Analysis section: one question per week (September 12–18)
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This post was last edited by dalian*aochao on 2011-9-12 at 16:47. 1. Please hide your replies; editing after posting is ineffective! Delete directly without hiding! 2. Hiding method: http://bbs.hcbbs.com/thread-492556-1-1.html. 1 i- E- R4 D( k0 b- C# h3. Rewards are available for those who participate. Those who have suggestions for topics can post replies at http://bbs.hcbbs.com/thread-899447-1-1.html; there will be a reward for that, and an additional 20 points will be given if the suggestion is adopted. This week’s topic: What are the common methods for analysis and determination, and which one do you use most often? What are the gains and thoughts? (You may write one or several of the most commonly used methods in chemical analysis or instrumental analysis)
This post was last edited by zbx on 2011-9-13 at 18:54. There are too many of these methods: industrial analysis of coal, elemental analysis, determination of calorific value, gas chromatography analysis of gas, infrared spectroscopy for analyzing molecular structure, nuclear magnetic resonance analysis for C and H spectra, chemical titration to identify various functional groups, and so on. These are all commonly used methods, with industrial analysis, functional group titration, and infrared analysis being the most frequently used ones! There are manual tests as well as instrumental tests, and all the testing and analysis are carried out with great precision. It is essential to be careful and thorough throughout the testing process, following the requirements of national standards; otherwise, significant errors can occur. This is especially true when it comes to chemical titration. In experiments involving the detection of functional groups, the amounts involved are very small, and only a few drops are used for titration, making it quite difficult to control the quantities precisely. Therefore, it is necessary to follow the standard requirements and strictly control the experimental conditions. The preparation of samples is also a crucial step – there’s no need to go into too much detail about this. In short, one must be careful and follow the standards!
We deal with ore analysis; most of the ores have high concentrations, so we conduct a lot of titration and atomic absorption tests. In titrimetric analysis, it is possible to achieve high accuracy for ores or products with high concentrations; separation and enrichment are relatively easy. In contrast, it is more difficult to separate impurities through extraction or enrichment, and instrumental testing is subject to significant interference. Moreover, the extractants or reagents used are often highly toxic, and the procedures involved are rather complicated. More efforts are needed in the analysis of non-ferrous metals in ores, as well as in the detection of trace amounts. . . . I also hope the company can purchase more advanced and convenient instruments to reduce the workload as well as the costs in terms of labor and resources
Common analysis methods include: high-performance liquid chromatography； Gas chromatography ； Spectrophotometry ； Titration Method: The methods commonly used in our company are gas chromatography and titration. Gas chromatography instruments are precise, while the relative error of the titration method is somewhat higher.
In college, I mainly used infrared XRD as well as mass spectrometry analysis, among other things. The graduation project mainly involves XRD and NMR. There aren’t many main sensations either; it’s mainly to check whether there are magazines and whether the structure of the materials meets the requirements
Metal analysis: ICP; Volatile and semi-volatile substances: GC/GCMS; Others: LPLC, UV, FDIR, IC.
Instrumental analysis includes: spectrophotometers, Karl Fischer titration, ultraviolet photometers, pH meters, gas-liquid chromatography, gas-chromatography-mass spectrometry, etc. Chemical analysis includes: titration methods, iodometry, preparation of various standard solutions, calibration, etc
Reply 1# *ngguanglueguo: Acid-base titration, complexometric titration, precipitation titration, and redox titration are all utilized; the analytical instruments include pH meters, spectrophotometers, conductivity meters, analytical balances, and gas chromatographs.
Reply 1# *ngguanglueguo: Chromatographic analysis and titrimetric analysis. Chromatographic analysis offers higher precision, but the appropriate method still needs to be chosen based on the quality requirements of the product.
Reply to 1# *ngguanglueguo: Gas chromatography – modern instruments are so advanced that you don’t really notice any differences anymore! Not feeling anything is the easiest