Chemistry Reference
In-Depth Information
YES
(Hg content >1.5
m
g g
−
1
)
ª
2.5
m
g Hg g
−
1
84%
100%
ª
2.0
m
g Hg g
−
1
55%
95%
5%
ª
1.5
m
g Hg g
−
1
2.5%
95%
2.5%
ª
1.0
m
g Hg g
−
1
70%
100%
ª
0.5
m
g Hg g
−
1
100%
ª
0.0
m
g Hg g
−
1
100%
NO
(Hg content <1.5
m
g g
−
1
)
Figure 11.4
Results obtained from the screening of Hg in real soil samples of different Hg concentrations.
Reproduced by permission of the Royal Society of Chemistry (http://pubs.rsc.org/en/Content/
ArticleLanding/2005/JA/b509645f). For more information, see Reference
[22].
Reproduced by permission of
The Royal Society of Chemistry © 2005.
needed, as there is an EC legal limit 1.5
g g
-1
for Hg. The screening method proposed allows obtaining a
reliable answer in 6-10 min per sample, and only for those samples with a Hg content very close to the legal
value (1.15-1.95
μ
g g
-1
), would the use of a complementary technique for further analysis be required.
Figure 11.4 shows the results obtaining when applying the method to real soil samples of varying
concentrations. It can be seen that in the majority of cases, samples can be screened correctly with only three
replicates (6 min). Only for those samples with contents close to the threshold it is necessary to carry out two
more replicates. Eventually, if the sample content is practically identical to that of the threshold (1.5
μ
μ
g g
-1
),
it is not feasible to obtain a reliable response.
Finally, some further examples of industrial samples that are very difficult to dissolve, such as very
refractory materials, and for which the use of direct solid sampling have proved advantageous are also shown
in Table 11.3 [86-88].
11.4
Future for green analytical atomic spectrometry
Despite the lack of literature highlighting this aspect, it is obvious that the use of direct solid sampling
techniques contributes to the development of greener atomic spectrometric methods. This issue, together with
other advantageous aspects (e.g., increased sample throughput and excellent sensitivity), may help in
counterbalancing the classical disadvantages of these techniques (e.g., limited precision), which can be
further deploy in many situations for which they are perfectly suited, such as analysis of materials of complex
dissolution or the development of screening schemes.
