Sixteen laboratories participated in an interlaboratory study conducted to provide precision and accuracy statements for the proposed EPA Method 610 for 16 selected polynuclear aromatic hydrocarbons(PNA's) which may be present in municipal and industrial aqueous discharges. Method 610 involves extraction of the pollutants with methylene chloride and subsequent analysis of the subject compounds by high performance liquid chromatography utilizing fluorescence and ultraviolet detection of the PNA's. The study design was based on Youden's plan for collaborative tests of analytical methods. Three Youden pair samples of the test compounds were spiked into six types of test waters and then analyzed. The resulting data were statistically analyzed using the computer program entitled 'Interlaboratory Method Validation Study' (IMVS). Mean recoveries of the PNA's were in the range of 41-100 percent. Overall precision was in the range of 23-91 percent and single-analyst precision was in the range of 11-48 percent. A statistically significant effect due to water type was established for six of the sixteen PNA compounds for which recoveries from distilled water were generally lower than from wastewaters. The effect was judged to be due to the analytical learning process and, therefore, of no practical importance. For the other 10 PNA's, there were no differences of practical significance due to water types among mean recoveries, overall precisions, or single-analyst precisions.

"June 1984." "EPA-600/4-84-063."