Determination of copper (II) at sub-picogram level by flow injection method using micellar enhanced chemiluminescence of 1,10-phenanthroline

Abstract

Micellar enhanced chemiluminescence(CL) is used to determine copper(II) at sub-picogram level by using the 1,10-phenanthroline-hydrogen peroxide-sodium hydroxide-hexadecylethyldimethylammonium bromide micelle system. The CL mechanism is based on the following chemical reactions; the superoxide radical anion which is produced through the catalytic decomposition of hydrogen peroxide by the copper (II)-1,10-phenanthroline complex, reacts with 1,10-phenanthroline to form the excited 3,3′-diformyl-2,2′-dipyridyl via a 1,2-dioxetane derivative intermediate. The system is composed of three flow lines, in which optimum conditions are specified. This method permits the determination of copper (II) much more selectively than any other CL methods with a limit of determination of 8.0×10−14g(20 µl sample injection) or 1.6×10−13 M(continuous sample flow at the sample feed speed 5.0 ml/min). The linear dynamic range is 4 orders of magnitude, the sampling rate is 180/h, and the reproducibility is less than 1.7% in terms of coefficient of variation for 5×10−13g copper(II) injection (n=10). Lead(II), the strongest enhancer after copper(II), provides signal 0.03% of that for copper (II). The method is successfully applied to the determination of copper (II) in the tap water. © 1986, The Japan Society for Analytical Chemistry. All rights reserved.