Authenticity control and identification of origin of synthetic creatine-monohydrate by isotope ratio mass spectrometry

Synthetic creatine-monohydrate is consumed as a dietary supplement (DS) worldwide. Up to now no analytical technique for authenticity control or identification of origin of creatine-monohydrate products has been reported. Isotope ratio mass spectrometry (IRMS) of different creatine-monohydrate samples was performed allowing to differentiate between production sites located either in Germany or China. The results obtained indicate that the carbon and nitrogen isotopic composition of industrially synthesised creatine-monohydrate depends on the isotopic composition of the raw materials rather than on different production processes. Statistical pattern recognition of isotope data allowed for classification of most of the creatine-monohydrates sold as DS into German and non-German origin, respectively. Four DS, cross-contaminated with anabolic androgenic steroids (AAS), could not be allocated to a single producer. This suggests that contamination with AAS did not occur during synthesis, but during handling by the distributors.