Results from an amino acid racemization inter-laboratory proficiency study; design and performance evaluation

► Describes the design and organisation of an inter-laboratory proficiency test. ► Compares method specific intra-laboratory and inter-laboratory precision estimates. ► Evaluates laboratory bias and analytical performance against consensus values. ► Explains why precision and bias must be included in AAR uncertainty estimates. ► Calls for a collaborative trial to define future reference materials to assist with bias control.