In this paper we review recent applications of high performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS), ultra performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS), ultra high performance liquid chromatography coupled with high-resolution time-of-flight mass spectrometry (HRTOF-MS), and matrix assisted laser desorption ionization-Fourier transform ion cyclotron resonance mass spectrometry (MALDI-FTMS) to determine penicillin residues in milk and dairy products and their major enzymatic metabolites in vivo. This review describes recent progress in the development of sample extraction, purification, chromatographic separation and mass spectrometry detection methods for the determination of penicillin residues in dairy products.

An ultra performance liquid chromatography-tandem mass spectrometry (UPLC-MS-MS) method for simultaneous determination of dicyandiamide in feed, milk and dairy products was developed. The extraction methods for feed, milk and dairy products were studied, and this was followed by selection of an appropriate chromatographic column. Samples were extracted with acetonitrile and the extract was then cleaned up on a C18 solid-phase extraction column, frozen and certrifuged to remove protein impurities, and separated on an Acquity BEH Amide column using a mobile phase composed of acetonitrile containing 0.1% formic acid and 10 mmol/L ammonium formate solution by gradient elution. Detection was performed by positive ion electrospray ionization (ESI) in multiple reaction monitoring (MRM) mode. The proposed method had good linearity in the concentration range of 1–1 000 μg/L with correlation coefficients more than 0.995. The quantification limit for feed was the highest, 40 μg/kg. Recoveries at different spiked concentrations were 80.5%– 108.4%, with RSD less than 7.0%. This method proved to be simple, rapid and suitable for the determination of feed, milk and dairy products.