Detection of formaldehyde in food samples by enhanced chemiluminescence

Abstract

In this study, chemiluminescence (CL) from oxidation of formaldehyde and luminol was investigated under alkaline conditions to develop a sensitive analytical tool for formaldehyde detection. The developed method was successfully applied for detection of formaldehyde in spiked soft drinks, wine, and raw fish storing solution. CL enhancement by optimized conditions of luminol, urea–H₂O₂, pH, and sequence of addition was investigated, which was not explored previously. The limit of detection was 10 pg ml⁻¹ and linear range 10 pg ml⁻¹ to 100 μg ml⁻¹ with a regression coefficient of R² = 0.998. The importance of these experimental parameters is discussed based on knowledge of oxidation of luminol by urea–H₂O₂ and further enhancement of CL by formaldehyde oxidation. Formaldehyde was spiked and recovered with 95–99.9%. The results obtained were compared with those of high-performance liquid chromatography (HPLC) and were well correlated.