Multiclass method for antimicrobial analysis in animal feeds by liquid chromatography–tandem mass spectrometry

Abstract

A rapid multiclass method that covers 50 antimicrobials from 13 different families in animal feeds was developed. Samples were extracted using a mixture of methanol, acetonitrile and a McIlvaine buffer combined with sonication. Feed extracts were simply diluted prior to injection, since the clean-up strategies that were tested, based on either solid-phase extraction or dispersive solid-phase extraction, were ineffective at minimizing matrix-related signal suppression/enhancement. Analysis was carried out by liquid chromatography coupled to tandem mass spectrometry using an electrospray ionization source operating in positive and negative modes. For the quantification, matrix-fortified standard calibration curves were used to compensate for matrix effects and losses in sample preparation. The method was validated in-house in pig, poultry and cattle feed matrices and showed satisfactory performance characteristics. Thus, the proposed approach was suitable for application in a routine high-throughput laboratory for the official control of feeds.

Rapid multiresidue and multi-class screening for antibiotics and benzimidazoles in feed by ultra high performance liquid chromatography coupled to tandem mass spectrometry

“…Although many authors have used ACN or a mixture of ACN, methanol, and water (Cronly et al, 2010;Lopes et al, 2012;Wang et al, 2014) to precipitate proteins and eliminate other interferences, we got best results with methanol. In agreement with other studies (Borr as et al, 2013;Lopes et al, 2012), we found ACN to yield "cleaner" extracts, but methanol to have a much better extraction capacity: some compounds present after methanol extraction were undetectable after ACN extraction. It is worth noting that Borr as, Company o, & Guiteras (2011) obtained "dirtier" extracts when ACN was used.…”

Desorption electrospray ionization-high resolution mass spectrometry for the screening of veterinary drugs in cross-contaminated feedstuffs

“…Feed samples, collected from farms and feed mills, that were received by the Laboratori Agroalimentari of the Generalitat de Catalunya (LAC) for their analysis by UHPLC-MS/MS [10] were used to demonstrate the applicability of the DESI-HRMS in this study.…”

“…The criteria applied to confirm the presence of the suspected compounds were the following: a mass accuracy of less than 5 ppm on the exact mass, a minimum signal-to-noise ratio of 3:1, and an isotope cluster fit higher than 80 % (both mass relative deviation and relative intensity differences, for each isotope peak within the cluster ion, were taken into account). Feed samples were also analyzed by a well-established UHPLC-MS/MS method for the quantification of the identified compounds [10]. Table 1 lists the positive samples and the veterinary drugs identified along with the DESI-HRMS identification criteria and the quantitative results obtained by target UHPLC-MS/ MS method.…”

“…To increase the productivity in agricultural and food laboratories, the rapid screening of (il)legal preparations to identify veterinary drugs in feedstuffs is widely demanded [7][8][9][10][11][12][13]. Today, liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS) is the technique most currently used for the determination of drug contamination in feed samples.…”

“…Today, liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS) is the technique most currently used for the determination of drug contamination in feed samples. However, the complexity of feed samples requires extensive and time-consuming sample treatment protocols to provide clean extracts to be analyzed by the selective target LC-MS/ MS methods [9,10,[12][13][14][15][16]. In the last decade, the introduction of high resolution mass spectrometry (HRMS) has improved selectivity and specificity of LC-MS methods.…”