How to Choose Solid Phase Extraction Method?
Selection of stationary phase (selecting the stationary phase according to the principle of similar compatibility): The stationary phase of SPE is the key to sample separation and purification. Because the stationary phase is related to the repeatability, recovery, sensitivity, and specificity of SPE, SPE Adsorbents have always been a hot spot of concern.
Since the invention of SPE, the contamination of the sample of polymer resin has been annoying. In 1978, Waters Company invented the C18-bonded silica gel to make a disposable small column (Sep-park), which has high reliability and stability and has been widely used. In clinical biochemical tests. Adsorbents that can be used in HPLC can be used in SPE, including “designer phase” for drug abuse testing in recent years. The choice of adsorbent should consider the affinity of each component of the sample to the stationary phase, the force of the analyte and the eluent, and also consider its versatility.
In the current chemically bonded phase, the non-polar bonded phase has C1, C2, C4, C6, C8, cyclohexane, phenyl, diphenyl, C18, etc.; polar and weak ion exchange phases are: cyanide Base, diol group, amino group, primary/secondary amine group, butyric acid group; strong ion exchange phase: propane sulfonic acid group, benzenesulfonic acid group, quaternary ammonium group, etc.; adsorption resin: XAD-2, GDX, X-5. Phenylsulfonic acid with selective specificity can be used to separate coplanar vicinal hydroxyl structural molecules.
For biological samples, most of them are dissolved in water-based substances, the analytes are ionized, and highly polar substances are separated by ion exchange extraction. Non-polar or weakly polar analytes are extracted with RP, and normal phase extraction is used for organic extraction. A polar substance in a solvent. The amount of adsorbent must ensure that all the analytes are effectively adsorbed from the sample, without retaining the matrix component. Increasing the amount of the adsorbent can increase the adsorption capacity, but at the same time increase the elution volume, dilute the analyte and dry it. And quantification brings difficulties. Therefore, a minimum amount of adsorbent is used on the premise of achieving effective adsorption. Hawach offers you solid phase extraction cartridges.