Determination of hormonal growth promoters in bovine hair: comparison of liquid chromatography-mass spectrometry and gas chromatography-mass spectrometry methods for estradiol benzoate and nortestosterone decanoate.

The detection of steroid residues in hair is a powerful strategy to demonstrate long-term administration of these growth promoters in meat production animals. Analysis of the ester form of administered steroids is an unambiguous approach to prove the illegal use of natural hormones. For detection, gas chromatography-mass spectrometry (GC-MS/MS) was generally used. However, recent advances in liquid chromatography-tandem mass spectrometry (LC-MS/MS) technology have improved the robustness and potential sensitivity of this method. This paper describes development and validation, according to Commission Decision 2002/657/EC, of LC-MS/MS and GC-MS/MS methods, in two separate laboratories, for determination of steroid esters in bovine hair. Bovine hair samples taken from animals treated with estradiol-3-benzoate and nortestosterone decanoate, as well as from an untreated animal, were used to evaluate the comparability of the results of the two validated methods. The results of the inter-comparison demonstrate that both the LC-MS/MS and the GC-MS/MS methods are fit for purpose and capable of determining steroid esters in hair samples from treated bovine animals.