Laserfiche WebLink
F <br />5.3.6 Replace the LN 2 Dewar flask with a Dewar containing hot <br />water at about 90 deg C. <br />5.3.7 Allow the trap to warm up. <br />5.3.8 Inject the sample into the carrier gas stream by turning <br />the GC sampling valve. The gas sample enters the GC <br />analyzer and is separated into component compounds. <br />1E, <br />5.3.9 <br />The instrument operating conditions are the same as <br />those described in Section 5.2.5 above. <br />5.3.10 <br />Each separated component passes through the electron <br />capture detector and yields a response proportional <br />to its response factor and concentration. <br />6 <br />Calculations <br />6.1 <br />The concentrations of halogenated hydrocarbons, in ppb, <br />are calculated by an electronic integrator using the <br />external standard method. <br />6.1.1 <br />Concentration = Area x Response Factor x Dilution Factor <br />6.2 <br />The Response Factor (RF) is calculated during calibration <br />by the equation: <br />RF = Concentration <br />Area <br />6.2.1 <br />Dilution Factor = Total volume of diluted sample <br />Initial sample volume before dilution <br />6.2.2 <br />Replicate calibrations are averaged and the arithmetic <br />mean is stored as the RF for subsequent analyses. <br />6.3 <br />Concentrations may be converted from ppb to mg/m 3 <br />by means of the following formula: <br />mg/m3 P x (M.W.) x (Ppb) x (10 6) <br />(82.05) it (T) <br />Where: <br />P = Pressure in atmospheres <br />M.W. Molecular weight of corresponding <br />halogenated hydroca bon <br />5 °K <br />82.05 Gas constant in cm x atm./ -mole <br />T = Absolute temperature (°K). <br />3 <br />6.4 <br />The concentration unit mg/m is equivalent to ng/cm3 <br />1E, <br />