Multielement determinations in ground water ultrafiltrates using inductively coupled plasma mass spectrometry and monostandard neutron activation analysis

Twelve ultrafiltrates of two ground waters rich in humic substances (up to 97.8 mg CL−1) and in salinity (up to: cations 44.3 meq L−1, anions 44.9 meq L−1) were investigated with ICP-MS and with NAA in parallel. With both techniques 22 elements were analysed in a wide concentration range (mg/L to ng/L). Ultrafiltration at pore sizes from 1000 nm down to 1 nm lowers the humic colloid content as well as the concentration of the colloidborne polyvalent cations. Carbon interferences were studied in detail using artificially prepared model waters. The detection limits of ICP-MS in the ultrafiltrates (0.01 μg/L–10 μg/L) and in pure analyte solutions (5 ng/L–600 ng/L) are compared with those of NAA for pure water analysis (0.004 ng/L–50 ng/L).