MONITORING OF METRONIDAZOLE AND ITS METABOLITE RESIDUES IN EGGS OF TWO STRAINS OF HENS USING HPLC-DAD

Abstract

HPLC-DAD method based on solid-phase extraction was developed for residual determination of metronidazole (MET) and its metabolite hydroxymetronidazole (MET-OH) in two strains of hen eggs (Alexandria egg line, AE and Fayoumi egg line, PP). The LC separation was performed on a RP C-18 analytical column (150 mm × 4.6 mm, 5 µm) with an isocratic elution system of 0.0 5 M phosphate buffer of pH 2.5–acetonitrile (95:5) as the mobile phase. The procedure was evaluated and fully validated. The calibration graphs for MET and MET-OH were rectilinear in the range of 0.3–16.0 µg g⁻¹ for MET and 0.2–20.0 µg g⁻¹ for MET-OH. No residues could be detected before the 3rd day or after 11th day after the drug administration. The drug and metabolite concentration levels in eggs for the two strains of hens were different owing to their change in genetic potential. PP has less ability to keep MET and MET-OH residues than AE.

Keywords:

• hen eggs
• HPLC-DAD
• hydroxymetronidazole
• metronidazole
• solid-phase extraction

ACKNOWLEDGMENT

The authors would like to thank Pharonia Pharmaceuticals, New Borg El-Arab City, Alexandria, Egypt, for gift samples of metronidazole. They extend thanks to the Poultry Research Center, Faculty of Agriculture, Alexandria University, for facilitating the field work and animal trials.

Notes

S_a is standard deviation of intercept, S_b is standard deviation of slope, and S_y/x is standard deviation of residuals.

*Theoretical value of t (a/S_a) = 2.31 at the 95% confidence level.

t _R: retention time, in minutes. N: number of theoretical plates. k: capacity factor. α, selectivity between each of two successive peaks. R _s: resolution, between each two successive peaks. A _f: asymmetry- factor.

Mean ± standard deviation of five determinations.

Means having the same letters for each trait are not different significantly at p ≤ 0.05.

*P ≤ 0.05 **P ≤ 0.01.