Rapid detection of volatile organic compounds in the subsurface by membrane introduction into a direct sampling ion-trap mass spectrometer†

The Triservice Site Characterization and Analysis Penetrometer System (SCAPS) was developed to reduce the time and cost required for site characterization. Direct-push sensors were developed to detect specific classes of contaminants, such as petroleum hydrocarbons, explosive compounds, radionuclides, metals, and volatile organic compounds (VOCs). This article describes the demonstration of a direct-push sensor that can quantify VOC contamination in the subsurface in real time. This system consists of a membrane interface probe (MIP) manufactured by Geoprobe Systems coupled to a direct sampling ion-trap mass spectrometer (ITMS). The ITMS-MIP system was shown to rapidly collect and analyze samples from the subsurface, regardless of matrix. Two of the five demonstrations discussed resulted in a strong linear correlation (r² = 0.9) with validation samples analyzed using EPA Method 8260. The other three demonstrations revealed that the calibration method used in this work introduced a bias compared to EPA methods.* © 2000 John Wiley & Sons, Inc. Field Analyt Chem Technol 4: 246–254, 2000