John Heim

Articles

Using Comprehensive GC×GC–TOF-MS for Enhanced Detection and Separation in Antidoping Control Screening

May 01, 2010

The misuse of androgenic anabolic steroids in sports was banned in 1976 by the International Olympic Committee and global sports community. The illegal use of anabolic steroids has reached disturbing levels worldwide. This worldwide problem is fueled partially by an ever-increasing demand for better athletic performance. The World Anti-Doping Agency has formulated strict guidelines for minimum allowable concentrations of exogenous anabolic steroids and their metabolites. The standard test methods for doping control are analyzed in urine samples with trimethyl-silyl derivatization. Urine is a complex and difficult biological matrix. This research shows the advantages of using comprehensive two-dimensional gas chromatography–time-of-flight-mass spectrometry (GCÃ-GC–TOF-MS) and illustrates the capability of GCÃ-GC-TOF-MS to be an effective instrumental option for antidoping control screening.

Analyzing Small Molecule Metabolite Profiles of Diabetic and Nondiabetic Urine Samples Using GCXGC–TOF-MS and Statistical Software as a Data-Mining Strategy

March 01, 2010

Two-dimensional gas chromatography–time-of-flight mass spectrometry (GCÃ-GC–TOF-MS) analysis has emerged as one of the technologies of choice for the analysis of small metabolite profiles. The results of these analyses produce substantial quantities of data that can be extremely time-consuming and labor-intensive for the analyst to interpret. New software provides a tool for the scientist to use as a data-mining strategy to find significant results from large, complex data sets. This proof of concept research was conducted using comprehensive GCÃ-GC–TOF-MS to elucidate the small-molecule metabolite profiles of diabetic and nondiabetic urine in search of key differences between disease-state and nondisease-state individuals.