New Method For Determination Of Formaldehyde Derived HPLC

Using hydroxylamine hydrochloride, methoxylamine hydrochloride and ethoxyamine hydrochloride as new derivative agents respectively, formaldehyde in different samples was determined by high performance liquid chromatography using UV detector. The formaldehyde can react with hydroxylamine hydrochloride, methoxylamine hydrochloride and ethoxyamine hydrochloride to yield oxime compounds. By this way, formaldehyde can detected indirectly by high performance liquid chromatography with UV detector. The main innovation in this paper is these novel methods which formaldehyde can be determined. The methods can be applied to derive on the line determination because of these reactions with the moderate condition and fast speed and the good solubility of product. The methods can simplify the determination process of formaldehyde in the complex samples and improve the precision and accuracy of the analysis results. These methods have been testified by the determination of formaldehyde in aquatic product, beer and air indoor. These methods can also be extended to the determination of formaldehyde of other pollutants. This research mainly focus on four parts as follows:1. After searching a lot of the related literatures, the progress of study on determination of formaldehyde and methods of sample pretreatment was summarized, the author illustrated the raising and execution of the methods used in the thesis.2.Methoxylamine hydrochloride was used as derivatizing reagent to determine formaldehyde using high performance liquid chromatography with UV detector. Syncronis C18(150mm×4.6mm i.d.) carried out high performance liquid chromatography separation of formaldehyde derivative; the mobile phase consisting of20mmol·L-1phosphate buffer-methanol (pH=3.0)(93:7, v/v) was delivered as an isocratic elution at a flow rate of1.Oml-min-1and at30℃. Aquatic product such as squid and pomfret was pretreated by steam distillation. In optimal conditions, retention time of the derivative was5.45min. The method presented good liner in the range of0.1-120.0mg-mL-1. The detection limit was0.03mg-L-1, and the relative standard deviations and recoveries are in the range of0.9-2.6%and92.5-108.1%, respectively.3.Hydroxylamine hydrochloride was used as derivatizing reagent to determine formaldehyde online using high performance liquid chromatography with UV detector. Compared with the value of absorbance and the shape of chromatographic peak of different saline solution in ultraviolet region, we finally chose the mobile phase consisting of100mmol-L-1phosphate buffer-methanol (pH=3.0)(95:5, v/v) at30℃.The gas was collected by homemade gas collected device. In optimal conditions, the method presented good liner in the range of0.3-150.Omg-mL-1. The detection limit was0.07mg-L"1and the relative standard deviations was less than2.4%. Recoveries are in the range of89.3-105.7%.4.Ethoxyamine hydrochloride was used as derivatizing reagent to determine formaldehyde. The concentration of derivatives, pH, reaction time and temperature are optimized by experiment. The beer was pretreated by steam distillation. In optimal conditions, retention time of the derivative was7.78min. The method presented good liner in the range of0.007-120mg-mL-1. The detection limit was0.002mg-L-1, and the relative standard deviations and recoveries are in the range of1.1-5.5%and87-108.1%, respectively. In the same chromatographic conditions, retention factors and resolution of these methods are compared.