RIBOFLAVIN DETERMINATION 6,7 Dimethyl-9-D-1-Ribitylisoalloxazine N N N O O HCH HOCH HOCH HOCH CH2 OH CH3 CH3 1 2 3 5 4 6 7 8 9 1 0RIBOFLAVIN DETERMINATION 6,7 Dimethyl-9-D-1-Ribitylisoalloxazine N N N O O HCH HOCH HOCH HOCH CH2 OH CH3 CH3 1 2 3 5 4 6 7 8 9 1 0