CADMIUM, COPPER, IRON, MANGANESE, SELENIUM, AND ZINC IN CANADIAN SPRING WHEAT

Abstract

Surveys of the average quality of different grades of the various classes of Canadian grains and oilseeds harvested each growing season are a major endeavor of the Grain Research Laboratory. With increasing interest in trace element levels in various cereal and oilseed crops, as part of the 1996, 1997 and 1998 Harvest Surveys, Western Canadian hard red spring wheat crops were characterized for cadmium, copper, iron, manganese, selenium and zinc. Samples were selected from producer submitted harvest survey samples received from crop districts in Manitoba, Saskatchewan and Alberta for the 1996, 1997 and 1998 crops. The methodology, including sample preparation, instrumentation and quality assurance, is described for each element. Data generated from the three crop years was evaluated with temporal and spatial variability studies. Year-to-year variations in grain chemistry are small for Cd, Mn, Se and Zn, but Cu and Fe contents show 12% and 9% decreases respectively over the three years. The overall variability for the plant-essential trace elements, Cu, Fe, Mn and Zn, is low in comparison with Cd and Se. It is demonstrated that the spatial variation in crop chemistry across the Canadian Prairie wheat producing region is greater than the year to year variations, and that soil properties are major factors controlling Cd and Se levels in grain.

ACKNOWLEDGMENTS

This presentation is based on a publication in the JAOAC International; E. Gawalko, R. Garrett and T. Nowicki; Trace Elements in Western Canadian Hard Red Spring Wheat (Triticum aestivum L.): Levels and Quality Assurance, Vol. 84, No. 6, 2001. The following laboratories participated in the GRL trace element interlaboratory studies; their collaboration is gratefully acknowledged: Agriculture and Agri-Food Canada: Brandon Research Centre; Agriculture and Agri-Food Canada: Swift Current Research Centre; Alberta Research Council; National Food Administration, Sweden; USDA: Plant, Soil and Nutrition Laboratory; and USDA: Environmental Chemistry Laboratory.