FRTR Field Sampling and Analysis Technologies Reference Guide

6 SAMPLE ANALYSIS TOOLS for VOCs, SVOCS, and PESTICIDES

6.2 EX-SITU ANALYSIS

6.2.9 GC/Ion Trap MS

Use:

Gas Chromatography/Ion Trap Mass Spectrometry (GC/Ion Trap MS) is a hybrid technique that combines the separation capability of the gas chromatograph (GC) (see 6.2.4), the analytical capability of the ion trap mass spectrometer (Ion Trap MS) (see 6.2.10), and the capability to provide real-time, on-site data. The Ion Trap MS determines the masses of atoms or molecules found in a solid, liquid, or gas, particularly VOCs.

Description:

GC/Ion Trap MS systems are similar to GC/MS systems (6.2.8). The GC separates a complex mixture into individual components, allowing the ion trap mass spectrometer to analyze the mixture as a series of pure components. The advantage of the ion trap mass spectrometer (compared with the mass spectrometer) is a more compact design and the ability to trap and accumulate ions to increase the signal-to-noise ratio of a measurement. The ion trap mass spectrometer uses three electrodes to trap ions in a small volume. The mass analyzer consists of a ring electrode separating two hemispherical electrodes. A mass spectrum is obtained by changing the electrode voltages to eject the ions from the trap.

Analytes:

1. Non-Halogenated VOCs	2. Non-Halogenated SVOCs	3. Halogenated VOCs
4. Halogenated SVOCs	5. PAHs	6. Pesticides/Herbicides

Media:

Soil/Sediment	Water	Gas/Air
Requires extraction to liquid or gas phase	Requires extraction to liquid or gas phase	BETTER

Selectivity:	Technique measures the specific contaminant directly.
Susceptibility to Interference:	Low.
Detection Limits :	100-100 ppb (soil); 1-50 ppb (water).
Turnaround Time per Sample:	Hours.

Applicable To:

Screen/Identify	Characterize Concentration/Extent	Cleanup Performance	Long-Term Monitoring
ADEQUATE	BETTER	BETTER	ADEQUATE

Quantitative Data Capability:	Produces quantitative data.
Technology Status:	Commercially available and routinely used field technology.
Certification/Verification:	Technology has not participated in CalEPA certification and/or CSCT verification program.
Relative Cost per Analysis:	Most expensive.

Limitations:

Setup time and calibration of portable GC/Ion Trap MS systems can be time consuming.
GC portion of the system requires a library of retention times to identify compounds, and non-target compounds could be difficult to identify if detected analytes are not in the library or the quality of the library match is too low to make positive identification.
Ion Trap MS portion of the system requires a library of spectra.
Can not detect certain semi-volatile compounds such as benzopyrenes.

ASTM Standards/EPA Methods:

No applicable ASTM standards or EPA methods are cited for this technology.

Sample Access/Collection Matrix

Sample Analysis Matrix

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