consumer transformer,audio isolation transformer,power low frequency transformer,epoxy encapsulated transformer IHUA INDUSTRIES CO.,LTD. , https://www.ihuagroup.com
Don't underestimate the sample processing of the medium, be careful that the experiment is full! -Huaqiang Electronic Network
In the context of sample preparation for analytical instruments, particularly in the field of chemical analysis, the transformation of solid samples into liquid form is a crucial step. According to a research report from Shanghai Jinma Laboratory, various methods exist for introducing samples of different states into analytical equipment such as atomic absorption spectrometers, atomic fluorescence spectrometers, and plasma emission spectrometers. While many techniques are effective depending on the specific requirements of a given sample, the most widely used and preferred method involves the introduction of liquid samples.
The advantages of liquid introduction are numerous. First, when a solid sample is processed and converted into a solution, the elements present are in an ionic state, which minimizes measurement errors caused by differences in element occurrence or physical properties. Second, during analysis, 0.1–1 g of solid samples are typically weighed and chemically treated, ensuring good sampling representativeness. Third, the liquid form reduces the fractionation phenomenon that occurs during evaporation from solid samples, leading to more uniform evaporation behavior and improved accuracy and precision. Fourth, this consistency allows for the simultaneous determination of multiple elements. Fifth, it is easier to prepare standard solutions and matrix-matched solutions using high-purity compounds. Lastly, liquid atomization methods can measure up to 70 elements, while plasma emission spectrometers can perform multi-element analysis at primary, secondary, and trace levels without changing conditions.
However, there are challenges associated with converting solid samples into liquid form. Chemical pretreatment is often required, increasing labor, cost, and the need for specialized facilities. Some procedures demand expertise, and after decomposition, the sample may be diluted over 50 times, reducing sensitivity. Additionally, contaminants or salts introduced during treatment can interfere with measurements.
When preparing solid samples for analysis, several key points should be considered. The sample must be properly prepared—crushed, sieved, and representative. The measured elements must be fully dissolved, and the chosen method should be efficient, simple, and suitable for large-scale processing. Separation techniques should be employed to remove interfering elements, but the target elements must not be lost. Contamination must be avoided throughout the entire process, including during sample preparation, reagent use, and vessel handling. The total dissolved solids in the test solution should be kept low (ideally below 1 mg/ml) to prevent matrix effects and interference.
Common sample preparation methods include acid digestion (open and closed containers), alkali fusion, and microwave digestion. Open container acid digestion is widely used due to its simplicity and efficiency, though some elements may be lost through volatilization. Closed container digestion increases pressure and temperature, improving dissolution efficiency and reducing reagent use. Microwave digestion is a modern technique that accelerates the process by rapidly heating the sample, making it highly effective for difficult-to-dissolve materials. Alkali fusion is used for refractory materials like silicates and oxides.
Separation and pre-enrichment are essential steps in reducing matrix effects and improving detection limits. These processes involve techniques such as volatile compound generation, solvent extraction, ion exchange, and coprecipitation. It's important to keep these steps minimal and ensure that no analytes are lost. Reagents and equipment used must be free of contaminants to avoid false readings.
Shanghai Jinma Bio has extensive experience and unique insights into sample preparation and preservation. For more information or assistance, feel free to reach out.