Empty Valley Baiju Net

Hello everyone, today the editor has paid attention to a more interesting topic, which is about General Youzu, so the editor has compiled a related introduction to General Youzu The answer, let's take a look. Detailed explanation of ase principle? Detailed explanation of ase principle? The principle of ASE® The physicochemical factors that generally affect solid-liquid extraction include: - Diffusion According to the Stokes-Einstein equation, the degree of diffusion D increases with increasing temperature T D = kT/ηπa (D = degree of diffusion, k = constant of proportionality, T = temperature, η = viscosity, a = activity) - Viscosity According to the Andrade equation, viscosity η decreases with the increase of temperature T, and the decrease of viscosity indicates that the solvent is more likely to enter the micropores of the sample particles lnη=A+B/T (η=viscosity T = temperature) - surface tension According to the formula σ = a–bT surface tension σ decreases with increasing temperature T, lower surface tension means that the solvent can better "wet" the sample matrix - solubility experimental data shows that the temperature increases from 0 °C At 0°C, the solubility of anthracene can be doubled, and the solubility of eicosane (C0) can be increased hundreds of times. -Physical/Chemical Forces Physsorption - Analytes can be physically adsorbed on the matrix; Chemical Binding - Analytes are bound to the matrix by chemical bonds, including van der Waals forces, hydrogen bonds, dipole moments, ionic bonds, etc.; increasing temperature It can reduce the adsorption/desorption force between solvent and solvent, solvent and matrix, and weaken hydrogen bond and ionic bond force. Sample pretreatment method and ASE® technology introduction Sample pretreatment method and ASE® technology introduction Summarize the above important factors, it is not difficult to see that increasing the temperature can increase the diffusion force, improve solubility, reduce viscosity, reduce surface tension, and reduce physical/chemical combination The force, as a result, speeds up the chemical process of dissolution. Another important factor to improve the efficiency of solvent extraction is the choice of solvent, which needs to be based on the principle of "like dissolves" and polar solvents are used for polar analytes. The particle size of the sample is also a factor affecting the extraction rate. Grinding the sample to small particles can increase the specific surface area of the sample, which is beneficial to solvent extraction. ASE® is a technique for extracting solid and semi-solid samples with a solvent. Its principle is to select a suitable solvent according to the above rules, and increase the efficiency of the extraction process by increasing the temperature (usually 0-00°C) and pressure (usually 00-000psi). ASE® can be used to replace Soxhlet extraction, ultrasonic extraction, microwave extraction, manual shaking, boiling and other extraction methods. The outstanding advantages of ASE® technology are fast, and the extraction can be completed in minutes. The amount of solvent is small, and 0 g of sample can be used in milliliters of solvent , low operating cost. The extraction residue is directly separated from the extract without filtration. The extraction efficiency is high and the repeatability is good. The influence of the sample matrix is small, and solid, semi-solid and water-containing samples can be extracted. Four solvents can be selected at the same time Non-volatile extraction, convenient method development. There is 00ml extraction pool, which can extract large volume samples. It can realize online purification, eliminating complicated and time-consuming purification steps. Safe, fully automatic, and truly unattended. EPA standard method: USEPAMethod, to So, the above is the introduction of the editor's questions about the Youzu General. I hope that the one-point answer about the Youzu General will be useful to everyone.