The formation of fatty acid esters of vitamin D3 was demonstrated in rat skin exposed to artificial ultraviolet rays by using multi-dimensional high-performance liquid chromatography, ultraviolet spectrophotometry, and gas-liquid chromatography-mass spectrometry. This result indicated that the fatty acid esters of 7-dehydrocholesterol in rat skin (at least 80% of 7-dehydrocholesterol in rat ski...

A methods for the determination of fenbufen and ketoprofen in pharmaceuticals by classical spectrophotometry--zero order derivative, first and second order derivatives spectrophotometry is described. using "peak-peak" (P-P) and, "peak-zero" (P-O) measurements. The calibration curves are linear within the concentration range of 2.0 - 12.0 microg x mL(-1) for fenbufen and ketoprofen. The procedur...

Although acidic peptides compose a substantial portion of many proteomes, their less efficient ionization during positive polarity electrospray ionization (ESI) impedes their detection in bottom-up mass spectrometry workflows. We have implemented a derivatization strategy based on carbamylation which converts basic amine sites (Lys, N-termini) to less basic amides for enhanced analysis in the n...

There are various methods for the analysis of Potassium Sorbate and Sodium Benzoate in food products, but a rapid and reliable method for identification of these preservatives in Doogh (an Iranian traditional dairy drink) is a procedure, in which high performance liquid chromatography (HPLC) utilized and followed by UV diode array detection of the two preservatives. The aim of this case study w...

Background: Jamu is commonly known as an Indonesian traditional herbal medicine that contains ingredients or derived from plants, animals, minerals, galenic, mixtures of these have been hereditary for medicinal use. Some studies reported the presence chemicals are deliberately added to Jamu. Jamuthat containing usually had a faster healing effect compared do not contain chemicals. cause serious...