Sulfur radioactive

Structure. The thiosulfate sulfur atoms have been shown to be nonequivalent by radioactive sulfur exchange studies (1). When a sulfite is treated with radioactive sulfur and the resulting thiosulfate decomposed to sulfur and sulfite by acids, the radioactivity appears in the sulfur ... 

The constants for the various treatments with radioactive elemental sulfur and with the radioactive sulfur acids are shown in Table I. 

The radioactivity of the hydrogen sulfide produced by 28 lemons treated with radioactive elemental sulfur dust, 28 lemons treated with radioactive sulfur dioxide gas, and 28 lemons treated with a radioactive sulfuric acid solution is expressed as per cent specific activity (Table II), which for the purpose of this report is defined as ... 

The alkali-soluble protein of the peel of lemons treated with hydrogen sulfide, sulfur dioxide, and sulfuric acid contained radioactive sulfur, but the fruit treated with hydrogen sulfide had a significantly lower per cent specific activity in the alkali-soluble protein fraction than did the sulfur dioxide or sulfuric acid treated fruits (Table VII). These results suggest that sulfur dioxide and sulfuric acid react with protein more directly, while hydrogen sulfide perhaps must be oxidized first, as indicated in Table III. It also appears (from Table VII) that the alkali-soluble protein may have been dismuted as the amounts isolated were less in both the hydrogen sulfide and sulfur dioxide treated fruit than in the incubated or nonincubated controls. Other evidence of dismutation has been obtained in experiments where incubation at 60° C. was accompanied by the production of free ammonia (18), and the recovery of free ammonia and six amino acids in the exudates of incubated and sulfur-dusted fruits (18). 

The authors wish to express their appreciation for the grants-in-aid made by the Texas Gulf Sulphur Company in the early stages of this work, without which it could not have been undertaken. The authors are also indebted to J. T. Middleton for the samples of muskmelon leaves. The radioactive sulfur 35 as H2S 04 was obtained from the Atomic Energy Commission, Oak Ridge, Tenn., and subsequently processed by Tracerlab, Boston, Mass. 

Radioactive sulfur has been used as a tracer in the study of the action of sulfur as an insecticide for red spider (a citrus-fruit pest). If 10.0 mg of S are absorbed by an orange, how much will remain after 6.00 months in storage ... 

The industrial application of the Co304 catalyst for ammonia oxidation is complicated by its sensitivity to poisoning action of small amounts of sulfur compounds in the ammonia-air mixture. This phenomenon was studied with the use of radioactive sulfur containing S3s that made it possible to measure very low concentrations of sulfur (168). Poisoning results in decrease both of selectivity and limiting load. A noticeable decrease in selectivity starts at sulfur concentrations in the gas mixture from 0.05 mg/m3. This concentration is many times lower than minimum H2S and S02 concentrations in air detected by smell. 

Amount of Sulfide Needed for Optimum Sensitization, sturmer and Blackburn (128) used radioactive sulfur to measure the concentration of sulfide ions formed on a silver bromide grain surface by thiosulfate. The number at optimum sensitization depended on the exposure irradiance to be used. The number was about 10,000 ions/pm for a high-irradiance exposure and about 20,000 for a medium-irradiance exposure. 

In Chapter 19, it was seen that solutions of thionyl chloride (SOCU) in liquid S02 are conductors, leading earlier workers to suggest that ionization into S02+ and Cl " occurred in such solutions. Recently, S-labeled thionyl chloride, SOCl2, was synthesized and dissolved in liquid S02. When the thionyl chloride was recovered, it was round that practically none of the radioactive sulfur had been transferred to S02. Now, an S02+ ion in solution should be solvated, probably as represented in I (for simplicity, only one molecule of solvent is shown). Here, however, the S—O—S linkage may break either at a or at b during the recovery of... 

As a result, if autoionization does occur, the extent must be slight. In fact, there is no experimental basis for assuming that any autoionization occurs. Radioactive sulfur in SOCl2 is not exchanged with the sulfur in liquid S02. If the two solvents undergo ionization to produce S02+, it would be expected that exchange of sulfur would occur. 

Balchum, O.J., J.Dybicki, and G.R.Meneely. 1960b. Pulmonary resistance and compliance with concurrent radioactive sulfur distribution in dogs breathing sulfur dioxide. J. Appl. Physiol. 15 62-66. 

Radioactive Sulfur to Study the Pick-up of Sulfur Dioxide by Paper, Pap. Technol. 1961, 2, 155-161. 

Insertion reactions of heterocycles with isocyanates 87ZC77. Investigation of reactions of heterocycles by the use of radioactive sulfur 88MI18 90MI14. 

As an example, a company that makes rubber tires might want to know what happens to the sulfur added to tires. Sulfur-35 is added to rubber along with non-radioactive sulfur. Researchers follow the radioactive isotope in the tires to see what happens to the sulfur when the tires are used. 

Suggest a way radioactive sulfur-35 could be used to show that the following reversible change takes place in a saturated solution of silver sulfide with excess solid on the bottom. 

If this sequence is started with elemental sulfur enriched with the radioactive sulfur-35 isotope, the isotope acts as a label for S atoms. All the labels are found in the sulfur precipitate in Equation (23.2) none of them appears in the final sulfite ions. Clearly, then, the two atoms of sulfur in 8203 are not structurally equivalent, as would be the case if the structure were... 

The dynamic aspect of interaction film formation is illustrated by Fig. 10-21, which shows the distribution of radioactive sulfur on an automotive cam in relation to the running time. The heaviest radioactivity is on the nose of the cam, which is the region of the highest contact pressure and the most active interaction of additive with the rubbing surface. 

---