A nanosilver-based spectrophotometry method for sensitive determination of tartrazine in food samples

A new method is reported for sensitive determination of tartrazine in the food samples. The method is based on the catalytic effect of silver nanoparticle (AgNPs) on the oxidation reaction of tartrazine by potassium iodate in the acetate buffer medium. The reaction is followed spectrophotometrically by measuring the change in absorbance (ΔA) at 420 nm using a fixed time method (70 s). The reaction variables were optimised in order to achieve the highest sensitivity. The thirty six criterion detection limit was 0.3 ng/mL, and the relative standard deviation for ten replicate measurements of 30 ng/mL of tartrazine was 0.98% (n = 10). The method was successfully applied to the determination of tartrazine in lemon, and papaya-flavoured gelatin, candy, and in fruit syrup.