Question

8. What kinds of functional groups or coatings are available in SPE cartridges and how does one elute the sample through the cartridges?

Answer 1

SPE cartridges in which SPE means Solid-phase extraction (SPE) extractive technique in this dissolved or suspended in a liquid mixture are separated due to their physical and chemical prppropert which are different from other compounds in the mixture.SPE technique used by various Analytical laboratories used to concentrate and purify samples for analysis such as isolation of so many components from a wide variety of samples including urine, blood, water, beverages, soil, and animal tissue.

SPE technique in which used two pahse one is mobile phase and second one is stationary phase. Mobile phase is formed by due to solubility of solute in liquid phase which then passed through a solid stationary phase which is made up of silica to separate a mixture into desired or undesired components. The result is that either the desired component are sepersepa or may remove impurtiimp present in a mixture or sample which retained on stationary phase . The portion that passes through the stationary phase is collected or discarded, depending on whether it contains the desired product or impurities. If the portion retained on the stationary phase includes the desired product then stationary phase collected and rinsed with an appropriate eluent.

The stationary phase now avilable ini the form syringe shape cartidge for example a 96 well plate, a 47- or 90-mm flat disk, or a microextraction by packed sorbent (MEPS) device, a SPE method that uses a packed sorbent material in a liquid handling syringe. Some time parallel mounted cartridges are used to speedup the process of extraxextr. Now a days SPE  are equipped with a vacuum port, where vacuum can be applied to speed up the extraction process by pulling the liquid sample through the stationary phase.

SPE cartridges are available with different type of stationary phases, by which we can choose specific stationary phase according to different chemical properties of compounds. Most stationary phases are based on silica that has been bonded to a specific functional group. Some of these functional groups include hydrocarbon such as saturated or unsaturated hydrocarbons with aavariable carbon chain, quaternary ammonium or amino groups (for anion exchange), and sulfonic acid or carboxyl groups (for cation exchange).