Milk occupies an important position in the human diet structure, while some studies indicated residues of various veterinary drugs in commercial milk. Meanwhile, detection of veterinary drug residues is difficult due to the complexity of milk matrix. As development of separation techniques based on magnetic materials has become a hot topic for international researchers, magnetic solid-phase extraction (MSPE) as a new mode of solid-phase extraction (SPE) has powerful advantages in the field of separation science due to its superparamagnetic character and adsorption selectivity. This paper describes the new SPE technique and reviews its current applications in the detection of veterinary drug residues in milk.

In recently years, estrogen, as a steroid hormone, has been intensively investigated due to its potential hazards to humans and animal endocrine systems. Milk occupies a considerable position in people’s daily diet. However, growing amounts of estrogen residue in commercial milk products have been reported recently. This paper presents the source and harm of estrogens in milk and reviews methods and recent advances for detecting estrogen residue.