Determination of transitions metal ions as complexes with 2, 6-pyridinedicarboxylic acid by capillary electrophoresis

Abstract

A capillary electrophoresis (CE) method for the simultaneous separation of transition metal ions was developed ona fused-silica column coated with poly(diallyldimethylammonium chloride) (PADDC). 2,6 -pyridine dicarboxylic acid (PDC)was used to form on-column complexation with metal ions and were detected at UV wavelength. Ten metal ions, Ni (II), Cu(II),Zn(II), Fe(II), Fe(III), Co(II), Cd(II),V(IV), Pb(II), and Mn(II), were studied using 5 mM 2,6- pyridine dicarboxylic acid containing4 mM tetrabutylammonium hydroxide at pH 4.0 as a background electrolyte. The external standard calibration curveexhibited good linearity (R2 is 0.9927 to 0.9982) and the detection limits (determined at signal to noise ratio equal three) were0.07-2.2 mg/L by using a 6 sec injection time, at 50 mbar and -20 kV power supply. The %-relative standard deviation (n=5) formigration time, peak area and peak height of ten metal ions were 0.52-0.95, 0.26-2.5, and 0.89-3.3, respectively. The developedcapillary electrophoresis method was successfully applied to determine metal ions in the plating solution.

Keywords

• transition metal ions
• complexation
• capillary electrophoresis
• 2
• 6-pyridine dicarboxylic acid
• plating solution