New Article on Bioanalysis of Dermorphin in Equine Urine with VIP Heated-ESI Technology

An article examining the difficult bioanalysis of thermally labile peptides performed on the recently launched Bruker EVOQ™ liquid chromatography mass spectrometer (LC-MS/MS) is described. The article entitled ‘Bioanalysis of Dermorphin, an Opioid Peptide in Equine Urine: Benefit of the VIP Heated-ESI Technology for the Quantitative Analysis of Thermally Labile Molecules’ from the Bruker CAM division, has been published in the November/December issue of Chromatography Today. Authored by product specialists from Bruker’s liquid chromatography mass spectrometry group the article explores the quantification of Dermorphin in equine urine using solid phase extraction cleanup. The linear dynamic range of the assay was 0.5-1000ng/mL and this was easily obtained on the EVOQ Elite™ LC-TQ.

Dermorphin is a naturally occurring hepta-peptide derived from the skin secretions of South American frogs (Phyllomedusa sauvegei). It is a unique analgesic 30-40 times stronger than morphine, containing D-alanine making it highly resistant to protease degradation, thus making it a very effective analgesic. Dermorphin use as a horse racing performance enhancing drug came to the public fore as an illicit drug, when it was found to be used to push racehorse performance beyond natural limits, often injuring the horse. Dermorphin has since been reclassified as a Class 1 prohibited substance as decreed by the American Association of Racing Commissioners International Model Rules and this practice has largely been adopted worldwide.

The quantification of Dermorphin in equine urine has been a challenge on several fronts because of the complex matrix of equine urine, a lack of stable labelled internal standards and the peptide is thermally labile during LC nebulisation. Crucially, the EVOQ’s novel vacuum insulated probe heated electrospray ionisation (VIP-HESI) technology delivers the greatest heat at the tip of the ESI probe at the point of ionisation, protecting it from over heating and degradation. By efficiently ionising thermally labile molecules, such as peptides and metabolites, at conventional flow rates the VIP-HESI enables the analysis of real-world samples. Even with no isotope labelled industry standard the EVOQ accurately quantified dermorphin in equine urine between the ranges of 0.1-1000ng/mL.