Method for sulphur

Other collection and analytical methods for soil-gas measurement involve the use of a portable mass spectrometer and the use of trained dogs (Kahma et al., 1975). Analytical methods for sulphur gases are summarised in Table 8-111. 

The CF-IRMS analytical method for sulphur is based on rapid oxidation of the samples by flash combustion at 1800°C. The released gases pass through a catalytic-oxidation-reduction column reactor from this they are chromatographically separated in a 0.8 m packed FIFE column, and then finally analysed in the mass spectrometer. The analytical cycle time is c. 430 s. The size of the samples analysed is optimized when possible to avoid potential linearity effects. One standard is analysed after every five samples, and a blank is run routinely after 10 analyses as a check. 

Another method for sulphur determination, based on a preliminary hydrogenation of the sample and GC determination of the resultant products, was developed by Okuno et al. [92]. There are two versions of the method the first consists in determining sulphur in relation to carbon, without weighing the sample in advance the second involves the determination of the absolute sulphur content in the sample. 

Extracts from sediment, and sometimes also from soils, generally contain amounts of elemental sulphur, which, in addition to compromising the chromatographic separation, may damage the chromatographic column. The typical methods for sulphur removal are treatment with copper powder and/or mercury, " " which can be admixed directly to the sample during extraction or added to the extraction solution in a separate step. Copper powder is activated beforehand with HCl (18%) and washed with acetone and finally with -hexane. 

Taieb, D., Ben Brahim, A. (2013). Electrochemical method for sulphur dioxide removal from flue gases application on sulphuric acid plant in Tunisia. Comptes Rendus Chimie, 16( ), 39-50. http //dx.doi.0rg/lO.lOl6/j.crci.2Oi2.O8.OO9. 

Direct titration method for sulphur dioxide with Vitex/iodine... 

Follow steps 1-3 of the method for sulphur, using a nickel crucible and a sample containing 0.03-0.04 g phosphorus. 

The sulphur can be determined directly by the method for Sulphur Ointment (see p. 614) or by flask-combustion. 

The Sodium Carbonate-Zinc Method for Detecting Nitrogen, Halogens and Sulphur in Organic Compounds. 

THE SODIUM CARBONATE - ZINC METHOD FOR THE DETECTION OF NITROGEN, SULPHUR AND HALOGENS IN ORGANIC COMPOUNDS... 

For deactivated compounds this limitation does not exist, and nitration in sulphuric acid is an excellent method for comparing the reactivities of such compounds. For these, however, there remains the practical difficulty of following slow reactions and the possibility that with such reactions secondary processes might become important. With deactivated compounds, comparisons of reactivities can be made using nitration in concentrated sulphuric acid such comparisons are not accurate because of the behaviour of rate profiles at high acidities ( 2.3.2 figs. 2.1, 2.3). 

Another method for slowing oxidation of rubber adhesives is to add a compound which destroys the hydroperoxides formed in step 3, before they can decompose into radicals and start the degradation of new polymer chains. These materials are called hydroperoxide decomposers, preventive antioxidants or secondary antioxidants. Phosphites (phosphite esters, organophosphite chelators, dibasic lead phosphite) and sulphides (i.e. thiopropionate esters, metal dithiolates) are typical secondary antioxidants. Phosphite esters decompose hydroperoxides to yield phosphates and alcohols. Sulphur compounds, however, decompose hydroperoxides catalytically. 

The best method for producing it artificially is to condense salicylic acid and methyl alcohol by means of sulphuric acid. It is a colourless oil, optically inactive, and possessing an intense wintergreen odour. It has the following characters —... 

This enzyme is of wide occurrence in bacteria where it is concerned with the reduction of nitrate and CO2 as well as sulphur. Methods for its estimation depend on measuring some activity of hydrogenase by (a) dye reduction (benzyl viologen or methylene blue), (b) isotopic exchange and (c) evolution of molecular hydrogen. Interpretation of quantitative results is difficult due to the complex relationship between the enzyme cell structure and the particular method selected. ... 

British Standard Method for Determination of Resistance to Intergranular Corrosion of A ustenltic Stainless Steels Copper sulphate-Sulphuric acid Method (Moneypenny Strauss Test) BS 5903 (1980)... 

On ferrous metals immersion deposition in the copper sulphate bath produces non-adherent deposits, and a cyanide copper undercoat is therefore normally used. Where the use of a cyanide strike cannot be tolerated, an electroplated or immersion nickel deposit has been used . Additions of surface-active agents, often preceded by a sulphuric acid pickle containing the same compound, form the basis of recent methods for plating from a copper sulphate bath directly on to steel ". 

Test methods for determining electrolytic corrosion with electrical insulating materials Method for determination of resistance to intergranular corrosion of austenitic stainless steels copper sulphate-sulphuric acid method (Moneypenny Strauss test) Specification for electroplated coatings of tin/lead alloys... 

Method A Standardisation with arsenic (III) oxide. Discussion. The most trustworthy method for standardising cerium(IV) sulphate solutions is with pure arsenic(III) oxide. The reaction between cerium(IV) sulphate solution and arsenic(III) oxide is very slow at the ambient temperature it is necessary to add a trace of osmium tetroxide as catalyst. The arsenic(III) oxide is dissolved in sodium hydroxide solution, the solution acidified with dilute sulphuric acid, and after adding 2 drops of an osmic acid solution prepared by dissolving 0.1 g osmium tetroxide in 40mL of 0.05M sulphuric acid, and the indicator (1-2 drops ferroin or 0.5 mL /V-phenylanthranilic acid), it is titrated with the cerium(IV) sulphate solution to the first sharp colour change orange-red to very pale blue or yellowish-green to purple respectively. 

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