A specification sheet for methylene blue, CAS 61-73-4, packs a lot of vocabulary into a single page, and most acceptance mistakes in the stockroom come from misreading one of those entries rather than from the material itself. The compound is a cationic phenothiazine dye, catalogued as methylthionine chloride, with the linear formula C16H18ClN3S and a […]
Sildenafil citrate, CAS 171599-83-0, arrives in a laboratory as a fine crystalline solid catalogued with the molecular formula C28H38N6O11S and a molar mass of about 666.7 g/mol. That formula covers the 1:1 citrate salt, not the free base, which is the single most common source of arithmetic error when working stock solutions are prepared. The […]
What the abbreviation stands for HHC is the catalogue shorthand for hexahydrocannabinol, a saturated relative of the cannabinoids isolated from hemp. Summary formula C21H32O2 with a formula weight of 316.48 Structurally a dibenzopyran skeleton with a fully saturated terpenoid ring Catalogued by analytical suppliers as a reference material, not as a bulk commodity Present in […]
The pages below collect the questions a control laboratory asks before a container of cannabidiol is allowed into a method. None of them concern what the compound is for; all of them concern whether the material in the pouch is what the label claims, and whether that claim can still be defended six months later. […]
Bromantane is a laboratory reagent whose structure is unusually convenient to verify: a saturated cage hydrocarbon, an aromatic ring and a bromine atom each leave a distinct trace in a different instrument. The notes below describe how such a batch is identified and how its purity is judged. Chemical identity of the sample The framework […]
Modafinil arrives in the laboratory as a crystalline powder that reveals neither its identity nor its purity to the eye. A batch is released for measurement only after the analytical sequence set out below. Chemical identity of the sample Three fragments matter analytically: two phenyl rings on a common benzhydryl carbon, a sulfinyl bridge, and […]
