How to determine whether powdered ammonium chloride is high in purity?
2024-01-15 15:03:35
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The purity of powdered ammonium chloride refers to the degree of purity of the ammonium chloride it contains. The higher purity of ammonium chloride means that it has a lower impurity content and is suitable for pharmaceutical, chemical and other fields. The following will describe some common methods to determine the purity of powdered ammonium chloride is higher.
Appearance inspection: First of all, the appearance of ammonium chloride can be observed from the appearance, the higher purity of ammonium chloride is usually white powder. If the presence of impurities is found, such as darker color or black spots, it may mean that the purity is low.
Solubility test: A small part of the ammonium chloride powder sample is added to a certain amount of water and fully stirred until completely dissolved, if the dissolution rate is faster and completely dissolved, it may mean a higher purity. If a portion remains or dissolves slowly, it may be because it contains impurities.
Chemical method: Other compounds in ammonium chloride samples were detected by chemical method. For example, an ammonia solution can be used to detect the presence of organic matter. If bubbles are produced in the solution, it indicates the presence of impurities of organic matter.
Crystal form: Determine the purity of ammonium chloride by observing its crystal form. The higher purity ammonium chloride crystals are generally cubic or hexagonal crystals, and the crystal shape is regular. But the lower purity ammonium chloride crystal form is irregular, the crystal is incomplete.
Thermal stability test: higher purity ammonium chloride usually has higher thermal stability. When the sample is heated to a certain temperature, if there is no significant decomposition or odor production, it indicates a high purity. Conversely, if the sample decomposes at a lower temperature or produces a pungent odor, it may indicate a lower purity of ammonium chloride.
Determination of nitrogen content: Ammonium chloride is a nitrogen-containing compound, so its purity can be indirectly determined by determining the nitrogen content of the sample. The commonly used methods include geometric nitrogen determination, gas chromatography and so on. Ammonium chloride with higher nitrogen content usually indicates higher purity.
Instrumental analysis: The use of instrumental analysis methods to detect impurities in ammonium chloride samples. Commonly used instruments include mass spectrometers, infrared spectrometers, ultraviolet-visible spectrophotometers, etc. Through the analysis of these instruments, the molecular structure, functional group and other information of ammonium chloride samples can be obtained, and then the purity can be judged.
In short, judging whether powdered ammonium chloride is of high purity requires a combination of appearance inspection, solubility test, chemical method, crystal morphology, thermal stability test, nitrogen content determination and instrumental analysis. The selection of these methods needs to be comprehensively considered according to the actual situation, and combined with a variety of methods to judge the purity of ammonium chloride.
