Stability-Indicating Photochemical Method for the Assay of Riboflavin: Lumichrome Method

Table 2

Concentrations of RF and photoproducts at pH 11.6.

Time (min)	RF (M × 10^−5)	FMF (M × 10^−5)	LC (M × 10^−5)	LF (M × 10^−5)	Total (M × 10^−5)^a
0	5.00	0.00	0.00	0.00	5.00
6	3.32	0.41	0.65	0.56	4.94
12	1.96	0.68	1.37	0.94	4.95
18	1.02	0.62	1.93	1.36	4.93
24	0.48	0.47	2.36	1.61	4.92
30	0.26	0.18	2.67	1.81	4.92
36	0.00	0.00	2.89	2.06	4.95

A little loss in molar balance is due to the formation of minor photoproducts such as CMF and others which have not been accounted for in the assay.