Determination of Residual Organic Solvents in Natural Color Preparations by Standard Addition Head-Space Gas Chromatography

A simple head-space GC method was developed for the simultaneous determination of 7 organic solvents in natural color preparations. Acceptable limits of organic solvents in natural colors are set by the FDA.Color preparations were measured in vials, to which water and sodium chloride were added. The vials were tightly capped and kept at 50°C for 1 hour in a water bath, followed by injection of 1ml of the vapor phase in the vial into the GC column. A packed column, a G-column and a capillary column were used for the separations. The standard addition method was used for the determination.Among 35 samples, methanol in 20, acetone in 3 and isopropanol in 1 exceeded the limits set by the FDA.