Sulfur dioxide treatment

Arsenates are oxidizing agents and are reduced by concentrated hydrochloric acid or sulfur dioxide. Treatment of a solution of orthoarsenate with silver nitrate in neutral solution results in the formation of a chocolate-brown precipitate of silver orthoarsenate, Ag AsO, which may be used as a test to distinguish arsenates from phosphates. With hydrofluoric acid, orthoarsenate solutions yield hexafluoroarsenates, eg, potassium hexafluoroarsenate [17029-22-0] (KAsFg)2 H2O. Arsenates of calcium or lead are used as insecticides sodium arsenate is used in printing inks and as a mordant. 

In all treated fruit the percentage of sulfur determined as sulfate in peel increased over the controls (Table IV). Of the four different treatments, the sulfate having the highest percentage specific activity was where elemental sulfur was applied. Specific activity was next highest in the hydrogen sulfide and lowest for the sulfur dioxide treatment. 

Use of conventional treating processes was the logical starting point for improving thermal stability since refiners already have these facilities. One of the first treating processes considered was sulfur dioxide treatment, although current capacity would possibly be insufficient in an all-out war. In tests carried out at one petroleum laboratory, a JP-5 fuel stability was increased twofold Untreated fuel had a stability rating of 57 minutes. After sulfur dioxide extraction, the time was increased to 119 minutes. However, for all intent and purpose, this is not considered to offer any benefits since the test defines acceptable stability as 300 minutes... 

The sulfur dioxide treatment prevents the product from becoming tan in color. 

Sulfur dioxide treatment. According to Chatonnet (59), the only way to limit the growth of Brettanomyces in red wines aged in oak barrels is to maintain a sufficient... 

The sulfur dioxide treatment prevents the formation of a very dark-colored product when the reaction mixture is acidified with a strong acid. 

The first step of the chenucal reduction process is usually the adjustment of the pH of the solution. With sulfur dioxide treatment of hexavalent chromium, for instance, the... 

Burow, D. F. Sharma, R. K. "Liquid Sulfur Dioxide Treatment of Coal," Conf. Chem. Phys. of Coal Utilization, Morgantown, W. Virginia, 1980, Paper T-4. 

Dimethoxythiophene (102) treated with PTAD in methanol affords a high yield of 103, a product of the Diels-Alder reaction and subsequent solvolysis with methanol [82JCS(CC)1033. Reaction of thiophene dioxides 104 bearing bulky substituents at positions 3 and 4 with excess of PTAD gives good yields of 105, products of bis addition and extrusion of sulfur dioxide. Treatment of these adducts with potassium hydroxide at room... 

Generally, the surfaee of a material that has not been subjected to a sulfur dioxide treatment is rich in hydroxyl groups, and the thermodesorption spectram presented in Figure 6.19 is typieal of this kind of situation. 

We note a profound change in the water spectrum of the sample that was subjected to a sulfur dioxide treatment (see Figure 6.20). We observe, indeed, that the peak at 550°C has practically disappeared, contraiy to the peak corresponding to 180°C. We also note that there are, at high temperatures, new species maiked by the ratio value m/e = 48. 

Figure 6.20. Themodesorption spectrum of the hydroxyl groups (m/e = 18) and oxygen (m/e = 32) bound to tin dioxide after the sulfur dioxide treatment...

Figure 6.51. Influence of sulfur dioxide treatment 1) pure air, post treatment, 2) benzene (500 ppm) prior to treatment, 3) benzene (500ppm) post treatment...

The characterization of these materials is mostly linked to the effect of the sulfur dioxide treatment. 

We seek here to characterize different films distinguished by their composition, their sintering temperature or the absence of sulfur dioxide treatment. These films are characterized, on a crystallographic level and on a stmctural plan, by the X-ray spectrometry and the scanning electron microscope respectively. 

SULFUR DIOXIDE TREATMENT OP FRUIT AND VEGETABLE PRODUCTS 105... 

SULFUR DIOXIDE TREATMENT OF FRUIT AND VEGETABLE PRODUCTS 107... 

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