Development of formaldehyde detection method using onion juice as chromogenic agent

Abstract

A B S T R A C TThis work reports an initial study on the use of natural compound, i.e. onion juice, as a novel environmental-friendly chromogenic agent to determine the concentration of formaldehyde. The method is based on the reaction of formaldehyde with yellow onion juice to produce a pink solution which absorb strongly at 514 nm. Factors affecting the extent of reaction between formaldehyde and onion juice such as temperature, pH of onion juice and reaction time were optimized using the response surface methodology approach via the Box-Behnken design. The experimental values obtained were close to the predicted values indicating good approximation of the model. The optimum response was obtained by heating the onion juice at 60˚C, pH 4.9, reaction temperature of 103˚C and reaction time of 17 min. A linear calibration curve was obtained using formaldehyde concentrations ranging from 0.5 to 15 mg L À1 . This study demonstrates the potential application of onion juice as a simple, safe and environmental friendly technique for quantitative determination of formaldehyde from various sources such as drinking water and aquaculture products.

The Research Progress of Endogenous Formaldehyde in Aquatic Products

“…The method has a linear range of 0.5 to 15 mg/L at 514 nm wavelength. This study demonstrates the potential application of onion juice as a simple, safe and environmental-friendly technique for determination of FA [26].…”