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Anonymous users2024-02-09That's what I've learned, and my knowledge is limited.
Monitoring of pigments.
Use photoelectric colorimetry (the principle is quite complicated).
Photoelectric colorimetry is to measure the absorbance of a series of standard solutions on a photoelectric colorimeter, plot the absorbance against the concentration, draw a working curve, and then check its concentration or content on the working curve according to the absorbance of the component solution to be measured.
Sodium and potassium ions can be used by ion-exchange chromatography.
Ion-exchange chromatography uses the surprising ability of ion exchange between the separated components and the stationary phase to achieve separation. The stationary phase of ion exchange chromatography is generally an ion exchange resin, and there are many ionized active centers in the molecular structure of the resin, and the ions in the components to be separated will be ion-exchanged with these active centers to form an ion exchange equilibrium, thus forming a partition between the mobile phase and the stationary phase. The intrinsic ions of the stationary phase compete with the ions in the components to be separated for the ion exchange center in the stationary phase and move with the movement of the mobile phase to achieve the final separation.
The partition coefficient of ion-exchange chromatography is also called the selection coefficient, and its expression is:
k_s=\frac
where [rx+ denotes the concentration of ions bound to the active center of the ion exchange resin, and [x+ denotes the concentration of ions free in the mobile phase.
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Anonymous users2024-02-08It's very complicated, and the general middle school does not have the conditions, so you can change the subject.
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Anonymous users2024-02-07Testing the composition of a beverage usually requires chemical or biological testing. Here are some ways to test the ingredients of your drink:
1.Chromatography: Chromatography is a commonly used chemical separation method that can be used to detect the composition of various organic substances. When testing organic components in beverages, methods such as gas chromatography or liquid chromatography can be used for analysis.
2.Mass spectrometry: Mass spectrometry is an analytical technique that can be used to detect the composition of specific substances in beverages. The composition of the sample can be determined by separating, ionizing, and accelerating the sample, and then interpreting the mass spectrum using different mass-to-charge ratios.
3.Ion chromatography: Ion chromatography is an analytical method used to analyze the composition of ions. It works by separating the sample into cations and anions and using a specific detection method to measure the amount of each group of ions.
4.Enzyme-linked immunosorbent assay (ELISA): ELISA is a widely used detection method in the biomedical field to determine the content of proteins and other biomolecules in food and beverages.
These methods require specialized personnel and equipment to operate. If you need to test the ingredients of your beverages, seek the help of a professional testing agency or laboratory.
Go to the agricultural technology extension station in your county. You can also go to your agricultural colleges and universities and ask the teachers of the Department of Agricultural Resources and Environment (formerly the Department of Soil Agrochemistry) of the College of Resources and Environmental Protection to help, they can give you a comprehensive soil test and guide you to improve, which may cost you.
Hehe, well, it's rare to see such a high score.
This question is very interesting, if only ions are measured, the above methods have many limitations, for example, liquid chromatography is indeed suitable for liquid detection, but the commonly used ultraviolet detector is not high, and calcium ions have no ultraviolet absorption, and the fluorescence detector with higher sensitivity in high-performance liquid phase needs to coordinate calcium ions, which is not good. Not to mention nuclear magnetic resonance, I have never heard of liquid nuclear magnetic resonance (NMR) with nuclear magnetic calcium spectroscopy, as for doing hydrogen spectroscopy in water, does it make sense? >>>More
I think there is a certain impact, the electrode brush electrode is difficult to brush clean, and the electrode brush will also remain on the residue of the previous zinc measurement, so, if the aluminum profile is directly transferred, the content of zinc in the aluminum will have a little impact, and the others will be less, some users who use the spectrometer will require the spectrometer manufacturer to match the spark plate, electrode brush, electrode, etc. when using multi-matrix instruments, and use a set for each substrate, and do spark table cleaning and corresponding replacement when replacing the substrate. To ensure that the impact of the process of replacing the measurement material is eliminated as much as possible, of course, this influence can be ignored when making alloys, and it will feel more obvious when doing pure metals.
International criteria for the diagnosis of blood lead: 100 micrograms or more than 100 micrograms for lead poisoning. >>>More
The main components of bird's nest are: water-soluble protein, carbohydrates; Trace elements: calcium, phosphorus, iron, sodium, potassium and amino acids (lysine, cystine and arginine) that play an important role in promoting human vitality. >>>More