【作者】 杨颖；

【导师】 张辉； 程祥圣；

【作者基本信息】 上海交通大学 ， 环境工程， 2009， 硕士

【副题名】以流动注射分光光度法在长江口区的监测应用为例

【摘要】 本文的研究是针对现行的国标方法中营养盐分析方法相对落后,不能满足海洋环境管理中对监测数据快速、简单、准确的要求,建立流动注射分析测定河口水中营养盐的方法,解决流动注射技术在上海海域监测中的应用问题。上海海域位于我国最大的河口——长江口海域,是我国海洋赤潮高发和严重富营养化区域之一,是国家海洋局划定的典型河口海域赤潮监控区、绿潮监控区和生态监控区,因此营养盐是长江口海域最主要的监测项目之一。但由于河口区处于地面水和海水的过渡性区域,盐度变化范围巨大,兼有地面水和海水的特点,而又物理化学性质复杂,借鉴流动注射测定海水中营养盐的分析方法应用于河口水营养盐监测,需要解决由于盐度变化范围大,而对分析造成的干扰的问题。本文研究了流动注射法测定河口水中营养盐的盐效应的干扰与校正办法,和紫外光还原代替镉铜还原测定水中的硝酸盐的方法。试验发现,流动注射测定河口水中的磷酸盐、氨氮、硅酸盐和硝酸盐,均会受到由于盐度变化大,样品折光率不同引起的纹影效应,可以通过修正样品峰的积分面积和位置,避开假峰的干扰,同时增加样品进样量体积和延长反应时间,提高方法灵敏度来克服。研究表明,流动注射测定河口水中氨氮和硅酸盐受到较强烈动力学盐效应的干扰。氨氮的干扰主要由于镁离子浓度和离子强度变化引起,并在低盐区域(盐度0-9)和高盐区域(盐度12-30)表现不同。硅酸盐的盐效应主要由于离子强度不同引起反应速率变化。本文给出了氨氮和硅酸盐测定动力学盐效应校正系数表,样品实测浓度乘以相应的系数,为样品的真实浓度。本文建立了紫外光还原代替镉铜还原测定河口水中的硝酸盐的方法,解决了常用的镉柱法中还原柱填装困难、使用时间短和环境污染严重的问题。本文还对仪器和试剂条件进行了优化,应用所建立的方法分析天然水样品和国际互校样品,并与国标法进行比对验证,两种方法分析结果之间无显著性差异。更多还原

【Abstract】 This paper research is for the flowing injection analysis technology application in the Shanghai sea area monitoring. The Shanghai sea area is located in the biggest river mouth in China- Changjiang estuary and sea area, it is one of the most red tides and serious eutrophication regions, and typical estuary sea area in China, it is selected as red tide monitoring and control area, green tide monitoring and control area, also ecology monitoring and control area by the State Ocean Administration, the nutrients salt is one of the most main monitoring parameters in the Changjiang estuary.But because the river mouth area is the transitional region between the ground water and the sea water, the variation of salinity range is huge, the water body of the estuary has all the ground water and the sea water characteristics, and the physico-chemical properties are very complex. Use the determination method of nutrient salt in the seawater with flowing injection analyzer for reference to the estuary water, we need to solve the problems come from the variation of salinity.This paper has studied salt effect disturbance in the FIA the nutrient salt determination method and correction of the effects. This paper also studied the nitrate determination method with ultraviolet reduction replaces the cadmium-copper column reduction.It is found that, the analysis of phosphate, the ammonia, the silicate and the nitrate in the estuary with FIA are all disturbed by the schlieren effect, which is happened because the salinity changes in a big way, the samples’index of refraction are different. We can correct the effects from these ways: move the windows of the sample peak, escapes the position of refraction influences, simultaneously increases the sample specimen handling volume and extends reaction time, enhances the method sensitivity, so we can overcome the effect.The research indicated that, the methods of determination ammonia and the silicate with FIA are influenced by the kinetic salt effect. The magnesium ion concentration and the ion intensity variety cause the effect when ammonia is determined. The disturbance is different between the low salinity (salinity is 0-9) and the high salinity (salinity is 12-30). The salt effect of silicate method is mainly caused by the ion intensity difference, which can affect the reaction speed.This article has given the correction factors of kinetic salt effect in ammonia and the silicate determination methods, the samples’results need to multiply the corresponding factors.The new method of nitrate measurement is established in this paper, which uses the ultraviolet reduction, replaces the cadmium-copper reduction. Compared to the cadmium-copper method, this new one is more excellence: operation is very simple, for cadmium-copper column must be refixed after several days, now this step is omitted, this system can run for a long time. and the most important , it does not produce pollution like cadmium .This article also does the optimization of the instrument and the reagent conditions, applies these methods to analyse natural water sample and international intercalibration samples, the results is satisfied.更多还原