Premium Chromatography Media for SPE

Solid-phase extraction (SPE) is an effective method for sample preparation and is used in most analytical laboratories today. For nearly 40 years diverse SPE phases, packed in columns, cartridges and 96-well plates have been available from the manufacturer of chromatography media MACHEREY-NAGEL. While at the beginning silica-based sorbents were predominant, polymers have been established as a standard in SPE in recent years.

Depending on the application, users can choose between a polymer HLB phase for an extraction of medium to polar analytes and the professional concept of HR-Xpert. It includes a polymer RP phase for nonpolar and different mixed-mode ion exchange phases for ionic analytes.

CHROMABOND® HLB for medium to polar analytes

The enrichment of hydrophilic polar analytes from polar matrices is a challenge because they often cannot be retained by C18 or C8 modified silica or hydrophobic polymer adsorbents. To overcome this issue MACHEREY-NAGEL developed CHROMABOND® HLB, a hydrophilic-lipophilic balanced N-vinylpyrrolidone-divinylbenzene copolymer.

Bonded hydrophilic groups of the HLB copolymer interact with polar functional groups of the analytes while the lipophilic backbone interacts with nonpolar hydrocarbon residues. In particular for polar substances, this results in increased retention and higher recovery rates in the subsequent chromatographic analysis. Furthermore, HLB phases show high loadability and good water wettability. Even if the column bed runs dry, SPE can be continued without significant performance loss.

CHROMABOND® HLB is applicable for a wide range of analytes. Applications for sulpha drugs, tetracyclines, and iodinated contrast media as well as for mixtures of pharmaceuticals were successfully developed. For complex extractions from food and beverages (e.g., chloramphenicol from honey) the HLB phase shows high recovery rates. CHROMABOND® HLB can also successfully be applied for pesticides as well as for drugs from tap water.

CHROMABOND® HR-Xpert for nonpolar and ionic analytes

For the extraction of various neutral nonpolar analytes the hydrophobic RP phase CHROMABOND® HR-X, part of the HR-Xpert concept, has turned out to be ideal. Many applications were developed with this spherical PS/DVB copolymer. Excellent recovery rates especially for the enrichment of pharmaceuticals (e.g., antiinflammatory drugs) were obtained due to the spherical structure of the particles, the very homogeneous surface and an optimised pore structure. Also in the fields of environmental (e.g., pesticides from water) and food (e.g., catecholamines from green tea) this polymeric phase is very successful.

The mixed-mode phases (ion exchange polymers based on PS/DVB) feature distinct ion exchange and reversed phase properties. They are suitable for extraction of polar or ionic analytes from complex matrices (e.g., urine, plasma, serum, pharmaceuticals, food). The strong cation exchanger CHROMABOND® HR-XC is recommended for extraction of basic compounds (e.g., codeine or methadone from serum or urine, fungicides from juice); the weak cation exchanger HR-XCW can be used for strong bases (e.g., paraquat/diquat from water). Accordingly, the strong or weak anion exchangers HR-XA and HR-XAW are used for an enrichment of acidic compounds (e.g., allantoin in cosmetic products) or for strong acids (e.g. perfluorated surfactants from water).

Further product information can be found at www.mn-net.com/SPE. A wide range of approved and new application notes are freely accessible online at www.mn-net.com/apps.