Paper on chromatographic analysis technology

Chromatographic analysis technology can realize the separation of raw materials and complete various tasks at the same time in the analysis process. The following is a paper on chromatographic analysis technology that I carefully recommend for you, hoping to help you.

Application and analysis of modern chromatographic analysis technology in paint detection

This paper first introduces the principle of gas chromatography coating inspection, and analyzes the common problems in inspection and their solutions. Judging from the advantages and disadvantages of technology. Secondly, the application principle of high performance liquid chromatography is emphatically analyzed, and the technical points of paint detection are summarized. It is helpful to improve the accuracy of test results.

Keywords: paint detection; Modern chromatography; Gas chromatographic analysis

1 high performance liquid chromatography

This technology combines the advantages of traditional technology, and at the same time optimizes the existing problems to solve the impact problems in the testing process more efficiently. This technology can realize the separation of raw materials and complete various tasks at the same time in the analysis process. Compared with the traditional method, it will obviously reduce the time, especially the analysis and judgment of the heating degree, which is more efficient and reasonable. The common heating problem in the inspection process has become the primary influencing factor of chromatographic analysis. If the temperature cannot be set reasonably, it is easy to cause the analysis combination to be inconsistent with the actual situation. Most of the coatings are in liquid form, and their properties are more stable, and the amount of raw materials can be controlled. With people's increasing attention to environmental protection and health, the country has successively issued some toxic and harmful standards related to coatings, and the production technology and formula of coatings have also been adjusted and optimized. However, there are also many manufacturers who use the toxic and harmful substances that are not limited in the current standards to replace the limited ones. This requires not only the inspection of paint samples according to the current standards, but also the active discovery of toxic and harmful substances that have not yet been limited. The composition of coating products is complex and diverse. HPLC is a separation and analysis method, which can analyze most organic substances, especially those with low volatility and easy decomposition at high temperature, and can obtain better and more stable results than other methods.

The chemicals contained in paint may pollute the environment, so most of the current testing work is aimed at ecological protection, with the aim of avoiding substances that do not meet the quality testing standards from being put into use. Therefore, the detection work should have a clear goal to judge the pollutants that may be contained in the substances to be detected. High performance liquid chromatography analysis of organotin, an antifouling agent for toxic coatings, plays a very effective role in inhibiting marine fouling by marine antifouling coatings. With the development of marine monitoring technology, the toxicity and harm of organotin to ecosystem are increasingly recognized by human beings. The concentration of organotin in marine environment is very low (10-12 ~10-9), and there are many kinds, so it is difficult to meet the requirements of high sensitivity and high selectivity with traditional instruments. Among them, the more mature method is to use GC (gel chromatography) as a separation means, with a detector suitable for metal ion analysis.

High performance liquid chromatography can analyze organotin which is not suitable for gas chromatography, and is suitable for the direct separation of most polar and nonpolar organotin compounds. Different forms of tin in the sample can be directly separated at room temperature without extraction and derivation, which not only shortens the analysis time, but also reduces the possible loss in the analysis process; The best separation can be obtained by changing the stationary phase and the mobile phase; It is especially suitable for the separation and morphological analysis of bioactive compounds. Gel chromatography is a kind of liquid chromatography, its separation principle is different from other chromatograms, and it is based on the size of molecular volume, so it is also called size exclusion chromatography. High performance gel permeation chromatography (HPCE) is a liquid chromatography method developed in 1960s. Its main purpose is to determine the relative molecular weight and distribution of polymers.

2 gas chromatography

2. 1 pyrolysis gas chromatography combined with Fourier transform infrared spectroscopy

Can be used to judge the composition of resin coatings, but also on the spectrum. The results obtained by this technical method are more comprehensive, which combines the advantages of the two technical methods and can directly display the results when judging the chromatographic type. With the development of production technology, the components in coatings become more and more complex, and the polymer structure is not easy to analyze under ordinary infrared spectrum. The research on this chromatographic technology started late in China, and the application links were also discussed according to the existing research results.

Chinese scholars extract the components in the paint during the research process, and input the detected components into computer equipment for analysis, so as to more accurately locate the functional relationship between chromatographic forms and paint content. This technology can choose any part of the paint to test, without selecting test points, saving time and reducing standard sample points, which is very helpful for future work. This feature is also the reason why this technology can be applied and realized.

Under the action of infrared illumination, the cracking reaction of coatings is the basis of detection, and the results can be analyzed directly according to the reaction process without selecting samples again for analysis. In the face of complex analysis objects, it is difficult to achieve the goal only by simple cracking. Simply increasing the temperature can promote the cracking of the coating, and then judge whether it reaches the detectable point according to the reaction. Infrared illumination plays a catalytic role in it and can deal with the detection of compounds. However, the morphology of the coating is not so simple, including polymer morphology, so the effect of infrared spectrum detection will be hindered.

2.2 Pyrolysis Gas Chromatography-Mass Spectrometry

Coatings are composed of several parts, and resin raw materials are often used to produce base materials. For materials with good high temperature resistance and difficult separation, high temperature pyrolysis test may not be carried out. However, the test methods are the same in principle, and the problem encountered is how to promote the cracking reaction. The common method is to destroy the molecular structure chain, and the components in the coating naturally decompose. At this time, it is better to complete the task by analyzing the chromatographic performance. Energy will be released in the process of fission, and the heat released during the change of different molecular structure chains is also different, which is also related to the high temperature resistance of the substrate itself.

When it is known that fission needs high temperature heating to realize analysis and detection, the key technology is to control the temperature. If the heating temperature exceeds the required range, it is easy to cause the molecular structure chain to be too fragmented, which will affect the judgment of the results. One thing that can't be ignored is that some substances in coatings are prone to oxidation reaction at high temperature, which decomposes unwanted substances in the detection process and hinders the completion of the task. It can be seen that although this method is simple in operation and accurate in result analysis, it is easily influenced by external factors.

The reaction change of coating at high temperature needs a period of fusion time, and the destruction of structural chain is completed at the moment of high temperature heating. In the detection process, the temperature can be raised instantly in a short time, which avoids the high-temperature oxidation reaction of substances and improves the reliability of detection results. The affected substances can't be completely eliminated, but the output should be controlled within a reasonable range as far as possible, which will not affect the inspection and analysis. According to the test results, different base materials will affect the chromatographic expression of coatings, and it is necessary to judge the composition of raw materials and clarify the possible reaction types at high temperature during the test. During the task, samples of different paints need to be selected for testing to avoid being mixed with other impurities. The selected numbers should be equal. While observing the test results, the original data should be sorted out and recorded, which can be used for subsequent analysis and inspection for better comparison. According to the reaction form, the chromatographic analysis of coatings will make obvious progress in this process.

3 Conclusion

The rapid and sensitive instrumental analysis method has largely replaced the tedious and time-consuming chemical analysis method, broken the limitations of chemical analysis, and greatly improved the efficiency, accuracy and reliability of analysis. Advanced chromatographic technology has become an indispensable and important means to detect paint components.

refer to

[1] Song Xiaobo, Lan Xiaojun, Ding Liqun. Application of modern chromatographic analysis technology in coating detection [J]. Shanghai Coatings, 20 13(03).

Yin Yan. Application of chromatographic analysis technology in food detection [J]. Agricultural Engineering, 20 12(08).

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