Electrochemical microsensors for the detection of cadmium(II) and lead(II) ions in plants.
Routine determination of trace metals in complex media is still a difficult task for many analytical instruments. The aim of this work was to compare three electro-chemical instruments [a standard potentiostat (Autolab), a commercially available miniaturized potentiostat (PalmSens) and a homemade micropotentiostat] for easy-to-use and sensitive determination of cadmium(II) and lead(II) ions. The lowest detection limits (hundreds of pM) for both metals was achieved by using of the standard potentiostat, followed by the miniaturized potentiostat (tens of nM) and the homemade instrument (hundreds of nM). Nevertheless, all potentiostats were sensitive enough to evaluate contamination of the environment, because the environmental limits for both metals are higher than detection limits of the instruments. Further, we tested all used potentiostats and working electrodes on analysis of environmental samples (rainwater, flour and plant extract) with artificially added cadmium(II) and lead(II). Based on the similar results obtained for all potentiostats we choose a homemade instrument with a carbon tip working electrode for our subsequent environmental experiments, in which we analyzed maize and sunflower seedlings and rainwater obtained from various sites in the Czech Republic.
Department of Chemistry and Biochemistry, Faculty of Agronomy, Mendel University in Brno, Zemedelska 1, CZ-613 00 Brno, Czech Republic. olga.krystofova@seznam.cz
Olga
O
Krystofova
Libuse
L
Trnkova
Vojtech
V
Adam
Josef
J
Zehnalek
Jaromir
J
Hubalek
Petr
P
Babula
Rene
R
Kizek
D001331:Automation; D015374:Biosensing Techniques / Q000295:instrumentation* / Q000379:methods; D002104:Cadmium / Q000032:analysis*; D002244:Carbon / Q000737:chemistry / Q000494:pharmacology; D004563:Electrochemistry / Q000295:instrumentation / Q000379:methods; D004784:Environmental Monitoring / Q000295:instrumentation / Q000379:methods; D007477:Ions / Q000032:analysis; D007854:Lead / Q000032:analysis*; D008839:Microelectrodes; D010944:Plants / Q000737:chemistry*; D014131:Trace Elements / Q000032:analysis; D003313:Zea mays / Q000737:chemistry
D007477:Ions; D014131:Trace Elements; D002104:Cadmium; D007854:Lead; D002244:Carbon