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Miniature Membrane Inlet Gas Chromatograph for Cone Penetrometers
EPA Contract Number: 68D99040Title: Miniature Membrane Inlet Gas Chromatograph for Cone Penetrometers
Investigators: Dvorak, Michael
Small Business: Dakota Technologies Inc.
EPA Contact: Manager, SBIR Program
Phase: I
Project Period: September 1, 1999 through March 1, 2000
Project Amount: $70,000
RFA: Small Business Innovation Research (SBIR) - Phase I (1998)
Research Category: SBIR - Monitoring and Analysis , Ecological Indicators/Assessment/Restoration
Description:
Dakota Technologies, Inc. (DTI) has successfully adapted three different gas chromatography (GC) detectors (photoionization, halogen-specific, and electron capture) for operation inside a cone penetrometer. They enable field screening for volatile organic compounds (VOCs) at concentrations below the mg/kg level in soil and the mg/L level in groundwater. A heated microporous membrane in the side of the soil probe transfers VOCs from the soil formation into a carrier gas stream leading to the detectors; data are collected continuously as the probe is advanced into the ground. In this Phase I project, DTI will achieve exceptional sensitivity and specificity by making GC measurements while the cone is stopped. A hollow fiber permeation membrane, a sorbent preconcentrator, and a short chromatographic column will be introduced between the microporous membrane and the detector. The result will be the complete functionality of a sophisticated gas chromatograph in a downhole configuration. In Phase II, DTI expects to specifically detect benzene, toluene, trichloroethylene, perchloroethylene, and methyl tertiary butyl ether in groundwater at concentrations down to 1 µg/L, which is less than their maximum contaminant levels (MCLs). The cycle time, measured from when the probe is advanced to the depth of interest to the completion of the elution/detection phase, is projected to be less than 3 minutes.The outcome of the Phase I and Phase II work will be a fully functional gas chromatograph that can be operated inside a cone penetrometer probe. It will allow rapid, automatic, specific, and sensitive measurements of VOCs in the subsurface without any need to bring material to the surface. Widespread commercial applications are envisioned, particularly in situations where groundwater sources are threatened by subsurface organic contamination. The technology will substitute and displace measurements currently performed in offsite laboratories on samples extracted from the ground.
Supplemental Keywords:small business, SBIR, monitoring, engineering, EPA. , Ecosystem Protection/Environmental Exposure & Risk, Toxics, Water, Scientific Discipline, Waste, Engineering, Chemistry, & Physics, Analytical Chemistry, Chemistry, Contaminant Candidate List, Contaminated Sediments, Groundwater remediation, National Recommended Water Quality, 33/50, Monitoring/Modeling, Trichloroethylene, Volatile Organic Compounds (VOCs), gas chromatography, chromatography, benzene, Methyl tert butyl ether, MTBE, groundwater, soil , measurement, Toluene, groundwater contamination, TCE, soil, VOCs, detect
Progress and Final Reports:
Final Report
Integrated Downhole Gas Chromatograph and Automated Sampler for Direct Push