Tekmar Talk Blog

Has your laboratory been having issues obtaining helium for your environmental analysis? As helium supplies become scarcer and more expensive, you may have been seeking alternative carrier gases or ways to conserve helium without sacrificing system performance. This blog will explore ways to conserve helium during your purge and trap (P&T) analysis.

In this last installment of our volatile organic compound (VOC) analysis troubleshooting series, the benchmark test will be covered. This benchmark test is available in the Teledyne Tekmar TekLink software tools menu. The tool allows for full electromechanical testing, including valving, heaters, vial handling systems, liquid delivery system, inputs and outputs.

Throughout this troubleshooting series, in nearly every topic discussed, the answer led to performing a leak check on the Purge and Trap (P&T). This part of the series will go over the preventative maintenance program and understanding the leak check troubleshooting tool in Teklink, the Teledyne Tekmar P&T software.

This is the forth 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 is linked here: Elusion Issues and Moisture Control

Troubleshooting linearity and reproducibility issues in your systems can be difficult. Problems with linearity and reproducibility can make calibrating your systems frustrating, and if internal standards are varying, it can cause all other target compound to look unstable.

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.

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

Part one is linked here, VOC Analysis Troubleshooting Part 1: How to Begin Troubleshooting

Part 2 will discuss No, or Low, Analyte Response and Carryover.

Troubleshooting your instruments can be a frustrating process, but I hope this series eases some of that pain and helps you through it. If you’re dealing with no or low response from your analytes, you first need to know if the analytes are even getting to the Gas Chromatograph and Mass Spectrometer (GC-MS). Following the advice in part one of this series, start with a direct injection into the GC of the same standards you use on your Purge and Trap (P&T), to confirm normal operation of the GC-MS. If you see poor chromatography and resolution or reduced response, you should change your inlet liner and clip the column.

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.

The last two Purge and Trap (P&T) settings we will discuss in this blog series might be the most important for moisture control in this volatile organic compound (VOC) analysis: desorb and bake settings.

We can adjust our desorb time to help reduce the amount of moisture we put onto the gas chromatograph (GC) and mass spectrometer (MS). A longer desorb time will remove more of compounds from the analytical trap and send them to the GC, but this includes water, leading to a longer water peak in the total ion chromatogram. If the desorb time is shortened, less of that analyte material is transferred to the GC, but we will have a much shorter water peak, giving the compound peaks better shape and resolution. This gives us an opportunity for method optimization with the desorb settings both in time and temperature.

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.

Hello all,

For those of you who are reading this from your office, or laboratory, please do be safe and thank you for the essential functions that you continue to serve, despite the risk to you and your family. We are all grateful for your efforts. However, if you’re like me right now, you are reading this from home. While it is certainly an adjustment (how is it possible that two toddlers can sound like a herd of elephants migrating through a bubble wrap factory!?), it is very important for those of us who can, to stay home and slow the spread of COVID-19. All the same, it is probably difficult being away from your instruments, even if this is a good time to catch up on other tasks. When all of this comes to an end, and eventually we return to work, in what kind of condition will we find our instruments?