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SPE Devices
| Choosing an SPE Product | Choosing an SPE Product For Environmental Applications Recommended SW-846 Cleanup Methods ANALYTE GROUP EPA METHOD NO. RECOMMENDED SPE SORBENTS Aniline and Derivatives 3620 C18 Chlorinated Pesticides 3620 C18, Florisil® Chlorinated Hydrocarbons 3620 C18, Phenyl Haloethers 3620 C18 | | General Solid-Phase Extraction Procedures | General Solid-Phase Extraction Procedures: Reversed-Phase To isolate relatively non-polar compounds from a polar matrix Conditioning Rinse device with 3-5mL of methanol followed by 3-5mL of deionized water/buffer (do not allow bed to dry before next step). Sample Application Apply sample to the top of the | | SPE Column Formats | SPE Column Formats Actual Size Drawings Extract-Clean™ and Ultra-Clean™ Columns Extended Volume Columns Maxi-Clean™ Cartridges Device Specifications DEVICE HOUSING FRIT MATERIAL DESCRIPTION Extract-Clean™ Columns Polypropylene 20μm Polyethylene For a Full Range | | SPE Sorbent Specifications | SPE Sorbent Specifications SPE Sorbent Specifications FUNCTIONAL GROUP BASE % CARBON ENDCAPPED AVERAGE PARTICLE SIZE PORE SIZE PAGE Reversed-Phases (Non-Polar) Prevail C18 Silica 11.0% Yes 50μm 60Å 10 Octadecyl (C18) Silica 6.0% Yes 50μm 60Å 12 High Flow C18 |
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Tips on Choosing an SPE Product
- Characterize the sample. Factors such as the analyte’s polarity relative to the matrix, the presence of charged functional groups, solubility, molecular weight, etc., determine how strongly the analyte is retained by the packed bed.
- Select a retention strategy. There are two basic methods for sample treatment:
- Select the packing bed to retain the desired analyte. The contaminants are washed off and the desired analyte is then eluted for analysis.
- Select the packing bed to retain the contaminants and the desired analyte passes directly through.
- Select the proper packing type for the cleanest extract with the highest recovery.
- Reversed-phase packings are hydrophobic, silica-based materials that retain moderately polar to nonpolar compounds from a polar matrix while washing off polar interferences. Or you can retain non-polar contaminants while the polar compounds pass through unretained.
- Normal-phase packings are hydrophilic, silica-based materials that retain polar compounds from a non-polar matrix while washing off non-polar interferences. Or you can retain polar contaminants while non-polar compounds pass through unretained.
- Ion-exchange resins retain charged compounds or remove ionic interferences.
- Optimize conditions for best results. Select proper bed size and suitable conditioning, wash and elution solvents.
- Poor sample recovery often occurs when the packed bed dimensions are not optimized. Too large a bed results in incomplete elution while too small a bed results in incomplete retention.
- Consider the solvent strength relative to the packing material. The final conditioning solvent should be weak so it doesn’t act as an eluting solvent. Buffers should be used to control ionization of potentially charged compounds.
- Wash solvents should remove weakly retained interferences without being strong enough to elute the analyte.
- Elution solvents should be strong enough to completely elute an analyte in a small volume (1-2mL).
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