环境水样中总磷分析方法及仪器的研究进展

Current Research Progresses in Analytical Methods and Instruments for Total Phosphorus in Environmental Water Samples

磷是生物不可或缺的营养元素之一,但由于人类活动影响,在地表水和近岸海水中总磷一直是主要污染指标。总磷测定通常分两步进行:一是将水样中各种不同形态的磷消解转化为可被检测的磷酸盐;二是测定消解后样品中的磷酸盐浓度。消解方法有硫酸-硝酸消解法、干法灰化法、微波辅助消解法、过硫酸钾-高温高压消解法、UV光氧化法等。测定方法包括电化学法、化学发光法、磷钼蓝分光光度法、磷钒钼黄分光光度法等。目前应用最为广泛的是过硫酸钾-高温高压消解法和磷钼蓝分光光度法。总磷测定仪器通常基于该消解法和测定法而开发,可分为用于实验室的水样离线分析仪和用于水体现场的在线分析仪两类。该综述总结了近20年来环境水样中上述总磷分析方法及仪器的研究进展,比较了各方法和仪器的特点,并分析了总磷分析方法和分析仪器的发展趋势。

Phosphorus is one of the essential nutrients for living things.However,in surface water and near shore seawater,total phosphorus has been the main pollution index due to the influence of human activities.Total phosphorus determination could generally be performed in two steps,namely various forms of phosphorus in water samples are firstly digested into orthophosphates,then determined by one of the detection methods.The digestion methods include sulfuric acid-nitric acid digestion,dry graying digestion,microwave assisted digestion,digestion with potassium persulphate and high temperature/pressure and UV photo-oxidation,while the detection methods contain electrochemical method,chemiluminescence method,phosphomolybdenum blue method and vanadomolybdophosphoric method.Currently,digestion with potassium persulphate and high temperature/pressure and detection with phosphomolybdenum blue are most widely used.Meanwhile,instruments for total phosphorus determination are developed based on the digestion and detection methods mentioned above,which are mainly divided in two types,i.e.,one type used in laboratory for water sample off-line analysis and the other used in the field for water body on-line monitoring.The research progresses of the above-mentioned analytical methods and instruments for total phosphorus in environmental water samples and water bodies in the past twenty years are summarized in this review.The characteristics of each method and analytical instrument are stated and compared,and the developing trends of the analysis methods and analytical instruments for total phosphorus are prospected.