Trisodium phosphate solution

Excellent results are obtained with warm 15 per cent, trisodium phosphate solution to which a little abrasive powder, such as pumice, has been added. This reagent is not suitable for the removal of tars. 

Tin alloys Dip for 10 min in boiling trisodium phosphate solution (15%). Scrub lightly with bristle brush under running water, and dry. 

Scrub all utensils, containers, working surfaces, and equipment with warm 10% trisodium phosphate solution after each sample. Wherever possible, rinse each utensil and piece of equipment with acetone and benzene. Because parathion residues adhere so tenaciously to glass surfaces, subject all glassware to the following sequence of washes warm 10% trisodium phosphate solution, distilled water, acetone, and benzene. Rinse stored glassware with benzene again just prior to use. 

In fruit penetration studies 8 pounds of fruit were first thoroughly scrubbed with warm 10% trisodium phosphate solution and then rinsed thoroughly with distilled water. Citrus fruits, if depth of penetration into the peel was of interest, were peeled in longitudinal sections with a buttonhook peeler and the albedo or white portion was separated from the flavedo or colored portion. The separated peel was placed in pie tins lined with waxed paper and dried in a forced draft oven at 65° C. for 16 hours. The dried peel was then crushed and steeped for 48 hours in a measured volume of benzene sufficient to cover the sample. If, on the other hand, only the total amount of DDT in the peel was of interest, the fruit was halved and juiced on a power juicer. The pulp was removed, the peel sliced, and the sample dried and treated as before. Thin-skinned fruits, such as apples, pears, and avocados, were peeled with a vegetable peeler, cores or seeds were removed, and the pulp was sliced in thin slices. Pulp and peel were then dried and treated in the same way as the citrus peel. The steeping completed, the samples were filtered through Sharkskin filter paper and the volume of benzene recovered was noted. 

Citrus Fruit Types. The method previously described 11) consisted essentially of scrubbing the fruits with a warm 10% trisodium phosphate solution, rinsing with distilled water, halving each fruit, and reaming the juice and pulp from each half with a power juicer. Pieces of pulp adhering to the insides of the individual hemispheres of peel were carefully scraped free and combined with the remainder of the pulp and juice. Independent analyses were then completed on the discrete peel and pulp-juice samples. Whenever desirable the flavedo and albedo components of the peel were separated with peeling tools, and each was pooled and analyzed. 

Approximately 8 pounds of fruit were scrubbed manually in warm 10% trisodium phosphate solution. One hemisphere of peel was then removed from each fruit, using a household-type peeler. From the pooled segments of peel a 1-pound subsample was used for processing. 

Meyerhof and Schulz86 studied this reaction in trisodium phosphate solution, and regarded it as coming to a triose-hexose equilibrium containing 92 % of hexose. Berl and Feazel67 examined the kinetics of hexose formation from trioses in alkaline solution, and noted that 75-90% of hexulose is formed from DL-glycerose alone, but that the yield is lower (about 60%) when dihydroxyacetone is added in equivalent quantity. Paper chromatog-... 

Trisodium phosphate solution. Glassware which does not contain tars may be cleaned with a 15 per cent solution of trisodium phosphate. A warm solution with the aid of an abrasive powder, such as pumice, is safer to handle and cleans as well as or better than chromic acid solutions. 

Aldolizations of trioses, with formation of hexoses, have been observed in several investigations. Meyerhof estimated that the triose-hexose equilibrium mixture from the condensation of OL-glycerose with 1,3-dihydroxy-2-propanone (in trisodium phosphate solution) contained 92% of hexose. Berl and Feazel, in their kinetic examination of this aldolization in sodium hydroxide solution, were unable to detect any triose by paper chromatography at the end of the reactions. Pyruvaldehyde formation complicates any glycerose or 1,3-dihydroxy-2-propanone reaction in alkaline medium, and this fact probably accounts for some of the disappearance of triose from these mixtures. Nevertheless, aldolizations of these short-chain sugars are side reactions to be reckoned with, whenever circumstances permit their occurrence. 

One of the most important parameters controlling iodine volatility is sump water pH not only will the I2 hydrolysis equilibrium and the iodine partition coefficient be affected by this parameter, but the product yields of radiolytic reactions and the extent of formation of organoiodine compounds as well. Because of the lack of practical experience, the sump water pH to be expected under severe accident conditions has to be calculated on the basis of assumed concentrations of potential sump water ingredients. In Table 7.17. (according to Beahm et al., 1992) an overview of substances to be expected in the sump water, which would effect a shift in solution pH either to lower or to higher values, is given. Besides these chemical substances, radiation may also affect sump water pH irradiation of trisodium phosphate solution (5.3 kGy/h) was reported to decrease the pH from an initial value of 9.0 to about 4.0 after 60 hours of irradiation (Beahm et al., 1992). It is obvious that in such a complicated system definition of the sump water pH to be expected in a real severe reactor accident is a difficult task. Nonetheless, a model for calculation has been developed by Weber et al. (1992). 

The effects of pH and the presence of some of the B vitamins on the precipitation of choline as the reineckate were studied by Bandelin and Tuschkoff (11). From 99.7 to 102.2% recovery of choline was observed when precipitation was carried out at pH 11.6 (5% trisodium phosphate). Riboflavin, pyridoxine, nicotinamide, nicotinic acid, and pantothenic acid formed reineckate precipitates soluble in alkaline solutions and did not interfere with the colorimetric choline analysis when precipitation was conducted in 6% trisodium phosphate solutions. Thiamine precipitated above pH 7 but decomposed within 30 minutes. The decomposition products did not precipitate at higher pH values and did not interfere with the recovery of choline. No interference by ascorbic acid in concentrations up to 20 times that of choline was observed (also Engel (27) and Glick (35)). 

M phosphate buffers in various pH were prepared by mixing 0.2 M monosodium phosphate, disodium phosphate and trisodium phosphate solution using a pH meter. The pH values of the phosphate buffer used were 2.1, 4.0,... 

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