Assessing the Profile of Glyphosate Residues in Maize Grains Sold in the Federal Capital Territory Abuja, Nigeria

Abstract

The profile of glyphosate residues in maize grains sold in the Federal Capital Territory Abuja (FCT), Nigeria was assessed. Methods Twenty-six maize grains samples of yellow and white morphotypes were collected from some selected markets within the FCT, Abuja. Analytical methods on the pulverized maize grains included solvent extraction using (acetonitrile/water (55:45), clean-up of pesticide residues and their quantification by HPLC/UV as described by AOAC - QuEChERS method. Results The results showed that the mean concentration of glyphosate in the maize grains ranged from 0 to 24.30 ± 0.002 mgkg_1 with a mean glyphosate concentration of 3.474 mgkg-1 was detected. Four samples representing 17.86% of the samples collected violated WHO/FAO CODEX standard of 5.0 mgkg-1 while values recorded for Acceptable Daily Intake (ADI) for all the samples were within an acceptable limit of 0 - 1 mgkg-1. Heath risk index values were <1 suggesting that the consumer populations were not at risk. Conclusion The high profile of glyphosate residue in maize grains from Gwagwalada Area Council of the FCT is of great concern and needed to be further investigated HIGHLIGHTS Maize grains had a low glyphosate residue contamination rate of 96.15% in the FCT, Nigeria. The concentration rate of glyphosate residue in the maize grains range was 0 - 24.3mg/kg Yellow maize grains from Gwagwalada Area Councils had the highest mean concentration of glyphosate residue. Four samples i.e. 15.38% of the maize grains violated the CODEX Maximum Residual limit. The Health Index (HI) for all the maize grains was ˂ 1 and signified no associated risk