Quantifying Uncontrolled Landfill Gas Emissions from Two Florida ...

ecoveries were performed with the LCS standard with 87.3- and 87.5-percent recovery for an
average of 87.4 percent. Two spike recoveries were performed with the second standard with
94.8- and 85.0-percent recovery for an average of 89.9 percent. The recovery criteria established
in the QAPP of 50 to 150 percent was met.
Laboratory matrix analytical spikes (sample + 2.000 ng) were performed on a batch QC sample
with recoveries of 90.9 and 102.4 percent with an average recovery of 96.6 percent, which meets
laboratory acceptance criteria for recovery. Blank values were less than 0.0014 ng per trap with
an average of 0.0007 ng per trap and an MDL of 0.0030 ng per trap.
Field spike recovery values for Site #1 was 25.7 and 62.6 percent for Site #2. The low spike
recoveries were possibly due to an over sampling of the landfill gas and degradation of the
matrix spike in the collection solution. Dimethyl mercury results may be higher than reported
due to the reactive properties of the landfill gas on the analytes in the acid collection solution.
Table 5-6 represents precision values calculated for dimethyl mercury of samples during Landfill
F and G sampling campaign. Precision goals established in the QAPP of