The Brief Introduction to SPE Cartridges
SPE cartridges, with a full name of Solid Phase extraction cartridges, is also called the SPE column( solid phase extraction column). The solid phase extraction column/cartridges is a pretreatment device for the sample being analyzed, which developed from the chromatographic column for extraction, separation, and concentration. It is usually fit for sample pretreatment of compounds in various fields, such as agricultural and food products. Most of the SPE cartridges are injection syringe devices made of polyethylene or medical PP level materials with wonderful chemical compatibility.
In actually, SPE cartridge is a normal phase extraction of polar compounds which is good for purifying polar compounds, and sorbent exhibit are often used to retain polar interference and pass through weak polar or non-polar compounds.
The structure of SPE cartridges is simple, in addition to plastic pipe, only the sieve plate, and packing. This simple structure brings convenience and inherent contradictions, some of which we will never encounter when extracting with solvent.
Principles of SPE cartridge
SPE mainly comply with the separation principle of selective adsorption and selective elution by liquid chromatography. Based on the theory of liquid-solid chromatography, selective adsorption and selective elution were used to enrich, separate and purify the samples. It is a physical extraction process including a liquid phase and solid phase, which can also be approximated as a simple chromatographic process.
A more common method is to pass a liquid sample solution through an adsorbent, retaining the substance under test. Then select the appropriate strength of solvent to flush impurities, and then use a small amount of solvent to quickly elution material, so as to achieve rapid separation and concentration of the purpose of purification.
Types of SPE cartridge
Since SPE Cartridge provided by Hawach Scientific is available in different types, and each type has its own special features, we made an endeavor to provide comprehensive instructions on our products.
Hawach SPE cartridge falls into different types, concretely including Iron-Exchange、Mixed Mode、 Normal Phase、Polymeric and Reversed-Phase types, and each type also has its own sub-product. For example, Normal Phase is divided into Normal Phase Cyanopropyl (CN) SPE Cartridges, Normal Phase Diol SPE Cartridge. Ion-Exchange is often applied to separation of basic compounds from particle aqueous and keep permanent negative charge in the range of pH, Iron-Exchange is divided into Ion-Exchange NH2 SPE Cartridge, Ion-Exchange PRS SPE Cartridges, Ion-Exchange PSA SPE Cartridges, Ion-Exchange SAX SPE Cartridges, and Ion-Exchange SCX SPE Cartridges. Reversed-Phase is more suitable for use in the biological macromolecules sample and used to extract lipid soluble and water vitamins at the same time from other compounds, reversed-phase is divided into Reversed Phase C18 SPE Cartridge. Mixed Mode is fit for purification of alkaline aqueous solution or neutral compounds in urine and blood, such as drugs and metabolites.
In a word, there are complete volume and style to choose or customize them to suit the customer’s configuration and requirements. Besides, the guide will be followed to help the customer choose the appropriated SPE Cartridges.
Operation of SPE cartridge
In order to achieve greater reproducibility and cleaner samples, enhance performance consistency, reduce extraction time and avoid sample contamination, there are some operational suggestions or tips for customers to follow, specifically as follows: firstly, making sure it in a cleaning state before operation, next, choosing and putting appropriate samples in cartridge, conditioning for a while, and then carrying out sample load and washing, finally, performing sample elusion. When the whole process is finished, cleaning and drying the SPE cartridgeimmediately, and place it in holding the box.
The influence of SPE cartridges
The analyte is not adsorbed or partially adsorbed:
1. Improper column selection;
2. The column was not pretreated well.
Poor reproducibility:
1. The column was dry before sample addition;
2. The column load.
Interference in the elution fraction: Interference from the SPE cartridges.
The choice of SPE cartridges
1. Agricultural residues and food field: Florisil, PestiCarb, Alumina-N, NH2;
2. Animal residues (tissue, feed) field: SCX, PCX, MCX, PEP, SUL-5, Alumina B, C18, Silica, Alumina A, Alumina-N, PRS, Florisil;
3. Environmental field: PEP, HXN, diatomaceous earth;
4. Medical field: C18, PEP, PCX, PAX.
The application range of the commonly used SPE cartridges
C18: reverse extraction, suitable for non-polar to medium polar compounds.
C8: reverse extraction, suitable for non-polar to medium polar compounds.
C2: compared with C18 and C8, C18 and C8 are suitable for non-polar compounds because of their short chains and much smaller retention effect.
SPE cartridges are mainly used in the sample pretreatment of target compounds in farm product and livestock products, various food, environmental samples, and biological samples. SPE technology has been widely used in many industry analysis standards and national standards(GB/T).
