Determination of TPH Content in Soil by Portable Mid - ATR System

Oral Presentation

Prepared by T. Miao, R. Mohler, K. Kong, T. Hoelen, A. Pradhan, M. Moir
Chevron, 100 Chevron Way 50-1289, Richmond, CA, 94801, United States

Contact Information:; 510 242 3157


The application of mid-infrared spectroscopy as a rapid screening tool for TPH concentrations in contaminated soils is presented. Currently, near and mid DRIFT (Diffuse Reflectance Infrared Fourier Transform) using portable spectrometers have given promising results. In this study, we describe an ATR (attenuated total reflection) mid-infrared technique for TPH in soil using a handheld spectrometer with no solvent extraction required. Our data show that neat whole soils with between 15-30 wt% water content could be used. Reflectance IR spectra can be acquired easily and rapidly because of the high sensitivity of alkyl-CH3 vibrational group. Partial least squares (PLS) and cross validation were used to develop equations for quantification of TPH. We have collected data for soils from different contaminated sites and compared ATR with the DRIFT technique. From this preliminary study, we show that mid IR-ATR can deliver promising results for field screening, providing real-time in-situ TPH data.