SPE Cartridge Has the Purpose of Separating and Enriching the Target Compound
SPE cartridge is a widely used and popular sample preparation technology, which uses solid adsorbent to adsorb the target compound in the liquid sample, separate it from the sample matrix and interfering compounds, and then wash it with eluent. Desorption or heating desorption to achieve the purpose of separating and enriching the target compound.
It is developed on the basis of traditional liquid-liquid extraction based on the principle of similar miscibility of similar interactions between substances and combined with the basic knowledge of the widely used liquid chromatography and gas chromatography stationary phases. The SPE cartridge is a silica gel-based aminopropyl extraction column. It has a stationary phase and a weak anion exchanger. It can be retained by weak anion exchange (aqueous solution) or sexual adsorption (non-sexual organic solution), so it has a double effect.
When used in a non-sex solution (such as n-hexane) for pretreatment, it can form hydrogen bonds with molecules with —OH, —NH, —SH functional groups. Amino acid pKa=9.8; the effect with anion is weaker than SAX. It can be used as a weak anion exchanger in PH<7.8 aqueous solutions.
Due to the effect of the propyl group attached to the amino group, the amino group appears weak, so it can be used to separate non-sexual compounds from sex samples, but the strength is still the main characteristic of the amino group.
The SPE cartridge is a strong adsorbent, with a certain acidity, the mechanism of action is hydrogen bonding or even interaction; 40μm irregular shape, average pore size 60, specific surface area 325 m2/g, suitable for separating weak structures with similar structure compounds, mainly used to adsorb analytes from non-sexual solvents such as hydrocarbons, halogenated hydrocarbons or weaker esters or ethers; then elute with stronger solvents such as sex ethers, esters, alcohols, acetonitrile or water.
The SPE cartridge gradually adds the concentration of the modifier to gradually improve the solvent property, and can obtain more extraction results and recovery rates; commonly used sexual modifiers include ethyl acetate.
In addition, silica gel can also be used as a weak cation exchange adsorbent in an aqueous medium. SPE cartridges are widely used to extract target analytes from various complex matrices so that the target analytes can be concentrated or purified before chromatographic analysis. Various matrices include biological fluids (blood and urine), water samples, Soil, food, etc.