Determination of calcium ion in sap using carbon nanotube-based ion-selective electrodes.
A new reduced-size solid-state electrode using carbon nanotubes as the transducing layer has been developed for the direct determination of Ca(2+) in sap, overcoming problems encountered by commercial ISEs analysing real complex samples. We show that this solid-contact ISE, which can be easily miniaturized, can be used directly in diluted real samples without any other pretreatment. The performance parameters of the new ISE include a Nernstian slope and excellent stability, good coefficients of selectivity, range of linearity (10(-5) to 10(-2.5) M) and limit of detection (10(-6.2) M), thus making it an excellent tool for determining Ca(2+) in a wide range of plant species.
Hernández
Rafael
R
Department of Analytical and Organic Chemistry, Universitat Rovira i Virgili, Campus Sescelades, C/Marcel.lí Domingo s/n, 43007 Tarragona, Catalonia, Spain.
Riu
Jordi
J
Rius
F Xavier
FX
D002118:Calcium / Q000032:analysis*; D004566:Electrodes; D028481:Euphorbia / Q000737:chemistry; D007477:Ions / Q000032:analysis; D037742:Nanotubes, Carbon / Q000737:chemistry*; D053147:Plant Exudates / Q000737:chemistry*
D007477:Ions; D037742:Nanotubes, Carbon; D053147:Plant Exudates; D002118:Calcium