Macherey-Nagel CHROMABOND® HR-Xpert SPE Columns
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Spherical, hydrophobic polystyrene-divinylbenzene resin in SPE columns. High-purity material with highest reproducibility and lowest blank values due to an optimized manufacturing process. Excellent recovery rates especially for the enrichment of pharmaceuticals/active ingredients due to the spherical structure of the particles, very homogeneous surface, and optimized pore structure.
General Specifications
| Method | Solid phase extraction (SPE) |
| Brand | CHROMABOND |
| Phase | HR-X |
| Mode | Reversed phase (RP) |
| Base material | PS/DVB copolymer |
| Surface chemistry | Hydrophobic spherical polystyrene-divinylbenzene copolymer (PS/DVB) |
| Endcapped | No |
| Column type | SPE column |
| Hardware | Polypropylene (PP) columns with polyethylene (PE) filter elements |
| Column shape | Open tubular syringe-shaped column with Luer tip outlet |
| Recommended application(s) | Active ingredients from tablets, Drugs, Drugs from plasma, Drugs from serum, Drugs from urine, Herbicide, PAHs and PCBs from water, PCB, Pesticides, Pharmaceuticals, Phenols |
| Particle type | Fully porous particles (FPP) |
| Particle shape | Spherical |
| pH stability | 1.0–14.0 |
| Filter element material | Polyethylene (PE) |
| Storage temperature | 15–25 °C |
| Hazardous material | No |
1) Conditioning
Conditioning of the adsorbent is necessary in order to ensure reproducible interaction with the analyte. Conditioning, also called solvation, results in a wetting of the adsorbent and thus produces an environment, which is suitable for adsorption of the analyte. Nonpolar adsorbents are usually conditioned with 2–3 column volumes of a solvent, which is miscible with water (methanol, THF, 2-propanol etc.), followed by the solvent in which the analyte is dissolved (pure matrix, e.g., water, buffer). Polar adsorbents are conditioned with nonpolar solvents. After the conditioning step the adsorbent bed must not run dry, because otherwise solvation is destroyed (deconditioning).
2) Sample application (adsorption)
Sample application can be performed with positive or negative pressure with a flow rate of ~3 mL/min. Sample volumes vary from a few mL up to liters.
3) Washing
Washing of the adsorbent is usually achieved with a special wash solution; however, in some cases it may not be necessary. If the polarity difference between wash solution and eluent is very large, or if both are not miscible, drying of the adsorbent bed after washing is recommended to improve elution and recovery.
4) Elution
Elution with a suitable eluent should not be too fast. The elution speed depends on the column or cartridge dimension and the quantity of adsorbent (about 1 mL/min).
Since analytes can either be adsorbed on the SPE packing material or directly flown through while the interfering substances are retained, two general separation procedures are possible – both cases are shown in the figure below.
- Environmental analysis
- Pharmaceutical and biochemical analysis
- Organic chemistry
- Food analysis
a) Retention of the analyte (top path)
- Analyte molecules are enriched on the adsorbent
- Interfering components and solvent molecules (matrix) are not retained
- Remaining interfering components are washed from the adsorbent
- The analyte is removed from the adsorbent by elution with a suitable solvent
b) Retention of interfering components (bottom path)
- Analyte molecules show no interaction with the adsorbent
- Interfering components and solvent molecules (matrix) are retained
- Analyte molecules are “washed” from the adsorbent
- The solid phase is used to “filter” the sample
