[Chaste]

Hi all, I have lanthanum nitrate, TiO2 and ruthenium chloride solution in separate containers and need to remove these inorganic metal ions before I send the samples for analysis on HPLC(because the column is sensitive to metal ions)

I'm not sure if TiO2 is dissolved in my solution is there any way to make sure that they are not present?

are there any simple ways to precipitate these 3 metals?

I was thinking of adding hydroxide but I search and didn't really return any positive results.

Thanks in advance.

[Yakimikku]

Well, depending on what you want to keep in the solution, you might just want to pass the solutions through a silica plug which may remove the highly polar metal-based impurities. This should ensure nothing too sticky will enter your HPLC

As far as precipitation, solvent and counter ion are important. Off the top of my head though I don't have any specific ideas for those three metals.

[Chaste]

Hi thanks a lot. Was thinking if there are ion exchange resins that are specific to these as well? And just a note to add, my samples are in low volume, less than 5ml. So, i'm not sure how much can i get through a silica plug and my wanted products are polar as well, like glucose and its derivatives.

[Yakimikku]

I'm not sure--you'd have to ask someone else about ion exchange resins. I've only known them to be used for bio-related columns (for proteins, etc). Low volume is okay, you'd need to use an elutant anyway to push your material through the silica plug (and strip the solvent afterwards). I've never worked with sugars, but there might be a solvent (or solvent combination) that would pull your material through while keeping the inorganic material behind. You could test out solvents using TLC. RuCl₃ should be dark colored so you could prob. see it on the TLC plate. I think TiO₂ however is white and I'm not sure about lanthanum nitrate. I'm not sure how you'd see the sugars, not sure if there is a stain out there for that.