The extraction mode and principle of solid phase extraction device
Shanghai Haozhuang Instrument Co., Ltd. has developed the LNB brand solid phase extraction device, which is energy-saving and environmentally friendly, leading the country. Professional manufacturing is more secure and affordable
The mode and principle of solid phase extraction: Solid phase extraction is essentially a kind of liquid chromatography separation, and its main separation mode is also the same as liquid chromatography, which can be divided into normal phase (adsorbent polarity is greater than eluent polarity) Reverse phase (adsorbent polarity is less than eluent polarity), ion exchange and adsorption. The adsorbent used in solid phase extraction is also the same as the stationary phase commonly used in liquid chromatography, except for the difference in particle size. The adsorbents used in normal phase solid phase extraction are all polar and used to extract (retain) polar substances. How the target compound remains on the adsorbent during normal phase extraction depends on the interaction between the polar functional group of the target compound and the polar functional group on the surface of the adsorbent, including hydrogen bonding, π-π bond interaction, and dipole -Dipole interaction and dipole-induced dipole interaction and other polar-polar interactions. Normal phase solid phase extraction can adsorb polar compounds from non-polar solvent samples. The adsorbent used in reverse phase solid phase extraction is usually non-polar or weakly polar, and the target compound extracted is usually a medium-polar to non-polar compound. The interaction between the target compound and the adsorbent is a hydrophobic interaction, mainly a non-polar-non-polar interaction, which is van der Waals force or dispersion force. The adsorbent used in ion-exchange solid-phase extraction is a charged ion-exchange resin. The extracted target compound is a charged compound. The interaction between the target compound and the adsorbent is electrostatic attraction. The choice of adsorbent (stationary phase) in solid phase extraction is mainly based on the nature of the target compound and the nature of the sample matrix (ie, the solvent of the sample). When the polarity of the target compound is very similar to the polarity of the adsorbent, the best retention (optimal adsorption) of the target compound can be obtained. The more similar the polarities of the two are, the better the retention (that is, the better the adsorption), so try to choose an adsorbent that is similar in polarity to the target compound. For example: when extracting hydrocarbons (non-polar), reverse phase solid-phase extraction (in this case, non-polar adsorbent) is used. When the polarity of the target compound is moderate, both positive and reverse solid phase extraction can be used. The choice of adsorbent is also limited by the solvent strength (ie, elution strength) of the sample.
Baby Crib,Multifunctional Baby Crib,Custom Baby Crib,Small Infant Baby Crib
DongGuan Baby-Plus baby ware Co., Ltd. , https://www.baby-plus.com