I have a suspension containing some amount of elemental silver particles (~ 50 nm), possibly silver nitrate and possibly silver acetate. UV/Vis data shows a plasmon resonance at 410 nm, indicating particles are present. ICP-MS data only gives the total silver content - not what type of silver is present. I want to quantify what percentage of the suspension are silver particles, silver nitrate, and silver acetate.
I’m finding very little information on doing so without also affecting the elemental silver particles. I’ve consulted a few experts and they have only been able to tell me what NOT to do, such as XPS and EDS probably won’t be sensitive enough. I don’t think electrolysis could work either.
Does anyone have any ideas?
Hi Harman Quantifying the specific forms of silver (elemental particles, silver nitrate, and silver acetate) in your suspension without affecting the elemental silver particles is a challenging analytical problem. However, several strategies might help to differentiate and quantify these components:
Use ultracentrifugation to sediment the silver particles (50 nm size should sediment well under high centrifugal force). The supernatant would primarily contain the soluble silver species (silver nitrate and silver acetate).
Analyze the sediment for elemental silver using techniques like Thermogravimetric Analysis (TGA).
Analyze the supernatant using Ion Chromatography (IC) or UV-Vis spectrometry for the nitrate and acetate ions.
Perform ICP-MS on both fractions to quantify total silver content, and by difference, infer the silver content in soluble form.
You can also check it Chemically
Add a reagent like sodium chloride (NaCl) to the solution. Silver chloride (AgCl) will precipitate, which can be filtered out, leaving the nanoparticles and possibly some soluble organics.
Wash the precipitate to remove any associated soluble compounds.