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NYC 9/11 Public Portal Document Pace Analylical Senicss, Inc. 1700 Elm Street, Suite 200 'ace Analytical" Minneapolis, MN 55414 Phone: 612.607.1700 mne.paeelabs.com REPORT OF; CHEMICAL ANALYSES Fax: 612.607.6444

PROJECT: PCDD/PCDF ANALYSES DATE: April 5, 2002

PAGE: 7 REPORT NO: 02-1055017

RESULTS

The results from the analyses are presented in the following;

Appendix A - Documentation Appendix B - PCDD/PCDF Analysis Results

The recoveries of the isotopically-labeled PCDD/PCDF internal standards in the sample extracts ranged from 64-117%. All of the internal standard recoveries for field samples were within the target limits for this method. Also, since the quantifications of the native 2,3,7,8-substituted isomers were based on isotope dilution, the data were automatically corrected for variation in recovery and accurate values were obtained.

A laboratory method blank was prepared and analyzed with the sample batch as part of our routine quality control procedures. The results, found at the beginning of Appendix B, show the blank to be free of PCDDs and PCDFs at the reporting limits. This indicates that the sample processing procedures did not significantly impact the results of the analyses.

A laboratory spike sample was also prepared with the sample batch by extracting clean wipes that had been fortified with native standard materials. The results, found at the end of Appendix B, show that the spiked native compounds were recovered at 68-121%. These results indicate a generally high degree of accuracy for these samples. It should be noted that one isomer in the . spike was recovered slightly below the target range for this method. The affected point is flagged "P" on the data summary sheet.

REPORT OF LABORATORY ANALYSIS This report shall not be reproduced, except in lull, without the written consent of Pace Analytical Services, Inc.

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