Analytical laboratory reports attachment for PCDDs and PCDFs, 2008

NYC 9/11 Public Portal Document

I Pan Aialytieal Services, Im. 1700 Elm Street, Suite 200 'aceAnalyticar Minneapolis, MN 55414 Phone: 612.607.1700 wwui.p8nlabs.eom REPORT OF: CHEMICAL ANALYSES Fax: 612.607.6444

I PROJECT: PCDD/PCE3F jySIALYSES DATE: January 9, 2002

PAGE: 7 REPORT NO: 01-1952682

I RESULTS

The results from the analyses are presented in the following:

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

fl DISCUSSION

R The recoveries of the isotopically-labeled PCDD/PCDF internal standards in the sample extracts is ranged from 72-124% and indicate a level of efficiency through the extraction and enrichment steps that is considered typical for this matrix. All of the internal standard recoveries for the 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. 2: J

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. This suggests that the sample processing steps did not impact the results of the analyses.

Laboratory spike samples were also prepared with the sample batch by extracting a clean wipe that had been fortified with native standard materials. The results, found at the end of Appendix B, show that the spiked native cornpounds were recovered at 96-115% with relative percent differences of 1.0-8.7%. This indicates high degrees of accuracy and precision for these determinations.

I 3

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

CONFIDENTIAL, CITY_21MC100_003432700 SUBJECT TO PROTECTIVE ORDER NO. 2, SEPT. 2008

NYC-WTC_000175733