Abstract: Synthetic pigments,such as amaranth,sunset yellow,tartrazine and ponceau 4R,have sensitive adsorptive voltammograms in a phosphate buffer(pH=5.7).The voltammetric waves of these pigments,however,are seriously overlapped and it is difficult to determine them without a preseparation,In this paper,the experimental conditions were investigated.The mixture was accumulated for 240 s at a HMDEwith a accumulate potential,-100 mV.After a 10 s quiet time the potential was then scanned from -100 to -100 mVusing linear sweep voltammetry(LSV) with a scan rate,100 mV/s.The voltammetric data of mixed pigments were processed by a chemometric approach,iterative target transformation factor analysis(ITTFA)and acceptable results with a total prediction error,8.35%,were obtained.

Key words: Adsorpative voltammetry, Pigment, Iterative target transformation factor analysis