Sulphide and sulphite

The ion chromatographic determination of weak acid anions is complicated by ion exclusion in the suppressor column, resulting in faster elution and sharper peaks, directly proportional to the degree of exhaustion of the suppressor column [7]. A lOmg L- nitrite standard showed a 37% increase in peak height over an 8h period when monitored with the conductivity detector while on only a minor 2% increase in peak height was observed over the same time period by using the ultraviolet detector after the separator column. 

The ultraviolet detector can also be used in some cases to resolve overlapping peaks. Determination of the nitrite peak by using the conductivity detector is complicated by both the ion exclusion effect and the incomplete resolution between the large chloride peak and the much smaller nitrite peak. 

The ion exclusion interference can be eliminated for ultraviolet active anions by placing the ultraviolet detector between the separator and suppressor columns (position 1). In addition, the problem of overlapping peaks can sometimes be resolved spectrophotometrically by proper choice of wavelength. 

Sulphide cannot be detected tmder normal ion chromatographic conditions. It is converted into hydrogen sulphide in the suppressor column. 

Source Reproduced by permission from Elsevier Science, UK [8] 

---

Fig. 10.3 Modulated electrotransmission (ET) and electroreflectance (ER) spectra of a CD CdSe film deposited from an NTA/selenosulphate bath at 30°C. The experiments were carried out in an electrolyte containing sulphide and sulphite (the latter to prevent formation of colored poly sulphide) at a pH of 10 (buffered with NaH2P04). 

Gonzalez et al. [8] have applied micelle analysis in the kinetic multicomponent analysis for the simultaneous determination of thiocyanate, sulphite and sulphide in non saline waters. The method involved reaction of the anions with S,S dithiobis(2-nitrobenzoic acid) in aqueous cetyltrimethyl ammonium bromide micelles. Cyanide, sulphide and sulphite were determined at concentrations, respectively, down to 0.5-1.5/10 4M 0.2-1 xl0 4M and 0.2-1.5><10 4M with a relative error of less than 5%. 

Tests with silver nitrate solution Sulphide and sulphite interfere in the tests with silver nitrate solution, hence must be removed first as follows. Acidify... 

Although stomach contents are usually concentrated enough to allow direct analysis, stomach washings may be too dilute to yield meaningful results. Such a sample may be concentrated by distillation or by dialysis procedures, but this often leads to the loss of certain anions, such as hypochlorite, sulphide, and sulphite. 

Mori T, Nonaka T, Tazaki K, Koga M, Hikosaka Y, Noda S (1992) Interactions of nutrients, moisture and pH on microbial corrosion on concrete sewer pipes. Wat Res 26 29-37 Moriarty DJW, Nicholas DJD (1970) Electron transfer during sulphide and sulphite oxidation by Thiobacillus concretivorus. Biochim Biophys Acta 216 130-138 Morikawa M, Imanaka T (1993) Isolation of a new mixotrophic bacterium which can fix C02 and assimilate aliphatic and aromatic hydrocarbons anaerobically. J Ferment Bioeng 76 280-283... 

Treatment of Lyes.—The spent lyes withdrawn from the soap-pans are cooled, and the soap, which has separated during the cooling, is carefully removed and returned to the soap-house for utilisation in the manufacture of brown soap. Spent lyes may vary in their content of glycerol from 3 to 8 per cent., and this depends not only upon the system adopted in the working of the soap-pans, but also upon the materials used. Although, in these days of pure caustic soda, spent lyes are more free from impurities than formerly, the presence of sulphides and sulphites should be carefully avoided, if it is desired to produce good glycerine. 

Sulphides and Sulphites,—The presence of these compounds is denoted by the evolution of sulphuretted hydrogen and sulphurous acid respectively when the sample is acidulated. Sulphides may also be tested for, qualitatively, with load acetate solution, or test-paper of... 

The employed analytical techniques are potentiometry for the determination of chloride and alkali chlorates, UVA IS for nitrite determination, GC-FID for fluoride derivatives, and LC with UV/VIS detector for iodate. Volumetry has also been applied for the determination of sulphides and sulphites. 

Further reaction between hydrogen sulphide and the sulphite ion yields sulphur together with thionic acids) ... 

Few kinetic studies of the decompositions of these salts are available and, of those which have been investigated, the sulphites have received greatest attention. In general, sulphites disproportionate [803] in an inert atmosphere to sulphides and sulphates, the latter decomposing at a higher temperature. 

According to G. Calcagni, 100 c.c. of a cold 66 per cent, of sodium hydroxide dissolves 24 55 grms. of sulphur or 57 parts of sulphur per 23 parts of sodium while 100 c.c. of a similar soln. of potassium hydroxide dissolves 17 70 grms. of sulphur, or 59 35 parts of sulphur per 39 15 parts of potassium. The soln. reacts for sulphides, polysulphides, thiosulphates, and sulphites. The reaction between alkali hydroxides and sulphur is complex probably sulphides are first formed from which thiosulphates are produced, and by the dissolution of more sulphur, polysulphides the thiosulphates Ipse part of their sulphur forming sulphites. In the more cone. soln. of sulphur part of the latter appears to be uncombined because these soln. yield sulphur to hot benzene. All the soln. are decomposed by carbon dioxide yielding sulphur and hydrogen sulphide. 

Physiological Effects of Lead and its Compounds.— With the exception of one or two of the most insoluble compounds of lead, all the others are known to have very active poisonous properties. The sulphide of lead, the sulphate, and sulphite, if possessed of such, are not,... 

In the first instance, while there is an excess of alkali, and little sulphur taken up, there is formed only sulphide of the alkaline metal and sulphite of the alkali but this sulphite, by being boiled with an excess of sulphur, takes up another equivalent of it, being itself converted into hyposulphite. The ulear liquid obtained in this way must be filtered or poured off the sediment, and excess of Bulphur, and either Bulphurio or hydrochloric VOL. ii. 

Sulphur is soluble in solutions of the sulphides of the alkali metals, including ammonium, with the formation of yellow solutions of polysulphides.6 The alkali carbonates and the hydroxides of the alkali and alkaline earth metals, in aqueous solution, also dissolve sulphur, producing sulphides or polysulphidcs together with thiosulphates and sulphites. In all probability the ideal equation for hydroxides is ... 

Sulphur Dioxide as an Oxidising Agent.—Sulphur dioxide does not support the combustion of most substances which burn in oxygen, but many metals, e.g. sodium, potassium, magnesium and finely divided lead, when heated in a stream of the gas undergo conversion into a mixture of sulphide and oxide or sulphite, so much heat being liberated that the mass becomes incandescent in the case of the alkali metals some thiosulphate also may be formed.12... 

A sensitive colour test for sulphite ions consists in adding, drop by drop, a 0-01 per cent, solution of Fast Blue R crystals, shaking after each addition, until the violet coloration disappears and a yellow solution is produced the test is sensitive to one part of sulphurous acid in about 175,000. Thiosulphates and polythionates do not interfere, but sulphides and hydroxides must be absent.1... 

Also, in the preparation of the thiosulphate from sodium sulphide and sulphur dioxide, or from sodium sulphite and hydrogen sulphide, as already described, if sodium hydroxide is first added to the solution in such quantity as to lead to the ultimate formation of the hydrogen sulphide and hydrogen sulphite salts in the proportions mentioned, then the reaction proceeds very smoothly and almost without separation of sulphur. 

On the other hand, much stronger evidence is available in favour of the earlier formula,4 which accords well with the relationship between the acid and the polythionic acids.5 The formation of sodium thiosulphate by Spring s synthesis from sodium sulphide and sodium sulphite (p. 194) is definitely favourable to this constitution, as also especially is the fact that an alkali thiosulphate will react with only an equimoleeular proportion of an organic (alkyl) halide,6 the product... 

Trithionate is also produced when sulphur dioxide is passed into a mixture of solutions of potassium sulphide and potassium hydrogen sulphite 4... 

The Tetrathionates.—These are generally soluble in water and can be caused to crystallise from solution by the addition of alcohol. When heated in solution the alkali salts decompose into trithionate and sulphur further change may also give rise to pentathionate, sulphate and sulphite. Aqueous solutions are less stable in the presence of thiosulphate.5 The salts of the other metals, for example barium or copper, are much less stable, the former readily forming thiosulphate 6 and the latter sulphide.2... 

Qrloff, J- Russ. Phys. Chem. Roc., 1904, 3d, 1311 j also Bosshard and Grob, loc,. cit. For a method of determination of eaoh of the sulphur aoids in a mixture containing sulphide, hydrosulphite, sulphite, thiosulphate and sulphate, see Binz and Sondag, Ber., 1905, 38, 3830. For monographs on the hydrosulphites, see Jellinek, Ahrens Sammlung, 1911 and 1912. 

---