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...

objective(s) developing and validating a simple, efficient, reproducible and economic reversed phase high performance liquid chromatographic (rp-hplc) method for the quantitative determination of pefloxacin in bulk material, tablets and in human plasma. materials and methods a shim-pack clc-ods column and a mobile phase constituting acetonitrile: 0.025 m phosphoric acid solution (13:87 v/v, ph ...

the occurrence and fate of trace-level contamination of pharmaceuticals in the aquatic environment has been recognized as one of the emerging issues in environmental chemistry. the effluents of wastewater treatment plants, usually directly emitted to the environment, often contain the anti-inflammatory drug diclofenac. diclofenac was chosen because it is of high consumption; by background liter...

There is no other naturally occurring defense agent against cancer that has a stronger effectthan paclitaxel, commonly known under the brand name of Taxol®. The major drawback for themore widespread use of paclitaxel and its precious precursor, 10-deacetylbaccatin III (10-DABIII), is that they require large-scale extraction from different parts of yew trees (Taxus species),cell cultures, taxane...