Potassium Ethyl Xanthate Research Articles

Qualitative separations on a microscale. Analysis of the gold group of A. A. Noyes and W. C. Bray

A procedure for the microqualitative analysis of the gold group ofA. A. Noyes andW. C. Bray is presented. The scheme provides for the isolation, estimation and confirmation of 10 micrograms of any member of the group in the presence of 100 micrograms of any other member. In the conversion of the procedure to the micro scale, the ethyl acetate extraction of gold is retained, if mercury is absent; in the presence of mercury, however, the gold is first precipitated with sodium nitrite, and this is followed by the separation of mercury withReinecke's Salt. The method ofGilchrist andWichers is adopted for the separation of the platinum from palladium, rhodium, and iridium by hydrolytic precipitation of the oxides or hydrated oxides of the last three. Rhodium is separated from iridium by precipitation with either potassium nitrite or potassium ethyl xanthate. New tests for palladium, rhodium, and iridium are used. The treatment of alloys containing the gold group metals either alone or associated with osmium and ruthenium is discussed.

Alkylene Trithiocarbonates and Attempted Syntheses of 2,3-Dimercaptopropanol (B.A.L.)

Alkylene trithiocarbonates are usually conveniently made from the corresponding alkylene oxide or sulphide by the action of potassium xanthate or sodium trithiocarbonate. Propylene and isobutylene trithiocarbonates have been prepared, and it is found that the alkaline hydrolysis of alkylene trithiocarbonates to give the corresponding 1,2-dithiol is a general one. This hydrolysis should produce 2,3-dimercaptopropanol when applied to the trithiocarbonates derived from epichlorhydrin, glycidol and its acetate. However, these reactive substances do not produce pure trithiocarbonates. Hydroxypropylene sulphide has been obtained by treating chlorpropylene sulphide with sodium carbonate.

Nature of the Cyst Wall of the Potato-Root Eelworm Heterodera rostochiensis, Wollenweber, and its Permeability to water

EELWORM cysts are white and soft when first formed on the roots of potato plants: afterwards they turn yellow and eventually become brown and hard. I have been able to demonstrate that this process is due to the activity of polyphenol oxidase* ; white cysts will oxidize catechol and tyrosine, and the action of the enzyme can be inhibited by carbon monoxide, hydrogen sulphide, potassium cyanide, potassium ethyl xanthate, and sodium diethyl carbamate, substances known to inhibit1,2 polyphenol oxidase1 ; the last two reagents react specifically with the copper in the enzyme, and it was possible partially to reverse their inhibiting action, as recently described for the enzyme from Mushrooms2, by the addition of cupric chloride. Moreover, the cysts (can be induced, by the addition of benzoquinone, to turn brown in the presence of an inhibiting substance such as carbon monoxide ; and the presence of polyphenols can be detected in the cyst wall with Tollen's solution (ammoniacal silver hydroxide). The process of hardening of the cyst wall, then, is fundamentally the same as that by which insect cuticle is hardened3. It has recently been demonstrated4,5 that insect cuticle owes its impermeability to water to an outer layer of a waxy substance and not to the nature of the bulk of the cuticle itself. I have been unable to detect such a layer on the eelworm cyst, and, as would be expected, therefore, the cyst wall is permeable to water.

179. The chemistry of xanthic acid derivatives. Part IV. The interaction of sulphonyl chlorides and potassium ethyl xanthate

179. The chemistry of xanthic acid derivatives. Part IV. The interaction of sulphonyl chlorides and potassium ethyl xanthate

178. The chemistry of xanthic acid derivatives. Part III. The interaction of carboxylic acid chlorides and potassium ethyl xanthate

178. The chemistry of xanthic acid derivatives. Part III. The interaction of carboxylic acid chlorides and potassium ethyl xanthate

Experiments on the Control of “Potato-Sickness” by the addition of Certain Chemicals to Soil infected with Heterodera schachtii.

1. Laboratory experiments have shown that solutions of ferric chloride, ferrous sulphate and chinosol, in sufficient concentration, have a lethal action on the larvae of H. schachtii. The vapours given off by potassium ethyl xanthate were also found to be lethal.2. Each of these four chemicals was mixed with moist infected soil and the mixture left for a period. When the cysts were separated and placed in a solution of potato-root excretion, the numbers of larvae which hatched were reduced as a result of the chemical treatments, in the order: potassium ethyl xanthate, ferric chloride, chinosol, ferrous sulphate.3. When ferric oxide was placed in a solution of root excretion containing cysts, the commencement of hatching was delayed.4. Experiments on a very small field scale were carried out, the chemicals being applied chiefly to the rows in which potatoes were planted. The plants growing on the treated areas did not, in general, show marked symptoms of root-eelworm infection as did those on the control areas.5. The yields of potatoes from each row are tabulated. The highest yields were obtained following the treatment with ferric oxide.

The Influence of Catalysts in the Reaction of Sulfur on Unsaturated Organic Substances. I. A Study of Vulcanization at Elevated Temperature

Abstract From these results it might be thought that in the presence of potassium xanthate or hexamethylenetetramine there is formed a compound of sulfur and cinnamate containing one atom of sulfur per molecule of the ester. This compound would not be identical to that found by Baumann and Fromm, which was mentioned in Section 1. It has been seen that it is formed at a higher temperature and that it contains two atoms of sulfur per molecule of the ester. We attempted to isolate the compound containing one atom of sulfur, the existence of which we suspected. To this end, we distilled under reduced pressure (13 mm.) the product extracted with acetone. However, at 143° C. the ethyl cinnamate distilled almost quantitatively, whereas the sulfur remained in the residue from the distillation. Moreover, we observed a very intense Tyndall effect in the acetone solution. Several reasons for these phenomena suggest themselves: 1. The compound formed is stable only in equilibrium with its components. By distillation the cinnamate is eliminated, equilibrium is destroyed, and the compound is quantitatively decomposed during distillation. 2. Upon the addition of acetone, with a view to extracting the substance, the compound is destroyed and the sulfur which is precipitated in the colloidal state is dissolved with ethyl cinnamate in the acetone. In the acetone solution, therefore, the cinnamate and colloidal sulfur are found in stoichiometric proportion. This would explain both the equivalence which was found and the colloidal aspect of the acetone solution. 3. A definite chemical compound is not formed, purely colloidal natural phenomena are involved, and the stoichiometric relations must he due purely to chance. We shall not pay any particular attention at this time to experiments which would lead to a choice among these explanations. They will be the object of a future work. Nevertheless it seems of interest to us to note the parallelism between the vulcanization of rubber and the sulfuration of a well-defined unsaturated compound, and particularly the action of catalysts of vulcanization. Finally another important similarity may be pointed out. In the case of vulcanized rubber, a definite compound has not been isolated. It is likewise known that sulfur, which alone is insoluble in acetone, passes over in large quantity when extractions are made with this solvent. The question has always arisen whether this is a case of phenomena of a colloidal nature or of the formation of chemical compounds. We shall continue our work with a study directed particularly to simple cases where the starting compounds are well-known ones. Our efforts will be especially directed to the existence or non-existence of definite compounds. We have pointed out in this first article the difficulties before us. We shall then continue with studies of isoprene and methylbutadiene. It is conceivable that by the progressive polymerization of these products the complex case of rubber will finally be reached.

Dependence of Angle of Contact on the Constitution of Adsorbed Organic Compounds

IN the course of an investigation conducted on behalf of the Broken Hill South, North Broken Hill, Zinc Corporation, Electrolytic Zinc, Mount Lyell, and Burma Corporation Mining Companies, measurements were made by two of us of the effect of xanthates on the angle of contact at a line of triple contact, mineralwater-air. These have been reported in Technical Publication No. 461 of the American Institute of Mining and Metallurgical Engineers. A trace of potassium ethyl xanthate, dissolved in the water, leads to an angle of contact which is independent both of the concentration of the xanthate and the nature of the mineral. Another compound containing the ethyl group, sodium di-ethyl dithiophosphate, leads to an identical angle of contact. At the time of publication of the above paper it was uncertain whether this was merely a coincidence.

The Copper Content of Sea-water

1. On comparing the potassium ethyl xanthate and the sodium diethyldithio-carbamate methods for estimating copper the latter was found to be preferable because (a) It is at least twice as delicate, (b) The reagent is absolutely colourless, (c) In very dilute solution ferric iron causes little or no disturbance.2. Estimation of copper may be carried out by electro-deposition from one litre of sea-water at about 90-100° C. for three hours at 2.0 volts with subsequent re-solution and colorimetric estimation using the carbamate method.3. In agreement with the spectroscopic determinations of Dieulafait in 1879, it was found that sea-water contains about 10 mg. per cubic metre of copper.

THE SURFACE RELATIONS OF POTASSIUM ETHYL XANTHATE AND PINE OIL. I

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTTHE SURFACE RELATIONS OF POTASSIUM ETHYL XANTHATE AND PINE OIL. IC. C. DeWitt and Edwin E. RoperCite this: J. Am. Chem. Soc. 1932, 54, 2, 444–455Publication Date (Print):February 1, 1932Publication History Published online1 May 2002Published inissue 1 February 1932https://doi.org/10.1021/ja01341a006RIGHTS & PERMISSIONSArticle Views143Altmetric-Citations16LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InReddit PDF (663 KB) Get e-Alerts Get e-Alerts

Potassium Xanthate as a Soil Fumigant—II1

Potassium Xanthate as a Soil Fumigant—II¹

Potassium xanthate as a reagent

Potassium xanthate as a reagent

Potassium xanthate as a soil fumigant

Potassium xanthate as a soil fumigant

The Copper Content of Cows’ Milk

Summary Copper was found to be a normal constituent of freshly drawn cows' milk. The amounts found in the milk of individual animals varied from 0.2 to 0.8 mgm. per liter. The average amount found in 23 such samples was 0.52 mgm. per liter. On the basis of results from several samples representing mixed milk taken during periods of pasture feeding and stall feeding, there appears to be no difference in the copper content of milk as affected by the two different types of ration. The maximum amount found in these samples was 0.6 mgm. per liter and the minimum was 0.4 mgm. per liter. The potassium ethyl xanthate method proved to be the most satisfactory method for the quantitative measurement of the small amounts of copper found in normal milk. Tests to determine the reliability and delicacy of this method show that as low as 0.005 mgm. could be measured with a fair degree of accuracy. Other methods however, were used to advantage for the qualitative detection of copper in large quantities of milk. The amount of copper in milk may be measureably increased by storing or heating in the presence of metallic copper. Slight increases in the copper content of milk may also result from the passage of milk through the sanitary type copper pipes from which the tin has been worn off. Copper taken up from this source however, is not as great as would result from the formation of copper compounds around brass or bronze fittings as a consequence of poor sanitary practices. The significance of minute amounts of copper in plant and animal tissues is as yet unknown. Its presence in milk, particularly when taken up as extraneous contamination may prove to be significant in connection with the high susceptibility of the antiscorbutic vitamine to oxidation. In fact, Hess (14) has already reported the destruction of this vitamine by accelerated oxidation as a result of pasteurizing milk in a copper vessel.