SIMULTANEOUS DETERMINATION OF SUGARS, URIC AND OROTIC ACIDS IN INFANTFORMULAS BY HPLC-UV RI/

In a simple, rapid isocratic HPLC method sugars (glucose, galactose, s accarose, maltose, lactose), uric and erotic acids were separated on a Spherisorb NH2, 5 mu m Chromatographic column and detected using refr active index and ultraviolet (lambda = 280 nm) detectors in series. Th e identification was made by comparison of the retention times with th ose of the corresponding standards xilose and melizitose were used as internal standards. The determinations were performed in the linear ra nge of 0.5-30.0 g/L for sugars, 1.0-18.0 mg/L and 0.5-20.0 mg/L for ur ic acid and erotic acid, respectively. The detection limits were 0.20 g/L for xilose, glucose, galactose, and lactose and 0.10 g/L, 0.35, g/ L, 0.40 g/L for saccarose, maltose, and melizitose, respectively. For uric and erotic acids the detection limits were 0.5 mg/L and 0.1 mg/L, respectively. The validity of the method was verified. For recovery s tudies of internal standards several determinations were conducted, us ing the standard addition method at three specific concentrations (1.0 , 5.0, and 10.0 g/l). The recoveries ranged from 95 to 101%. The preci sion of the method was also evaluated, the %CV being 1.01, 0.51, 0.45, 0.73, 0.82, 0.82, and 0.74 for xilose, saccarose, maltose, lactose, m elizitose, uric acid, and erotic acid, respectively. The sample pre-tr eatment was simple with a single er;traction. The good precision and a ccuracy obtained proved that this method is suitable for routine analy sis.