Sodium borohydride estimation

Economic Aspects. U.S. capacity for production of merchant sodium dithionite (soHds basis) was estimated at 93,000 metric tons in 1994. There are three North American producers of sodium dithionite. Hoechst Celanese is the largest producer (68,000 tons capacity) with two formate production locations and one zinc process location. Olin (25,000 t capacity) produces solution product only at two locations using both the amalgam and electrochemical processes. In 1994, Vulcan started a small solution plant in Wisconsin using the Olin electrochemical process. In addition, it is estimated that 13,000 t/yr is produced at U.S. pulp mills using the Borol process from sulfur dioxide and sodium borohydride. Growth is estimated at 2—3%/yr. The... 

A. Salbutamol Sulphate Boron shows its presence in the above compound as a result of the use of sodium borohydride (NaBH4) in the manufacturing process. The estimation depends upon the conversion of boron to borate and the organic matter is subsequently destroyed by ignition with anhydrous sodium carbonate. The quantity of boron is finally determined by colorimetric assay. 

The reduction was done essentially as described previously (Robins, 1976). After several washings with 0.9% (w/v) sodium chloride, 0.05 M sodium phosphate, pH 7.4, at 4°C, the stirred demineralized root powder was reduced with 0.71 g sodium borohydride, an estimated one-twentieth of the collagen mass. After one hour, the solution was acidified (pH < 4, pH paper) to inactivate remaining borohydride. Thereafter, the pH was readjusted to 7.5. The solution was centrifuged and the pellets were hydrolyzed by heating for 24 hours at 112°C in 6 M HCl under N2 in bottles with Teflon-sided screw caps. The dark hydrolyzate was paper-filtered, evaporated under reduced pressure at 50°C, and mixed with 5 ml 0.1 M acetic acid. The hydrolyzate was assayed for hydroxyproline. 

Attempts were made to reduce any aldehyde and ketone function with sodium borohydride. A 1.5-gram sample was weighed into a 100-ml. reaction flask and suspended in 10 ml. of methanol. A solution of 0.3 gram of sodium borohydride in 25 ml. of 0.1 IV sodium hydroxide was added to the sample over a period of 15 minutes. The mixture was refluxed under nitrogen for 6 hours, filtered, and washed thoroughly with water. The amount of aldehyde and ketone was estimated by the decrease in the 5.8 micron peak in the infrared spectrum of the treated sample as compared with the untreated sample. 

They also behave practically like an aldehyde and can be reduced or oxidized to a glucitol or gluconic acid moiety. Reduction with sodium borohydride is often used for a quantitative estimation of the reducing endgroup content [69]. Oxidation may be achieved by a variety of agents [85], but the yield is generally... 

The use of sodium borohydride with palladium chloride has been described for the reduction of olefins in excellent yields. The method is quite reliable and it has been applied as an analytical technique for the quantitative estimation of the degree of unsaturation of a compound or of a mixture. 

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