Identification Of Sudan Dyes (I To Iv) In Palm Oil Using Liquid Chromatography Tandem Mass Spectrometry (LC-MS) from Local Markets in Greater Accra Region After the Ban by the Food and Drugs Authority (FDA)

Abstract

This study investigates the persistent contamination of palm oil with carcinogenic Sudan dyes (I IV) in Ghana's Greater Accra Region, assessing the effectiveness of the Food and Drugs Authority's (FDA) prohibition of these substances. Despite regulatory prohibitions, economic incentives for colour adulteration remain, posing significant public health risks. To address this, an efficient and robust analytical method using Liquid Chromatography Tandem Mass Spectrometry (LC-MS/MS) was developed and validated. The method demonstrated excellent linearity (R² > 0.97) across a range of 0.05 to 5 mg/kg, with high mass accuracy (< 5 ppm) ensuring definitive identification. The method was applied to 104 palm oil samples collected from ten major markets. The findings reveal a critical public health failure: Sudan IV was detected in 61.5% of samples, with concentrations reaching an alarming 15,638.95 mg/kg, far exceeding international safety limits. Statistical analysis of variance (ANOVA) confirmed that adulteration was not random but geographically concentrated, with significant variation across markets (F = 6.40, p < 0.001), identifying specific hotspots. Sudan I and III were present in 5.8% and 12.5% of samples, respectively, while Sudan II was not detected. The study concludes that the FDA's ban has been largely ineffective in the domestic market, revealing a stark enforcement gap between export-oriented controls and local consumer protection. The widespread and geographically clustered adulteration underscores an urgent need for a paradigm shift in food safety strategy. This research provides critical empirical evidence and a validated methodological framework to guide targeted regulatory action, enhanced surveillance, and public health interventions to mitigate this preventable risk to Ghanaian consumers.