Validation of an analytical method for the determination of glyceroltriheptanoate (GTH) in processed animal by-products: Results of a collaborative study

The performance characteristics of a method for the determination of the marker substance glycerol triheptanoate (GTH) in processed animal by-products (ABPs) based on gas chromatography (GC) coupled to mass spectrometry (MS) were determined via a collaborative study. Within the European Union, GTH needs to be added to the portion of processed ABPs that must not enter the feed and food chain (Categories 1 and 2) at a minimum concentration of 250 mg kg−1 related to the fat fraction of the test samples analysed. The test materials included in the validation study consisted of three meat and bone meal (MBM) and three fat samples that contained GTH at different concentrations ranging from 61 to 455 mg kg−1. The relative standard deviation of repeatability (RSDr) varied from 3.4 to 7.8% and the relative standard deviation of reproducibility (RSDR) varied from 9.0 to 16.5%, corresponding to HORRAT values that were, in all cases, equal or below the critical value of 2.0. The estimated trueness expressed in terms ...