AbstractRecently an improved gas chromatographic method to determine the total and free adipate content of acetylated cross‐linked starches has been developed. Within the auspices of an ISO/TC 93 work group, these protocols were validated in 1993 by an international collaborative study. Statistical evaluation is essential to confirm validation, but the recommended protocols to apply have evolved with time. When the test was first done, the Dutch Normalisation protocol NEN 6303 (1988) based on ISO 5725 (1986) was current. However, in 1994 a revised ISO 5725 was issued, which should now be the preferred version of statistics. A study of the respective protocols shows that they differ in respect to the criteria applied for outlier detection and removal. When making an evaluation with each of the statistical protocols, somewhat different values for reproducibility and repeatability are obtained.Applying the latest version of ISO 5725, the validation of the international collaborative study gave the following results: (1) for the total adipate determination the repeatability (r) and reproducibility (R) are respectively 60 and 120ppm adipic acid, and (2) for the free adipate determination the repeatability (r) and the reproducibility (R) are respectively 10.1 and 55.4ppm adipic aci