The metal analyses are now made of acidified unfiltered water samples, which means that some metals that are loosely adsorbed onto particles are unintentionally included in the analysis. However, the amount of acid is not sufficient to break the particles down to a considerable extent; therefore, for most metals, there is little difference between the analysed "total content" and the content of dissolved metals. Read more about this in a report (in Swedish) comparing the effect of different sample treatments on the analysed metal content, and in another report (in Swedish) describing the proportion of metals coupled to particles and dissolved in the water.
When analysing the nickel content in water samples, the calcium content has a certain influence on the result, which now is compensated for directly during the analysis. However, samples analysed before 2002 have not been corrected for this interference. The possibilities of correcting the values retroactively are investigated in a report. Results show that correction is simple if there is also information about the calcium content of the water. Even in cases where calcium data is lacking, it is possible to satisfactorily correct the nickel content retroactively. Read more about this in the report "Analys av nickel med ICP-MS - Kalciuminterferensens betydelse 1985-2007 (in Swedish, "Analysis of nickel with ICP-MS - The significance of the calcium interference 1985-2007").
Aluminium can be analysed with several different methods. Read more in our method comparison (in Swedish).
Valid since January 2018
Method: Metod: ICP-MS, SS-EN ISO 17294-2:2016
Instrument: Agilent.
2007-08 – 2017-12
Method: ICP-MS, SS-EN 17294-2:2005. The samples are conserved by acidification upon arrival at the laboratory (0.5 ml HNO3/100 ml).
Instrument 2016-2017: Agilent.
Instrument 2007-2015: Elan DRC-e ICP-MS with MiraMist Nebulizer. Direct injection of unfiltered water sample (via sample changer).
1995-08 – 2007-08
Method: Direct injection of acidified unfiltered water sample (0.5 ml HNO3/100 ml).
Instrument: PerkinElmer ELAN 6000.
1989-01 – 1995-07
Method: Atomic absorption with graphite furnace. Direct injection of acidified unfiltered water sample (0.5 ml HNO3/100 ml). Swedish Standard SS 02 81 83, -84.
Instruments: Philips PU 9200 Atomic absorption spectrophotometer, PU 9390 Electrothermal atomiser, PU 9380 Furnace autosampler.
1978-01 – 1988-12
Method: Atomic absorption with graphite furnace. Direct injection of acidified unfiltered water sample (0.5 ml HNO3/100 ml). Swedish Standard SS 02 81 83, -84.
Instrument: Hitachi 170 -70 Atomic absorption spectrophotometer with background correction according to Zeeman.
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