[kart007k]

I am a first time poster. I am trying to find an analytical method that I can use to determine the lowest possible Fe concentration. Now I use ICP-MS, AA, UV-Vis and ICP-AES, but I am getting some interferences from other dissolved salts in my process fluid. I can tell you that the solution ranges from 0.1M - 3M H3O+.

Any feedback is appreciated.

[Stepan]

AA and ICP will give you sensitivity of 0.1-1 ppm (depends on instrument). Cross interference from other metals is usually insignificant. For even better sensitivity and selectivity you can use ICP-MS.

[MJH]

Most new ICP-OES will be able to measure as little as 100 ppt (i.e. 0.0001 ppm).  It is a very sensitive method for Fe determination.  ICP-MS will go slightly lower, but it gets expensive and the advantage probably outweighs the price.

The H3O+ concentration is given as 0.1 - 3 M.  This means that the samples range in acidity.  The samples should best be prepared in the same acid concentrations as the calibration samples, to minimise the difference in transport effects (i.e. how well the sample is nebulised in the nebuliser and transported to the plasma).

Send more details about the analysis required and I will try to assist.

[SE_K800i]

I don't know the concentration of your Fe3+ solution.
I think you should use UV-VIS method (coordinated with SCN-). ICP should use when you want to determine some of elements. It's not the economical solution.

[Pradeep]

He may also doesn't know the concentration of his solution. That is why he is analyzing it. 1 ppm can be detected by flame AAS also. Fe in ppb levels can be detected by graphite furnace.ICP-MS have the best sensitivity and u can achieve fractions of ppb.