Spray selenium

The fumes from the roaster are passed through a train of water-spray scmbbers and an electrostatic precipitator. In the scmbber, selenium dioxide [7446-08-4] reacts with sulfur dioxide (eq. 37) to produce elemental selenium, which is purified to provide a commercial product. 

Liquid parafTin selenium as 2,1,3-naphthoselenodiazole 25-fold spray solution, 67% m n-hexane (Fig 53 [240])... 

Spray solution Dissolve 3 g selenium dioxide in 100 ml water [1]. 

The literature on the distribution of natural selenium in the soils, the absorption by vegetation, the toxicity of compounds of either natural or applied selenium to man and animals, and the use of selenium as a spray for insect control is voluminous and no attempt is made to cover it here. The literature has been well reviewed fairly recently ( ). Very little has been published on the increase in selenium content of apple peelings, due to the application of selenium-bearing sprays. 

Selocide is reported (4) to be a 30% solution of a mixture of potassium hydroxide, ammonium hydroxide, sulfur, and selenium in the proportions corresponding to the empirical formula (KNH4S)6Se. The commercial material contains 48 grams of selenium per liter, or approximately 6.4 ounces per gallon. The reactions that occur when a concentrated solution of Selocide is diluted with water to prepare a spray mixture, in the presence of carbon dioxide and oxygen of the air, may be represented as follows ... 

The Selocide spray residue remaining on the fruit is red metallic selenium (5). 

The selenium residue on and in the peel of the non-selenium-sprayed fruit is presented in Table II. 

Selenium Residue on and in Peel of Non-Selenium-Sprayed Fruit... 

To establish the level of selenium on and in the peel of selenium-sprayed apples, samples were collected from five commercial Jonathan apple orchards and eight commercial Delicious apple orchards by representatives of the packing warehouses and submitted to the laboratory for analysis. The sampling and analytical procedure used for these samples was identical to that used for the samples reported in Table II. Sufficient fruit was available for duplicate analysis of most of the samples. 

The results obtained from these samples and the dates of the selenium sprays are presented in Table III. 

Sample Weight, No. of Fruit Selenium, Average Selenium, Dates Selenium Sprays... 

Single-tree plots of Jonathan, Delicious, and Winesap apples were sprayed on June 2 and 28 with 1 pint of Selocide and 1 pound of actual DDT per 100 gallons. Samples of one full box were selected from the north, south, east, and west sides and from the top of the tree to determine the effect of prevailing winds, amount of sunshine, etc., on the selenium residue. These samples were subsampled in the laboratory, stored, and analyzed by the same procedure as the samples in Table II. The results are presented in Table IV. 

An accidental spray of selenium dioxide into the eyes of a chemist caused superficial burns of the skin and immediate irritation of the eyes. Within 16 hours, the subject s vision was blurred and tbe lower portions of both corneas appeared dulled. Sixteen days after the accident, the corneas were normal. ... 

The presence of up to 30 pg in the portion analysed does not interfere in this procedure, but 100 mg copper depresses the selenium signal by 9%. Therefore, one should be aware of copper interference in the case of plant material which is contaminated with copper spray residues. 

Selenium and tellurium The elements are present as selenite and tellurite in dilute nitric acid solution. The mixture is spotted upon paper and dried thoroughly in the air. The solvent is dry n-butyl alcohol containing 4 per cent (v/v) of dry methanol. The atmosphere in the separation vessel is saturated with respect to the solvent vapour and the relative humidity is also maintained at 50 per cent by means of a saturated solution of calcium nitrate. The solvent is allowed to diffuse 8-10 cm down the strip (c. 2 hours). After evaporation of the solvent, the strip is sprayed with 0 5m tin(II) chloride in dilute hydrochloric acid. The tellurium is indicated by a black band (RF 0 1) and the selenium as an orange band (RF 0 5). It is possible to detect 1-5 pg of Se in the presence of 1 mg of Te by this method (see also Fig. VI.5g). 

Chorioptic mange Doramectin injection 0.3 mg/kg s.c. Fipronil spray applied to affected areas Selenium sulfide shampoo Ivermectin injectable applied topically to affected areas Repeat after 30 days Repeat three times at 5 day intervals Do not use ivermectin as a pour on as it is irritant to equine skin repeat after 14 days All listed treatments are extra-label use topical treatments applied after clipping leg hair and general skin hygiene... 

Mutanen M, Koivistoinen P, Morris VC, et al. 1987. Relative nutritional availability to rats of selenium in Finnish spring wheat (Triticum aestivum L.) fertilized or sprayed with sodium selenate and in an American winter bread wheat naturally high in Se. Br J Nutr 57 319-329. 

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