Optimal conditions for determination of zinc bacitracin, polymyxin B, oxytetracycline and sulfacetamide in animal feed by micellar electrokinetic capillary chromatography

Abstract

A separation technique for zinc bacitracin, polymyxin B, oxytetracycline and sulfacetamide in animal feedstuffs by micellar electrokinetic capillary chromatography (MEKC) was developed. The running buffer was 20 mmol l(-1) borate, 20 mmol l(-1) phosphate, pH 8.4, containing 20 mmol l(-1) sodium dodecylsulphate and 10% (v/v) methanol. MEKC was performed at 25 degrees C; the applied voltage was 25 kV with a running pressure of 10 mbar. Simultaneous UV detection for all analytes was at 215 nm. The method was validated for specificity, accuracy, linearity, precision and robustness. It was shown to be specific, accurate (recoveries were 99.7 +/- 0.3, 99.9 +/- 0.9, 99.8 +/- 1.0 and 99.5 +/- 0.4, respectively, for oxytetracycline-, sulfacetamide-, polymyxin B- and zinc bacitracin-spiked samples of feed for cow, pigs, chicken and cattle), linear over the tested range (correlation coefficients > or =0.9987) and precise (RSDs below 1.8% for each analyte). The method was applied to determine zinc bacitracin, polymyxin B, oxytetracycline and sulfacetamide as additives in animal feed.

Comparative study of robustness between micellar electrokinetic capillary chromatography and high-performance liquid chromatography using one-variable-at-a-time and a new multi-variable-at-a-time approach

“…Varying the physical nature of the micelle (size, charge, geometry) by using different surfactants can yield dramatic changes in selectivity, similar to those obtained by changing the stationary phase in liquid chromatography. The influence of SDS on the migration time was described in our previously published papers [18][19][20][21][22]. The results demonstrated that the SDS concentration dramatically affected the migration time of all investigated compounds due to the changes in viscosity.…”

“…Numerous types of surfactants can be used in MEKC, but SDS is one of the most commonly used [5,6,10,11,[18][19][20][21][22]. In MEKC, selectivity can easily be manipulated.…”

“…A fractional factorial design was used in order to investigate robustness of MEKC method in previously published papers of our research group [18][19][20][21][22]. The optimum MEKC conditions set for the developed methods have been slightly modified in order to evaluate the robustness.…”

Analytical procedure for the determination of tetracyclines in medicated feedingstuffs by liquid chromatography-mass spectrometry

“…There are several analytical techniques used to quantify TCs in feeds: TLC (15), HPLC (4,11,16,17,20), HPCE (11,22), LC/MS, LC-MS/MS (6,8,10), and microbiological assays (15). Nowadays, liquidchromatography coupled with mass spectrometry and tandem mass spectrometry seem to be the techniques of choice for analysis of these groups of antibiotics.…”

Determination of five sulfonamides in medicated feedingstuffs by liquid chromatography with ultraviolet detection

“…The majority of techniques for sulfonamide detection in feedingstuffs described in recent papers most commonly use chromatographic methods. These methods comprise thin-layer chromatography (TLC) (5), enzyme immunoassay (EIA) (20,27), high performance liquid chromatography (HPLC) with ultraviolet (UV) detection (8,10,13,17,25,26,28), HPLC-UV in premix (28,29), HPLC with diode array detector (DAD) (1,11), HPLC-DAD in premix (2), HPLC with fluorescence detector (FLD) (13,2), HPLC connected to mass spectrometry (MS) (3,14,15,18,19,23), and micellar electrokinetic capillary chromatography (MEKC) with UV detection (12). The study of the literature allowed us to select and successfully optimise the chromatographic method with UV detection as a procedure, which can be easily implemented by any laboratory.…”