Voltammetric determination of 5-nitroimidazole derivatives in honey and HPLC-MS/MS confirmation

The method of voltammetric determination of nitroimidazoles in honey is developed. This method is based on the reduction of nitroimidazoles nitro group on the mercury drop indicator electrode. The obtained values of LODs for nitroimidazoles are as follows: 1.5 x 10(-7) M, 8.6 x 10(-8) M and 2.0 x 10(-7) M for metronidazole, dimetridazole, and ipronidazole, and the linear correlation coefficients are 0.99974, 0.99987 and 0.99849, respectively, which tend towards to 1. The minimum amount of metronidazole that can be detected by means of our method, using simple dissolving of honey sample in water is 300 mu g of metronidazole per 1 kg of honey. The developed voltammetric technique's accuracy was confirmed by the added-found method and by HPLC-MS/MS analysis. The calculated amount of metronidazole in the tested model solution is in good agreement with the amount, introduced into honey. The calculated values of t(exp) are 0.52, 0.48 and 0.43 for three different concentrations. Significant advantages of the method are effortless sample preparation, fast procedure of analysis, the possibility of miniaturization, low cost, not necessary use of organic solvents.

Automated summary

The developed voltammetric method for determining nitroimidazoles in honey, based on the reduction of nitro group, offers advantages of easy sample preparation, fast analysis, low cost, and absence of organic solvents. The accuracy of the method was confirmed through validation studies, making it a reliable technique for quantifying nitroimidazoles in honey.