[Study on the application of methybenzeneazosalicylfluorone to spectrophotometric determination of microelement molybdenum modality distributions in soy hydrolysate hydrolyzed by enzymes].

A new method has been developed for spectrophotometric determination of molybdenum modality distributions in soy hydrolysate hydrolyzed by enzymes, based on the study on the color reaction of methybenzeneazosalicylfluorone (abbreviated as MBASF) with molybdenum (VI). In hydrochloric acid medium, MBASF reacts with molybdenum (VI) sensitively to form a stable red complex, its apparent molar absorptivity is 1.54 L x mol(-1) x cm(-1), and 0-12 microg of molybdenum obeys Beer's law in 25 mL of solution. Besides normal metal ions, protein, peptide and amino acid also have high tolerance limits. Soy hydrolysate hydrolyzed by enzyme (A) was precipitated at its isoelectric point, and the filtrate (B) was obtained. Subsequently, B was transferred to the chromatogram column with D301R resin. The column was purged by using 20 mL of HAc-NaAc (pH 3.6) and NH4Cl-NH3 x H2O buffer solution(pH 9) orderly and the effluent solutions C and D were obtained. A, B, C and D solutions were used for the spectrophotometric determination of total molybdenum, hydrolyzed molybdenum, chelated molybdenum by peptide or amino acid, and dissociative molybdenum, respectively.