acid 5 ppm iron 140 ppm sodium less than 100 ppm chloride and less than 100 ppm sulfate its melting point was 102 u00b0 to 104 u00b0 c its rotary value 28 8 u00b0 the procedure was as in example 1 but the eluate was evaporated to the extent that the content of l malic acid increased to 56 and it was then filtered at 4 u00b0 c the filtrate contained 48 7 grams of l malic acid corresponding to 96 yield as well as 0 06 fumaric acid 2 ppm iron 22 ppm sodium less than 100 ppm chloride and less than 100 ppm sulfate by evaporating the solution to dryness there were obtained 48 6 grams of l malic acid corresponding to a yield of 96 the malic acid contained 0 11 fumaric acid 4 ppm iron 40 ppm sodium less than 100 ppm chloride and less than 100 ppm sulfate its melting point was 103 u00b0 c its rotary value 28 8 u00b0 the procedure was as in example 1 but after the treatment with the cation exchanger duolite c 26 h form sulfonated styrene divinylbenzene resin the mixture was evaporated to the extent that the content of l malic acid increased to.