OBJECTIVE The alteration of steroid hormonal status in premenopausal breast disease (benign and malignant) were investigated by comparing the urinary profile of androgens and corticoids. METHODS The urinary concentrations of 25 androgens and corticoids were quantitatively determined by a gas chromatographymass spectrometry system in patients with benign breast disease (35 cases, 20-54 years),...

In the present study, the safety and toxicity of Dendrophthoe pentandra (DP) extracted using ethyl acetate were investigated. DP ethyl acetate (DPEA) extract was screened for its phytochemical constituents using standard procedure and active compounds present in DPEA extract were determined using gas chromatographymass spectrometry (GC-MS), the toxicity of DPEA extract was investigated using br...

Drcarboxylic aciduria is a condition sometimes encountered during routine urine screening for inborn errors of metabolism [l] and may be due to ketosrs, a transient condition m some neonates [2] or a number of enzyme deficiencies mainly involving fatty acid metabolism or transport. Unsaturated dicarboxylic acids have also been reported m some of these conditions. These compounds are usually det...

Background and aims: A selective and sensitive high performance liquid chromatography-electrospray ionization mass spectrometry method has been established for determination of methotrexate in human plasma. Methods: Methotrexate was extracted from plasma with acetonitrile. The mobile phase consisted of acetonitrile-water-formic acid 74: 25: 1(v/v). Twenty...

background and aims: a selective and sensitive high performance liquid chromatography-electrospray ionization mass spectrometry method has been established for determination of methotrexate in human plasma. methods: methotrexate was extracted from plasma with acetonitrile. the mobile phase consisted of acetonitrile-water-formic acid 74: 25: 1(v/v). twenty µl of sample was chromatographically an...

Today, 2D online or offline liquid chromatography/mass spectrometry is state of the art for the identification of proteins from complex proteome samples in many laboratories. Both 2D liquid chromatography methods use two orthogonal liquid chromatography separation techniques. The most commonly used techniques are strong cation exchange chromatography for the first dimension and reversed phase s...

Liquid chromatography (LC) coupled with mass spectrometry (MS) detection is one of the most powerful analytical tools for organic compound analysis. The advantages of using LC/MS methods over HPLC methods include: selectivity, chromatographic integrity, peak assignment, structural information, and rapid method development. In this paper, a new liquid chromatography-tandem mass spectrometry (LC-...

The techniques and measurement methods developed in the Environmental Survey and Monitoring of Chemicals by Japan's Ministry of the Environment, as well as a large amount of knowledge archived in the survey, have led to the advancement of environmental analysis. Recently, technologies such as non-target liquid chromatography/high resolution mass spectrometry and liquid chromatography with micro...

In previous studies, mebudipine, a dihydropyridine calcium channel blocker, showed a considerable potential to be used in cardiovascular diseases. The aim of the current study was to develop a valid method using reversed-phase high performance liquid chromatography coupled with electrospray ionization mass spectrometry to assay mebudipine in the human plasma. Separation was achieved on a Zorbax...

A major limitation in quantitative analysis with electrospray ionization mass spectrometry (ESI-MS) is represented by the so-called matrix effects in which the matrix coextracted with the analytes can alter the signal response, causing either suppression or enhancement, resulting in poor analytical accuracy, linearity, and reproducibility. In the direct electron ionization liquid chromatography...