Abstract
Automatic Karl Fischer titrators of the motor-driven buret type and the coulometric generation type were applied to the determination of moisture in grain. Techniques were developed to optimize the performance of the Karl Fischer titration method and to overcome disadvantages attributed to it. The imprecision (1 standard deviation) of a determination is typically 0.06% moisture content at a moisture content of 15%; the systematic uncertainty from known sources is estimated to be ±0.05% moisture content at a moisture content level of 15%. It is suggested that the method be designated as the primary reference method for grain in general and for corn and soybeans in particular.
Abstract
Data from a recent interlaboratory study of the determination of water (moisture) in animal feed, grain, and forage (plant tissue) by Karl Fischer titration were re-analyzed using Youden plots. The purpose was to show the unique ability these plots possess of separating random and systematic errors visually while providing numerical estimates of the precision and the systematic error of the method. Furthermore, the usefulness of the technique is underscored because AOAC INTERNATIONAL allows the use of matched pairs in collaborative studies to obtain estimates of repeatability and reproducibility.
Youden Analysis of Karl Fischer Titration Data from an Interlaboratory Study Determining Water in Animal Feed, Grain, and Forage
