Food testing methods

The development of analytical chemistry provides accurate and reliable analytical methods for food safety inspection. With the rapid development of science and technology, food inspection technology has been able to achieve an accuracy of one millionth or even one billionth. The indicators of food inspection mainly include the analysis of general ingredients of food, analysis of trace elements, analysis of pesticide residues, analysis of veterinary drug residues, analysis of mycotoxins, analysis of food additives and analysis of other harmful substances, etc. According to the characteristics of the item being inspected, the inspection of each indicator corresponds to the corresponding inspection method. In addition to traditional conventional analysis methods, instrumental analysis methods have gradually become the main means of food hygiene inspection, including spectrophotometry, atomic fluorescence spectrometry, electrochemical methods, atomic absorption spectrometry, gas chromatography, high-performance liquid chromatography, etc. The above inspection methods can be roughly divided into inorganic component analysis methods and organic component analysis methods according to the inspection items. The analysis and inspection items of inorganic components mainly include copper, lead, zinc, manganese, cadmium, calcium, iron, etc. in trace elements. Analysis methods mainly include atomic spectroscopy, spectrophotometry, electrochemical methods, ion chromatography and other methods. Due to its unique advantages, atomic spectroscopy has become the most important, most commonly used and most trustworthy analysis method among inorganic component analysis methods. Atomic spectrometry has the advantages of fast analysis speed, low equipment cost, relatively simple operation, and the test results are less affected by the proficiency of the operator. UV-visible spectrophotometry has a long history and is widely used. According to statistics, nearly 50% of the tasks faced by analytical chemistry are completed by UV-visible spectrophotometry. The biggest feature of this method is that the instrument is simple and easy to operate. The inspection of inorganic components in food occupies a very important position in food safety inspection. For example, the measurement of mercury has always been an inspection item that has attracted special attention from the government and the public. Because mercury is easily transferred in living organisms, it can be accumulated in water bodies. Mercury can hardly be excreted after entering the human body, especially the human brain. If it accumulates to a certain extent, it will cause poisoning and damage the central nervous system. The analysis of mercury is generally done by atomic absorption or atomic fluorescence spectrometry. The analysis of organic components is generally completed by gas chromatography or high-performance liquid chromatography and molecular spectroscopy. In related inspections, especially the determination of pesticide residues, such as organochlorines, benzo(a)pyrene, pyrethroid lipids, organophosphorus, etc., has received widespread attention. Chromatography is a very effective method for separating mixtures and identifying compounds. It can both identify compounds and accurately measure content, and is relatively easy to operate. It has the characteristics of high separation efficiency, fast analysis speed, high sensitivity, accurate quantitative results and easy automation, so it is widely used in the inspection of organic components. Infrared spectroscopy is widely used in molecular spectroscopy. Usually, infrared spectroscopy is used in combination with other analytical methods such as Raman spectroscopy, and can be used as the main means to identify compounds and determine molecular structures.