THE APPLICATION OF STATISTICAL METHODS OF QUALITY MANAGEMENT BY GMP+ STANDARDS USING FERROMAGNETIC MICROTRACERS

Abstract

The GMP+FSA Feed Certification scheme is considered and analyzed which was developed in 1992 by the Dutch feed industry in response to various incidents involving contamination in feed materials. Currently it is an international scheme that is managed by GMP+ International in collaboration with stakeholders from numerous European countries. One of the most important and responsible steps in the feed production is mixing - creating a completely homogeneous mixture. In this paper, a statistical quality assessment of mixing of multicomponent feeds using the distribution of added particles – microtracers was performed. The testing procedure of the homogeneity of feeds and premixes using microtracers is presented in the Standard GMP+ BA2 ―Control of residues‖. The ferromagnetic variety of microtracers manufactured by American Company Micro-Tracers, Inc (San Francisco, California) are elementary iron particles or particles of stainless steel which are coated with a FD&C dye of different colors. The most common microtracers are Microtracer F that consists near 25000 of iron particles with a size distribution of 150 – 300 μm. These microtracers are used in the feed industry to ensure the quality of mixing feeds for animals and poultry during the last 20-30 years. The additional areas of use of microtracers include the marking of vitamins, mineral additive or medicament which introduced into premixes, which allows to mark the presence of the premix in the finished feeds. In quantitative analysis, MicrotracersTM can be used not only to document efficacy of mixing, but also to assess the adequacy of batch to batch ―cleanout‖ of mixers and other feed manufacturing equipment. In the present article the analytical results of evaluation of the mixer performance are interpreted in the terms of a Poisson statistics and chi-squared distribution. The value of probability by Poisson (p) was chosen as criteria for evaluation of homogeneity. Treating a series of counts as a Poisson distribution, the mix is judged complete if p>5% and judged incomplete if p<1%. The mix is judged ―probably incomplete‖ (marginal) if the probability value is in the range of 1%<p<5%.

Keywords

• feed certification,
• ferromagnetic microtracers,
• Poisson distribution,
• chi-squared