Method for measuring total phosphorus concentration in seawater

Abstract

The invention discloses a method for measuring the total phosphorus concentration in seawater. The method comprises the following steps: preparing 1mL of phosphate working solutions with different phosphate concentrations; adding 1mL of potassium persulfate into each phosphate working solution, uniformly mixing, and digesting in a digestion instrument; adding 0.2 mL of a first ascorbic acid solution into each working solution subjected to digestion treatment, uniformly shaking, adding 0.8 mL of a mixed solution and 0.2 mL of a second ascorbic acid solution into each working solution subjected to reduction treatment, uniformly mixing, and developing; determining the light absorption value of the working solution and the light absorption value of the blank by taking the blank as a reference; drawing a standard working curve, and solving a regression equation of the standard working curve; measuring 1mL of a seawater sample, and measuring and recording the light absorption value of the water sample according to the same treatment steps as the phosphate working solution; and calculating a result. Compared with the national standard, the method has the advantages of large seawater total phosphorus concentration measurement range, high safety, simplicity in operation, high working efficiency, low measurement cost, reduction of secondary pollution and the like.

Description

technical field [0001] The invention specifically relates to a method for determining the concentration of total phosphorus in seawater. Background technique [0002] With the progress of society and the development of science and technology, marine ecological resources are gradually being developed and utilized by humans, including energy, water sources, biological resources, mineral resources, chemical energy and the use of the ocean's own space. Phosphorus is the basis of marine productivity and an important nutrient element for the growth of marine organisms, which affects and restrains the development of the ocean. The main forms of phosphorus in marine water are soluble inorganic phosphorus and organic phosphorus, and insoluble suspended particulate phosphorus: soluble inorganic phosphorus is mainly phosphate, including polyphosphate and colloidal inorganic phosphorus; solubility Organic phosphorus is mainly colloidal organic phosphorus; suspended granular phosphorus ...

AI Technical Summary

Problems solved by technology

In the national standard "Marine Survey Standards for Determination of Total Phosphorus in Seawater by Potassium Persulfate Method" (GB / T 12763.4—2007), the sample is processed by potassium persulfate digestion method, and the sample is measured and analyzed by ammonium molybdate spectrophotometry. The current method for the determination of total phosphorus in seawater is simple and more precise and accurate. However, the national standard method has a narrow test range. For water samples exceeding the upper limit of the test, the sample needs to be diluted gradually. The operation process is not only cumbersome, but also affects the measurement accuracy; and its reaction The system uses a 25mL system, which needs to be digested in an autoclave, which is not only complicated to operate, but also high-pressure steam is potentially dangerous

In addition, this system needs to clean a large number of glass instruments, which requires a large workload, takes a long time, and has a large amount of waste liquid, which is easy to cause secondary pollution to the environment, and is not suitable for the increasingly urgent needs of marine ecological environment monitoring and scientific research.

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