One of eight Food Blue No. 1 aluminum lakes (B-1Als) used in the o$cial inspection of coal-tar colors in fiscal year 1999 had a violet sub-spot during paper chromatography and was rejected. To clarify the orgin of the sub-spot, the violet subsidiary color (Sub-V) was isolated from the sample. On the basis of NMR and MS analyses and ion chromatography, the structure of the subsidiary color was elucidated to be 2- [[4-[N-ethyl-N-(3-sulfophenylmethyl)

The HPLC determination of organic impurities in Food Red No. 40 aluminum lakes (R-40Als) as directed by Japan's Specifications and Standards for Food Additives, 7th Ed. (JSFA-VII), has problems, such as reproducibility and low recovery. ICP analyses suggested that the problem was caused by the aluminum in the test solution. In the improved method for preparation of the test solution, aluminum was precipitated as a hydroxide gel by boiling with 1 aqueous ammonia. After centrifugation, the supernatant was used for the HPLC analysis of the organic impurities in the lakes. Recoveries of organic impurities were more than 85 from R-40Al spiked at the 0.1 and 1.0 levels of R-40. The proposed method was also adapted for Food Yellow No. 5 aluminum lakes.