Cwk. Chow et al., DETERMINATION OF COPPER IN NATURAL-WATERS BY BATCH AND OSCILLATING FLOW-INJECTION STRIPPING POTENTIOMETRY, Analytica chimica acta, 330(1), 1996, pp. 79-87
Copper trace analysis in natural waters rich in chloride ions add orga
nic matter mas performed by means of a copper-selective electrode (Cu-
ISE), inductively coupled plasma-atomic emission spectrometry (ICP-AES
), anodic stripping voltammetry (ASV), batch potentiometric stripping
analysis (PSA) and oscillating flow injection stripping potentiometry
(OFISP). The results obtained by the first two analytical methods show
ed that copper was present mainly in the form of various complexes wit
h inorganic (mainly chloride) ions and organic ligands, The organic co
nstituents impeded the application of ASV in the quantitative determin
ation of labile copper concentration in the water samples mainly due t
o adsorption of organic matter onto the working electrode. Consistent
analytical data concerning the labile fraction of copper were obtained
by both batch PSA and OFISP in hydrochloric acid medium when standard
addition or direct calibration were used. However, discrepancies betw
een the batch PSA results obtained by the two calibration methods ment
ioned above in nitric acid medium were observed. Unlike batch PSA, OFI
SP appears to be versatile with respect to the sample matrix in both s
tandard addition and direct calibration approaches. On the basis of th
is and the other well-known advantages of OFISP it was concluded that
this analytical technique is suitable for fast and inexpensive trace h
eavy metal analysis in natural waters with unknown matrices.