A new method for the determination of nitrite and nitrate in foods will accurately determine concentrations as low as 1 ppm. 1-Naphthylamine is diazotized by nitrite and coupled with excess amine to give 4-(lnaphthylazo)-l-naphthylamine. The compound is extracted into CHCI3, the extract is acidified with methanol-hydrochloric acid, and absorbance is measured at 555 mµ. Nitrate is quantitatively reduced by passage through a cadmium column and determined as nitrite; nitrite passes through the column unaltered. Therefore, in samples containing both forms of nitrogen, nitrate is determined by difference. The method was applied to 194 samples of baby foods. Spinach, beets, wax beans, squash, “garden vegetables,” green beans, carrots, and “mixed vegetables” were found to contain, on the average, more than 20 ppm nitrate nitrogen.

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An unknown yellow pigment formed from bixin during the thermal extraction of annatto food colors has been isolated and characterized. A mechanism has been proposed for its formation from methylbixin and bixin. The presence of m-xylene, another product of bixin and methylbixin degradation, in commercial annatto food colors is demonstrated.

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The stereochemical structure of bixin is demonstrated in this paper by isolating the yellow hexaene pigment as the free acid, preparing its ethyl ester, and degrading it to its aromatic fragments, which were identified by gas chromatography. Results indicate that the described structure is correct.