Tekmar Talk Blog

This is the third in our Troubleshooting series for VOC Analysis. 

• Part one is linked here, VOC Analysis Troubleshooting Part 1: How to Begin Troubleshooting
• Part two is linked here, Troubleshooting Part 2: No or low analyte response and carryover

Part three will discuss elusion issues and moisture control for VOC analysis.

Water vapor entering the gas chromatograph (GC) inlet, column, and, ultimately, the mass spectrometer (MS) can minimize the sensitivity of our early eluting compounds, including our gases. It can also cause poor peak shape, compounds to co-elude, and shift in retention time, even in compounds outside of the water peak. So, once the water is introduced into our system, it starts to wreak havoc on all our compounds. Some say water doesn’t affect column phase or lifespan, but some have seen an effect, especially if you’re running a lot of samples; water can shorten the column life of your GC column and can cause vacuum issues if you’re using a MS system, which could lead to shorter filament lifetime and having to clean the source more often.

Throughout this blog series, we’ve discussed ways to minimize the amount of water vapor introduced to the GC-MS, using Teledyne Tekmar’s moisture control fitting and application control. We can continue to control moisture not only through this hardware designed for the Purge and Trap, but also through method parameters we can adjust and using smart method parameters on the GC.

In part one of this series, we learned why water vapor is bad for volatile organic compound (VOC) analysis. In part two, we will explore ways we can optimize moisture control in the Purge and Trap (P&T) system.

Analyzing volatile organic compounds (VOCs) is an essential part of environmental monitoring, flavor and fragrance analysis, and analysis in the pharmaceutical and petrochemical industries. Gas Chromatograph (GC) columns and detectors, namely Mass Spectrometers (MS), do not perform well in the presence of water. Before the sample is introduced to the GC, it must become a vapor.

For this reason, there are many samples, such as