Chitosan from shrimp shells: A renewable sorbent applied to the clean-up step of the QuEChERS method in order to determine multi-residues of veterinary drugs in different types of milk.

Clean extracts are essential in LC-MS/MS, since the matrix effect can interfere in the analysis. Alternative materials which can be used as sorbents, such as chitosan in the clean-up step, are cheap and green options. In this study, chitosan from shrimp shell waste was evaluated as a sorbent in the QuEChERS method in order to determine multi-residues of veterinary drugs in different types of milk, i.