Salicylic acid the OH group is "ortho" to the carboxyl group. It is also known as 2-hydroxybenzoic acid. It is poorly soluble in water (2 g/L at 20 °C). Aspirin (acetylsalicylic acid or ASA) can be prepared by the esterification of the phenolic hydroxyl group of salicylic acid with the acetyl group from acetic anhydride or acetyl chloride. Salicylic acid can also be prepared using the Kolbe-Schmitt reaction. Salicylic acid is used as a food preservative, a bactericidal and an antiseptic. Sodium salicylate is a useful phosphor in the vacuum ultraviolet spectral range, with nearly flat quantum efficiency for wavelengths between 10
Technetium (99mTc) medronic acid Technetium (99mTc) medronic acid Technetium (Tc) medronic acid (MDP) is a pharmaceutical product used in nuclear medicine to localize bone metastases as well as other diseases that can alter the natural turn-over in the bone by bone scintigraphy. The drug is a complex of medronic acid, the simplest bisphosphonate, with technetium-99m (Tc), a radionuclide that emits gamma rays. The exact structure of the complex is not known. Tc-MDP must be prepared in a radiopharmacy. It is usually supplied as a "cold kit" to which radioactive Tc from a generator is added. Kit composition may vary between suppliers, but contents typically