Flow Injection Simultaneous Determination of Copper and Iron in Lubricating Oil Using a New Spectrophotometer with Dual Light-Emitting Diode

Original Paper

Abstract

A dual light-emitting diode-based spectrophotometer was newly designed for the determination of two components by a flow injection (FI) method. The FI system was demonstrated for the simultaneous determination of copper and iron in lubricating oil used for marine diesel engines. The chemistry relied on the complex formations of copper(II) and iron(II) with 2-(5-Bromo-2-pyridylazo)-5-(N-propyl-N-sulfopropylamino)aniline (5-Br-PSAA). Copper(II)- and iron(II)-5-Br-PSAA complexes were detected at 560 and 710 nm. The analytical results obtained by the proposed method are compared with those obtained by inductively coupled plasma atomic emission spectrometry.