Preparation of quality control materials for the determination of sulfonamides in animal feed

Abstract

International audienceA feasibility study of the preparation of quality control materials for the analysis of medicated feeds has been carried out. Two analytical methodologies for the analysis of sulfonamides in feeds have been developed, validated and applied to the homogeneity and stability studies. Pig feeds spiked with sulfadiazine and sulfadimidine have been prepared. The drugs were spiked at 500 µg g^-1, representing what can be expected in a commercial medicated feed, and at 2 and 5 µg g^-1 which roughly correspond to drug-free feeds cross-contaminated during the fabrication process. The homogeneity of both the bulk and the bottled materials was verified. A stability study of the materials containing 2 and 5 µg g^-1 of sulfonamides has been carried out over an eighteen-month period at room temperature, at 4˚C and at -20˚C. The determination of sulfadiazine and sulfadimidine in samples coming from these homogeneity and stability studies of the quality control materials was carried out by liquid chromatography with either UV or fluorimetric detection, depending on the concentration of the analytes in the samples

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

“…Highly sensitive HPLC tandem mass spectrometry detection is associated with a high sensitivity but also with expensive equipment. Thus, HPLC-UV analysis is a simple and low-cost technique; however, it involves appropriate sample preparation step (8,10,13,17,30). Furthermore, no papers were found concerning five sulfonamides analysis in feedingstuffs in the range of concentrations used in this study.…”

“…The first step in the development of a feedingstuff extraction method was the selection of extraction solution and purifying procedure. Aqueous solution showed poor recovery and numerous impurities were reported in other papers describing the methods of sulfadiazine and sulfadimidine analysis (13,28). Following buffer extraction, a special sample cleaning process, e.g.…”

“…As a result, recovery lowering (13) and exclusion of contamination are difficult to achieve (11). Final overcoming, based on addition of the solid sulfunamide standards into the feedingstuff (11,13,17), followed by accurate mixing, allowed to obtain homogenous matrix. Both satisfactory precision and recovery were reported when the above preparation of HRMs grinding step was conducted by Smallidge et al (25).…”

“…Despite the fact that SCX cartridges were adequate to sulfaguanidine determination, variability of results and low recovery factors for other sulfonamides excluded them. Considering the high concentration of sulfonamides in samples, SPE phase was eliminated, which allowed to shorten the time of sample preparation and simplified the method (13,17).…”

“…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.…”