Considering the new norms in feed quality checking (ANSVSA Order 51/2005 on the
performance of the analytical methods and data interpretation), which are aligned
to the European norms, the market for feeds implemented a checking system similar
to the one for the food industry. These requirements stipulate that the laboratories
for feed control must have validated methods for each sample assay. We therefore
proposed to validate two chromatographic methods (HPLC and GC) for vitamin E
and linolenic acid from the polyunsaturated fatty acids-enriched feeds for layers
supplemented with 250 ppm vitamin E. The determined parameters were in
agreement with SR EN ISO / CEI 17025:2005 as follows: exactness, reproducibility,
sensitivity, accuracy, detection limit, quantification limit. We used for validation
only certified reference materials and blanks, of analytical purity. We determined
the incertitude for each validated method. We worked on two types of compound
feeds for layers enriched in polyunsaturated fatty acids (I); with addition of flax
seeds and with enriched linolenic acid (II). While the calculation of incertitude
(10,62±0,44µg/g and 15,409±0,6µg/g for linolenic acid and 400±24 µg/g for
vitamin E) shows that the methods range within admissible limits. The validated
methods are proper for the determination of vitamin E and linolenic acid from feeds
enriched in plant fat with a significant supplement of α-tocopherol