Method for combined test of total nitrogen and total phosphor phosphorus in soil

Abstract

The invention relates to a method for the combined test of total nitrogen and total phosphor phosphorus in soil, which comprises the following steps: (1) synchronous digestion treatment of soil: weighing a dried and screen soil sample, placing the sample into a digestion tube, adding an accelerator, adding solution of concentrated sulfuric acid and placing the digestion tube in at high-temperatureenvironment for digestion; (2) preparation of soil liquid to be tested: after the digestion liquid obtained after digestion is cool, fixing the volume of the digestion liquid by adding distilled water, using the digestion liquid to test the total nitrogen content of the soil, adjusting the pH value of soil total nitrogen liquid to be tested by using alkaline liquid and using the resulting liquidto test the total phosphor content of the soil; and (3) test of the total nitrogen content and total phosphor content of soil: automatically testing the total nitrogen content and total phosphor content of soil by using a constant flow injection analyzer. The method has the advantages of: 1, avoiding repeated soil sample weighing and soil digestion and simplifying experimental operation process; 2, avoiding damages of selenium powder to human bodies by using potassium sulfate and copper sulfate in place of the accelerator for soil digestion treatment; and 3, improving accuracy and precision bytesting total nitrogen content and total phosphor content of soil by using constant flow injection analyzer.

Description

technical field [0001] The invention relates to a technique for measuring soil total nitrogen and total phosphorus, in particular to a method for joint determination of soil total nitrogen and total phosphorus. Background technique [0002] At present, the biogeochemical cycle process (mainly the cycle of carbon, nitrogen and phosphorus) has become an important research content in the fields of ecology, soil science and geology. With the further aggravation of global change problems such as global nitrogen deposition and water eutrophication, the research on the accumulation, turnover and migration of nitrogen and phosphorus elements in soil ecosystems has attracted extensive attention from scholars at home and abroad, and a large number of researches in related fields have been carried out. [0003] An important basic condition for the study of soil nitrogen and phosphorus cycle process is that we can accurately and quickly measure the content of nitrogen and phosphorus ele...

AI Technical Summary

Problems solved by technology

The operation process of conventional chemical analysis techniques is cumbersome, with low accuracy and high toxicity of chemical reagents. For example, the use of selenium powder in the soil total nitrogen semi-micro Kjeldahl method, the use of perchloric acid in the soil total phosphoric acid solution-molybdenum antimony anti-colorimetric method use, etc.

Although instrumental measurement technology simplifies the operation process, improves accuracy, and reduces the toxicity of chemical reagents to a certain extent, the instruments and equipment required for instrumental measurement technology are relatively expensive.

In addition, the biggest problem still exists in the above-mentioned soil total nitrogen and total phosphorus measurement technology, that is, the simultaneous analysis and determination of soil total nitrogen and total phosphorus content cannot be achieved, and repeated soil sample weighing, soil pretreatment and other operations are extremely difficult. It increases the workload of experimental analysis, the toxic effect of chemical reagents and the cost of experimental analysis, and also affects the accuracy of data

Images