Assay of Tartrazine Dye Concentration in Foodstuff Products by New Potentiometric Carbon Paste Electrode

Tartrazine (E102) dye (Na₃TZ) in real samples was determined by a new modified carbon paste electrode based on Tartrazine-Cetryltrimethyl ammoniumbromide (TZ-CTAB) as a chemical modifier. The construction, performance, and applications of E102 dye carbon paste electrode are described. The best performance was exhibited by the electrode having the paste containing 3.0 wt% ion-exchangers (TZ-CTAB), 46.2 wt% graphite and 50.8 wt% dioctyl phthalate (DOP). The modified electrode showed a near-Nernstian slope of 18.1±0.5 mV over the concentration range of 8.3 × 10⁻⁷ – 1.0 × 10⁻² M with the limit of detection 4.7 × 10⁻⁷ over the pH range 3.2–7.6. The proposed sensor revealed good selectivities over a wide variety of anions and sugars. The developed electrode was applied to the potentiometric determination of tartrazine ion in its aqueous solution and in different kinds of foodstuffs: Solid jelly (strawberry and custard) powder samples and soft drink (orange) samples with satisfactory results. The proposed potentiometric method offers the advantages of simplicity, accuracy, automation feasibility and applicability to turbid and colored sample solutions.