Issues related to the recovery and treatment of the mobile phase
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What do people do with the mobile phase after liquid chromatography analysis?
To be honest, we already have quite a few of them left now, and we don’t know what to do with them. I want to dispose of it, but both methanol and acetonitrile are toxic, and disposing of them is not easy either ； Furthermore, with reagents that are so expensive, and since the liquid chromatography result doesn’t show many impurities, it seems wasteful to discard them directly.
If a single product is used, it can be recycled. As mentioned above, it’s possible to reuse the mobile phase, and the results are pretty much the same; some people can use it up to ten times. PF, right~~ Of course, it can also be redistilled, but that’s too troublesome and not worth it. Another option is to spend money on environmentally friendly treatment methods~~
As a supplement, a small amount of debris does not affect the analysis, so you can give it a try~~
We mainly use methanol, and our workshop has a unit for its recovery, so relatively speaking we don’t have any problems: lol. Generally, however, there seems to be a dedicated system for recovery, but the amount in the analysis laboratory is so small that no one comes to collect it. Therefore, it’s important for those of us who are involved in quality control to have an environmental awareness and to collect it proactively, contacting the relevant departments or recycling personnel as needed; if that’s not possible, then incineration is the option, for our own sake and for the sake of the planet
1. Dehydration 2. Simple laboratory distillation 3. Testing; if possible, recycling. If the boiling point of your sample is high, recycling is no problem at all
Domestic companies rarely consider recycling; of course, distillation can be an option, but considering labor costs, water and electricity expenses, etc., there isn’t much value in recycling in such cases
Our waste liquids are mixed together. The boiling point of methanol is 64.7 °C, that of acetonitrile is 81.1 °C, and that of pure water is 100 °C. As for the samples to be analyzed, they are mostly high-boiling-point substances (for which gas chromatography cannot be used). It seems that simple distillation could be used to separate them! But will mixing the three together form an azeotrope? Have any of you who have done this shared their practical experience? There is also the issue of the purity of the obtained fractions; could using a mobile phase have adverse effects on the column?