Mass Spectrometric characterization and identification of endogenous and synthetic insulins

Project Title: Mass spectrometry characterization and identification of endogenous and synthetic insulins

Researcher: W. Schänzer

Institution: German Sport University, Cologne, Germany

Year accepted: 2006

Summary: The mass spectrometric characterization of endogenous as well as synthetic insulins provides the platform to reveal synthetic insulin misuse in sports as the modified analogues can be distinguished from endogenously produced insulin by molecular mass and diagnostic fragmentation pattern. The efficient isolation of various insulins from human plasma is accomplished by immunoaffinity chromatography followed by solid-phase extraction and allows an identification by liquid chromatography interfaced to mass spectrometry. This approach can be transferred to urine specimens, but improvements/modifications are required owing to the reduced concentration of intact insulins in urine samples compared to blood specimens. Hence, pre-concentration steps as well as parameter optimisation to assure utmost sensitivity of analytical instruments is necessary to enable the determination of synthetic insulins in urine samples. This procedure provides a complementary point and larger time frame to detect the abuse of synthetic insulins as growth promoting agents. Moreover, newly released synthetic insulins have to be considered and incorporated into the analytical assays for doping control purposes.