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Table 2: Requested Soil Gas Compound List Compound CAS Number Quant Mass RPn7PnP 71-41-9 72 Toluene 108-88-3 91 Ethvl Benzene 100-41-4 q1 m.o-Xvlene 108-38-3/106-42-3 91 o-Xvlene 95-47-6 91 Cumene 98-82-8 105 Stvrene 100-42-5 104 1.3 — Butadiene 106-99-0 54 Hexane 110-54-3 57 Unknown (TIC's) NA NA The detection limit for compounds on the soil gas list will be 0.2 ppmv (between 0.5 ug/L and 1.0 ug/L). The upper end of the calibration curve will be 100 ppmv. Samples with concentrations higher than the upper end of the calibration curve will be diluted appropriately. Unknown compounds above 1.0 ppmv will be reported as Tentatively Identified Compounds. Analytical System Gas Chromatography/Mass Spectrometry(GC/MS) FPA utilizes an Inficon Hapsite GC/MS. This is a portable GC/MS designed specifically for the analysis of volatile compounds. The unit is a full featured quadrupole GC/MS capable of meeting EPA's stringent SW-846 QC criteria. It weighs only 35 pounds and can be carried over the shoulder. The Hapsite GC/MS uses a sampling wand with an internal pump to collect the sample. The sample is pulled into a sample loop with variable injection capabilities. The column is a 30-meter OV-1 with a 3 meter backflush column. The backflush column allows the volatile organic target compounds onto the column, then backflushes off the non-target semi volatile compounds. This keeps the instrument free of contamination and eliminates the need to increase column temperature between analyses. The interface between the GC and MS is a methyl silicone membrane. This membrane allows organics to migrate to the MS while sweeping most non-organics through the vent. SP Environmental Services©November, 2000 Page 5 of 7 Air Monitoring Plan-DRAFT Sukut Construction,Inc. Tracy Tire Fire Suppression Project