The CNA method is becoming the world standard for protein determination. Consequently, the results for any given wheat sample may be higher by 0.2-0.3 percentage units. The difference between CNA and Kjeldahl results increases with increasing protein content. Dough is mixed to peak consistency at the second mixing stage. As vessels are loaded at terminal and transfer elevators, a series of samples is taken at specific intervals by a mechanical grain sampler.
Canadian grain is cleaned to export specification at terminal elevators before it is shipped.
Canadian cargoes must be free of dockage, unless the buyer agrees in writing to accept grain containing dockage. Each sample, referred to as an incremental sample, represents the grain loaded during the interval. Incremental samples are analyzed for commercial cleanliness, visual quality, total foreign material, and non-visual criteria such as test weight, moisture and protein content. An official loading record for the cargo is generated from the data for all incremental samples taken. Representative samples are taken for each grain and grade loaded to a vessel.