Research Report RR:D19-1183
This ASTM Research Report includes the results of two studies performed to validate ASTM D7575. The earlier study was a single-lab validation involving three phases of testing of real-world samples containing oil and grease to estimate single-laboratory precision, and comparing the results to those of an existing oil and grease method, EPA 1664A. The first phase involved testing seven different collections of one matrix in triplicate, the second phase involved testing five other matrices in triplicate, and the third phase involved testing two matrices seven times each. D7575 was found to provide results that were not statistically different from EPA 1664 at the 95% confidence level. Single laboratory precision results from this study were later superseded by results of the more recent mutli-laboratory validation, which determined inter- and intra-laboratory precision and quality control acceptance limits. This validation involved testing three real-world matrices in Youden concentration pairs at twelve independent laboratories. The range of concentrations covered from double the expected lower reporting limit to half the upper reporting limit. The overall average relative standard deviation was found to be 13.1% and the single-operator relative standard deviation was found to be 9.7%.
D7575-11 Standard Test Method for Solvent-Free Membrane Recoverable Oil and Grease by Infrared Determination
Committee D19 on Water
Subcommittee D19.06 on Methods for Analysis for Organic Substances in Water