[Studies on rejected food blue no. 1 (Brilliant Blue FCF) aluminum lake]

One of the brilliant blue FCF aluminum lakes (B-1Als) in the official inspection of coal-tar dyes in fiscal year 1999 was rejected. The results of tests of the rejected sample were submitted to JSFA-VII except for a violet sub-spot by paper chromatography. Its visual spectrum had same lambda max 630 nm as B-1 standard and a very small shoulder at 580 nm in comparing to B-1 standard. HPLCs detected at 625 nm of subsidiary dyes and 580 nm were performed on the rejected sample of B-1Al. A sub-V in HPLCs of th sample which eluted at 37.6 min had its relative peak area of 7.9% at 580 nm and 0.24% at 625 nm, and its peak ratio (at 580 nm/at 625 nm) was extremely large. Consequently, it was presumed that the sub-V in those HPLCs corresponded to the violet sub-spot in paper chromatography.