柱前衍生法在氨基酸分析测定中的应用

介绍了目前柱前衍生法分析氨基酸常用的几类衍生试剂及相应的衍生方法，并且比较了各类柱前衍生试剂的优缺点,对近期氨基酸分离分析中的色谱检测方法做了系统综述。     

土壤中氨基酸分析方法的研究进展

本文对土壤中氨基酸的分析方法做了较详细的评述,并针对土壤氨基酸的特点,就土壤样品的前处理(主要包括水解和纯化)及目前常用的色谱分离分析方法进行了总结(主要包括柱后衍生阳离子交换色谱、气相色谱、柱前衍生反相高效液相色谱、阴离子交换色谱-积分脉冲安培检测等方法)。     

花生油中游离脂肪酸的HPLC-FLD分析

采用柱前衍生-高效液相色谱荧光检测法(HPLC-FLD)分析了花生油中的游离脂肪酸.用荧光衍生试剂2-(11 H-苯[a]咔唑)乙基对甲苯磺酸酯(BCETS)作为柱前衍生化试剂对11种脂肪酸标准品(9种不饱和脂肪酸和棕榈酸、硬脂酸)进行衍生,经梯度洗脱实现了11种游离脂肪酸BCETS衍生物的完全分离,使用外标法定量,建...     

氨基酸分析方法的研究进展

对目前应用于氨基酸分析的主要方法作了较详细评述。这些方法包括柱后衍生高效阳离子交换色谱法、柱前衍生反相高效液相色谱法、高效阴离子交换色谱-积分脉冲安培检测法等。引用文献73篇。     

高效液相色谱-光度法测定金属离子的进展

评述了近年以来柱前衍生高效液相色谱一光度法分析痕量金属离子的进展,并简要介绍了一些新方法（引述文献61篇）。     

对酞内酰胺苯甲酰氯柱前衍生化高效液相色谱法检测痕量酚类化合物

将对酞内酰胺苯甲酰氯作为酚类化合物的高效液相色谱柱前衍生化试剂。分别对烷基取代酚及其与苯酚和氯代酚的混合物同对酞内酰胺苯甲酰氯的衍生反应、衍生物色谱分离及定量测定等条件作了研究。本法对酚类化合物的检测限为８０～１６０ｆｍｏｌ。     

高效液相色谱法对粉条中甲醛含量的快速检测

建立了Nash试剂柱前衍生高效液相色谱法快速测定土豆粉条样品中甲醛含量的分析方法.考察了衍生试剂、衍生反应条件及衍生物的稳定性.Nash试剂柱前衍生,产物经Agilent Zorbax Eclipse XDB-C18(4.6mm× 250 mm,5μm)柱分离,采用可变波长扫描紫外检测器(VWD)检测,检测波长412 ...     

草甘膦的邻硝基苯磺酰氯柱前衍生高效液相色谱分析

以邻硝基苯磺酰氯(NBSC)为衍生化试剂,建立了柱前衍生草甘膦的反相高效液相色谱紫外检测法,并对衍生化条件进行了优化.最佳衍生化条件为:衍生温度25℃,反应时间10 min,硼砂缓冲溶液浓度0.25 mol/L(pH 9.0),草甘膦与NBSC的摩尔比为1:5.HPLC分析条件为:采用Lichrospher C18柱,...     

柱前衍生HPLC-MS法测定海藻中脂肪酸

建立以N,N-二甲基乙二胺作为柱前衍生试剂,在C18反相色谱柱上,采用梯度洗脱,电喷雾电离源测定羊栖菜、紫菜、海带中饱和脂肪酸和不饱和脂肪酸的柱前衍生高效液相色谱串联质谱法。各脂肪酸衍生物均在进样质量浓度为2~100μg/m L时表现出良好的线性关系,相关系数均≥0.9905。检出限(LODs)在20~50 ng/m L之间,方法比未衍生脂肪酸的方法提高了1000倍左右的灵敏度。     

高效液相色谱荧光衍生法检测醇和酸的进展

高效液相色谱荧光衍生化醇和酸能提高检测灵敏度,改善分离效果,综述了最近十多年来高效液相色谱荧光衍生法检测醇和酸的进展情况。列出了衍生化试剂的结构,评述了衍生化的反应条件。指出了今后的发展方向。     

Derivatization procedures for detection of prostaglandins in biological matrices by liquid chromatography/electrochemistry

Conventional reversed-phase HPLC conditions have been optimized for resolution of a mixture containing prostaglandins PGE(1), PGE(2), PGF(1alpha), and PGF(2alpha). Electroactive derivative-forming reagents, such as p-nitrobenzyloxyamine, 2-bromo-2'-nitroacetophenone, and 2,4-dinitrophenylhydrazine have been evaluated for use as precolumn reagents for forming prostaglandin derivatives. The results indicate that detection limits of 120 pg are achievable with amperometric detection. The utility of the procedures developed is illustrated by the detection of prostaglandins in human urine and plasma.     

Extraction-liquid chromatography with electrochemical and spectrophotometric detection for the determination of copper and iron in biological and river water samples

Reversed-phase liquid chromatography using cupferron as a precolumn derivatizing agent was developed for the determination of Cu(II) and Fe(III) in biological materials and natural water samples. In the direct method, the metal cupferronates formed in acetonitrile-water (1 + 1) are injected onto an ODS column followed by separation with a mobile phase containing acetonitrile-acetate buffer (pH 3.5) (7 + 3) and other reagents. Amperometric detection with a glassy carbon electrode at ?0.40 V vs. Ag/AgCl can be used to determine both metals simultaneously. The electrochemical detection method has better sensitivity for the determination of Fe(III) than the usual spectrophotometric detection at 375 nm. If a large volume of aqueous sample is available, concentration of the two metal ions can be made by extraction with ethyl acetate prior to the chromatographic determination. In this case, liquid chromatographic separation and determination can be performed with the ODS column using a mobile phase consisting of acetonitrile-methanol-ethyl acetate-0.02 M acetate buffer (pH 3.5) (45 + 20 + 5 + 30).     

Determination of transition and rare earth elements in low-alloy steels as chelates with 4-(2-Thiazolylazo)resorcinol by reversed-phase high performance liquid chromatography

4-(2-Thiazolylazo)resorcinol (TAR) is used as a chelating reagent in the reversed-phase HPLC separation and determination of transition and rare earth elements in low-alloy steels. A precolumn derivatization method is used, followed by separation on an octadecyl-bonded silica stationary phase with a sodium octane-1-sulphonate-tartaric acid mobile phase. The eluted metal chelates are detected by uv-visible spectrophotometry. The requirements for sample preparation, characterization of precolumn derivatization and the optimum conditions for the sensitive detection of metal ions after liquid chromatography (LC) separation are discussed. The influence of the pH of the chelating medium and the eluent, the concentration of TAR and the eluent were investigated. The results are compared with those of other methods such as atomic absorption spectrometry (AAS) and inductively coupled plasma atomic emission spectrometry (ICP-AES).     

Chiral high-performance liquid chromatography analysis of alpha-amino acid mixtures using a novel SH reagent--N-R-mandelyl-L-cysteine and traditional enantiomeric thiols for precolumn derivatization

Several chiral thiols, i.e. traditionally used enantiomerically pure SH reagents and novel N-R-mandelyl-L-cysteine (R-NMC) containing additional chiral center, have been applied as co-reagents in precolumn derivatization with o-phthalaldehyde for enantiomeric HPLC analysis of individual alpha-amino acids and their mixtures. The R-NMC-derived isoindoles as well as adducts with other thiols have a characteristic absorption maximum at 340 nm, and are highly fluorescent allowing detection of 10 microg/l of an amino acid. Investigated 19 amino acids were analyzed separately and in a mixture by a gradient HPLC after precolumn derivatization. The chromatographic behavior of formed isoindoles substantially differs for each of the thiols used for modification. In contrast to traditional enantiomeric thiols application of diastereomeric R-NMC provides higher resolution for alpha-amino acid enantiomers, with L,D-elution order (except for Arg). Combined use of R-NMC and other thiol enlarges the possibilities of this method, allowing accurate chiral analysis of complex amino acid mixtures.     

Strong complex formation of carbohydrates with metal ions at alkaline pH studied by ligand exchange chromatography

Summary At alkaline pH, carbohydrates are highly retained on a sulphonated polystyrene resin loaded with rare earth or uranyl metal ions. The complex formation is governed by the ionization of the carbohydrate moiety. pH and the type of metal ion were found to have a decisive influence on the complex formation. Binding of the metal ion to the cation exchanger and to different carbohydrates is described. The competitive complexation between solute and hydroxide to the metal ions is described as a ligand exchange reaction and a retention model is proposed. The ligand exchange column was used as precolumn in a coupled column separation system and the high selectivity is demonstrated by the separation of paracetamol glucuronide from a urine sample after filtration and direct injection.     

2-Pyridylaldehydebenzoylhydrazone derivatives as highly selective precolumn chelating reagents for nickel (II) ion in kinetic differentiation mode high-performance liquid chromatography

2-Pyridylaldehydearoylhydrazones have been examined as reagents for precolumn derivatization of metal ions in the HPLC-spectrophotometry system. With the simplest analog, 2-pyridylaldehydebenzoylhydrazone (PAB), among 11 metal ions only Ni(II) ion gives the peak while the other metal chelates seem to be dissociated on an HPLC column where no added PAB is present in the eluent solutions. All other PAB analogs exhibit the peak for Ni(II) ion as well as Co(III) ion. In one reagent system, V(V) and Fe(II) chelates also appear in the chromatograms. It has been stressed that the selectivity principle is the kinetic differentiation (KD) towards metal chelates associated with the HPLC processes. The specificity for Ni(II) ion is in close relation to a key structure of the ligand molecules which provides an N,N,O coplanar coordination environment to form two five-membered chelate rings. An extremely selective and sensitive KD-HPLC method for the quantitation of Ni(II) ion at the ultra-trace levels was assessed; the detection limit (3 _Blank) for Ni(II) ion was down to 5.34 × 10^–9 mol l^–1 (31.5 pg in a 100 l injection) and the excellent applicability was checked using coal fly ash samples.     

碱土金属与多卤代偶氮氯膦类试剂显色反应的研究

近年来合成的多卤代偶氮氯膦类试剂有希望成为一类有效的碱土金属显色剂。本文研究了此类试剂与钙、锶、钡所生成配合物的吸收光谱、显色酸度、选择性、灵敏度和配合物的组成,以及试剂结构与性能的关系等。说明了不同取代助色基对显色反应各方面的影响。通过研究筛选出了较好的碱土显色剂,这几种试剂的结构如下:     

Synthesis of water-soluble phenylazosalicylaldehyde analogues and their application to capillary electrophoretic determination of primary amines

Several primary amines are known to be endogenous substances, and they are to be detected at very low concentration level. Novel water-soluble azo dyes as precolumn derivatizing reagents were synthesized for the analysis of primary amines with strong visible-light absorption by CZE. A coupling reaction was used to introduce a sulfophenylazo group to salicylaldehyde or 1-hydroxy-2-naphthaldehyde to extend the conjugation and to improve the solubility in water of the derivatizing reagents, as well as the target compounds of the reaction products with the primary amines. Two azo dyes of 5-(4-sulfophenylazo)salicylaldehyde sodium salt (AZO1) and 4-(4-sulfophenylazo)-1-hydroxy-2-naphthaldehyde sodium salt (AZO2) were synthesized. Separation of eight kinds of n-alkylamines was performed by CZE after the derivatization with AZO1 or AZO2. The addition of Brij 35 to the running electrolyte and to the sample solutions was necessary to improve the solubility and the resolution among the analytes. Both reagents, AZO1 and AZO2, were compared with each other in terms of the reaction time of derivatization, the detection sensitivity and the total analysis time. The derivatization process using AZO2 was applied to the determination of four biogenic amines, histamine, tyramine, cadaverine and putrescine, and LODs at around micromolar level were achieved for the four amines.     

Synthesis of chromogenic crown ethers and liquid-liquid extraction of alkali metal ions

New crown ethers carrying a pendent phenolic chromophore were synthesized. These crown ethers, on dissociation of the phenolic proton, provide lipophilic anions which can extract alkali metal cations into 1,2-dichloroethane by forming highly-colored uncharged metal complexes. Structural effects on the extraction were studied for possible use of these crown ethers as extraction—spectrophotometric reagents selective for alkali metals. The following factors are discussed in detail: (i) nature of the crown ether ring (ring size. aza-crown or standard crown ether), (ii) nature of the pendent phenolic group, and (iii) geometry between the crown ether center and pendent phenolic group. 15-Crown-5 or smaller ring-sized reagents favored the extraction of lithium ion when the basicity of the pendent phenolate was relatively high and a six-membered “chelate” ring was possible for the phenolate and the crown ether-bound metal. 15-Crown-5 type reagents were sodium-selective when an eight-membered “chelate” ring was possible between the phenolate and the crown ether-bound metal. 18-Crown-6 type reagents were generally potassium-selective. However, these selectivities were not absolute, and other structural parameters, steric and conformational, must be considered to explain in detail the selectivities of the individual reagents.     

新型二维气相色谱系统的理论研究──双柱条件对保留时间及峰扩展的影响

从色谱动力学角度推导出微填充柱-毛细管柱二维气相色谱系统流出曲线一级矩及二级中心矩的表达式,并据此讨论了柱温、柱间分流比等条件对保留时间及峰扩展的影响规律。结果表明:柱间分流是主毛细管柱与预微填充柱之间联系的纽带,分流比是影响峰特征的重要因素。预柱条件的改变对二维气相色谱保留时间及峰扩展的影响较小。双柱条件对峰特征的影响表现出一些特殊的规律性。