A biologically active vitamin D(3) metabolite ("peak V metabolite") more polar than 25-hydroxycholecalciferol has been isolated from chicken intestines in pure form as a mono(trimethylsilyl)ether derivative. The molecule has been identified as 1,25-dihydroxycholecalciferol by means of mass spectrometry, ultraviolet absorption spectrophotometry, and specific chemical reactions.

One common method of illicit methamphetamine manufacture utilizes an alkali metal, typically lithium, and liquid ammonia to chemically reduce ephedrine or pseudoephedrine to form methamphetamine. This method is often referred to as the lithium-ammonia reduction method or the Birch reduction method. While the hydroxyl group of ephedrine is more reactive than the aromatic ring, excess alkali meta...

Objective: The present work describes complexation study of sulfonylurea based drug, glimepiride with divalent metal ions (Mg2+, Ca2+, Cu2+and Zn2+ Methods: The stoichiometry of resulting metal ion-glimepiride complexes were ascertained by molar conductance vs. mole ratio of glimepiride/metal ion plots, Job’s method of continuous variation and liquid chromatography-mass spectrometric analysis. ...

6. We have established Atomic Absorption Spectrophotometry as the most suitable method for estimation of gold in semen. For this, some samples were estimated by using Neutron Activation, Polarography and Atomic Absorption Spectrophotometry (7). Gold is present in sea water where life ong1nated. So its presence in present forms of life is not surprising. The total amount of gold present in an ad...

Serum lead concentrations measured by stable isotope dilution with a thermal ionization mass spectrometer and blood lead concentrations measured by graphite furnace atomic absorption spectrophotometry are reported for 73 women of child bearing age resident in Los Angeles, California. The two quantities are related by the line y=0.00030+0.00241x (r=0.83), where y is serum lead concentration and ...