A highly sensitive and selective high-performance liquid chromatographic (HPLC) method has been developed for the determination of microbial lipopeptides of fluorescent derivatization with 1-bromoacetylpyrene to overcome the limitations of trace detection of lipopeptides in aqueous solutions. The derivatization of lipopeptides with 1-bromoacetylpyrene was conducted at 60°C for 20 min under cata...

A high performance liquid chromatographic (HPLC) method with chemiluminescence (CL) detection was developed for the sensitive determination of 1,3-diaminopyrene (1,3-DAP), 1,6-DAP, 1,8-DAP and 1-aminopyrene (1-AP). The HPLC conditions were as follows: column, Cosmosil 5C18 (4.6 mm i.d.X250 mm); mobile phase, 10 mM imidazoleperchloric acid buffer(pH 7.6)-acetonitrile (1:1, v/v); CL reagent, 0.02...

BACKGROUND We developed a simple and inexpensive thin-layer chromatography (TLC) assay for semiquantitative detection of saliva concentrations of nevirapine in resource-limited settings. The method was validated in an African target population. METHODS Paired plasma and saliva nevirapine concentrations were assayed by high-performance liquid chromatography (HPLC); saliva concentrations of nev...

The chromatographic baseline was converted to power spectrum by Fourier transform to show the frequency dependence of noise. The spectral analysis of chromatographic baseline was made under various experimental conditions for high-performance liquid chromatography with electrochemical detection (HPLC-ECD). From the spectral analysis, it was found easily that a system using a small stroke pump a...

A number of analytical methods have been established to quantify methylphenidate (MPH). However, to date no HPLC methods are applicable to human pharmacokinetic studies without the use of mass spectrometry (MS) detection. We developed a sensitive and reliable HPLC-fluorescence method for the determination of MPH in human plasma using 4-(4,5-diphenyl-1H-imidazol-2-yl) benzoyl chloride (DIB-Cl) a...

Due to the complex nature of the proteome, instrumentation and methods development for sample cleanup, fractionation, preconcentration, chromatographic separation and detection becomes urgent for the identification of peptides and proteins. Newly developed techniques and equipment for separation and detection, such as nanoHPLC and multidimensional HPLC for protein and peptide separation, enable...

PURPOSE To analyze and compare the high performance liquid chromatography (HPLC) runs of tear proteins from diabetic (DIDRY) and non-diabetic (DRY) dry-eye patients, and healthy subjects (CTRL). The patterns were analyzed using multivariate statistical methods. METHODS Tears (total 56 eyes: CTRL: n=16, DIDRY: n=21, and DRY: n=19) were analyzed by HPLC, using a size-exclusion column with an el...

Analysis of caffeine and its metabolites is of interest with respect to caffeine exposure, for kinetic and metabolism studies and for opportunistic in vivo estimation of drug metabolizing enzyme activity in humans and animals. For the latter, analysis is usually done by high-performance liquid chromatography (HPLC) with UV detection. However, this method is close to the detection limit for cert...

BACKGROUND Xuesaitong (XST) injection, consisting of total saponins from Panax notoginseng, was widely used for the treatment of cardio- and cerebro-vascular diseases in China. This study develops a simple and global quality evaluation method for the quality control of XST. METHODS High performance liquid chromatography-ultraviolet detection (HPLC-UV) was used to identify and quantify the chr...

A rapid, simple and specific reversed-phase HPLC method has been developed for analysis of karanjin in Pongamia pinnata Linn. leaves. HPLC analysis was performed on a C(18) column using an 85:13.5:1.5 (v/v) mixtures of methanol, water and acetic acid as isocratic mobile phase at a flow rate of 1 ml/min. UV detection was at 300 nm. The method was validated for accuracy, precision, linearity, spe...