- FDA certification lot number
- Every batch of FD&C Blue No. 1 must carry an FDA certification lot number; check that the number on the COA and the drum match.
- Total color (pure dye)
- Total color content, by spectrophotometry or titration, against the minimum in the 21 CFR part 74 specification; it sets how much dye each kilogram delivers.
- Volatile matter, chlorides and sulfates
- Sum of moisture (loss at 135 °C) and salts, which make up most of the non-dye portion of a straight color.
- Subsidiary colors and intermediates
- Subsidiary colors and unreacted intermediates by HPLC, each against its regulatory limit.
- Heavy metals
- Lead, arsenic and mercury by ICP-MS, reported against the limits in the color additive regulation and the supplier specification.
- Water-insoluble matter
- Insoluble residue after dissolving, which shows up as specks or haze in clear beverages.