甘草次酸差向异构体的高效液相色谱分离分析

应用整体化色谱柱,反相条件下对18H-甘草次酸差向异构体的拆分进行了探讨。采用Chromolith RP-18e整体化色谱柱,乙酸铵-乙腈-甲醇三元流动相体系,考察了乙酸铵浓度、有机添加剂含量、柱温等因素对甘草次酸差向异构体拆分的影响,在优化的色谱条件下,甘草次酸差向异构体达到了基线分离,分离度可达5.30。18α-甘草次酸与18β-甘草次酸分别在2.16~23.76μg/mL与4.24~46.64μg/mL范围内呈良好的线性关系。建立的方法简便快速,可应用于甘草次酸类药物的质量监测与控制,以及甘草次酸异构体的转化评价。     

高效液相色谱法测定甘草酸粉中甘草酸的含量

目的用高效液相色谱法测定甘草酸粉中甘草酸的含量。方法色谱柱:内径4~6mm,长15~25 cm的不锈钢管。填充剂为液相色谱用硬脂酸硅胶5~10um,流动相:稀乙醇(1~15)/乙腈混合液(3:2);结果甘草酸在20.72~124.32μg/mL范围内有良好的线性关系,r=0.9999(n=5),平均回收率为97.08%。结论此法分离度高,重现性好,简便,准确,可用于止咳胶囊的质量控制。     

液相色谱柱外效应对分离的影响

在同一型号不同配置的两台高效液相色谱仪上做对比实验，考察了柱外效应对色谱分离的影响。柱外效应的降低将会减少色谱扩散，提高色谱分离效果。     

高效液相色谱-串联质谱法测定猪肝中5种α2受体激动剂

高效液相色谱串联质谱测定猪肝中5种α2受体激动剂残留量.样品加入碳酸钠缓冲液,乙酸乙酯提取,MCX固相萃取净化后用甲酸-乙腈溶解,高效液相色谱-串联质谱测定.结果 显示,5种α2受体激动剂在0～20μg/L浓度范围内线性良好,相关系数(r)均大于0.995;在0.5～4.5 μg/kg添加水平下,5种α2受体激动剂回收...     

糖醇高效液相色谱柱的再生

介绍了一种糖醇高效液相色谱柱的再生方法。考察了温度、再生液浓度、再生顺序、再生时间、再生流速等因素，对液相色谱柱再生效果的影响。结果表明，在温度为85℃，再生液浓度为0．2mol／L时，以0．2mL／min的再生流速，用硝酸钙溶液对色谱柱进行24h的再生，取得的再生效果比较好。     

18%克·福种衣剂高效液相色谱测定

本文采用高效液相色谱法，以甲醇：水（５０：５０）作为流动相，采用ＯＤＳ－Ｃ１８色谱柱， 成功地测定了克·福种衣剂中有效成分含量。     

制备型高效液相色谱分离过程的放大研究(Ⅱ)柱尺寸

以牛血清白蛋白（BAS）和牛血清红蛋白（HG）为物系,在制备型高效液相色谱（HPLC）分离装置上,考察了柱尺雨对柱效和分离度的影响。结果表明,增加柱长,可以显著地提高分离效率,但在满足分离要求的前提下,宜采用较短的制备柱。增加色谱柱的内径,虽然分离效果会有一定程度的损失,但在满足分离要求前提下,加大色谱柱的内径,可以显著地提高制备量。     

高效液相色谱手性柱拆分喹禾灵

论文以β-环糊精有机骨架晶体材料构筑反相高效液相色谱(HPLC)手性固定相拆分手性农药喹禾灵.分别从流动相配比、流速和缓冲溶液pH值等几个方面探究拆分喹禾灵的最佳色谱条件.实验结果表明,以柠檬酸三乙胺(浓度20 mmol/L、pH值4.00)和甲醇为流动相,在柠檬酸三乙胺缓冲液和甲醇体积比为45％:55％,流速0.5 ...     

个人护理用品中甘草酸二钾含量的测定

建立高效液相色谱法检测不同基质类型的个人护理用品(洗发露、沐浴露、护发素、洁面乳)中甘草酸二钾含量的测定方法。采用ZORBAX SB-C18 (4.6 mm×250 mm,5 μm)色谱柱,以0.01 mol/L磷酸溶液-乙腈为流动相(体积比63∶37)等度洗脱。样品经甲醇超声提取,采用二极管阵列检测器检测。由实验结果可知,甘草酸二钾质量浓度在1～200 μg/mL时线性关系良好(R~2=0.999 7),洗发露、沐浴露、护发素和洁面乳中甘草酸二钾测定的加标平均回收率分别为92.92%～101.69%。该方法具有较高的准确度和精密度,可快速对个人护理用品中甘草酸二钾定性定量分析。     

香橼中β-胡萝卜素含量的反相高效液相色谱测定

用反相高效液相色谱对香橼中的β -胡萝卜素进行了测定 ,所用方法快速、便捷 ,回收率在 ( 10 6.8± 0 .70 ) % ,结果满意     

A new ionic liquids‐based monolithic column for determination of caffeine and theophylline

The present study has concentrated on finding a new stationary phase in liquid chromatography. To improve the selectivity of monolithic column, a new ionic liquids–based (ILs‐based) monolithic column (150 × 4.6 mm i.d.) is synthesized. Characteristic and evaluation of monolithic column are investigated by field emission‐scanning electron microscopy (FE‐SEM) and determination of caffeine and theophylline in high performance liquid chromatography (HPLC). FE‐SEM images show that this monolithic column has a porosity structure. At the condition of mobile phase was 0.06 mol L^?1 Na₂HPO₄ (pH 9.0) and flow rate was 0.7 mL min^?1, a good linear relationship was demonstrated when the concentrations of caffeine and theophylline were in the range of 0.1–60.0 μg mL^?1. These two compounds can obtain better resolution on the ILs‐based monolithic column than non‐ILs monolithic column, and the recoveries ranged from 97.40% to 108.00% and the interday and intraday relative standard deviations were less than 5%. The HPLC method, developed in this study, was proved to be acceptable for drugs assay, and this ILs‐based monolithic column as the stationary phase was a potential tool for future HPLC separation. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010     

Preparation of hemin polymer monolithic column and its application in the separation of proteins and small molecules

A poly(hemin-co-C16-co-TEGDA) monolith was prepared using hemin and 1-hexadecene (C16) as monomers; triethylene glycol dimethacrylate (TEGDA) as crosslinking agent; N,N-dimethylformamide and isopropyl alcohol as porogens; and dibenzoyl peroxide and N,N-dimethyl aniline as initiators in 50?×?4.6?mm i.d. stainless steel column. The morphology and structure of the monolith were characterized by scanning electron microscopy and nitrogen adsorption/desorption isotherm measurement, respectively. Compared with poly(C16-co-TEGDA) monolith, poly(hemin-co-C16-co-TEGDA) monolith had better mechanical properties, higher permeability, and better separation ability. The prepared monolith was used to separate not only proteins but also small molecules.     

HPLC法测定藿香清胃胶囊中甘草酸的含量

目的:建立测定藿香清胃胶囊中甘草酸含量方法.方法:采用高效液相色谱法,以BDS-C18色谱柱分离,以甲醇:0.2mol/L醋酸铵溶液:冰醋酸=62:38:1为流动相,流速为1.0ml/min,检测波长250nm.结果:甘草酸在0.3616～1.8080μg范围内线性良好,r=0.9996;测得平均回收率98.68%,RSD=2.20%.结论:高效液相色谱法高效、快速、灵敏,可作为藿香清胃胶囊质量控制的有效方法.     

HPLC法测定痰咳净片中甘草酸的含量

目的:用反高效液相法测定痰咳净片中甘草酸的含量.方法:选用岛津VP-ODS C18(150mm×4.6mm)色谱柱,流动相为甲醇:1%冰醋酸(70:30).检测波长248nm,流速1.0mL/min,柱温:40℃.结果:甘草酸在0.096～3.072μg内呈线性(r为0.9999).加样回收率为100.2%(RSD为1.37%).结论:此方法简便、可靠,为进一步研究其质量标准提供一个很好的途径.     

Separation of butyric acid in fixed bed column with solvent impregnated resin containing ammonium ionic liquid

Batch equilibrium and fixed bed column extraction experiments for the extraction of butyric acid (BA) into solvent impregnated resin (SIR) have been done. Microporous Amberlite XAD-1180N was impregnated with an ammonium ionic liquid (IL) trialkylmethylammonium bis(2,4,4-trimethylpentyl)phosphinate. The BA extraction capacity isotherm has not a Langmuir type shape and no finite capacity was observed. The loading of the impregnated IL with the extracted BA at 37 °C is in agreement with the loading from L/L extraction equilibrium of BA at 25 °C. Capacity of freshly prepared SIR particles is superior to classical porous ion-exchangers. Both the temperature and the superficial velocity in column influence the shape of the breakthrough-curve in fixed bed extraction of BA using SIR. Sharpening of the breakthrough curve was observed with the increasing temperature and decreasing superficial velocity. Stripping with water is not efficient for the regeneration of the loaded column after extraction because of low concentration of the product acid in the obtained effluent. Higher BA concentration was achieved by stripping with 0.15 kmol m⁻³ and 0.075 kmol m⁻³ NaOH solutions. The combination of initial water stripping coupled with consecutive stripping by alkali can be beneficial for decreasing the consumption of chemicals and further processing of the product. After two extraction/stripping cycles, a stable capacity was achieved and sustained for 14 cycles, showing the possibility of long-term application of the prepared SIR in real technology.     

Separation of glycyrrhizic acid from licorice root extract using macroporous resin

Glycyrrhizic acid (GA) is the major active ingredient of licorice which has many pharmacological activities. In the present study, separation of GA from licorice root extract has been carried out by adsorption on five different macroporous resins. Static and dynamic adsorption of GA from crude licorice root extract is studied on ion exchange resins followed by desorption. Indion 810 shows the maximum adsorption as well as desorption capacity. The adsorption experiments indicate that equilibrium can be achieved in 360 min. The adsorption equilibrium data is well fitted in the Langmuir isotherm. The separation process is optimized by investigating the effect of pH on adsorption capacity and effect of concentration of ethanol on desorption capacity. The dynamic adsorption is carried out in a column packed with Indion 810 resin and effect of feed flow rate and initial concentration of GA in extract has been studied. The results showed that increase in feed flow rate as well as initial feed concentration of GA lowers the dynamic binding capacity and mass transfer coefficient while increases the HETP. The purity of GA is increased from 14.3% to 71.5% by the dynamic desorption with 60% ethanol. Indion 810 resin can efficiently separate GA from licorice root extract with the HPLC recovery of 63.6%. This study forms the basis for large scale preparation of GA by resin adsorption.     

Comparison of adsorption equilibrium of glycyrrhizic acid and liquiritin on C18 column

The adsorption isotherms of glycyrrhizic acid (GA) and liquiritin (LQ) on a C₁₈ column were compared and the competitive adsorption of the two compounds was investigated. The experimental parameters in the equilibrium isotherms were estimated by linear and nonlinear regression analyses. The adsorption equilibrium data were correlated into the linear, Langmuir, competitive Langmuir, Freundlich, and Langmuir–Freundlich isotherm models. Over a moderate concentration range, the competitive Langmuir isotherm provided the best fit to the experimental data. The regression coefficients of the competitive Langmuir adsorption isotherms were 0.9754 and 0.9855 for the mixtures of GA and LQ, respectively. The coefficients obtained for the five isotherm models confirmed the superiority of the competitive Langmuir isotherm for analyzing the adsorption data of solutes.     

Fabrication of a polymer monolithic column via redox system and its application in efficient separation of Chinese herb Rheum palmatum L.

A polymer monolithic column was prepared via redox system in a stainless steel column (50 × 4.6 mm i.d.) by using 1,6‐hexanediol diacrylate as monomer and ethylene dimethacrylate as cross linking agent. Characteristics of the homemade monolithic column were investigated by scanning electron microscopy, nitrogen adsorption‐desorption and mercury intrusion porosimeter, respectively. The results showed that the resulting monolithic column occupied relative uniform porous skeleton structure. Furthermore, the monolith was tested by separating aromatic compounds in conjunction of high performance liquid chromatography with the highest column efficiency of more than 21,000 plate per meter, which was relative high for polymer‐based monolithic column with 4.6 mm i.d. At last, the monolithic column was used to simultaneously separate and quantitatively analyzes five active compounds in Chinese herb Rheum palmatum L. The validation of the method was carried out, which indicated that the accuracy represented by recovery was in the range of 98.48% to 101.57%. Limit of detection and limit of quantification for the five active compounds were less than 33.7 ng and 90.8 ng, respectively. All the results indicated that the present method was simple and efficient for quantitative analysis of the five active compounds from Chinese herb Rheum palmatum L. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134, 44874.     

Purification of phosphoric acid in a gravity wash column

A gravity wash column is a common type of continuous solid–liquid separator, which can be applied in the final step in the suspension crystallisation process of purifying phosphoric acid. In this work, a mathematical model based on material balance was presented for the purification process in a gravity wash column, and the experimental data of suspension crystallisation of phosphoric acid hemi‐hydrate were correlated. The developed purification model can be used to calculate concentration profiles of impurities along the column axis and to predict the effect of operating conditions on the purity of the product stream of phosphoric acid. The model parameters were also estimated by fitting the model with experimental data. © 2012 Canadian Society for Chemical Engineering     

关于进树脂塔前盐水加酸问题的探讨

通过原理分析和具体例证说明进树脂塔前盐水是否加酸要据实情而定。