To know about the chemical state of fluorine, it could be interesting to perform Electron Energy Loss Spectroscopy (EELS) within a (S)TEM. It could give information about the chemical state. Regarding the dopant exact concentration, SIMS is usually the most reliable choice, used even for every low concentrations. Nevertheless, for both cases, I am not sure if these techniques apply to your system in particular.

About EDS, it is not the best technique, it will much dependent on many morphological parameters and is not regarded as good for low concentrations. Also, good quantitative analysis depend on standards which are normally not used in routine EDS analysis. If you must use EDS, some standards should be obtained and used for EDS calibration, particularly for Si(Li) detectors with thick windows.

Depends on the compound and the atomic number of the dopant. RBS can be useful as can be XAS. If you have standards SIMS will work splendidly.

As Luiz said EELS is the best technique. It not only gives composition, but will also give distribution map. Other option is XPS.

You can use XPS. It will give you quantitative information about elements present in your sample than the EDS.

EDX is really bad and wil not give you unless its alloy and not dopant.

XPS and Auger have poor sensitivity (few%). SIMS is best if you have really low dopant concentration. If you want really sensitive and want to charactrize very low dopant level, go for TOF SIMS

XPS may or may not help, being strongly dependent on the average size of your nanoparticles. As a mater of facts, you may probe just few nanometers beneath the open surface of your samples. If you have large NPs XPS would give you only the F chemical state and amount in the most external selvedge. I agrre with collegues in that SIMS and TOF-SIMS may be the best solution. Of course also EELS by TEM is quite good a choice, but statistics may be cumbersome

I frequently used EDX to probe the exact content of rare earth content in my glass and its really worked well. The problem may arise if i want to detect the atomic content with Z numbers is less than oxygen. I think this is due to the limitation of the detector installed in the system. In some systems, the lowest Z number that can be detected is 12 (for carbon) . So other system exhibits their own sensitivity. I advice you to please check your system.

It seems that most methods have their own advantages and disadvantages. But the basic point to stress out is the sensitivity of the system.

Chemical analysis you can perform by XPS, XRD or Ramman. But, all these techniques works for main elements alone. Dopants chemical composition can be estimated (only)! from EDX (>0.1% level) XRF (>0.01%), RBS (>0.01) or SIMS (ppb level) data. SIMS analysis will be complicated by the complex sample structure (powder) and a standard necessary. One of the best way for you would be to use a quit rare method - SNMS (Secondary Neutral Mass Spectrometry, INA-3 or INA-X instrument,from SPECS, Germany) with true quantitative analysis and the DL of around 1E-3 atomic%.

dear researchers.. thank you all for your valuable suggestions... characterization techniques which you had stated above are very rare to perform here. how about X-ray fluorescence characterization?

how about X-ray fluorescence characterization?

A good chose, but ... your XRF system shoeld be equipped with a new generation X-Ray detector, which can detect all elements, starting from Boron. Previous generation of XRF systems analyzed elements starting from Na.

Icp-ms the rest you can forget, too insensitive for low amounts.

I know this question is 4 years old but this (see linked file) is a nice comparison of the various analytical tools.

http://www.eaglabs.com.tw/cmss_files/attachmentlibrary/analytical-resolution-versus-detection-limit-BR004.pdf