What method should be used to analyze samples containing concentrated sulfuric acid?
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In the liquid-phase reaction experiments I am conducting now, concentrated sulfuric acid is used as a catalyst, at a concentration of around 0.1%. What method should be used for sample analysis? Due to its high boiling point, sulfuric acid is difficult to separate and tends to remain in the chromatography column; over time this can cause contamination of the injection port, the chromatography column, and the detector. Due to the high intensity of the experiments, samples need to be analyzed every half hour or so. After two days of testing, it seems that the chromatography column has become contaminated; even when standard samples are injected, impurity peaks appear. What should be done in such a situation? How to analyze an unknown sample containing a small amount of sulfuric acid? Please give me some advice! ! Thank you! !
I forgot to mention that I am currently using an Agilent 7890A gas chromatograph for sample analysis, with manual sampling
Could we consider using Ba2+ first to remove the sulfate ions (through titration), and then filtering out the precipitate? That should work. I’m not sure if it’s feasible; please advise, teachers.
It should be noted that when the concentration is only 0.1%, the sulfuric acid concentration is already very low; it is no longer considered concentrated sulfuric acid, so it cannot be treated as such. Generally, sulfuric acid is required for reactions that involve the removal of water. Before analysis, soluble barium salts can be added to remove sulfate ions first, and then analysis can be carried out. The downside of this approach is that it is difficult to control the amount of barium salt used, which can introduce new impurities that in turn interfere with the analysis results.
So it still can’t be analyzed? Will Ba salts also remain in the chromatography column?
Could an insoluble barium salt be used? Try barium carbonate.
One of my colleagues has encountered such a problem; experts are welcome to offer suggestions