Is there a gas chromatograph that can analyze HF gas?

This post was last edited by qugd on 2018-2-11 10:17. Analyzing this highly pure hydrogen fluoride gas is a challenging task using any analytical method. Chromatography should be possible, but it definitely requires chromatography column systems and detection systems that are specially designed and made from special materials, as hydrogen fluoride is a gas with very high polarity and high chemical reactivity; conventional materials find it difficult to withstand the effects of this gas (not necessarily due to corrosion alone). Additionally, for the purity analysis of high-purity gases, it is necessary to analyze their impurity content, and appropriate analysis methods must be selected based on the type and concentration range of these impurities. Personally, I believe it would be better to use an infrared or tunable laser gas analyzer for this gas. After all, a fixed gas colorimetric cell is easier to design than a system equipped with a chromatographic column. Moisture and sulfur dioxide can certainly be accurately determined through gas analysis, but the same cannot be said for silicon tetrafluoride, as too little is known about the properties of this component.

I have conducted analyses of H2, O2, N2, CH4, CO, CO2, and SiF4 in high-purity HF (99.999%) for Foshan Huate Gas. A DID helium ion detector and an anti-corrosion gas path system were utilized. For HF of this purity level, the SO2 content should be around 100 ppb, while the H2O content should be less than 1 ppm. The cavity ring-down technique can also be used to analyze trace amounts of water.

Uncle, long time no see. Do you still remember me? ;P

Dear brother, hello. Of course I know the former version

Haha, I’m so happy. Although it’s been a long time since I last visited the forum, Uncle’s name is mentioned everywhere in the community

Turns out I always called him “senior”. . ;P

If we use chromatographic analysis, actually the separation system is quite acceptable. However, attention should be paid to the sample introduction system and the outlet; sample introduction can be performed in a sealed manner with nitrogen purging. Outlet with absorption system or closed recovery, nitrogen purging. General-purpose, high-sensitivity HID or DID is both acceptable. Additionally, if the requirements are not high and the components are known, using a gas detection tube is also an option.

What is used as the tube material for your gas detection tubes, and what is used as the filler inside the tubes?

It seems to be made of glass; even if a reaction occurs in an atmosphere with a low concentration of gases, its impact on the results is minimal. Moreover, the gas detection tubes themselves have considerable errors. Depending on the concentration, there are two types of fillers. One is a pH indicator; it might be bromophenol blue, as the color ranges from blue to yellow. One is Zr(OH)4.