Mercury orange

Mercury orange [l-(4-chloromercuriophenylazo)-2-naphthol] [3076-91-3] M 483.3, m 291.5-293°(corr) with bleaching. Wash several times with boiling 50% EtOH and recrystallise from 1-butanol (0.9g/L of boiling alcohol). Fine needles insoluble in H2O but slightly soluble in cold alcohols, CHCI3 and soluble in aqueous alkalis. [J Am Chem Soc 70 3522 1948.]... 

Philbert, M.A., Beiswanger, C.M., Waters, D.K., Reuhl, K.R. and Lowndes, H.E. (1991) Cellular and regional distribution of reduced glutathione in the nervous system of the rat histochemical localization by mercury orange and o-phthaldialdebyde-induced histofluorescence. Toxicol. Appl. Pharmacol. 107 215-227. 

Another application of the Mach-Zehnder interference microscope is to detect free sulfhydryl groups as in reduced glutathione, using mercury orange (Schiller 1974,1975). 

Fig. 226. Free sulfhydryl groups in the neurosecretory ganglion cells of the nucleus suprachiasmaticus of an unmedicated rat. The unfixed cryostat section was incubated with mercury orange, mounted in glycerol and photographed under a Mach-Zehnder interference microscope. Interference contrast...

Concurrent with requirements for low levels of mercurials in discharge water is the problem of their deterrnination. The older methods of wet chemistry are inadequate, and total rehance is placed on instmmental methods. The most popular is atomic absorption spectrophotometry, which rehes on the absorption of light by mercury vapor (4). Solutions of mercury compounds not stabilized with an excess of acid tend to hydrolyze to form yeUow-to-orange basic hydrates. These frequendy absorb onto the walls of containers and may interfere with analytical results when low levels (ppm) of mercury are determined. 

A third form of cadmium pigments includes the mercury cadmiums. Mercuric sulfide (HgS) forms soHd solutions up to about 20 mol % with the oranges, reds, and maroons. The heat stabiUty is improved up to 370°C, and the costs are somewhat lower than the CP grades. The mercury cadmiums are slightly more reactive, but have excellent bleed resistance. 

Discussion. J. Nessler in 1856 first proposed an alkaline solution of mercury(II) iodide in potassium iodide as a reagent for the colorimetric determination of ammonia. Various modifications of the reagent have since been made. When Nessler s reagent is added to a dilute ammonium salt solution, the liberated ammonia reacts with the reagent fairly rapidly but not instantaneously to form an orange-brown product, which remains in colloidal solution, but flocculates on long standing. The colorimetric comparison must be made before flocculation occurs. 

I2 (0.0267 g, 0.21 mmol) in THF (1 mL) was added to a suspension of the mercury derivative 17 (0.0093 g. 0.016 mmol) in THF. The mixture was added to H20 (2 mL) and the resulting suspension was extracted with EtzO (2x5 mL). The combined extracts were washed with H20 (2 mL), dried (MgSQ4) and evaporated. The oily residue was submitted to flash chromatography (petroleum ether) yield 4.5 mg (89%) yellow-orange crystals mp 62 — 63 C (Et20/petroleum ether). 

Mercury and its compounds may also be determined by ICP/AES. The method, however, is less sensitive than the cold vapor-AA technique. The metal also can be measured at low ppb level by colorimetry. Mercury ions react with dithizone in chloroform to show an orange color. Absorbance is measured at 492 nm using a spectrophotometer. 

The bromide separates in prismatic needles which are reddish in colour and less soluble than the chloride. The mercury double salt with mercuric iodide is produced by mixing the chloride with mercuric iodide and hydriodie acid. The salt is very sparingly soluble in water and separates as an orange-coloured powder.1... 

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