Chemical sensor and field screening technology development: fuels in soils field screening method validation

摘要

A new screening method for fuel contamination in soils was recently developed as American Society for Testing and Materials (ASTM) Method D-583 1-95, Standard Test Method for Screening Fuels in Soils. This method uses low-toxicity chemicals and can be used to screen organic-rich soils. In addition, it is fast, easy, and inexpensive to perform. The screening method calls for extracting a sample of soil with isopropyl alcohol following treatment with calcium oxide. The resulting extract is filtered, and the ultraviolet absorbance of the extract is measured at 254 nm. Depending on the available information concerning the contaminant fuel type and availability of the contaminant fuel for calibration, the method can be used to determine the approximate concentration of fuel contamination, an estimated value of fuel contamination, or an indication of the presence or absence of fuel contamination. Fuels containing aromatic compounds, such as diesel fuel and gasoline, as well as other aromatic-containing hydrocarbon materials, such as motor oil, crude oil, and coal oil, can be determined. The screening method for fuels in soils was evaluated by conducting a collaborative study on the method and by using the method to screen soil samples at an actual field site. In the collaborative study, a sand and an organic soil spiked with various concentrations of diesel fuel were tested. Data from the collaborative study were used to determine the reproducibility (between participants) and repeatability (within participant) precision of the method for screening the test materials. The collaborative study data also provide information on the performance of portable field equipment versus laboratory equipment for performing the screening method and a comparison of diesel concentration values determined using the screening method versus a laboratory method. Data generated using the method to screen soil samples in the field provide information on the performance of the method in atypical real-world application.