Recent progress in carbohydrate separation by high-performance liquid chromatography based on hydrophilic interaction

This article surveys recent developments in the separation and analysis of carbohydrates by high-performance liquid chromatography, in adsorption or partition modes, on polar sorbents with less polar eluents, a technique that is now termed hydrophilic interaction chromatography. A variety of chromatographic methods are included under this generic heading, the most important being adsorption chromatography on silica and partition chromatography on silica-based sorbents bearing bonded polar phases. Examples are given of the applications of these stationary phases, as well as the newer polymer-based polar sorbents, in high-performance liquid chromatography of carbohydrates and their derivatives.     

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。     

现代分析检测技术在润滑油氧化中的应用

介绍了近20年来用于润滑油氧化测试中分析检测技术的进展情况,包括高效液相色谱、气相色谱、凝胶渗透色谱、热分析、红外光谱、核磁共振、化学发光及电化学技术,并讨论了今后发展的方向。     

Peptide maps at picomolar levels obtained by reversed-phase high-performance liquid chromatography and pre-column derivatization with phenyl isothiocyanate. Microsequencing of Phenylthiocarbamyl Peptides

A new reversed-phase high-performance liquid chromatography approach to the production of analytical peptide maps by pre-column derivatization using phenylisothiocyanate is described. Tryptic peptide digests were derivatized with phenyl isothiocyanate to form the phenylthiocarbamyl peptides followed by reversed-phase high-performance liquid chromatographic analysis. The phenylthiocarbamyl peptides were separated by reversed-phase high-performance liquid chromatography with the conventional gradient elution system of water-acetonitrile containing trifluoroacetic acid. The sensitivity of detection of these peptide derivatives was within the range 5-10 pmol with a constant baseline at 254-260 nm. The isolated phenylthiocarbamyl peptides can be subjected to automatic Edman degradation. The effectiveness of this method was exemplified by microsequencing of phenylthiocarbamyl peptides isolated from tryptic digests of three different proteins: alpha-lactalbumin, beta-lactoglobulin and a lambda light-chain immunoglobulin.     

A review of chromatographic methods for the assessment of phospholipids in biological samples

Phospholipids are important constituents of all living cell membranes. Lipidomics is a rapidly growing field that provides insight as to how specific phospholipids play roles in normal physiological and disease states. There are many analytical methods available for the qualitative and quantitative determination of phospholipids. This review provides a summary of the methods that were historically used such as thin layer chromatography, gas chromatography and high-performance liquid chromatography. In addition, an introduction to applications of interfacing these traditional chromatographic techniques with mass spectrometry is provided.     

High-performance liquid chromatographic determination of cyclohexylhydantoin and cyclohexylidenehydantoin formed during the synthesis of phenylhydantoin from hydantoin and cyclohexanone

-Phenylhydantoin can be converted into -phenylglycine by an enzymatic process. -phenylglycine is an important starting material in the production of β-lactams such as semisynthetic penicillins and cephalosporins. In our laboratory, the synthesis of phenylhydantoin was achieved from hydantoin and cyclohexanone in the presence of a base. An efficient and fast isocratic reversed-phase high-performance liquid chromatography method was developed for the determination of phenylhydantoin, cyclohexylhydantoin and cyclohexylidenehydantoin. Quantitative analysis was carried out by an external standard method.     

High-performance affinity chromatography

High-performance affinity chromatography is a new technique for the fast and efficient purification of biologically active molecules. It combines the biospecificity of affinity chromatography with the high speed and resolution obtained in high-performance liquid chromatography. In particular, the immobilization of ligands to different silica derivatives and their suitability for high-performance affinity chromatography are discussed.     

超临界流体色谱在生物工程中应用的新进展

超临界流体色谱（SFC）是高效液相色谱（HPLC）和气相色谱（GC）的重要补充技术。用SFC可以分离多数不能用GC分离的低挥发性物质。与传统的HPLC相比，SFC的分离速度更快、效率更高。本文综述了SFC在生物分子分离分析方面应用的新进展。引用文献74篇。     

Analysis of natural food pigments by capillary electrophoresis

Lac, cochineal, safflower, gardenia, Monascus and elderberry pigments are used as food color additives in Japan. These natural pigments can be analyzed by capillary electrophoresis (CE). CE has several advantages over thin layer chromatography, gas chromatography and high-performance liquid chromatography, such as low capillary cost, reduced operating costs, small sample amounts, low production of waste materials and short analysis time. CE is shown to be a useful technique for the analysis of these natural food pigments and the pigments extracted from commercial food samples by solid-phase extraction method.     

Fluorescence determination of 5-fluorouracil and 1-(tetrahydro-2-furanyl)-5-fluorouracil in blood serum by high-performance liquid chromatography

Fluorescence derivatization of 5-fluorouracil (5-FU) and 1-(tetrahydro-2-furanyl)-5-fluorouracil (ftorafur, FT) with 4-bromomethyl-7-methoxycoumarin using 18-crown-6 as a catalyst is studied with aim of developing a sensitive and selective liquid chromatographic method. 5-FU and FT form virtually substituted derivatives which possess maxima in their fluorescence emission spectra near 400 nm. These derivatives are separated by thin-layer chromatography and high-performance liquid chromatography to confirm the completion of reaction. For the determination of 5-FU and FT in serum, the reversed-phase high-performance liquid chromatographic separation of the derivatives is studied with a C13 column. This chromatography is of importance for the accurate determination of 5-FU and FT, which are, respectively, an important antitumour agent for the treatment of solid tumours in clinical medicine and a masked form of 5-FU generated in vivo.     

Separation of stereoisomers of several furan derivatives by capillary gas chromatography-mass spectrometry,supercritical fluid chromatography,and liquid chromatography using chiral stationary phases

The direct separation of several stereoisomers (enantiomers and geometrical isomers) of furan derivatives, important intermediates for the synthesis of physiologically active natural products, was achieved using capillary gas chromatography/mass spectrometry with a per-O-methyl-beta-cyclodextrin, supercritical fluid chromatography and high-performance liquid chromatography with a tris(3,5-dimethylphenylcarbamate) of cellulose or amylose for the chiral stational phases, respectively. The temperature dependence of the peak resolution (Rs) and the retention factor (k) over the range of 110-130 degrees was studied using crotyl furfuryl ether in gas chromatography. Successive increases in the Rs value and of the difference between the k value of the E-isomer and the k value of the Z-isomer were observed when the gradient temperature was decreased. The per-O-methyl-beta-cyclodextrin column was suitable for use with volatile furan ethers whose molecular masses are between 150 and 180. In conclusion, the separation of thermally unstable furan derivatives was accomplished using supercritical fluid chromatography and high-performance liquid chromatography.     

Chromatographic methods as tools in the field of mycotoxins

Achievements in the applications of chromatographic techniques in mycotoxicology are reviewed. Historically, column chromatography (CC) and paper chromatography (PC) were applied first, followed by thin-layer chromatography (TLC), high-performance liquid chromatography (HPLC) and gas chromatography (GC). Although PC techniques are no longer used in the analysis of mycotoxins, selected applications of PC are included to underline historical continuity. The most important achievements published from 1980 onwards are described. They include clean-up methods, TLC, CC, HPLC and GC of mycotoxins in environmental samples, foods, feeds, body fluids and in studies on biosynthesis and biotransformations of mycotoxins. Advantages and disadvantages of chromatographic techniques used in mycotoxicology are also evaluated.     

Monitoring of protein conformation by high-performance size-exclusion liquid chromatography and scanning diode array second-derivative UV absorption spectroscopy

Genetic methods now allow the rapid production of mutant proteins for structure-function analysis. To properly interpret any change in biologic activity resulting from modification in primary sequence, it is essential to monitor conformational changes resulting from mutations. Several methods allow low-resolution protein conformational analysis. One method, second-derivative UV absorption spectroscopy, is particularly useful for proteins containing tyrosine and/or tryptophan residues. Using high-performance size-exclusion liquid chromatography and scanning diode array detection we have demonstrated that it is possible to monitor the degree of aggregation as well as conformational perturbation for a series of interleukin-2 structural mutants. Furthermore, the combination of high-performance liquid chromatography and second-derivative UV absorption spectroscopy avoids a potential artifactual contribution in non-chromatographic analysis due to protein aggregation.     

Polysaccharide-based chiral stationary phases for high-performance liquid chromatographic enantioseparation

Recent developments of polysaccharide-based chiral stationary phases (CSPs) for the direct separation of enantiomers in high-performance liquid chromatography (HPLC) are mainly reviewed together with the results on mechanistic studies by means of chromatography, NMR and mass spectroscopies, and computational methods. Miscellaneous applications of polysaccharide derivatives to the newly developed, chiral dynamic high-performance liquid chromatography (DHPLC) for obtaining a nonracemic compound are also described.     

Drug detection in hair by chromatographic procedures.

This article reviews the analysis of 31 drugs and drug metabolites in human hair by thin-layer chromatography, high-performance liquid chromatography, gas chromatography, gas chromatography-mass spectrometry and mass spectrometry. The most important detection method after chromatographic separation of the components is the mass spectrometry because of its sensitivity and specificity. Washing steps to exclude external contamination, extraction, derivatization, stationary phases, detection modes and detection limits of the mass spectrometric and gas chromatographic-mass spectrometric procedures are presented in five tables. Additionally, a method for a gas chromatographic-mass spectrometric screening procedure is presented.     

Estimating measurement uncertainty in high-performance liquid chromatography methods

In every measurement procedure, it is important to know the components of measurement uncertainty affecting the quality of measured result and reliability of quantified result. The procedure for recognizing measurement uncertainty is not universal but depends on the method and sample type. It has to be made according to good laboratory practice. This paper aims at showing the comparison of measurement uncertainty component estimations for three methods using the high-performance liquid chromatography techniques: determination of the type and content of aromatic hydrocarbons in diesel fuels and petroleum distillates by normal phase high-performance liquid chromatography, determination of nitrates in water samples by ion chromatography, and determination of molecular weights of polystyrene by size exclusion chromatography technique. Both similarity and differences were found during the measurement uncertainty component estimation, and conclusions about influences of certain components on the result uncertainty were made.     

Comparison of different analytical methods for speciation of seven gadolinium-based magnetic resonance imaging contrast agents and the applications in wastewater and whole blood

Three methods, high-performance liquid chromatography hyphenated with inductively coupled plasma mass spectrometry, high-performance liquid chromatography-tandem mass spectrometry, and ion chromatography, were compared for simultaneous speciation of seven commercial gadolinium-based contrast agents for magnetic resonance imaging. Optimizations of experimental conditions for individual method were conducted, respectively. Methods of high-performance liquid chromatography hyphenated with inductively coupled plasma mass spectrometry and high-performance liquid chromatography-tandem mass spectrometry showed the capability of speciation for all seven target compounds, whereas ion chromatography was only suitable for three of them when using electronic conductivity detector. The limits of detection and limits of qualification by the three methods were compared, and high-performance liquid chromatography hyphenated with inductively coupled plasma mass spectrometry was found to be the most sensitive one. The limits of detection for seven target compounds by high-performance liquid chromatography hyphenated with inductively coupled plasma mass spectrometry were in the range of 0.15–0.55 pg. Thus, high-performance liquid chromatography hyphenated with inductively coupled plasma mass spectrometry was chosen as the final method and successfully applied to speciation analysis of seven gadolinium-based contrast agents in wastewater and whole blood. Compounds of gadoxetic acid disodium, gadobenate dimeglumine, gadodiamide, and gadobentetate dimeglumine were found in wastewater.     

Separation of basic drugs by high-performance liquid chromatography using dynamically modified silica

Separation of basic drugs by high-performance liquid chromatography is often impeded by peak tailing and poor efficiency due to unwanted interactions between the nitrogenous moiety in the molecules and the surface of the silica-based column material. However, when using the dynamically modified silica approach in reversed-phase high-performance liquid chromatography most of these drawbacks are eliminated.     

Development and validation of a method for measuring the glycine and taurine conjugates of bile acids in bile by high-performance liquid chromatography

We developed and validated a simple method for measuring the individual glycine and taurine conjugates of bile acids in bile by high-performance liquid chromatography with a C18 reversed-phase column using an isocratic solvent system of acidified methanol--potassium phosphate. Without preliminary derivatization or purification, complete separation of the ten major conjugated bile acids present in bile could be achieved in 65 min. Total bile acid concentrations were identical when measured enzymatically and by summing the individual bile acids determined by high-performance liquid chromatography. Bile acid composition determined by gas-liquid chromatography correlated with results by high-performance liquid chromatography. Finally, measurements of individual glycine and taurine conjugates in human bile and in mixtures of bile acid standards by high-performance liquid chromatography and thin-layer chromatography gave similar results. This high-performance liquid chromatographic system permits simultaneous quantification of total and individual bile acids and their glycine and taurine conjugates in bile.