简介:2.1 Prior to analysis by Method 7060, samples must be prepared in order
to convert organic forms of arsenic to inorganic forms, to minimize organic
interferences, and to convert the sample to a suitable solution for an简介:2.1 Prior to analysis by Method 7060, samples must be prepared in order
to convert organic forms of arsenic to inorganic forms, to minimize organic
interferences, and to convert the sample to a suitable solution for analysis.
The sample preparation procedure varies depending on the sample matrix. Aqueous
samples are subjected to the acid digestion procedure described in this method.
Sludge samples are prepared using the procedure described in Method 3050.
2.2 Following the appropriate dissolution of the sample, a representative
aliquot of the digestate is spiked with a nickel nitrate solution and is placed
manually or by means of an automatic sampler into a graphite tube furnace. The
sample aliquot is then slowly evaporated to dryness, charred (ashed), and
atomized. The absorption of hollow cathode or EDL radiation during atomization
will be proportional to the arsenic concentration. Other modifiers may be used
in place of nickel nitrate if the analyst documents the chemical and
concentration used.
2.3 The typical detection limit for water samples using this method is
1 ug/L. This detection limit may not be achievable when analyzing waste samples.详细>