Sulfur methods

Table 5-1. Comparison of X-ray, Bomb-Sulfur, and Lamp-Sulfur Methods for the Determination of Sulfur in Distillate Fuels...

I object to the use of the term alicyclicity in this connection. The methods used by Peover, Wender, and Fuks are selective for that group of alicyclic substances capable of yielding aromatic structures on dehydrogenation—i.e., for hydroaromatic rings. If the sulfur method really dehydrogenates any alicyclic structures (e.g. cyclooctane or camphene), then it would yield olefins rather than aromatics and could probably also convert saturated chains to olefins. On the other hand, if it attacks only hydroaromatic structures, then alicyclicity is an incorrect and misleading expression, and hydroaromaticity should be used. 

The term pseudo (or synthetic) sulfur dyes refers to dyes that have application properties similar to those of sulfur dyes but are obtained by the insertion of mer-capto groups or their precursors into the dye precursors or pigments rather than by the classical sulfurization method. These dyes thus have some of the characteristics of sulfur dyes. 

Pseudo sulfur dyes are not prepared by the classical sulfurization method. Instead, mercapto groups or their precursors are introduced into dye precursors or pigments by preparative means. 

The carbohydrate content of the purified enzyme was determined using the phenol-sulfuric method of Dubois et al. (17) with mannose as standard. Protein content was measured by the method of Lowry et al. (18) with bovine albumin as standard. 

Calculations using the CNDO method gave a positive value for the sulfur atom (0.136) when the, -orbitals of sulfur (method I) were not included in the calculations <1968T2663>. When the basis set included the sulfur 3, -orbitals (method II) the value calculated was —0.0358, and —0.0514 when the As- and 4/i-orbitals were also included. 

La(OH)3, Nd(OH)3, nanowires Sulfide, LnS2 Boron-sulfur method 400-450 °C, 24 h, more S Not observed Huang et al. (2008b)... 

The thiols themselves are best made by the lithiation sulfur method, followed by acidification.198-199 IR and NMR studies show that furan-2-thiols and furan-3-thiols are tautomeric but that the thiol, not the thione, is always by far the major isomer. This differs from the oxygen analogs. Evidence from the ionization potentials supports the thiol structure. Furylthioethers have IP values about 0.3 eV higher than do the parent thiols, just as in the benzene series.199... 

In an I.G. Farben patent [180] the use of disulfur dichloride is described in place of sulfur (method BJ. Possibly the intermediates here are 1,3,2-benzothiazathiolium chlorides (CV) which react with carbon disulfide to give benzothiazoline-2-thiones (CIII). In some instances, the cycUzations are carried out in the presence of sodium hydrosulfite or sodium sulfide. A peculiarity of this reaction is that, simultaneously with the cyclization, chlorination of the arylene ring occurs. Thi.s is not a general rule though. It happens with aniline, o-toluidine, o-anisidine and oc-naphthylamine but not with /)-phenetidine, )S-naphthylamine or benzidine. It seems quite clear therefore that the para position of the aniline must be free if chlorination is to take place, since it is in this position that the chlorine atom is brought in. With anthranilic acid there is formed 4-carbox -6-phenylaminobenzothiazoline-2-thione which shows that the chlorine atom, which is substituted during the reaction, is replaced by a second molecule of anthranilic acid and that decarboxylation occurs at the same time. 

Chromium reduction to measure reduced inorganic sulfur compounds in sediments was proposed by Zhabina and Volkov (1978). Since then it has found wide use internationally (Sullivan etal. 1999), particularly when pyritic sediments and acid volatile mono-sulfides are expected. The method is not measurably affected by sulfur in organic matter or sulfates (Canfield etal. 1986 Morse Cornwell 1987). Accordingly, this chromium reducible sulfur method (SCr) is especially useful on samples with appreciable organic matter and also for sandy soils where the %S action criterion is very low (e.g. as low as 0.03%S). 

Stumm, W. Morgan, J.J. (1996) Aquatic Chemistry. 3rd Edn. Wiley-Interscience, New York, NY. Sullivan, L.A., Bush, R.T. McConchie, D.M. (2000) A modified chromium-reducible sulfur method for reducing inorganic sulfur optimum reaction time for acid sulfate soil. Aust. J. Soil Res., 38,... 

The sulfur method has much greater flexural strength, racking strength, and tensile or bond strength. Impact and durability tests also indicate superior performance. 

The white disulfide, only slightly soluble in toluene or mesitylene, is a useful reagent for the sulfurization of phosphines. The range of applicability for the sulfur transfer reagent has not yet been tested. In comparison with the known R2BS2BR2 boranes, the (9-BBN)2S2 compound is more readily available and can be synthesized in a pure form, free of monosulfide and thiol. The disulfide can be prepared in two different ways from (9-H-9-BBN)2 or 9-1-9-BBN, respectively, with elemental sulfur (methods A and B). 

Starting from 9-iodo-9-borabicyclo[3.3.1]nonane and elemental sulfur (method B), one obtains the colorless disulfide in boiling toluene under elimination of iodine after 5 h according to the above equation. Because further 9-iodo-9-BBN reacts only extremely slowly with the disulfide with formation of the monosulfide, the pure disulfide can be isolated nearly quantitatively. In contrast to the reduction of the disulfide with the iodide, the monosulfide is oxidized by bromine in hot toluene, forming the disulfide. ... 

D7041 Combustion gas chromatography with flame photometric detection Gasoline and diesels On-line sulfur method widely used in the field... 

Kohl, K., Titness for Use of Sulfur Methods, ASTM RR-D02-1456, ASTM International, West Conshohocken, PA, 1999. 

Table 8.10. Influence of aging conditions and sulfuring method (burning sulfur or adding SO2 solution) on the ethyl-phenol content of a red wine (Chatonnet et ah, 1993a)...

Barrels used Sulfuring method Bung position Free SO2 at racking S Ethyl-phenols (Egd) Phenol character (0-5)... 

Figure 13.9 TEM images and energy dispersive X-ray spectroscopy (EDX) spectrum of mesoporous WS2-SBA-15 replicas prepared via a high-temperature reductive sulfuration method with H2S gas at600°C (a) low-magnification TEM image (b) high-magnification TEM image ...

It was found that by using succinic-sarcosinyl -type linker 9, the solid-phase automated synthesis of dodeca(deoxyadenosine phospho-rothioate) (d[(Aps)n A]) can be performed via the oxathiaphospholane method with an average of 95% effectiveness of a single coupling step. Purity of this material, as indicated by polyacrylamide gel electrophoresis and HPLC, is comparable with that of sample prepared by phosphoramidile-stepwise sulfurization or H-phosphonate-tandem sulfurization methods (35). P-NMR spectrum did not contain any signal within the phosphate region. The synthesis is outlined within Fig. 4, and synthetic protocol is given in Table 1. 

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