This inventory of the peat and peatland resources of Ontario was intended to provide information on possible fuel peat deposits as a means of encouraging increased energy self-sufficiency, as well as information on the resources of horticultural peat in the province. The inventory undertook laboratory analyses of over 1700 peat samples collected during the studies, the analysis of which entailed the development and standardization of required laboratory methods, and the assessment of the precision and accuracy of the reported data. This report details the specific laboratory methods which were used, and evaluates the results of internal and blind quality control tests. It also reports the results of several tests of particular methods, and suggests the precision levels from the use of these techniques.