Cyanide sulfide

Calcium and magnesium can be titrated readily with disodium ethylenediaminetetraacetate, with Eriochrome Black T as the indicator. The solution is buffered at pH 10.0. Certain metal ions interfere with this procedure by causing fading or indistinct end points. Cyanide, sulfide, or hydroxjiamine can be used to eliminate or minimise the interferences. 

Obtain all available information about the material. If it is a surplus or off-specification product, obtain an analysis or a Material Safety Data Sheet. If it is a waste, check for previous analyses, and if none exists, obtain one. (Even if a previous analysis exists, consider running a few screening-type field analyses for confirmation of important properties such as pH, redox potential, or other oxidizer test such as cyanide, sulfide, and flashpoint.)... 

Smith L, Kruszyna H, Smith RP. 1977. The effect of methemoglobin on the inhibition of cytochrome c oxidase by cyanide, sulfide or azide. Biochem Pharmacol 26 2247-2250. 

Rocklin RD, Johnson DL. 1983. Determination of cyanide, sulfide, iodide, and bromide by ion chromatography with electrochemical detection. Anal Chem 55 4-7. 

Solubility data (pA sp) for two dozen hexacyanoferrate(II) and hexacyanoferrate(III) salts, and Pourbaix (pe/pH) diagrams for iron-cyanide-water, iron-sulfide-cyanide-(hydr)oxide, iron-arsenate-cyanide-(hydr)oxide, and iron-copper-cyanide-sulfide-(hydr)oxide, are given in a review ostensibly dedicated to hydrometallurgical extraction of gold and silver. " The electrochemistry of Prussian Blue and related complexes, in the form of thin films on electrodes, has been reviewed. ... 

Amperometric detection is a very sensitive technique. In principle, voltammetric detectors can be used for all compounds which have functional groups which are easily reduced or oxidized. Apart from a few cations (Fe , Co ), it is chiefly anions such as cyanide, sulfide and nitrite which can be determined in the ion analysis sector. The most important applications lie however in the analysis of sugars by anion chromatography and in clinical analysis using a form of amperometric detection know as Pulsed Amperometric Detection (PAD). 

Environmental applications require detoxification of hazardous substances to a level of parts per million (ppm) and even parts per billion (ppb). These purity levels, which were rarely considered in product synthesis, are now possible for wastewater due to Fenton s reagent. Fenton s oxidant is cost effective and relatively fast in destroying many toxics (Bigda, 1996). It attacks all reactive substrate concentrations under acidic conditions. Hydrogen peroxide is used to remove such contaminants as cyanide, sulfides, sulfites, chrome, and heavy metals by varying batch conditions. With an iron catalyst, the process often oxidizes organics, as well as reducing hexavalent chrome to trivalent precipitable form. 

Several ions interfere in this analysis. These include bromide, iodide, cyanide, sulfide, sulfite, and thiosulfate. The latter three ions may be removed by treatment with H202. The sample should be diluted when iron and orthophosphate are present at concentrations above 10 mg/L. 

There is another oxidase present in S. acidocaldarius (DSM 639) [120], a cytochrome aa3 oxidase (a peak at 605 nm). The cytochrome oxidizes horse-heart cytochrome c and TMPD-ascorbate. The ability to oxidize cytochrome c is lost during purification, whereas the oxidation of TMPD-ascorbate increases. The purified cytochrome (Mr 120000) is composed of a single subunit (Mr 38000) and contains two heme molecules as well as two copper atoms per subunit. TMPD-ascorbate oxidation is inhibited by cyanide, sulfide (1-3 mM) and azide (20 mM). The purified enzyme also oxidizes reduced cytochromec but at too slow a rate to be physiologically significant. The absence of cytochrome c in S. acidocaldarius and the loss of the ability to oxidize cytochrome c upon purification indicates this cytochrome is not a cytochrome c oxidase. The cytochrome oxidizes the indigenous quinone found in the membranes, caldariella... 

Heat to boiling, and filter. (The test tube is to be cleansed immediately and put away.) The filtrate should be clear and colorless. Portions of this stock solution are used to test for cyanide, sulfide, and halide ions. 

Keilin and Mann (1940a) reported that cyanide inhibits the enzyme 85 % in concentrations as low as 4 X 10 M. They found inhibition completely reversible. The inhibition with carbon monoxide, found by Meldrum and Houghton (1933) and Van Goor (1934), was not observed by Kiese and Hastings (1940). Keilin and Manir (1940a) adduce the instantaneous and reversible inhibition brought about by cyanide, sulfide, and azide as important evidence that a metal, in this instance zinc, must be the active group of carbonic anhydrase. 

Ions that can be analyzed by electrochemical detection include cyanide, sulfide, hypochlorite, ascorbate, hydrazine, arsenite, phenols, aromatic amines, bromide, iodide, and thiosulfate [53], nitrite and nitrate [54.55], cobalt and iron [46], and others. The list may be extended through the technique of post-column derivatization to include many more ions such as carboxylic acids, halide ions, alkaline earth ions, and some transition metal ions [57,58). An example of an electrochemical reaction to detect ions is shown by Eq. 4.8. 

Because of the difficulties involved in removing oxygen (and keeping it removed) from the sample and eluent solutions, most applications of electrochemical detectors in ion chromatography have been the detection of relatively easily oxidized species (cyanide sulfide, sulfite, nitrite, or phenols, for example). 

The protein-bound copper can be removed by dialysis against cyanide, sulfide, and other copper complexing agents. Subsequent reintroduction of the copper restores the oxygenating ability of hemocyanin. However, the resynthesis of hemocyanin from apohemocyanin can be achieved only with cuprous, not cupric salts (6, 13). Practically quantitative reconstitution is obtained by the use of the acetonitrile complex of copper (21). The apoprotein appears specific for copper since the binding of other metal ions denatures the protein (6). 

CHEMICAL PROPERTIES strong oxidizer reacts with water to produce heat corrosive in presence of traces of oxides attacks all base metals except aluminum and special chromium steels reacts vigorously with combustibles, organic solvents, metallic powders, carbides, cyanides, sulfides, or readily oxidizable materials reacts with alkalies vigorous reaction caused by addition of water to concentrated nitric acid FP (NA) LFL/UFL (not combustible) AT (NA) HC (NA) HF (-174.1 kJ/mol liquid at 25°C) Hf (2.503 kcal/mol) HID (-7971 cal/mol at 25°C). 

Iodide in solution was determined by means of a piezoelectric crystal with silver electrodes connected to a normal TTL oscillator (104). In a follow-up- study (105), iodide was determined in the range 0.5 - 7 jM by electrodeposition on the silver electrodes of a crystal. Thiosulfate, cyanide, sulfide, Fe(III), Hg(II), and Ag interfered, but procedures to eliminate their interferences were described. 

Liquid wastes generated by refineries have different chemical compositions including oil and grease, phenols, BTEX, ammonia, suspended solids, cyanide, sulfide, nitrogen compoimds and heavy metals such as iron, cadmium, nickel, chromium, copp>er, molybdenum, selenium, vanadium and zinc. Seeking to evaluate and monitor the environmental imp>act caused by the discharge of effluents in water bodies, toxicity tests are often used as indicators of damage to the aquatic environment. Tests on fish, invertebrates and seaweeds have revealed that most of... 

General purpose, but is most suitable for the analysis of nitrite, sulfide, bromide, iodide, cyanide, sulfide, disulfides, etc. 

Cyanide, sulfide, thiosulfate, thiocyanide, bromide, iodide, hydrosulfide Carbohydrates, amino acid, peptides, polypeptides, protein Carbohydrates, alcohols, amino acid Aromatic hydrocarbons... 

Molecular weight Reaction Optimum pH Reaction temperature Cofactor requirements Isoelectric point Inhibitors 140000 Cleavage of phosphate, release of monphosphate 9.8 Zn"+, Mg"+ 5.7 EDTA, other chelators, pH <6 40000 Oxidation by H2O2 of substrate 7,0 25°C None 7,2 Cyanide, sulfide, azide... 

The potentiometric detection of the endpoint of precipitation titrations is very often used because not many visual indicators are available, in particular when mixtures of analytes are titrated. Halides, cyanide, sulfide, chromate, mercaptans, and thiols can be titrated with silver nitrate, using the silver sulfide-based ISE. Also complex mixtures, such as sulfide, thiocyanide, and chloride ions, or chloride, bromide, and iodide ions, can be titrated potentio-metrically with silver(I) ions. When the solubility of a compound formed during titration is too high, nonaqueous or mixed solvents are used, for example,... 

When the fusion mixture is dissolved in distilled water, the cyanide, sulfide, and halide ions can be detected by standard qualitative inorganic tests. 

Hypochlorite, ascorbate, hydrazine, arsenite, thiosulfate, nitrite, nitrate, cobalt and iron are a partial list of the ions that have been detected using amperometric detection [55]. The most common ions determined by amperometric detection in 1C include inorganic anions forming complexes with cyanide, sulfide, and iodide at a silver electrode [56]. The relevant chemical reaction is shovra below. 

The application of direct potentiometry with silver bromide precipitate-based ion-selective electrodes for bromide measurements in water samples as been investigated [65]. Cyanide, sulfide, and iodide ions represent the major interferences. A 20 times higher concentration of chloride also can cause positive error. TTierefore, the applicability of direct potentiometry in the analysis of bromide concentration of water samples is limited. 

These reactions are carried out in aqueous/organic two-phase solvent systems with one of the reagents in an alkali metal salt form. Some examples of the anionic nucleophilic reagents (Y) are hydroxides, halides, cyanides, sulfides, cyanamides, carboxylates, sulfonates, and so forth. In fact, one of the most studied PEG phase transfer catalyzed reaction is the formation of carboxylate esters, such as acetates [159,1601. 

Note The spent slurry had a pH of 8.0 and contained no heavy metals, cyanides, sulfides, or chlorinated organic compound, , Data of Bhaiia and Al(ford (1986) ... 

Varma (2006) has reported the use of urea and hydrogen peroxide as an oxidant for converting alkyl cyanide, sulfides, o-hydroxybenzaldehyde and pyridine into an amide, sulphoxide or sulphone, catechon and pyridine-oxide, respectively. The reactions were carried out on recyclable mineral support like alumina, silica, clay, etc. 

Effluents from the Annacis and Lulu Island STPs frequently contain higher levds of contaminants than permitted by the provincial government. For the Annacis plant permit, noncomphance is most apparent for Biochemical Oxygen Demand (BOD), toxicity, oil and grease, and dissolved oxygen. For example, in 1985 toxidty levels were exceeded 50 percent of the time for Annacis and 66.7 percent of the time for Lulu Island STPs. The toxic compotinds identified in municipal STP effluent include im-ionized ammonia, cyanide, sulfides, chlorine, chloramines, phenols, anionic siufactants, heavy metals, and organic compounds. Table P-5 provides a... 

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