Trichromates

Dreifachverbindung, /. ternary compound. Dreifarben-, three-color, trichrome, -druck, m. 

Endoscopy with scrapings or biopsy and stained slides (iron hematoxylin or trichrome) may provide more definitive diagnosis of amebiasis. 

A number of staining procedures have been described. Some stains, such as chlorazol black, require fresh specimens and are not widely used. A variety of stains for fecal smears preserved by Schaudinn or PVA fixative have been described, including various hematoxylin stains. The stain most widely used in the United States is the Wheatley trichrome stain, which is the only permanent stain described in this chapter. The trichrome staining procedure uses reagents with a relatively long shelf life and is easy to perform. Note that there are differences in staining times depending on whether the specimen is fixed in Schaudinn or PVA fixative, as penetration is slower in the latter. 

Table elsewhere outlines the steps in the trichrome staining procedure. 

Except for problems with delayed or inadequate fixation as noted above, problems with the trichrome stain are usually related to reagents other than the stain. If crystalline material is apparent after the specimen is stained, the crystals are probably mercuric chloride in the fixative which was not adequately removed because the iodine in the alcohol-iodine solution was too weak or because the slide was in this solution too short a time. If crystals are present after treatment with proper-strength iodine-alcohol, they are present in the specimen, which is thus unsatisfactory, and another specimen should be requested. 

The trichrome may become diluted by carry-over alcohol if more than 10 slides per day are stained in one Coplin jar. To restore the... 

Sanmartin, M.L., Iglesias, R., Santamarina, M.T., Leiro,J. and Ubeira, F.M. (1991) Anatomical location of phosphorylcholine and other antigens on encysted TrichineUa using immunohistochemistry followed by Wheadey s trichrome stain. Parasitology Research 77, 301-306. 

Ammonium nitrate, 4522 Ammonium permanganate, 4518 Ammonium tetrachrornate(2—), 4253 Ammonium tetranitroplatinate(II), 4578 Ammonium trichromate (2—), 4252 Anilinium nitrate, 2379... 

In Rb2Cr30io the trichromate ions consist of three Cr04 tetrahedra sharing corners and in RbCr40i3 the tetrachromate ions consist of four such cornersharing tetrahedra. In these anions the terminal and bridging Cr—O bonds... 

Dichromates. See under Chromates, Dichro-mates, Trichromates and Tetrachromates in... 

Ammonium Salts Which are Explosive, examined by H.Kast and described in SS 21, 205-9(1926) and SS 22, 6-9, 30-4, 56-61, 77-80, 99-102 131-5(1925) included azide, bichromate, chlorate, nitrate, nitrite, perchlorate, permanganate and trichromate... 

Chromates, dichromates, trichromates and tetrachromates 3 C274—C275... 

Noteworthy properties were discovered in ammonium trichromate (NH4)3Cr3O10, produced while crystallizing ammonium bichromate from nitric acid, d = 1.39 (Siewert [47]). At 190°C the compound undergoes explosive decomposition, evolving nitric oxide and nitrogen dioxide. 

The kinetics of the ammonium chromate, bichromate and trichromate decomposition were investigated by Fischbeck and Spingler [48] who measured the increase of pressure with time in an evacuated vessel. The activation energy is 40.0, 49.0 and 34.0 kcal/mole, respectively. 

In addition to chromate and dichrumate. inchrom-uc. Cr 0m) . exists. Postulate a structure for the inchromale ion. Compare its structure to that of PjO,h - Trichromate hydrolyzes in water Predict the hydrolysis products. 

TRICHROMATES are dfirivs of hypothetical trichromic acid, H2Cr301Q. They are strong oxidizing agents and for this reason are briefly described here Ref Mellor 11, 349-51... 

List of Trichromates Ammonium Trichromate, (NH4)2Cr3010, mw 352.11 dk garnet-red, rhmb bipyramids mp-darkens at 110-20° decomp at 150-60°... 

Can be prepd by evapg a soln of Amm dichromate in coned soln of chromic acidfRefs 1 3). It can also be prepd by crystn of Amm dichromate from nitric acid d 1.39(Ref 2). Combustion of Amm trichromate is discussed in Ref 4. Its heat of formation is, accdg to Kast, 678.1kcal /mole(Ref 2) and 580 j 6kcal/mole, accdg to KapustinskiifRef 5). Its uses are not described in the literature... 

List of Tetrachromates Ammonium Tetrachromate, (NH4)2Cr40)3, mw 452.12 brn-red hygroscopic crysts, less stable than Amm trichromate mp - blackens at 160°, melts at 170° and decomp spontaneously giving off nitrous fumes. Can be prepd by evapg, in cold over coned sulfuric acid, a soln of Amm trichromate in nitric acid, d 1.39(Refs 1 2). 

Accdg to Mr. R. Baumann of PicArsn, these compds are not catalysts, but rather "modifiers , or additives . They are incorporated into solid proplnts in order to modify or affect their combustion characteristics The compds which affect burning rate include Prussian blues, Aram dichromate, trichromate or tetrachromate, etc). Some compds may be employed to reduce the variability of burning rate with combustion pressure and temperature (Eg Pb stearate or salicylate). Other compds may be used to reduce the tendency toward oscillatory combustion(Eg A1 powder in small quantity), or to affect flash characteristics of exhaust gases [Eg KaS04, Ba(N03)2,... 

AN 75 catalyst 6 cellulose acetate -glycoldiglycolate mixt 19%. The proplnt becomes even more effective when 0.5 5.0% of a synergist catalyst is added. The synergists include phenothiazine,linseed oil sucrose or Mg stearate(or ricinoleate, or oleate) in the presence of hydrocarbons] 10)R.W. Lawrence USP 2978305(1961) CA 55, 25260(1961) (Combustion catalysts for comp proplnts include Amm trichromate or tetrachromate or riieirmixts, added in quantity 0.1-4% of total proplnt) 11)W.G. Proell, USP 2987388(1961)... 

Chromates, Dichromates, Trichromates T etra-chromates. See p C274-Lff Chromic Acid. See p C298-R to C299-L Chromium and Its Compounds. See pp C300-Lff Diazonium compounds and sodium sulfides react vigorously and are known to explode. Similar explosive reactions have been observed with H2S, also (Refs 40 41)... 

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