Flow analysis of transition metals by thermal lensing

The conditions for the flow determination of Al(III), Bi(III), Cd(II), Co(I I), Cr(III), Cu(II), Fe(III), Mn(II), Nd([II), Ni(II), Pb(II), Pr(III), and Zn(II) by reaction with Xylenol Orange in aqueous solutions at pH 4.5 and the determination of Cd(II), Co(II), Cu(II), Fe(II), Ni(II), Pb(II), and Zn (II) by reaction with 4-(2-thiazolylazo)resorcinol in water-ethanol mixture s (5 : 1) at pH 5.0 using an injected sample volume of 80 muL were proposed . The limits of detection were n x 10(-8)-n x 10(-7) mol/L; the linearity r anges in the calibration graphs were of about three orders of magnitude; th e relative standard deviation was of 3-7%.