Determination Of Formaldehyde And Clenbuterol Hydrochloride By Sequential Injection Analysis With Chemiluminescence Detection

In this thesis, the sequential injection (SI) technique coupled with chemiluminescence (CL) detection was developed for the determination of formaldehyde and clenbuterol hydrochloride (CLB).The first section of the thesis introduced the sources of formaldehyde in atmosphere, the toxicity hazard, the contamination and the maximum permitted concentrations of formaldehyde. And the section especially reviewed the development for the determination of formaldehyde in air. The section also briefly introduced the damage of clenbuterol hydrochloride.In the second section, a procedure for the determination of formaldehyde by sequential injection analysis was proposed, which was based on the chemiluminescence reaction of formaldehyde, gallic acid and hydrogen peroxide in an alkaline solution. The experimental parameters including the sampling sequence, the concentration and volume of reagents, sample volume, and the flow rates were optimized by univariate procedure. Under the optimized condition, the chemiluminescence intensity was linear with the concentration of formaldehyde over the range 1.0×10-7mol/L-2.0×10-3mol/L, with a correlation coefficient of 0.9993. The relative standard deviations of the method for 1×10-6mol/L formaldehyde was 2.1%(n=11). The detection limit was 5.0×10-8mol/L and sample throughput was 140 samples per hour. Good recoveries were obtained for spiked samples and the results achieved were in good agreement with the certified values in standard reference material. The proposed method has several merits including sensitivity, automation, simplicity, less reagent consumption and waste generation.In the third section, the SI-CL approach was applied to the determination of clenbuterol hydrochloride. Under the optimized condition, the chemiluminescence intensity was linear with the concentration of clenbuterol hydrochloride over the range 2.0×10-2 mg/L-4.0 mg/L, with a correlation coefficient of 0.9980. The relative standard deviation of the method for 0.20 mg/L clenbuterol hydrochloride was 2.2%(n=11) and the detection limit was 7.2×10-3 mg/L. The sampling frequency was 100 per hour. The method had been successfully applied to the determination of clenbuterol hydrochloride in tablets and the recoveries were over the range 96.6-102.9%.The fourth section summarized the research and raised some prospect and applications of the proposed methods.