lFirst: dissolution of glass with HF. Then elliminate HF in other acids ( as H2SO4

Then AA for suspected metals

I suppose than you want to measure heavy metals in particles deposited on the glass fiber filter You may leach your filter with 1 M HCl or HNO3 and then scan the leachate with ICP-OES or/and ICP-AES. Parts of heavy metals are well dissolved. If you try a dissolution with stronger conditions, you could destroy the structure of you filter and obtain a soup of fibres. Centrifugation will help you in this case. At least, HCl/HF/HNO3 digestion can be done. For some semi-quantitative examination, you can use a X-Ray Fluorescence gun, or a more classical X-Ray Fluorescence spectrometer. A LIBS can do the job also.

Be careful because for glass fiber filters, blanks are often contaminated with a lot of metals. If your target is heavy metals and if you have the opportunity to sample by yourself, prefer cellulose filters or polycarbonate or cellulose-ester membranes.

Hi. There is an european standardized method called 'Ambient air quality. Standard method for the measurement of Pb, Cd, As, and Ni in the PM 10 fraction of suspended particulate matter', EN 14902:2005. I suggest you use it. It refers to PM10 particles, but it is valid regardless to particles size (it is widely used for PM 2.5). Previous answers are valid too, but I suggest you use a standardized method in order to assure reproducibility and valid comparison with other data. Others metals can be analyzed with the same procedure, with the noticeable exception of Hg (for ambient air quality and Hg, you can also refer to EN 15852:2010, 'Ambient air quality. Standard method for the determination of total gaseous mercury').

Thanks to everyone. The information are very helpful very helpful.