Application Of Flow-Injection In The Detection Of Formaldehyde

In order to ensure healthy food supply, to improve the quality of indoor environment and to protect human health, it is quite important to study the toxicity, source, producing mechanism and the detection method of formaldehyde. In this paper, spectrophotometry and chemiluminescence combined with flow injection method for the determination of formaldehyde were carried out. The analytical conditions were optimized. Formaldehyde in coating was analyzed.In chapter one, the characteristics, toxicity, sources and the concentraion standard of formaldehyde were briefly reviewed. Methods for formaldehyde analysis were summarized. Flow injection method and its application in spectrophotometry and chemiluminescenece were introduced.In chapter two, a flow analysis system with spectrophometric detection for formaldehyde detemination was developed. The method was based on the reaction of formaldehyde with 3-methyl-2-benzothiazolinone hydrazone hydrochloride, which formed pyrazine that could be oxygened into bluish green compound by Fe³⁺ in acid solution. There was a positive correlation between the colour depth and the formaldehyde concentration. This method has the advantages of both spectrophotometry and flow injection such as simple, fast, high sensitivity, strong anti-interference capability and less consumption of reagents.In chapter three, a modification of the Trautz-Schorigin reaction into a flow-injection analysis configuration was described. Different approaches were used at the optimization of chemiluminescence determination of formaldehyde in water based on the reaction of formaldehyde, gallic acid and hydrogen peroxide in an alkaline solution. Due to simple instrumentation, speed, reproducible, selectivity and sensitivity, the proposed FIA-CL method can be advantageously used for the routine determination of formaldehyde in the water-based coating.