ESTCP Project #1011, Rhizosphere
Final Report
Appendix A. Chemical Analysis
Soil samples from the site were analyzed using three basic methods, each of which is described
in detail below:
1. High-resolution gas chromatography with flame ionization detection (HRGC/FID) using
modified EPA method 8015. This yields total petroleum hydrocarbons (TPH) and
fraction specific hydrocarbons (FSH) for both volatile and semi-volatile constituents and
it provides gas chromatography traces (GC fingerprints) that are used to characterize the
sample for product type and weathering state.
2. GC Fingerprints provide information about the composition of the sample.
3. High-resolution gas chromatography with mass spectrometry (HRGC/MS) using
modified EPA method 8270. This is used for selected samples to characterize polycyclic
hydrocarbons (PAHs), selected heteroaromatic compounds, and the biomarkers hopane.
A.1 HRGC/FID Analyses (EPA Method 8015M): TPH, GC Fingerprints, and
FSH
Soil samples were analyzed for total petroleum hydrocarbons (TPH) and fraction-specific
hydrocarbons (FSH) using high-resolution gas chromatography flame ionizing detection
(HRGC/FID). The analyses were performed according to Battelle Standard Operating Procedures
(SOP) 5-202, Determination of Low Level Total Petroleum Hydrocarbons and Individual
Hydrocarbon Concentrations in Environmental Samples. The procedures were modifications of
existing EPA method 8015B.
Before sample analysis, a five-point response factor calibration was performed to demonstrate
the linear range of the analysis and to determine the individual response factors (RF) at each
calibration solution concentration. The calibration solution was composed of selected n-alkanes
standard solutions range from 0.05 ng/L to 200.0 ng/L. The individual target-compound
response factors at each calibration concentration were determined, and the total petroleum
hydrocarbon (TPH) response factor was based on the average response factors of all the target
analytes in the calibration solution over the entire dynamic range.
Samples were screened based on color, and low-level (clear) samples were run before high-level
(amber to brown) samples to minimize baseline drift and carry over.
The gas chromatograph (GC) operating conditions were:
Capillary column
0.32 mm x 30 m DB-5 (0.25
m)
Initial column temperature:
35C
Initial hold time:
5 minutes
Program rate:
6C/minute
Final column temperature:
320C
Final hold time:
10 minutes
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