This document describes a method for determining 61 volatile organic compounds (VOCs) using gas chromatography-mass spectrometry (GC-MS). The method uses a purge and trap (P&T) concentrator, a gas chromatograph (GC), and a mass spectrometer (MS), and does not require the use of cryofocusing. Tables 1 and 2 list the P&T and GC-MS conditions, which detail the instrument settings. The method development for analyzing 524.2 analytes was refined by members of the GC-MS Volatile Organics Analysis (VOA) group at Quanterra in Tampa, Florida.
This document describes a system comprised of a purge and trap concentrator, an Agilent 6890 gas chromatograph, and an Agilent 5973 mass spectrometer used to determine 61 volatile organic compounds (VOCs). The method meets all U.S. EPA Method 524.2 criteria without using cryofocusing. The procedure involves purging compounds from water samples using helium, trapping them on a solid sorbent, and then desorbing them onto the head of a GC column for analysis by the mass spectrometer.
The document provides specific instrumentation and conditions for the purge and trap system (Tekmar LSC 3000) and the GC-MS system. It details the configuration of the Agilent 6890 GC, including the use of an EPC split/splitless inlet and a DB-624 column, as well as the operating parameters for the Agilent 5973 MS. The text also outlines the quality assurance procedures, calibration curves, and the typical instrument sequence for analysis.
| Purge rate | 50 mL/min |
|---|---|
| Desorb temperature | 260 °C |
| Bake temperature | 270 °C |
| Inlet temperature | 200 °C |
| Split ratio | 35:1 |
| Column length | 20m |
| Column diameter | 180 ym |
| Source temperature | 200 °C |
| Transfer line temperature | 250 °C |
The system was used to determine 61 volatile organic compounds (VOCs).
No, all U.S. EPA method 524.2 criteria were met without using cryofocusing.
The sequence starts with a BFB tuning verification, followed by a CCV standard, LCS/LCSD, a method blank, and then field samples.