HPLC测定VC中的三聚氰胺

1原理 试样用三氯乙酸-乙腈提取,经阳离子交换固相萃取柱净化后,用高效液相色谱测定,外标法定量 2试剂和材料 除非另有说明,所有试剂均为分析纯,水为一级水甲醇色谱级乙腈色谱级氨水含量25%-28%三氯乙酸柠檬酸辛烷磺酸钠色谱级甲醇水溶液准确量取50ml甲醇和50ml水,混匀后备用。     

色谱纯乙腈制备新工艺研制成功

在80年代初,我国只能生产试剂级乙腈,但还不能制备色谱纯乙腈。随着高压液相色谱的广泛应用和在医药、卫生、食品、兴奋剂的检验和研究中的独特作用,它的应用范围也逐年扩展。因此,色谱纯乙腈的供求矛盾越来越突出,造成了市场上色谱纯乙腈极为短缺的现象,只好从国外进口色谱纯乙腈。     

果蔬中多种农药残留液相色谱串联质谱法的测定

正本实验采用HPLC-MS/MS法同时测定多种在果蔬种植中常用的农药。前处理使用了新的QuEChERS方法,减少了分析的时间,有利于提高了回收率。1试剂与仪器设备1.1试剂乙腈:色谱纯;冰醋酸:色谱纯;无水乙酸钠(CH_3COONa):色谱纯;无水硫酸镁(MgSO_4):研磨后在500℃马弗炉内烘5h,贮于干燥器中,冷却后备用;键合硅固相萃取吸附剂PSA,粒度     

梯度级色谱纯乙腈的产业化制备工艺研究

为了研究高纯乙腈的产业化制备工艺,生产出与国际同类产品质量相当的色谱试剂。以工业乙腈为原料,利用康科德公司自制精馏装置,通过吸附-氧化-还原-干燥-精馏等一系列工艺流程,生产出梯度级色谱纯乙腈成品。以纯度、水分、紫外吸光度、酸度、梯度实验等为质控指标,检测产品质量。与现有其他方法相比,本工艺具有产品纯度高、操作简便、运行稳定以及适于规模化生产的优点。其各项指标均达到康科德公司企业标准,产品的合格率为85%~90%。其中梯度级占80%~85%,同时符合美国化学会ACS标准。与国外5家知名试剂品牌相比,质量相当,性价比名列前茅。本产品可以满足高效液相色谱(HPLC)客户在梯度洗脱中的应用需求,填补了国内空白,降低了对国外试剂的依赖性,为国内用户提供了替代进口的质优价廉的高性价比试剂。     

高效液相色谱法分离测定吡虫清成品及制剂

采用高效液相色谱法 ,Ｎｏｖａ -ＰａｋＣ18不锈钢柱 ,甲醇、乙腈、水三元流动相 ,对吡虫清成品及制剂进行分离和测定。1　实验部分1.1　仪器与试剂仪器Ｗａｔｅｒｓ高效液相色谱仪 ,具可变波长紫外检测器色谱数据处理机色谱柱 :150ｍｍ× 3.9ｍｍ (ｉｄ) ,Ｎｏｖａ -ＰａｋＣ18不锈钢柱。试剂水 :二次蒸馏水甲醇 :分析纯乙腈 :分析纯吡虫清标准品 ,已知含量≥ 98%1.2　色谱操作条件流动相 :甲醇 乙腈 水 =2 5 15 6 0 (体积比 ) (超声波脱气 )流量 :1 0ｍｌ/ｍｉｎ检测波长 :λｍａｘ=2 70ｎｍ柱温 :室温进样体积 :10 μｌ1.3　测定步骤1.…     

绿草定的高效液相色谱分析

绿草定其化学名称为三氯吡啶氧乙酸,是一种高效除草剂。由于目前该化合物在国内还未工业化生产,与其有关的文献报道较少,特别是有关分析研究的文章未见公开报道。我们通过大量实验,用高效液相色谱法对其进行了定量分析研究,找到了准确精密的分析条件和迅速快捷的操作步骤,该方法适宜于原药及成品中绿草定含量的测定。1　实验部分1.1　仪器与试剂Ｗａｔｅｒｓ液相色谱仪,996光电二极管阵列检测器;甲醇(ＨＰＬＣ色谱级);乙腈(ＨＰＬＣ色谱级);乙酸(分析纯);酸性水(0.5%的乙酸水溶液);ＨＰＬＣ级水;已知其准确含量的绿草定标准品。1.2　色谱条…     

5种LC-MS级试剂的技术指标及适应性检测方法

液相色谱-质谱联用(LC-MS)检测作为一种常规分析手段,对流动相试剂的纯度要求非常高。然而,国产LC-MS色谱级试剂质量不够稳定,国内难以检索到公开的LC-MS级色谱试剂的技术标准,使得绝大部分科研实验室只能采用进口试剂。因此,建立公开透明的LC-MS级试剂技术指标以及产品分析检测方法意义重大。分析了国内外LC-MS色谱试剂生产现状,以甲醇为例,列出了国外LC-MS甲醇的技术指标,简要概括了各指标的检测方法。并以5种国产LC-MS级试剂(甲醇、乙腈、乙酸乙酯、正己烷、异丙醇)为实验对象,建立了各试剂的LC-MS适应性检测分析方法,同时采用相应的进口LC-MS色谱试剂进行对照,证明了所建方法的可行性。     

色谱双组分标准化试剂在标定气相色谱仪性能方面的应用

制备色谱已经成为色谱科学的一个独立分支,因此单组分色谱纯试剂早已作为商品出售,并已在色谱科学研究工作和定性、定量分析中得到了广泛的应用。随着色谱科学和色谱分析工作的发展,具有一定组成并稳定不变的色谱双组分标准试剂,已成为色谱学科中重要的标准化试剂。作为双组分色谱标准试剂,需要具有组成准确和稳定不变的特点。显然,如果用单一的色谱纯试剂按所需要的成分进行配制,将因操作者的不同而引入误差,更重要的是这种双组     

氯氟氰菊酯乳油的气相色谱分析

氯氟氰菊酯分析有过报道,本文用气相色谱对其乳油进行定量分析。 实验部分 一、仪器与试剂 1.仪器:山东鲁南化工仪器厂生产的SP-501N气相色谱仪,氢火焰离子检测器,10微升微量注射器。 2.试剂与样品 丙酮、氯仿等溶剂均为分析纯 内标物:邻苯二甲酸二壬酯(色谱纯) 标准样品:英国卜内门化学有限公司进口     

科研用高纯乙醇、乙酸乙酯、正己烷试剂标准规范及其纯化工艺研究进展

随着科学研究的进步.检测仪器和技术的提高,传统规格试剂已经不能满足要求,为适应不同领域科研需要,陆续出现了光谱纯、色谱纯、农药残留级等不同规格的高纯有机溶剂.高纯有机溶剂具有极高的纯度、低紫外吸收、低酸碱度、低水分和低蒸发残渣的特点.常见的科研用高纯有机溶剂包括甲醇、乙醇、丙酮、乙腈、乙酸乙酯和正己烷等.国外高纯有机溶...     

Gradient Hydroxyapatite Chromatography with Small Sample Loads. IV. Gaussian Expression of the Chromatogram and a Further Consideration on the Resolving Power of the Columns

Abstract

In earlier papers a pair of equations that represent a theoretical chromatogram using an intermediate parameter was derived. In the present paper the two equations are reduced into a single Gaussian form; essentially the same chromatogram can be calculated from the new equation. For a practical purpose, this equation is much more useful. Introducing a further approximation, the change in the chromatographic resolution occurring with a change in the experimental condition can explicitly be understood. This approximation, with a slight modification, is useful for roughly estimating the optimal chromatographic condition with a very simple calculation. A limit of the application of the theory occurring in an extreme case is discussed.     

Quantitative analysis of triglyceride species of vegetable oils by high performance liquid chromatography via a flame lonization detector

A method for the quantitative analysis of triglyceride species composition of vegetable oils by reversed-phase high performance liquid chromatography (RP-HPLC) via a flame ionization detector (FID) is described. Triglycerides are separated into molecular species via Zorbax chemically bonded octadecylsilane (ODS) columns using gradient elution with methylene chloride in acetonitrile. Identification of species is made by matching the retention times of the peaks in the chromatogram with the order of elution of all of the species that could be present in the sample on the basis of a random distribution of the fatty acids and comparision of experimental and calculated theoretical carbon numbers (TCN). Quantitative analysis is based on a direct proportionality of peak areas. Differences in the response of individual species were small and did not dictate the use of response factors. The method is applied to cocoa butter before and after randomization, soybean oil and pure olive oil.     

BAND SPREADING MODELING ANDCORRECTION IN SIZE EXCLUSION CHROMATOGRAPHY NEW METHODS FOR BAND SPREADING PART II CORRECTION

The evaluation of the band spreading corrected chromatogram (the “ideal” chromatogram) from the observed one knowing the shape of single component chromatograms (described by the dispersion function) requires the solution of a Fredholm's integral equation of the first kind (Tung's equation), a mathematically ill-posed problem if details of the unknown chromatogram are sought at a scale narrower than that of single component chromatograms

Most often, chromatogram deformation by instrumental spreading is not too severe and a correction method can be implemented which is based on a Taylor's series expansion. Such a method is proposed in the present paper. The correction is expressed as a function of the derivatives of the observed chromatogram and of the moments of the dispersion function, with an appropriate truncation. The derivatives are calculated from a polynomial approximation of the observed chromatogram which is fitted at each point. Numerical simulations show that the method withstands the problems caused by noisy data and can be applied to any shape for the dispersion function, not necessarily translation-invariant. The Taylor's series method can also be generalized to encompass the analysis of oligomers. Its simplicity and flexibility make it a candidate for widespread use in current analytical practice.     

DryLab软件在大学液相色谱分析实验中的初步应用

提出了DryLab软件在本科液相色谱实验教学中使用的观点。详细介绍了Drylab软件的组成,并以苯、甲苯、萘和菲四种优控污染物的混合体系作为分离对象。针对上述四种物质混合体系列出了Drylab操作步骤,并通过软件得到最佳分离条件,用Drylab软件进一步模拟出相应的色谱图,最后用真实的实验结果加以验证。     

香料硫代丙酸烯丙酯的合成研究

对可用于配制肉类香精的香料硫代丙酸烯丙酯进行了合成研究 ,以烯丙硫醇和丙酰氯为原料 ,产率为50.8%。对所合成的产品做了气相色谱、红外光谱和质子核磁共振分析 ,确定了其化学结构。     

现代离子色谱在测定痕量元素方面的进展

离子色谱自问世以来一直是分析化学领域快速发展的技术之一。文章介绍了现代离子色谱的一些发展情况,特别是固定相,抑制剂等两方面的技术更新,并就离子色谱和其他现代大型检测仪器联用在测定复杂基体中痕量、超痕量元素方面的进展进行了综述,着重于离子色谱与质谱联用测定阴离子和离子色谱与原子荧光联用测定阳离子两方面。     

粘土原料用于陶瓷注浆泥料的开发模式研究

以黑泥粘土原料的开发为依据,确定高岭石类粘土原料开发模式为:首先将待开发黑泥粘土原料的物理化学性质与苏州土的物理化学性质进行分析比较,确定其为高岭石类粘土原料后再用该粘土原料代替苏州土并进行陶瓷注浆泥料配方设计.     

Characterization of cellulose acetate in acetone solution. Studies on prehump II in GPC pattern

Cellulose acetate in acetone solution is known to show some peaks in its chromatogram as measured by gel-permeation chromatography. These peaks are named from the shorter elution time as prehump I, prehump II, and main hump. In our previous paper, we characterized prehump I. In this study, the second peak, prehump II, was fractionated by using the large-scale GPC column and its molecular properties were investigated. The results have shown that the molecules of prehump II are not aggregated but molecularly dispersed with some anionic residues. These anionic groups may be sulfuric acid groups introduced during the acetylation process as a catalyst that interact repulsively with the anionic groups of the GPC column gel. This resulted in the phenomenon that the prehump II elutes earlier than the main hump in the GPC chromatogram. © 1993 John Wiley & Sons, Inc.     

线性VLE模型对C_5烃-乙腈体系实用性的实验验证

曾报道过下列最简单的线性汽液平衡模型可以适用于C_5-DMF体系. 本文按文献数据回归了一套适合于C_5-乙腈(包括含水乙腈)体系的模型参数M、B值.同时,在小型筛板塔上进行了以乙腈为溶剂全循环全回流萃取精馏碳五馏份的试验,并用上述关系式和M、B值进行了试验塔沿塔身浓度、温度分布的逐板计算.结果证明所用计算模型及参数值是适用的,可供设计乙腈萃取精馏碳五馏份工业塔时选用.浓度计算值与实测值平均偏差为0.45%(mol),温度平均偏差为3.6℃,校正后为0.7℃.提出了一个利用试验塔的实测数据和计算模型,例算部分组分模型参数的方法,用此方法求取了反式-2-戊烯的参数.     

Analysis of Phenacylester Derivatives of Fatty Acids from Human Skin Surface Sebum by Reversed-Phase HPLC: Chromatographic Mobility as a Function of Physico-Chemical Properties

A set of 13 fatty acids was transformed into their phenacyl esters by reaction with phenacyl bromide in acetonitrile using 18-crown-6 as phase-transfer catalyst. Conditions for the RP-18 HPL chromatographic separation of most of the esters has been worked out. Using this standard the fatty acid spectra from skin surface sebum lipids of 17 test persons was taken after microwave-assisted hydrolysis, neutralization and extraction with n-hexane. Quantitative evaluation of the chromatograms exhibits that oleic acid predominates in the sebum of all test persons. In the second part of the work the chromatographic mobility (R_E values) of fatty acid phenacyl esters is correlated with calculated physico-chemical parameters of the corresponding acids. The best linear correlation was found between the R_E and the logP values. This is helpful for the structural elucidation of un-identified fatty acids in a chromatogram.