Analytical chemical aspects of the determination of aluminium in ground and drinking water by inductively coupled plasma mass spectrometry
Analytisch-chemische aspekten van de aluminiumbepaling in grond- en drinkwater met ICP-MS
Velde-Koerts T van der , Boer JLM de
RIVM Report 714301003
The aim of this project was to investigate whether ICP-MS is a suitable method for determining aluminium at low concentration levels in ground and drinking water. The determination was performed at m/z=27 with indium as an internal standard. The calibration curve was linear up to at least 100 mug/l A1 ; the detection limit (3s; n=25) was 0.4 mug/l. This detection limit could only be achieved if labware was thoroughly cleaned with 1% HNO3, if solutions were kept in polyethene bottles and if the metal parts of the autosampler were cleaned or replaced by synthetic materials. The short term stability (RSD) was 1.8% and the long term stability (RSD) was 3.0%. Spectral interferences and matrixeffects due to the most abudant ions in ground and drinking water and interferences like 11B16O+, 1H12C14N+ and 26Mg1H+ could be neglected. Only the addition of 400 mg/l sulphate resulted in an 10% positive shift in sensitivity. ICP-MS results compared well with ICP-AES results for concentrations above the detection limit of ICP-AES (20 mug/l). 70% of the 109 analyzed ground and drinking water samples (from the Netherlands) had concentrations within the linear working range (0.8-200 mug/l).