Quick detection method and detection kit of ammonium nitrogen in fertilizer

Abstract

The invention provides a method for quickly detecting ammonium nitrogen in a fertilizer. The method includes the following steps that firstly, a plurality of ammonium chloride aqueous solutions with concentrations sequentially changed are prepared to serve as standard solutions, the standard solutions with different concentrations are obtained, a sodium potassium tartrate tetrahydrate solution, a potassium mercuric iodide solution and a stabilizer are sequentially added, evenly mixed and still standing, and standard developing solutions with known ammonium nitrogen contents and certain color gradients are obtained; secondly, an extracting agent is added into a fertilizer sample, and a sample treatment solution is obtained through vibrating extraction; thirdly, the sample treatment solution is obtained, a sodium potassium tartrate tetrahydrate solution, a potassium mercuric iodide solution and a stabilizer are sequentially added, evenly mixed and still standing, and a colored sample developing solution is obtained; fourthly, the color of the sample developing solution is compared with the colors of the standard developing solutions, and the ammonium nitrogen content in the detected fertilizer sample is obtained. Ammonium nitrogen in the fertilizer can be quickly and easily detected, sensitivity is high, and the method is suitable for in-situ quick measuring of non-professional personnel.

Description

technical field [0001] The invention relates to the technical field of chemical fertilizer analysis, in particular to a chemical reaction-based rapid detection method for ammonium nitrogen in chemical fertilizers and a detection kit thereof. Background technique [0002] Chemical fertilizer is an indispensable and important agricultural material in agricultural production. Nitrogen fertilizer is the first of the three elements of chemical fertilizer and occupies a very important position in agricultural production. Ammonium nitrogen is an important form of nitrogen fertilizer. Ammonium sulfate, ammonium bicarbonate, diphosphate The nitrogen in commonly used fertilizers such as ammonium is ammonium nitrogen. The nutrient content is usually marked on the outer packaging of chemical fertilizer products. In order to reduce costs, some chemical fertilizer manufacturers use methods such as adulteration and material reduction to artificially reduce the nutrient content of the produ...

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Problems solved by technology

The formaldehyde method utilizes the action of formaldehyde and ammonium salt in a neutral medium to form hexamethylenetetramine, and at the same time releases a free acid equal in molarity to the ammonium salt, and titrates it with alkali. This method is suitable for ammonium salt mixtures, and the sample cannot contain ammonium phosphate. and pentachlorophenolate; the distillation method uses heating in the presence of excess sodium hydroxide to decompose the ammonium salt to release ammonia, absorb it with standard sulfuric acid, and titrate it with sodium hydroxide. This method is not applicable when urea or organic nitrogen exists; magnesium oxide distillation The method uses heating and distillation under magnesium oxide alkaline conditions, and the ammonium salt is also decomposed to release ammonia, which is absorbed by standard sulfuric acid; the ventilation method is used in potassium carbonate solution, and air is introduced at room temperature to drive away ammonia, absorbed by standard sulfuric acid, which is suitable for urea When coexisting with calcium cyanamide; flow injection analyzers have high requirements for measuring instruments, and the cost of measuring is high, which is not conducive to popularization