High performance liquid chromatographic determination of riboflavin in food--a comparison with a microbiological method.

The riboflavin content of commercial products of different origin was determined by reversed phase liquid chromatography. The method was compared with a standard microbiological assay with Lactobacillus casei. A comparison between the two methods gave a correlation coefficient of 0.9996 for vitamin enriched foods, dairy and health-food products. For these products the LC-method is well adapted for use in routine work. The results obtained from unenriched flours and flours with a high rate of extraction showed significantly lower values for the LC-method. The sensitivity for the LC-method is good with a minimum detectable quantity of 50 pg.