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L %W� �%d <br /> SAMPLE HANDLING._ <br /> Soil samples collected for chemical analysis will be immediately capped and placed in a cooler <br /> Lwith blue-ice pending delivery to the analytical laboratory. Each sleeve will be covered with <br /> plastic end caps over teflon sheets. A label is placed on the sample sleeve that includes a unique <br /> sample number, date and time that the sample was collected, name of the person handling the <br /> L sample, and the specific analyses being requested from the lab. The sample sleeve will then be <br /> placed into a zip-lock plastic bag and secured with evidence tape. <br /> L <br /> HEAD-SPACE ANALYSIS <br /> `„ Head-space analyses are performed as a field .screening technique using an organic vapor <br /> analyzer calibrated on site. Each soil sample is placed to a sealed container and filled with an <br /> approximately equal volume of clean air. After being left at ambient temperature for <br /> approximately 10 minutes, the head-space in the bag is analyzed using a Foxboro (or equivalent) <br /> Flame Ionization Detector (FFD) or Photovac Microtip (or equivalent) Photoion nation Detector <br /> (PID). These instruments register the concentration of total organic vapors in the head-space <br /> which is an indication of the presence of volatile organic materials in the soil. Both instruments <br /> measure the concentration of airborne ionizableases and vapors spore in the C2 to C12 range. The <br /> LFID will also detect methane (CH4). Because these instruments measure the total concentration <br /> of ionizable chemicals in air, there may be differences between the instrument readings and <br /> laboratory analytical results. <br /> LThe instruments should be calibrated every morning and periodically during the day as needed. <br /> During calibration, the instruments are allowed to intake and measure a hydrocarbon free air <br /> (zero gas), followed by a known concentration of a reference gas. The PIDs are calibrated with a <br /> isobutylene gas commerically available in the range of 95 to 105 ppm; whereas, the FIDS are <br /> calibrated with a methane gas eommerically available in the range of 90 to 100 ppm. <br /> E <br /> L <br /> 0 <br /> L. <br /> L <br /> 1 <br /> !r. <br /> L <br /> C-2 <br /> bw <br /> L <br />