samples.
3.9. Application of the method
The proposed method has been applied to the determination
of trace Hg(II) in certified reference materials (GBW 08301, river
sediment and GBW 08303, polluted farming soil). According to the
results listed in Table 3, the estimated content by the proposed
method were in good agreement with the certified values of Hg(II).
For the analysis of Yellow River water and tap water samples, the
standard addition method was used. The results listed in Table 4
shows that the recoveries of Hg(II) were in range of 97.2–100.8%.
The obtained results indicated the suitability of the SG-OHC for the
preconcentration of Hg(II) from environmental samples prior to
ICP-AES analysis.
3.10. Comparison with other methods
Table 5 shows the comparison of the suggested method with
other SPE methods reported in the literature [31–35,17]. As seen
from the data, the present method possessed the advantages
of higher enrichment acidity and adsorption capacity than the
reported other SPE methods.
4. Conclusion
In this work, a simple, rapid, accurate and reliable method
was developed for determination of trace level of Hg(II) in environmental
samples based on adsorption of silica gel modified
with 2-(2-oxoethyl)hydrazine carbothioamide. This sorbent exhibited
good characteristics for separation and preconcentration of
Hg(II) in aqueous solution, such as excellent selectivity, fast
adsorption equilibrium, easy elution, good adsorption capacity and
interference-free extraction of trace Hg(II). Moreover, the preparation
of SG-OHC was relatively simple and convenient. The proposed
method was successfully applied to the analysis of trace Hg(II)
in certified and environmental samples with satisfactory results.
In summary, the new sorbent shows good analytical potential for
analysis of trace Hg(II) from environmental samples.