A field filtration method for the concentration and separation of suspended particulate matter (SPM) from freshwater systems for subsequent determination of major elements (Si, Al, Ca, Fe, Mn, Mg, Na, K, P, Ti and S) is validated with respect to precision and bias. The validation comprises the whole procedure including filtration, sample digestion and instrumental analysis. The method includes two digestion procedures (microwave acid digestion and alkali fusion) in combination with inductively coupled plasma atomic emission spectrometry (ICP-AES). Total concentrations of the elements have been determined in suspended particulate matter from lake and river water with low levels of suspended solids (