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LABORATORY NARRATIVE <br /> +" Modified TO-3 <br /> Geological Technics <br /> Workorder#0407540 <br /> Three t Liter Tedlar Bag samples were received on July 29, 2004. The laboratory performed analysis for <br /> volatile organic compounds in air via modified EPA Method TO-3 using gas chromatography with photo <br /> ionization and flame ionization detection. The method involves concentrating up to 200 mL of sarnple. The <br /> concentrated aliquot is then dry purged to remove water vapor prior to entering the chromatographic system. <br /> The TPH (Gasoline Range)results are calculated using the response factor of Gasoline and correspond to the <br /> range of hydrocarbons from C5 to C10. A molecular weight of 100 is used to convert the TPH (Gasoline <br /> a <br /> Ranmy result to <br /> Range)pp ug/L.. See the data sheets for the reporting limits for each compound <br /> Method modifications taken to run these samples include: <br /> Requirement TO-3 ATS Modifications <br /> Daily Calibration Standard Prior to sample analysis Prior to sample analysis and after the analytical batch</=20 <br /> Frequency and every 4-6 hrs samples <br /> Initial Calibration Calculation 4-point calibration 5-paint calibration using average Response Factor <br /> using a linear <br /> r.. <br /> regression model <br /> Initial Calibration Frequency Weekly When daily calibration standard recovery is outside 75-125 <br /> %,or upon significant changes to procedure or <br /> instrumentation <br /> Moisture Control Nafion system Sorbent system <br /> Minimum.Detection Limit(MDL) Calculated using the 40 CFR Pt. 136 App. B <br /> equation DL=A+3.3S, <br /> where A is intercept of <br /> calibration line and S is <br /> the standard deviation <br /> �.. of at least 3 reps of <br /> low level standard <br /> Preparation of Standards Levels achieved Levels achieved through loading various volumes of the ga. <br /> La through dilution of gas mixture <br /> mixture <br /> L. Receiving„ otes <br /> Sample identifications on the chain of custody were not unique. The time of collection was added to the <br /> identification to insure uniqueness. <br /> Anal t' al Notes <br /> Samples EW-1 (1700), EW-1 (0040) and EW-1 (0800) were transferred from Tedlar bags into summa <br /> �- canisters to extend the hold time from 72 hours to 14 days. Canister pressurization resulted in a dilution factor <br /> which was applied to all analytical results. <br /> There were no analytical discrepancie& <br /> Definition of-Data Oualifving Flags <br /> Seven qualifiers may have been used on the data analysis sheets and indicate as follows: <br /> Page 2 of 9 <br />