Supposedly you know the exact weight of your supported catalyst that you've sent for analysis. You can also know the weight of your total amount of digested nitrate solution that you analyze by ICP MS. Dividing the calculated metal weight in solution by the amount of original catalyst amount you should obtain the correct loading (assuming you have used the correct digestion procedure).

[ Concentration of metal (ppm or mg/liter) x Volume of the extract (liter) ] / Weight of the solid sample taken for extraction (gram)

For example you have taken 0.5 gram of your solid sample and extracted it using nitric acid or any other acid combination of acids (microwave digestion or open digestion) and the final volume was made up to 25 ml. Then you analyzed the solution using ICP MS and find the concentration of metal as 72.2 mg/liter in the solution. Then the concentration of metal in the catalyst will be

[ 72.2 x 0.025 ] / 0.5  = 3.61 mg/gram

Metal concentration in a sample can be calculated as follows:

 Sample concentration (μgl/g) = [C (μg metal/mL) x V (mL) x DF] / W (g)

C = concentration in extract determined by ICP-MS (μg metal/mL)

V = Digestion volume (mL)  

DF = Dilution factor (undiluted =1)

W = weight of sample aliquot extracted (g)

Any reference for the above answers?

METHOD 6020B INDUCTIVELY COUPLED PLASMA—MASS SPECTROMETRY (https://www.epa.gov/sites/production/files/2015-12/documents/6020b.pdf)

Hi, May I know how you convert your result mg/g back to ppm or ppb?

you use the same equation, but rearrange matematically.

Thank you Luyza