The determination and application of (87) Sr/(86) Sr ratio in verifying geographical origin of wheat.

As Sr/ Sr ratio plays a significant role in authenticating the geographical origin of foodstuff, it is important to identify where the Sr/ Sr signature in food comes from, and the methods of Sr/ Sr ratio analysis in food and environmental samples. Wheat with three genotypes, soil and groundwater samples were collected from three regions of China during harvest time of 2014. The Sr/ Sr ratios in the samples were determined by thermal ionization mass spectrometer in order to investigate the possible source of Sr/ Sr in wheat, and the concentrations of Rb and Sr in wheat and soils were also detected by inductively coupled plasma mass spectrometry and combined with Sr/ Sr ratio in order to trace the geographical origin of wheat. The Sr/ Sr ratio, the contents Rb and Sr, and Rb/Sr ratio of wheat and soil samples showed significant differences among three regions. The Sr/ Sr ratios and the concentrations of Rb and Sr in soils were higher than those in corresponding wheat. The Sr/ Sr ratio in wheat was identical to that corresponding soil NH NO extracts (labile fraction of soil) and groundwater. Wheat uptake more Rb than Sr. 3D distribution of Sr/ Sr, Rb and Sr could identify wheat samples from different regions clearly. The Sr/ Sr ratio of wheat reflects the Sr/ Sr ratio of the associated environment including soil and groundwater. It is expected that the use the parameters of Sr/ Sr ratio, the contents of Rb and Sr will allow to trace geographical origin of wheat. Copyright © 2017 John Wiley & Sons, Ltd.