passages.id: split_5_test_1879_passage
passages.type: progene_text
passages.text: Riboflavin ( vitamin B2 ) gave two distinct waves in Britton Robinson buffer at pH 1.8 with E(1/2 ) values = - 0.13 and - 0.34 V versus SCE and at pH 6.5 with E(1/2 ) = - 1.10 V and E(p) = - 1.2 V versus SCE .