1 Type of sample
The method is applicable to the analysis of potable waters, ground waters, and lightly polluted surface and sea waters.
2 Substance determined
The method determines filterable (dissolved) and acid-soluble aluminium.
The method includes low range determination up to 100 μg/l Al with 50 mm cells and high range determi-nation up to 500 μg/l Al with 10 mm cells. The effec-tive range depends on the sensitivity of the spectrometer and can be extended upwards by taking smaller test portions.
4 Limit of detection
The limit of detection is 2 μg/l when cells of optical path length 50 mm and a 25 ml test portion are used.
An aluminium concentration of 100 μg/l gives an absorbance of about 0,20 ± 0,05 optical absorption units, using a 25 ml test portion and cells of optical path length 10 mm.
If not specified, the precision of volumes and masses mentioned in this International Standard is ± 1 % of the value.