Spectrophotometric Determination of Small Amounts of Choline

Application of Bubble Separation for Quantitative Analysis of Choline in Dioscorea (Yam) Tubers

“…It was found that hydrolysis for 5 h with 25% HNO 3 did not increase the yield of choline when compared to a 20% HNO 3 , and more consistent results were obtained with a longer hydrolysis time. Some researchers have shown that the sensitivity of this method could be increased by measuring the absorbance of choline reineckate in acetone solution at 327 nm ( , ). Argoudelis and Tobias () examined the ultraviolet spectrum of choline reineckate in a number of solvents and concluded that acetonitrile was the best solvent.…”

Determination of Choline Chloride and Choline Citrate by Means of Cadmium Chloride

“…This method is in widespread use for biological samples, but its utility for the purpose of this study is limited by the fact that spectrophotometric methods in general do not have a precision better than 1 or 2 parts per 100 parts of the constituent being determined. A number of in- vestigators confirm this conclusion (2,13,14) and at least one points out the lack of specificity of the method (14)• Another type of method, which was also considered, involves the precipitation of choline as the periodide followed by the determination of nitrogen in the precipitated periodide (4, [10][11][12] or by an iodometric determination with sodium thiosulfate (7). This method is reported to have a maximum error of ±5% (7), and according to Thornton and Broome (13) is rather difficult to use, as it involves working with a very unstable compound and it gives low results when used as described by the author.…”

Food

“…The ultraviolet absorption maximum (325 µ) for choline reineckate in acetone solution is suggested as the basis for estimation of choline (384). An improvement in the specificity of reineckate methods has been described (350) in which the derivative is treated with dilute alkaline permanganate and converted to trimethvlamine.…”