Gas Chromatagraph: Continuous or Plused Operation?

  • Thread starter flatmaster
  • Start date
  • Tags
    Gas
In summary, there have been several instances of gas chromatography being used in space exploration, including on the Pioneer Venus2 mission where four probes were sent into the Venusian atmosphere to collect data before being destroyed upon impact. One of the devices on these probes was a gas chromatograph, which can determine the identity of a gas by the amount of time it takes to travel through a column. It is possible to create a continuously running or pulsed gas chromatograph, with some limitations on resolution. This has been demonstrated in various space missions, such as using a pulsed GC with a quadrapole mass spectrometer as the detector. Additionally, a two-dimensional chromatograph has been built using a pulsed column.
  • #1
flatmaster
501
2
I'm intreaged by our history of space exploration. On Pioner Venus2, four sacrificial probes were sent through the Venusian atmosphere while they quickly streamed back their data to the orbitor. They were destroyed when impacting the surface. One of the devices on the probes was a gas chromatagraph. The gas chromatagraph I know of can only take a given sample of gas, and determines the identity of the gas by the amount of time it takes for that gas to travel through the column.

My question is can you make a continusly running or plused GC? I assume you could make a really short column, but this would reduce your resolution on the time-in-column measurement.
 
Chemistry news on Phys.org
  • #3
I recently attended a lecture by my schools chemistry department where they built a two-dimensional (GCxGC) chromatagraph using two columns, one being pulsed. So yes you can do it.
 

1. What is the difference between continuous and pulsed operation in gas chromatography?

Continuous operation involves a constant flow of carrier gas and sample through the chromatograph, while pulsed operation involves periodically stopping the flow of carrier gas and injecting the sample into the system.

2. Which type of operation is better for separating complex mixtures?

In general, continuous operation is more effective for separating complex mixtures because it allows for a longer separation time and better resolution. Pulsed operation is typically used for faster analyses or for separating less complex mixtures.

3. How does the choice of operation affect the sensitivity of a gas chromatograph?

Continuous operation typically provides higher sensitivity compared to pulsed operation, as the constant flow of carrier gas allows for better detection of small sample components. However, pulsed operation may be more sensitive for certain compounds that are difficult to detect in a continuous flow.

4. Are there any limitations to using pulsed operation in gas chromatography?

One limitation of pulsed operation is that it can only be used for samples that are compatible with the carrier gas. Additionally, there is a risk of sample contamination when injecting into a stopped flow system.

5. Which type of operation is more commonly used in gas chromatography?

Continuous operation is the more commonly used method in gas chromatography, as it allows for better separation and sensitivity for most samples. However, pulsed operation may be preferred for certain applications where speed is more important than resolution.

Similar threads

  • Astronomy and Astrophysics
Replies
1
Views
2K
  • Sci-Fi Writing and World Building
Replies
21
Views
993
  • Astronomy and Astrophysics
2
Replies
48
Views
12K
  • Mechanics
Replies
2
Views
2K
  • Other Physics Topics
Replies
0
Views
724
  • Sci-Fi Writing and World Building
Replies
15
Views
3K
  • MATLAB, Maple, Mathematica, LaTeX
Replies
5
Views
2K
  • MATLAB, Maple, Mathematica, LaTeX
Replies
5
Views
2K
Replies
109
Views
54K
Back
Top