Chemistry Reference
In-Depth Information
Table 7.12
Interference effects
Interference effect
(mg L
−1
N)
Interfering substance
Species
Concentration
(mg
L
−1
)
With carbon
filtration
Without carbon
filtration
2500
a
Chloride
0.02
0.02
5000
0.06
0.06
Bromide
1.0
a
0.02
0.02
2.0
0.04
0.04
0.65
a
Iodide
0.02
0.02
1.30
0.05
0.05
Iron
13.5
<0.02
<0.02
27
<0.02
0.08
1000
b
<0.02
1.4
Iron
0.2
<0.02
>0.02
0.4
<0.02
0.08
1000
b
<0.02
1.75
0.15
a
Dichromate
0.02
0.02
0.30
0.08
0.08
Manganese
100
<0.02
>0.02
1000
b
<0.02
0.4
Dodecylbenzenesulphonic acid,
sodium salt
3.5
<0.02
>0.02
7.0
<0.02
0.06
1000
b
<0.02
1.8
a
Indicates 'interference limit'
b
Indicates highest concentration investigated
Source: Reproduced with permission from the Royal Society of Chemistry [48]
direct ultraviolet methods, such interference is eliminated in this method as a result of the
formation of insoluble hydroxides at the elevated pH, the precipitates being removed by
the GF/C paper on the filter. It is apparent that the interference effects of anions are not
reduced by carbon treatment.
De Fulvio and Olori [50] determined nitrate in drinking water by ultraviolet
spectrophotometry at 210nm, and matrix interferences were overcome by control of the
ionic strength.
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