7 Petchey M, Crabbe JC. Analysis of carbohydrates in lens, erythrocytes and plasma by high-performance liquid chromatography ofnitrobenzoate derivatives.Ibid., 1984;307:180-4. 8. Kuo JC, Yeung ES.Determination of carbohydrates in urine by high performance liquid chromatography and optical activity detection. Ibid., 1981;223:321-9. 9. BuchbergerW, Winsauer K, BreitwieserC. Separation ofsugars by HPLC with electrochemicaldetection.FreseniusZ Anal Chem 1983;315:518-20.