Quantitative determination and safety assessment of tartrazine and Sunset Yellow in commercial orange juices from Syrian markets using high-performance liquid chromatography

Synthetic colorants, such as Tartrazine (E102) and Sunset Yellow (E110), find good use in the food industries to beautify food products. However, their safety concerns, particularly related to health effects, are noticed, mostly in children, thereby necessitating monitoring and regulation. This study investigates the presence and concentration level in orange juice products found in Syrian markets and an evaluation of their compliance to international safety standards. The study collected 11 samples of commercially sold orange juice, and these were analyzed using High-Performance Liquid Chromatography (HPLC) with UV-visible detection at 230 nm. Sample preparation involved extraction with 10% ammonia in methanol, followed by ultrasonication for 30 min and filtration through 0.45 μm syringe filters. Chromatographic separation was performed on a C18 column (4.6 × 250 mm, 5 μm) using an isocratic mobile phase consisting of methanol and acetate buffer (pH 4.5, 30:70 v/v) at a flow rate of 0.6 mL/min, with a total run time of 12 min. Different analytical parameters like retention time, detection limits, and quantification limits were validated according to ICH Q2(R1) guidelines. The novelty of this method lies in its simplicity (isocratic elution vs. gradient), reduced solvent consumption (12-minute runtime vs. 15–25 min in previous studies), and suitability for routine quality control in resource-limited settings, representing the first comprehensive analysis of synthetic dyes in the Syrian market. The quantification of Tartrazine and Sunset Yellow was performed against their levels with permissible intake limits related to body weight (4 mg/kg/day for Sunset Yellow and 7 mg/kg/day for Tartrazine). Results showed that Tartrazine and Sunset Yellow were present in all tested juice samples, with concentrations ranging from 13.68 to 175.5 ppm for Tartrazine and 9.72 to 98.88 ppm for Sunset Yellow. The mean concentrations across all samples were 90.67 ± 44.75 ppm for Tartrazine and 55.64 ± 28.58 ppm for Sunset Yellow. Using the Acceptable Daily Intake (ADI) values (4 mg/kg body weight/day for Sunset Yellow and 7 mg/kg body weight/day for Tartrazine), we calculated that a 10 kg child would exceed the ADI for Sunset Yellow after consuming approximately 404.5 mL of sample 5. Furthermore, When compared with the Codex Alimentarius maximum permitted concentration (100 mg/kg for both dyes), Tartrazine exceeded this limit in 5 out of 11 samples (45%), while Sunset Yellow remained within this limit in all samples (0% exceedance). Cumulative exposure from ingestion of both colorants simultaneously posing potential health risk was suggested by the calculations based on consumer body weights (10 kg child and 60 kg adult), with a 10 kg child exceeding the acceptable daily intake for Sunset Yellow after consuming approximately 404.5 mL of sample 5. Such differences were also noted in other samples regarding what was otherwise claimed in product label concerning dye content, particularly the ‘Fruuty big’ brand which did not declare colorant concentrations on its label. In summary, the validated HPLC method was highly efficient in sensitive and accurate quantification of synthetic colorants under orange juice conditions. Most products were within the prescribed limits; however, both dyes, present at differing levels, and inconsistencies in their labeling, warranted the need for stricter regulatory enforcement. Continuous monitoring and transparent labeling will safeguard public health, especially at-risk groups such as children.