HPLC- Ms/Ms-based Estimation of Oxytetracycline, Ciprofloxacin and Gentamicin Residues and Assessment of the Effect of Boiling and Frying on their Reduction in Table Eggs

A total of 180 eggs (20 batches each represented by 3 eggs) of the farm, balady, and organic egg samples were collected in October 2021 from markets in Ismailia governorate, Egypt, and examined for detection of the oxytetracycline, ciprofloxacin, and gentamicin residues by using HPLC-Ms/Ms. The farm and balady eggs contained 20% with mean values of 69.95±1.78 and 43.6±2.65 ppb, respectively, and all of them were below the permissible limits and accepted. They contained 20% and 60% with mean values of 26± 0.21 and 39.58±5.58 ppb, respectively, and all positive samples were unaccepted. Both egg types were free from gentamicin residues, meanwhile, all organic eggs were clear from the three antibiotic residues under investigation. The study also revealed the distribution of oxytetracycline and ciprofloxacin in albumin and yolk after oral administration and their residues in the 6th-day eggs were (750 and 500 ppb) and (500 and 319 ppb), respectively. The effect of boiling for 15 minutes on oxytetracycline and ciprofloxacin residues in albumin and yolk was also investigated and showed a reduction% of (88 and 90) and (90.5 and 87.5), respectively. Meanwhile, the frying of whole eggs for 5 minutes reduced their concentration by 94.3% and 94.5%, respectively. In conclusion, the antibiotic residues in edible eggs are a serious risk that should be monitored, and it's significant to highlight the importance of efficient boiling and frying of eggs in reducing these residues and relieving their hazards to the consumer's health.