| This research mainly focuses on the determination of formaldehyde and hydrazines in samples of different state using high performance liquid chromatography. The formaldehyde can react with hydrazines including hydrazine, methylhydrazine and unsymmetrical dimethylhydrazine to yield hydrazones, which can be detected by high performance liquid chromatography using UV detector. By this way, formaldehyde and hydrazines can all be detected indirectly by high performance liquid chromatography with UV detector. The most innovation in this paper is that two kinds of pollutants can be determined by one method. This method has been testified by the determination of unsymmetrical dimethylhydrazine in B9, "three hydrazines" in wastewater, and formaldehyde in methanol-gasoline fuel emissions and aquatic products. This method can be extended to the determination of formaldehyde and hydrazines of four sources of pollutants. This paper was systematically studied through six parts as follows:1. Review. After searching and analyzing the related literatures, the progress of study on determination of formaldehyde and hydrazines was summarized, the author illustrated the raising and execution of the methods used in the thesis.2. The UV spectrum of hydrazones, which were reacted from formaldehyde and hydrazines, has been studied. The apparent molar absorbances efficient of the three hydrazones were obtained according to lambort-bill law. And the molar absorbances efficient of methylhydrazone and unsymmetrical dimethylhydrazone were confirmed by Benesi-Hilderbrand equation.3. Formaldehyde was used as derivatizing reagent to determine the residual unsymmetrical dimethylhydrazine using high performance liquid chromatography with UV detector. Zorbax ODS carried out high performance liquid chromatography separation of unsymmetrical dimethylhydrazine derivative; the mobile phase consisting of 20mmol phosphate buffer-methanol (pH=7.0)(94/6 v/v) was delivered as an isocratic elution at a flow rate of 1.0ml·min-1. The UV detection wavelength was 237nm. The limit of detection was 0.13μg·g-1, the recovery were 97.5%103.4%, and RSD were 0.9%～1.8%. Standard calibration curve for unsymmetrical dimethylhydrazine was linear (r2=0.9998) over the concentration range of 0.056960mg·L-1 .4. Formaldehyde was used as derivatizing reagent to determine the three hydrazines in wastewater. Akasil-C18 was used as column; monobasic sodium phosphate (pH=7.0)-methanol (90/10 v/v) was used as mobile phase. The UV detection wavelength was 230nm. The linearity concentration range of unsymmetrical dimethylhydrazine, methylhydrazine and hydrazine were 0.12～912mg·L-1 , 0.18552mg·L-1 and 0.27～532mg·L-1, respectively. The limit detection of unsymmetrical dimethylhydrazine, methylhydrazine and hydrazine were 0.015mg·L-1, 0.023mg·L-1 and 0.033mg·L-1, respectively. On this column, the capacity factor of unsymmetrical dimethylhydrazone, methylhydrazone and hydrazone were: 4.184, 1.481 and 0.463. The resolution of hydrazone and methylhydrazone was 4.7; the resolution of methylhydrazone and unsymmetrical dimethylhydrazone was 7.9.5. Unsymmetrical dimethylhydrazine was used as derivatizing reagent to determine formaldehyde in the methanol-gasoline fuel emissions using high performance liquid chromatography with UV detector. Formaldehyde was transformed from liquid form to gas form by a gas device; RSD of this device was≤3.5%. The method was linearity over the concentration range of 0.0836-6.688mg·L-1; RSD of the method were 2.6%～3.7%; the recovery were 91.9%～110.5 %.6. Unsymmetrical dimethylhydrazine was used as derivatizing reagent to determine formaldehyde in aquatic products by high performance liquid chromatography with UV detector. Diamonsil-C18 was used as column; monobasic sodium phosphate (pH=6.7)-methanol (75/25 v/v) was used as mobile phase. The detection limit of formaldehyde was 0.5μg·g-1, the recovery were 88.0%～110.0%, the concentratrion range was 0.12～1200mg·L-1 and RSD was≤5.7%. |
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