Determination of 2-furaldehyde in transformer oil using flow injection with pulsed amperometric detection

Abstract

An on-line flow injection (FI) system suitable for the on-site determination of 2-furaldehyde in transformer oil has been developed. This paper examines the feasibility of combining FI with pulsed amperometric detection (PAD) to produce a method for the rapid on-line analysis of 2-furaldehyde. The determination of 2-furaldehyde by FI with PAD is direct and simple. PAD was applied to the determination of 2-furaldehyde at a platinum electrode in alkaline media. Plots of peak height versus concentration gave linear regions for concentrations in the range 5–40 ppm at a pump rate of 0.4 ml min^–1 and detection potential (E₁) of –750 mV (versus SCE), and in the range 1–8 ppm at a pump rate of 0.8 ml min^–1 and E₁ of –800 mV. Detection limits of 1 ppm (S/N = 3) were found for E₁=–750 mV (pump rate = 0.4 ml min^–1; injection volume = 67 µl) and 0.5 ppm for E₁=–800 mV (pump rate = 0.8 ml min^–1; injection volume = 100 µl), respectively. 2-Furaldehyde was extracted from transformer oil through a partitioning membrane in a flow through macrodialyser cell. Under optimized conditions the extraction efficiency for 2-furaldehyde from transformer oil, using differntial pulse polarography experiments, was found to be 15% at oil/reagent flow rates of 0.3 ml min^–1.