For the analysis of residues of veterinary drugs, liquid chromatography (LC) is of increasing importance: some of these molecules are polar, heat-sensitive and/or difRcult to analyse by gas chromatography}mass spectrometry (GC-MS). Moreover, LC is the method of choice for components of high molecular mass. Since the introduction of benchtop LC-MS instruments, there has been an increasing number...

background diazinon is one of the most widely used organophosphrous pesticides in the world may affect animals and human. objectives this study was done to assess whether pseudomonas plecoglossicida can grow on diazinon as the sole carbon metabolic source in laboratory and agricultural soil. materials and methods serial dilutions of pure and commercial diazinon in minimal salt medium were made ...

in recent years there has been considerable interest in the synthesis and separation of enantiomers of organic compounds especially because of their importance in the biochemistry and pharmaceutical industry. high-performance liquid chromatography is a very useful method for the direct separation of enantiomers. however, about 30−40 years ago, commercially available chiral stationary phases wer...

Centrifugal partition chromatography is a liquid-liquid separation method well adapted for the fractionation or purification of natural compounds from plant extracts. However, following the preparative isolation, the fractions collected must be analysed by high-performance thin-layer chromatography or high-performance liquid chromatography to evaluate their composition and/or their purity. Thes...

polycyclic aromatic hydrocarbons (pahs) which are toxic pollutants are released by various sources of urban combustion. ahvaz in iran with around a million population and the industrial and oil centers, has encountered air quality problems. samples of dibenzo (a,h) antheracen were collected from six stations in ahvaz particle and gas phase in summer 2010. dibenzo(a,h) antheracen were collected ...

background: the most reliable indicator of vitamin d status is circulating concentration of 25‑hydroxycalciferol (25(oh) d) routinely determined by enzyme‑immunoassays (eia) methods. this study was performed to compare commonly used competitive protein‑binding assays (cpba)‑based eia with the gold standard, high‑pressure liquid chromatography (hplc). methods: concentrations of 25(oh) d in sera ...

the lack of authentic standards has limited the quantitative analysis of herbal drugs in biological samples. the present work demonstrated a practicable strategy for the assay of herbs and their metabolites independent of authentic standards. a liquid chromatography–electrospray ionization–mass spectrometry (lc–esi–ms) method for the qualitative and quantitative determination of the metabolites...