C. G. King

Factors influencing the vitamin C content of vegetables.

FRESH raw vegetables have long been known to possess antiscorbutic properties. In 1747 James Lind, a surgeon of the British Navy, indicated that scurvy could be cured by the eating of green vegetables. In 1912 Holst and Frolich demonstrated that experimental scurvy in guinea pigs could be cured by the addition of small amounts of cabbage, turnips, or dandelion to the vitamin C deficient diet. There is little agreement, however, concerning the amount of vitamin C contained in a given vegetable. In a recent survey of the literature relating to the vitamin C content of spinach,1 we have found that the amount of ascorbic acid reported by various workers ranged from 0.07 to 0.62 mg. per gm. of spinach. These calculations are based upon the assumption that 0.5 mg. of ascorbic acid per day is required for protection of a guinea pig from scurvy (Bessey and King 2). Similar variations in the reported ascorbic acid content of most other vegetables may be noted. While variations in technic em-

Ion exchange separation of ascorbic acid and isolation of the 2,4-dinitrophenylosazone.

Abstract A method has been developed for the separation of small amounts of ascorbic acid from the neutral and basic constituents of rat urine by adsorption on Amberlite IR-4B anion-exchange resin and subsequent elution with hydrochloric acid. The procedure separates the ascorbic acid from the nonacidic substances present, with an over-all recovery of 85–90% of the ascorbic acid originally present. A detailed study of optimum conditions for the formation of the ascorbic acid 2,4-dinitrophenylosazone was made, resulting in a method which permits osazone formation to be complete in 3 hr. The ascorbic acid 2,4-dinitrophenylosazone was shown to be chemically and radioactively pure by accepted standards, including data for the near ultraviolet, visible, and infrared absorption spectra.