Gluten in Oats Working Group Meeting Book (March 12, 2019)

(4) Appendix F: Guidelines for Standard Method Performance Requirements, Official Methods of  94  Analysis of AOAC INTERNATIONAL (2019) 21st Ed., AOAC INTERNATIONAL, Rockville, MD, USA  95  ( http://www.eoma.aoac.org/app_f.pdf ) 

96  97  98 

Table 1. Method performance requirements 

Parameter 

 Acceptance criteria 

Analytical range, ppm 

 ≤5 to ≥ 15 

LOQ, ppm 

 ≤5 

LOD, ppm 

 ≤5 

Recovery, % a

 50 to 200 b

99  a  For validation purposes, individually measured as gluten from wheat, rye, and barley spiked individually  100  in the prepared oat flour test samples, calculated from the slope of the dose response curve.  101  A sample series shall consist of one sample of unspiked oat flour; two samples spiked with wheat; two  102  samples spiked with rye; and two samples spiked with barley.  103  104  Gluten content for wheat, rye, and barley used for spiking will be estimated as proteins that are  105  insoluble in water and 0.5 M NaCl (see reference in J. AOAC Int. (future issue)). follows:  106  Wheat: Gluten = (Dumas nitrogen content) x 5.68 x 0.80  107  Rye: Gluten = (Dumas nitrogen content) x 5.68 x 0.60  108  Barley: Gluten = (Dumas nitrogen content) x 5.68 x 0.60  109  110  See Estimating Recovery of a Gluten ELISA Kit Method for details on procedures for spiking the flour  111  samples [J. AOAC Int. (future issue)]. Sample providers shall develop an SOP for producing, storing, and  112  shipping the materials.  113  114  b  Criteria for recovery are larger than traditionally used for SMPRs. There are two reasons for this. First,  115  method results for gluten in oats are highly variable due to sample inhomogeneity. This lack of  116  homogeneity may result in a wider range of recovery estimates than would normally be expected at  117  ppm levels. Second, the different relative specificities of the antibodies against wheat, rye, and barley  118  make balancing the response difficult.  119