Chemistry Reference
In-Depth Information
−1
)
1 Mohr titration
25 0.065
2.6
200 0.52 0.26
6.1
0.31 5.1/
106
0.38 0
2 Mohr titration
50 (0.0.) (0.0)
250 0.49 0.20
54 0.68 1.3
99 0.58 0
3 Mercuric
nitrate
titration
20 0.29 1.5
180 0.42 0.23
47 0.55 1.2
139 0.70 0
4 Mercuric
nitrate
titration
8 0.12
1.5
80 0.14 0.18
16 0.091 0.57
65 0.073 0
5 AutoAnalyzer
20 0.71 3.6
180 1.6 0.89
42 0.94 2.2
124 2.4
6 AutoAnalyzer
20
1.2
6.0
180
2.1
1.2
40
0.89 2.2
137
1.6
7 AutoAnalyzer
30
1.1
3.7
270
2.7
1.0
18
0.97 5.4/
III
1.5
8 AutoAnalyzer
5 0.19 3.8
45 0.15 0.33
26 0.24 0.92
45 0.19 0
9 AutoAnalyzer
5
0.17
3.4
45 0.42 0.93
23
0.71 3.1
36
1.0
10 SMA
AutoAnalyzer
20 0.84 4.2
180 1.6 0.89
53 1.52 2.9
144 1.38 0
a
The estimate of the standard deviation of any one result in any one batch of analyses; the estimates
have between 9 and 19 effective degrees of freedom.
b
The standard deviation expressed as a percentage of the concentration of the solution.
*
Not statistically significantly greater than 5.0% (0.05 probability level).
Source: Reproduced with permission from the Royal Society of Chemistry [165]
or
The values for the maximum bias shown in Table 2.6 are almost invariably less than
10% and often much less.
It is concluded that precision and bias are satisfactory in all three methods for the
determination of chloride mentioned above.
Chloride can be automatically titrated with standard silver nitrate solution using a
chloride selective electrode [167], and non-ionic detergent must be added to prevent
fouling of the electrodes by precipitated silver chloride. A modification to the titrant-
delivery tube on the commercial apparatus used is required to deliver the titrant against
the indicating surface of the chloride-selective electrode. Reproducibility is good for all
concentrations in the range 1 to 100mg L
−1
chloride; the standard deviation was ±0.28 to
0.47mg.
Kuttel
et al.
[168] have described a potentiometric titration procedure for the
simultaneous determination of chloride (and bromide and iodide) in non saline waters.
Errors caused by adsorption of the common ion on to the surface of the precipitate in the
potentiometric titration of mixtures of halides with use of a silver electrode or a AgI,
AgBr or AgCl membraneelectrode can be overcome by the addition of sodium nitrate at a
concentration exceeding 1N. Because of the small difference in the solubilities of silver
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