TES Technology

Triad Environmental Solutions, Inc. (TES) is the sole commercial vendor of Direct Sampling Ion Trap Mass Spectrometer (DSITMS) services under a license agreement from US DOE Oak Ridge National Laboratory.  The DSITMS has been deployed at over 300 Federal, state and private facilities.  The DSITMS provides real-time detection of volatile organic compounds (VOCs) in three minutes allowing the rapid in-field development of high resolution data sets.

The use of high resolution sampling and analysis allows site investigators to address the largest uncertainty in environmental site characterization: sample representativeness due to subsurface heterogeneity.  TES has pioneered the use of application of geophysical cone, MIP and DSITMS for the rapid and accurate characterization of complex contaminated sites.  TES provides our clients with cost effective solutions site characterization challenges, especially DNAPL sites that may have been under investigation for decades.

Direct Sampling Ion Trap Mass Spectrometer (DSITMS) and EPA Method 8265

The DSITMS is the basis for US EPA SW846 Method 8265.  This method is very robust for the detection of VOCs in soil, groundwater and vapor samples.  The method is capable of identification and quantification of petroleum related and chlorinated solvent VOC contaminants of concern from very low levels (single ppb) to rather high levels of contamination (100s-1000s ppm).

The use of EPA Method 8265 with dynamic work plan supports on-site decisions in Triad Approach site characterizations.  The real-time quantification of VOC contaminants of concern (2-3 minutes/sample) allows sample location selection to be made on a point by point basis, whether on a plan view (horizontal) or at a depth within a particular bore hole (vertical).

Using the US EPA Method 8265 data combined with three dimensional mapping and statistical analysis, TES provides accurate real-time and final conceptual site models of separate phase and dissolved plume contaminant distributions.

No Down Time from High level Samples Overloading System

A unique feature of the DSITMS is that it is significantly less subject to cross contamination from high level samples than other techniques used for real-time data collection (i.e. GC/MS with EPA Method 8260).  Decontamination of the DSITMS after a very high level sample (>1000 ppm) takes approximately 10 minutes, this includes running a blank analysis after decontamination to ensure the system has been properly cleaned.  When a high level sample (>10 ppm) is run on a conventional instrument by EPA Method 8260, it can take 8-12 hrs to recover the system.  The DSITMS ability to recover from high level sample analysis significantly reduces down time in the field, increasing sample through put and client cost saving.

DSITMS Advantages as a MIP Detector

The DSITMS is currently the only system available for the real-time direct speciation of VOC in the sample vapor stream produced by the GeoProbe MIP.  The conventional detectors used with the MIP (FID, PID and ECD) provide only a gross indication of the total VOC contaminants of concern (FID and PID) with the ECD capable of providing an indication of the total chlorinated VOCs.  The DSITMS provides real-time identification of the individual VOC contaminants as the vapor sample from the MIPis returned to the surface.  The DSITMS distinguishes PCE, TCE, DCE and vinyl chloride from each other in real-time. Using conventional MIP detectors, the vapor must be collected and analyzed off line by gas chromatography to provide contaminant identification.  TES is the sole commercial provider of the DSITMS  and  real-time direct speciation of VOC contaminants from the MIP.

DSITMS Ideal for Complex Sites

Changing between discrete soil, groundwater, vapor or MIP sample introduction methods to the DSITMS takes under 5 minutes.  This means a single DSITMS instrument can be used as a very powerful MIP detector and moments later, as a stand alone tool to analyze discrete soil or groundwater sample samples to quantify the MIP results.

The MIP is a very powerful site characterization tool capable of providing high resolution mapping of subsurface VOC contamination.  However, it is important to verify MIP results because MIP data are semi-quantitative and known to be subject to soil matrix effects.   Discrete soil or groundwater samples analyzed on-site using the DSITMS, allow project managers to address potential MIP data soil matrix effects in the field as the investigation progresses.

Contaminant Fate and Transport

TES has worked with GeoProbe to integrate the MIP with a geophycial cone sensor containing a piezocone.  These sensors allow the simultaneous collection of VOC data along with soil type (stratigraphy) and subsurface pore pressure.   These data are used together to rapidly delineate subsurface contaminant migration pathways.   The VOC and geologic data collected with this system are used to construct and refine the CSM, in real-time.  This CSM is used with site specific decision processes to further guide investigation during a particular deployment and to determine when the site has been adequately characterized.