 mm,5μm),流动相为甲醇-乙腈-甲酸-水(体积比27∶9∶1.1∶62.9,含10 mmol/L的四丁基溴化铵),检测波长为285 nm,流速为1.0 mL/min,柱温为31℃时,丹酚酸B得到较好的分离;丹酚酸B进样量在0.264~1.584μg范围内线性良好,r=0.999 8,方法平均回收率为98%,为香丹注射液质量控制提供了分析方法。     

反相HPLC测定食物中的有机酸

本文研究了反相HPLC同时测定食物中草酸、酒石酸、苹果酸、乳酸、乙酸、柠檬酸和琥珀酸的条件,提出了用C_(18)固定相、2.5%NH_4H_2PO_4(pH2.50)溶液的流动相和在200nm下紫外检测这七种有机酸的测定方法。该法简便快速、具有较高的准确度和精密度。另外,还对有机酸的分离机理作了探讨。对十种食物中的有机酸进行了定量测定。     

高效液相色谱法测定印刷线路板热解油中的酚类化合物

建立了反相液相色谱法测定废旧印刷线路板热解油中的酚类化合物的方法,热解油经过滤并溶解在甲醇溶剂中可直接进样进行反相高效液相色谱分析,采用色谱柱为kromasil C18(4.6 mm i.d.×250 mm,5μm);流动相为乙腈/乙酸-乙酸铵缓冲溶液(0.01 mol/L,pH 4.0);柱温25℃;流速为1.0 mL/min,梯度洗脱进行分离,讨论了流动相的组成及其pH值等因素对组分分离产生的影响。实验结果显示,4种酚类化合物线性回归方程的相关系数r为0.9985~0.9996,高、中、低3个添加水平的加标回收率为96.3%~102.6%,相对标准偏差小于6%。     

相转移催化酯化反相高效液相色谱法测定食品中有机酸

在不预分离水相中有机酸的情况下,用α—溴苯乙酮作酯化试剂,以18-冠醚-6作相转移催化剂直接酯化有机酸,酯化液直接用高效液相色谱分析,紫外检测器检测,操作简便、干扰小,变异系数CV%=1.4～5.6%,检测下限5～20μg/L,实际样品回收率90.9～103.3%。     

Analysis of Flavonoids and Phenolic Acid in Propolis by Capillary Electrophoresis

A high-performance capillary electrophoresis (CE) is developed for the determination of six ingredients – rutin, ferulic acid, apigenin, luteolin, quercetin and caffeic acid – in Propolis and its extract capsules in this work. The effects of several factors such as the acidity and concentration of the running buffer, the separation voltage, the injection time and the wavelength of UV detector were investigated to find the optimum conditions. Under the optimum conditions, the analytes were separated within 14 min in a borax buffer (pH 9.2). Notably, excellent linearity was obtained over two orders of magnitude with detection limits (S/N=3) ranged from 3.7 × 10^–7 to 1.8 × 10^–6 g mL^–1 for all six analytes. The relative standard deviations of the migration times of six constituents ranged between 1.06% and 1.53%. The recoveries of six constituents ranged from 94.9% to 108.4%. This method was successfully used in the analysis of Propolis and its extract capsules with a relatively simple extraction procedure, and the assay results were satisfactory.     

In Vitro and In Silico Investigation of Diterpenoid Alkaloids Isolated from Delphinium chitralense

This study reports the isolation of three new C₂₀ diterpenoid alkaloids, Chitralinine A–C (1–3) from the aerial parts of Delphinium chitralense. Their structures were established on the basis of latest spectral techniques and single crystal X-rays crystallographic studies of chitralinine A described basic skeleton of these compounds. All the isolated Compounds (1–3) showed strong, competitive type inhibition against acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) in comparison to standard allanzanthane and galanthamine however, chitralinine-C remained the most potent with IC₅₀ value of 11.64 ± 0.08 μM against AChE, and 24.31 ± 0.33 μM against BChE, respectively. The molecular docking reflected a binding free energy of −16.400 K Cal-mol⁻¹ for chitralinine-C, having strong interactions with active site residues, TYR334, ASP72, SER122, and SER200. The overall findings suggest that these new diterpenoid alkaloids could serve as lead drugs against dementia-related diseases including Alzheimer’s disease.     

Analysis of Phenolic Priority Pollutants by High Performance Liquid Chromatography with Electrochemical Detection

Application of high performance liquid chromatography coupled with electrochemical detection (HPLC/EC) to the analysis of phenolic priority pollutants was studied. This method is highly sensitive and selective. Under optimum experimental conditions, the detection limits range from 0.05 ng for phenol to 1.20 ng for pentachlorophenol. The method was successfully applied to the direct determination of trace phenols in industrial wastewaters.