This European Standard specifies two methods for the determination of chromium in water by atomic absorption spectrometry. The two methods are covered in separate clauses as follows: Clause 3: Determination of chromium by flame atomic absorption spectrometry;
Clause 4: Determination of chromium by electrothermal atomization atomic absorption spectrometry.
Clause 3 is applicable to the analysis of water and waste water when the concentration range is between 0,5 mg/l and 20 mg/l of chromium. When the concentration is below 0,5 mg/l the determination can be carried out after carefully evaporating an acidified sample to small volume, taking care to avoid the formation of a precipitate.
WARNING: The use of evaporation will increase the effect of interfering substances and therefore for concentrations below 0,1 mg/l the method in clause 4 is given. Clause 4 is applicable to the analysis of water and waste water when the concentration range is between 5 ug/l and 100 ug/l of chromium by injecting a sample volume of 20 ul. It is applicable to the determination of higher concentrations by using a smaller sample volume.
Diese ÖNORM beschreibt zwei Verfahren für die Bestimmung von Chrom in Wasser mittels Atomabsorptions-Spektrometrie. Verfahren A behandelt die Bestimmung von Chrom mittels Flammen-Atomabsorptions-Spektrometrie, Verfahren B mittels AAS nach elektrothermischer Atomisierung (Graphitrohr- technik). Verfahren A ist für den Bereich zwischen 0,5 mg/l und 20 mg/l geeignet, Verfahren B für den Bereich von 5 mg/l bis 100 mg/l.