OSCILLO-POLAROGRAPHIC DETERMINATION OF VITAMIN B₁ IN HYGIENIC FOODSTUFFS

In a citrate buffer of pH 5 and a base solution of 0.15 mol·L-1 KCl,a sensitive polarographic wave of vitamin B1 was observed at -1.40 V.Based on this phenomenon,a rapid and sensitive oscillopolarographic method for the determination of vitamin B1 in hygienic foodstuffs was proposed.In the pH range of 4.7-5.2,a symmetric 2nd derivative peak was obtained.Linear relationship between the peak current (ip) and the concentration of vitamin B1 in the range of 0.1-8.0 mg·L-1 was obtained with a detection limit of 0.078 mg·L-1.The within-day and between-day RSD′s were determined in 6 days successively,and 6 times every day,and the values obtained were less than 4.78% and 5.76% respectively.Recoveries in the range from 92.0% to 107.2% were found.By analyzing 5 foodstuff samples both by the present method and the national standard method,no significant differences were found in the analytical results tested by the t-test (t=1.76,P>0.05).