HDL-cholesterol (HDL-C) values measured by precipitation (sodium phosphotungstate-MgCl2) and direct methods were compared with those obtained by HPLC with a new column (TSKgel Lipopropak) and an eluent (TSKeluent LP-1). The HDL-C values determined by the precipitation method were significantly (P <0.001) lower than those by the HPLC method, whereas the HDL-C values by the direct method were sli...

Due to the proteomics revolution, multi-dimensional separation and detection instruments are required to evaluate many peptides and proteins in single samples. In this study, electrospray ionization (ESI) ion mobility spectrometry (IMS) was evaluated as an additional separation after HPLC separations. Common HPLC mobile phase compositions (solvents, acid modifiers, and buffers) were assessed fo...

Herein, I describe pyridylamination for versatile analysis of sugar chains. The reducing ends of the sugar chains are tagged with 2-aminopyridine and the resultant chemically stable fluorescent derivatives are used for structural/functional analysis. Pyridylamination is an effective "operating system" for increasing sensitivity and simplifying the analytical procedures including mass spectromet...

a new method for analysis of benzene, toluene, and xylene (btx) using high performance liquid chromatography-uv detection (hplc-uv) is described and compared to the gas chromatography (gc) method. a charcoal adsorption tube connected to a small pump was used to obtain samples from an atmosphere chamber standard. samples were extracted with methanol and analyzed by hplc-uv. chromatography was is...

New carotenoids, cryptocapsin-5,6-epoxide, 3'-deoxycapsanthin-5,6-epoxide, and cryptocapsin-5,8-epoxides, have been isolated from the ripe fruits of red mamey (Pouteria sapota). Cryptocapsin-5,6-epoxide was prepared by partial synthesis via epoxidation of cryptocapsin, and the (5R,6S)- and (5S,6R)-stereoisomers were identified by HPLC-ECD analysis. Spectroscopic data of the natural (anti) and s...

High-performance liquid chromatography (HPLC) with UV, circular dichroism (CD) and intrinsic fluorescence detection was applied to monitor conformational properties of recombinant human interferon alpha2b when performing size exclusion chromatography (SEC) and reversed-phase HPLC (RP-HPLC). In this way native conditions during SEC and structural changes of the protein during RP-HPLC were demons...

oligosaccharide prepared from Pl.-B was eluted as a single peak on both reversed-phase {RP-) HPLC and size-fractionation (SF-) HPLC, and its strueture was estimated to be Manoct-qManal -. 3)(Xylfi1-.2) Manfi1-4GlcNAcfi1-4(Fuc=1-3)GlcNAc by a combination of component analysis, successive exogl)'cosidase digestions, IS-MS anal)'sis, and 500MHz 'H-NMR, Two tryptic gl)'copeptides were isolated from...

In this study, a high-performance liquid chromatographic method (HPLC) and UV spectrophotometric method were developed, validated and applied for the determination of theophylline in biological fluids. Liquid- liquid extraction is performed for isolation of the drug and elimination of plasma and saliva interferences. Urine samples were applied without any extraction. The chromatographic separat...

Nicotinamide, one kind of Vitamin B, plays an important role for humans. To ensure quality control of nicotinamide in infant formula, a Certified Reference Material for nicotinamide in infant formula is being prepared in China for the first time. Studying on the procedure of sample preparation and HPLC analysis with different detectors like UV and MS, HPLC-UV and HPLC-IDMS are selected as the v...

Simultaneous quantitative analysis of 10 indole compounds, including indole-3-acetic acid (IAA, one of the most important naturally occurring auxins) and some of its metabolites, by high performance liquid chromatography (HPLC) and liquid chromatography-mass spectrometry (LC-MS) after solid-phase extraction (SPE) was reported for the first time. The analysis was carried out using a reverse phas...