NYC-WTC_000219925

NYC 9/11 Public Portal Document I Search - 1 Result - APPENDIX A TO SUBPART E - INTERIM TRANSMISSION ELEC...Page 5 of 38

Pump calibration Before and after each field series 90% Sample custody Review of chain-of custody record Each sample 95% complete Sample shipment Review of sending Each sample 95% complete report

C. Sample Shipment Ship bulk samples to the analytical laboratory in a separate container from air samples.

D. Sample Receiving

1. Designate one individual as sample coordinator at the laboratory. While that individual will normally be available to receive samples, the coordinator may train and supervise others in receiving procedures for those times when he/she is not available.

2. Bulk samples and air samples delivered to the analytical laboratory in the same container shall be rejected.

E. Sample Preparation

1. All sample preparation and analysis shall be performed by a laboratory independent of the abatement contractor.

2. Wet-wipe the exterior of the cassettes to minimize contamination possibilities before taking them into the clean room facility.

3. Perform sample preparation in a well-equipped clean facility.

NOTE: The clean area is required to have the following minimum characteristics. The area or hood must be capable of maintaining a positive pressure with make-up air being HEPA- filtered. The cumulative analytical blank concentration must average less than 18 s/mm<2> in an area of 0.057 mm<2> (nominally 10 200-mesh grid openings) and a single preparation with a maximum of 53 s/mm<2> for that same area.

4. Preparation areas for air samples must not only be separated from preparation areas for bulk samples, but they must be prepared in separate rooms.

5. Direct preparation techniques are required. The object is to produce an intact film containing the particulates of the filter surface which is sufficiently clear for TEM analysis.

a. TEM Grid Opening Area measurement must be done as follows:

i. The filter portion being used for sample preparation must have the surface collapsed using an acetone vapor technique.

ii. Measure 20 grid openings on each of 20 random 200-mesh copper grids by placing a grid on a glass and examining it under the grid on a glass and examining it under the PCM. Use a calibrated graticule to measure the average field diameters. From the data, calculate the field area for an average grid opening.

http;//lexis/research/retrieve?_m=el35f2ca3d266867e53d261df3205722&_fintstr=FULL6... 02/04/2002 CITY_21MC1OO_O12558669

NYC-WTC_000219929