Aqua

It was emphasized (Kuhn 2004) that, in selecting peptides for use as internal standards, their hydropho-bicity, number of amino acid residues, peptide location within the protein sequence and lack of sites that could be subject to potential post-translational modification should be considered in addition to a high degree of uniqueness in the protein-peptide connectivity (Section 11.6.1). Although multiple MRM transitions were not required (Kuhn 2004) to obtain data of good accuracy and precision for more abundant target proteins, use of relative intensities of more than one (up to five) MRM signals increased the specificity of detection for peptides derived from low abundant proteins in complex proteomics mixtures and thus also increased the confidence of protein identification. 

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Mercury(II) chloride, HgC, corrosive sublimate, m.p. 280 C, b.p. 302"C. Essentially covalent material (Hg plus CL Hg plus aqua regia). Forms complex halide ions, e.g. (HgCU) (HgCL)" in excess HCl and forms complexes. Very poisonous. 

Telluric acid, TefOH), is formed from Te in aqua regia and a chlorale(V). Forms tellurales, e.g. Na[TeO(OH)s], Na2[Te02(0H)4]. 

Richens D T 1997 The Chemistry of Aqua-ions (Chichester Wiley)... 

It is dissolved by aqua regia (a mixture of concentrated hydrochloric and nitric acids). The product here is chlorauricil 11) acid, HAUCI4 in the complex chloraurate ion [AuClJ gold is in oxidation state + 3, auric gold. ... 

When platinum is dissolved in aqua regia it is first converted to platinic chloride, PtCl, and the latter at once unites with the excess of hydrochloric acid to give the stable soluble dibasic chloroplatinic acid, HjPtCle.f... 

Method- 3. From platinum metal or platinum residues. Dissolve the platinum metal or platinum residues in aqua regia, evaporate just to dryness several times with concentrated hydrochloric acid, dissolve the final residue in a httle water and precipitate as ammonium chloro-platinate with excess of saturated ammonium chloride solution. Filter and dry the precipitate at 100°. Then proceed according to Method 1. 

The palladium may be recovered by heating the spent catalyst to redness in order to remove organic impurities this treatment may reduce some of the barium sulphate to barium sulphide, which acts as a catalytic poison. The palladium is then dissolved out with aqua regia and the solution evaporated the residue is dissolved in hot water and hydrochloric acid to form palladium chloride. 

Tetrafluoroethylene. Emulsion polymerisation of tetrafluoroethylene, catalysed by oxygen, yields polytetrafluoroethylene (Tejlon) as a very tough horn-hke material of high melting point. It possesses excellent electrical insulation properties and a remarkable inertness towards all chemical reagents, including aqua regia. 

Technetium is a silvery-gray metal that tarnishes slowly in moist air. The common oxidation states of technetium are +7, +5, and +4. Under oxidizing conditions technetium (Vll) will exist as the pertechnetate ion, TcOr-. The chemistry of technetium is said to be similar to that of rhenium. Technetium dissolves in nitric acid, aqua regia, and cone, sulfuric acid, but is not soluble in hydrochloric acid of any strength. The element is a remarkable corrosion inhibitor for steel. The metal is an excellent superconductor at IIK and below. 

L. Ruthenia, Russia) Berzelius and Osann in 1827 examined the residues left after dissolving crude platinum from the Ural mountains in aqua regia. While Berzelius found no unusual metals, Osann thought he found three new metals, one of which he named ruthenium. In 1844 Klaus, generally recognized as the discoverer, showed that Osann s ruthenium oxide was very impure and that it contained a new metal. Klaus obtained 6 g of ruthenium from the portion of crude platinum that is insoluble in aqua regia. 

It is insoluble in hydrochloric and nitric acid, but dissolves when they are mixed as aqua regia, forming chloroplatinic acid. 

L. iris, rainbow) Tennant discovered iridium in 1803 in the residue left when crude platinum is dissolved by aqua regia. The name iridium is appropriate because its salts are highly colored. 

Iridium is not attacked by any of the acids nor by aqua regia, but is attacked by molten salts, such as NaCl and NaCN. The specific gravity of iridium is only very slightly lower than osmium, which is generally credited as the heaviest known element. Calculations of the densities of iridium and osmium from the space lattices give values of 22.65 and 22.61 g/cm 3, respectively. These values may be more reliable than actual physical measurements. At present, therefore, we know that either iridium or osmium is the densest known element, but the data do not yet allow selection between the two. 

Neutral and Cationic Ligands. Neutral and cationic ligands are used without change in name and are set off with enclosing marks. Water and ammonia, as neutral ligands, are called aqua and ammine, respectively. The groups NO and CO, when linked directly to a metal atom, are called nitrosyl and carbonyl, respectively. 

Dissolve 1.000 g Pt in 40 ml of hot aqua regia, evaporate to incipient dryness, add 10 ml HCI and again evaporate to moist residue. Add 10 ml HCI and dilute to volume. 

Aqua regia mix 3 parts of concentrated HCl and 1 part of concentrated HNO3 just before ready to use. 

Sonnenschein s reagent (alkaloid detection) a nitric acid solution of ammonium molybdate is treated with phosphoric acid. The precipitate so produced is washed and boiled with aqua regia... 

Anabaena azollae Anabaena cylindrica Anabaena flos-aquae 0-anabasine [494-52-0] Anabasine [494-52-0] Anabolic steroids Anaerobic digestion Anaerobic treatment Anafranil... 

American Cyanamid Company Aqua Ben Corporation Bet2 Laboratories, Inc. 

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