Tintometer Lovibond MD 100 Instrucciones página 26

Nitrate T / M260
Removeable Interferences
1. If there is nitrate in the original water sample, it will lead to high values of nitrate nitro-
gen. For correction, carry out a nitrite determination using
method 270 in NO2-N and subtract the result from the nitrate reading for the correct
result. The result displayed does not show the actual concentration of nitrate nitrogen
in the water sample being analysed.
2. Concentration of nitrate nitrogen above 1 mg/l results in an erroneous measurement
after the reaction time of 10 minutes (in this instance, a colour change to apricot
colour instead of the reddish pink solution). The range of the test can be extended by
first diluting the water sample with deionised water. The subsequent result of the test
must then be multiplied by the dilution factor.
Derived from
ASTM D 3867-09
APHA 4500 NO3- E-2000
US EPA 353.3 (1983)
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EN Method Reference Book 1.0