Method for measuring dicyandiamide in soil and water body

Abstract

The invention discloses a method for measuring dicyandiamide in soil and a water body. The method is characterized by comprising the following steps of: preparing dicyandiamide standard solution; pretreating a sample, namely weighing a quantitative soil sample and / or water body sample, adding ultrapure water of which the volume is 2 times that of the quantitative soil sample into the quantitative soil sample, performing ultrasonic extraction, centrifuging, filtering supernatant fluid by using a filter to obtain sample filtrate and adding water to reach constant volume, or directly filtering the quantitative water body sample and adding the water to reach the constant volume; measuring the sample, namely injecting the sample filtrate and the prepared dicyandiamide standard solution into a high performance liquid chromatography respectively, and measuring the areas of dicyandiamide absorption peaks in the standard solution and the sample according to chromatograph conditions; and calculating a result, namely examining the concentration of dicyandiamide in the sample filtrate through the concentration of the dicyandiamide standard solution and a linear relation curve corresponding to the areas of the absorption peaks, and calculating the content of the dicyandiamide in the sample according to the formula of a solid sample or a liquid sample. The invention has the advantages that: the method is advanced, quick and practicable, and is low in detection limit (the detection limit of the solid sample is 0.1mg / kg, and the detection limit of the liquid sample is 0.02mg / L) and high in recovery rate (93.13 to 99.42 percent).

Description

1. Technical field [0001] The invention belongs to a detection method (relating to a method for detecting the content of dicyandiamide by using high performance liquid chromatography), in particular to a method for measuring dicyandiamide in soil and water (high performance liquid chromatography detection method) ). 2. Background technology [0002] Dicyandiamide (DCD), also known as dicyandiamide, is a white crystalline powder. It is often used as a fertilizer for nitrification because of its nitrification inhibition properties that inhibit the activity of soil nitrifying bacteria and delay the conversion of ammonium nitrogen to nitrate nitrogen in the soil. Inhibitors are used in the production of long-acting new fertilizers, stable fertilizers, fertilizer synergists and other products. It can also be applied together with various nitrogen fertilizers, including urea, ammonium salt, nitrogen fertilizer aqueous solution, animal manure, etc. Relevant research reports at ho...

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Problems solved by technology

The disadvantages of these methods are that the price of the chromatographic column is high, the service life is short, the peak retention time of dicyandiamide is short during chromatographic separation, it is difficult to separate from the solvent peak baseline, the specificity is not strong enough, and the reproducibility of chromatographic conditions is not good, etc.

In addition, it is more critical to apply the chromatographic conditions of some of the methods to detect the content of dicyandiamide in the soil, which fails to separate the dicyandiamide chromatographic peak from other miscellaneous peaks.

In short, my country currently lacks monitoring of the degradation of dicyandiamide in farmland and water after long-term application. Therefore, it is necessary to explore a suitable detection method for dicyandiamide in soil and water in combination with the actual situation in our country.

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