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eurofins <br />I <br />Air Toxics <br />• <br />LABORATORY NARRATIVE <br />Modified ASTM D-1946 <br />Brusca Associates, Inc. <br />Workorder# 1802350B <br />Two 1 Liter Summa Canister samples were received on February 16, 2018. The laboratory performed <br />analysis via Modified ASTM Method D-1946 for Methane and fixed gases in air using GC/FID or <br />GC/TCD. The method involves direct injection of 1.0 mL of sample. <br />On the analytical column employed for this analysis, Oxygen coelutes with Argon. The corresponding <br />peak is quantitated as Oxygen. <br />Since Nitrogen is used to pressurize samples, the reported Nitrogen values are calculated by adding all <br />the sample components and subtracting from 100%. <br />Method modifications taken to run these samples are summarized in the table below. Specific project <br />requirements may over -ride the ATL modifications. <br />Requirement <br />ASTM D-1946 <br />ATL Modifications <br />Calibration <br />A single point <br />A minimum of 5 -point calibration curve is performed. <br />calibration is <br />Quantitation is based on average Response Factor. <br />performed using a <br />reference standard <br />closely matching the <br />composition of the <br />unknown. <br />Reference Standard <br />The composition of any <br />The standards used by ATL are blended to a >/= 95% <br />reference standard <br />accuracy. <br />must be known to <br />within 0.01 mol % for <br />any component. <br />Sample Injection Volume <br />Components whose <br />The sample container is connected directly to a fixed <br />concentrations are in <br />volume sample loop of 1.0 mL on the GC. Linear range <br />excess of 5 % should <br />is defined by the calibration curve. Bags are loaded by <br />not be analyzed by <br />vacuum. <br />using sample volumes <br />greater than 0.5 mL. <br />Normalization <br />Normalize the mole <br />Results are not normalized. The sum of the reported <br />percent values by <br />values can differ from 100% by as much as 15%, either <br />multiplying each value <br />due to analytical variability or an unusual sample matrix. <br />by 100 and dividing by <br />the sum of the original <br />values. The sum of the <br />original values should <br />not differ from 100% <br />by more than 1.0%. <br />Precision <br />Precision requirements <br />Duplicates should agree within 25% RPD for detections <br />established at each <br />> 5 X's the RL. <br />concentration level. <br />Page 3 of 10 <br />