Hydrogen- saturated atmosphere flame ionization detector (HAFD)
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I would like to ask my seniors and colleagues: Does anyone know anything about the Hydrogen-Protected Atmosphere Flame Ionization Detector (HAFD) instrument? Used for the selective detection of organometallic compounds and silicon compounds. I would appreciate some advice from those with more experience. Thank you
Well, I asked many chromatography manufacturers, and they’ve never come across it either
This post was last edited by qugd on 2021-5-13 10:44. Can the original poster describe the problem in clear terms? Your title mentions a hydrogen-saturated atmosphere, while the text refers to a hydrogen-protected atmosphere; if you can’t even describe the problem accurately, then what kind of correct response are you expecting?
Well, the personal details weren’t described clearly; the correct information is “Hydrogen-protected atmosphere flame ionization detector””
In my understanding, a hydrogen-preserved atmosphere flame ionization detector operates by maintaining a hydrogen concentration in the combustion chamber that is higher than that required for normal combustion; this creates a strongly reducing atmosphere for the fragments of the components being analyzed, thereby providing a protective reducing environment for those fragments that tend to form stable oxides during the combustion process. The flame of a detector is reducing; in contrast, there are also oxidizing flames.
As Teacher Q suggested, the flow ratio of fuel gas to oxidizing gas should be adjusted according to the actual conditions. Achieve a reducing atmosphere for the testing process.
This post was last edited by qqgd on 2025-6-26 at 12:55. It is essentially a special type of FID detector; however, during combustion, the proportion of hydrogen is quite high, creating a strongly reducing atmosphere around the flame. This helps to prevent organic molecule fragments that are prone to forming oxides, such as metal-organic compounds and organosilicon compounds, from forming oxides in this high-hydrogen flame environment, thus avoiding a decrease in detection sensitivity. Due to the need to maintain a high fuel ratio in its structure, this type of detector may differ from a FID in terms of its combustion head, and it has specific requirements regarding the gas distribution pipeline and the gas distribution ratio.
Generally, FID detectors have relatively low hydrogen levels, with air constituting 10–15 times the flow rate of hydrogen, thus creating an oxygen-enriched oxidation atmosphere. Only a few studies report using the detector in reverse, with an excess of hydrogen and a shortage of air; this approach may yield special response characteristics. The specific properties can be determined through experiments.