Dj. Whitworth et al., VALIDATION AND IN-SITU APPLICATION OF AN AUTOMATED DISSOLVED NICKEL MONITOR FOR ESTUARINE STUDIES, Analytica chimica acta, 371(2-3), 1998, pp. 235-246
The validation of a fully automated dissolved Ni monitor for in situ e
stuarine studies is presented, based on adsorptive cathodic stripping
voltammetry (AdCSV). Dissolved Ni concentrations were determined follo
wing on-line filtration and UV digestion, and addition of an AdCSV lig
and (dimethyl glyoxime) and pH buffer (N-2-hydroxyethylpiperazine-N'-2
-ethanesulphonic acid). The technique is capable of up to six fully qu
antified Ni measurements per hour. The automated in situ methodology w
as applied successfully during two surveys on the Tamar estuary (south
west Britain). The strongly varying sample matrix encountered in the
estuarine system did not present analytical interferences, and each sa
mple was quantified using internal standard additions. Up to 37 Ni mea
surements were performed during each survey, which involved 13 h of co
ntinuous sampling and analysis. The high resolution data from the wint
er and summer tidal cycle studies allowed a thorough interpretation of
the biogeochemical processes in the studied estuarine system. (C) 199
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