Evaluation of Greenhouse Gas Emissions from Septic ... - Geoflow

3.3 Gas AnalysisThe gas samples were analyzed by a Shimadzu gas chromatograph (Model GC- 2014)with a 63Ni electron capture detector (ECD) linked to a Shimadzu auto sampler (Model AOC-5000). The samples were analyzed for CH 4 , CO 2 and N 2 O. The autosampler uses a gas-tightsyringe to remove 5 mL gas from a sample vial and inject it into the GC port. The instrumentwas operated by experienced technicians with specialized training using a well establishedanalytical protocol at the geochemistry laboratory of the UC Davis Plant and EnvironmentalScience Department.Figure 3-9. Sludge Measurement Taken at Site 4. The Red Marks are Located Every Foot.3.4 Quality Control for the SamplesBefore each sample event, one person from the research team was in charge ofevacuating the vials and placing a mark on the vial’s cap each time the vial was evacuated. Afterthree subsequent evacuations, the septum inside the cap was replaced. All vials were labeled withthe date and a code for each site prior to the sampling event (i.e., Septic Tank 1, inlet, time = 0was labeled ST1 in 0).During each sampling event one person from the research team was designated to be incharge of handling the samples taken on that particular day including protecting them from sunexposure, breakage or damage and delivering them to the laboratory for analysis.3-10