About 30 years ago MACHEREY‑NAGEL designed and introduced CHROMABOND SPE cartridges containing silica-based adsorbents.
SPE is a form of digital (step-wise) chromatography designed to extract, partition, and / or adsorb one or more components from a liquid phase (sample) onto a stationary phase (adsorbent or resin). An adsorbed substance can be removed from the adsorbent by stepwise increase of elution strength of the eluent (step gradient technique).
SPE extends a chromatographic system’s lifetime, improves qualitative and quantitative analysis, and the demand placed on an analytical instrument is considerably lessened.
Coarse-grained kieselguhr (also known as diatomaceous earth, hydromatrix, celite)
Surface chemistry
Kieselguhr (amorphous silica)
Column type
SPE column
Hardware
Polypropylene (PP) columns with polyethylene (PE) filter elements
Column shape
Open tubular syringe-shaped column with Luer tip outlet
Column volume
45 mL
Filling quantity
8300 mg
Column volume/adsorbent weight
45 mL/8300 mg
Recommended application(s)
Clinical chemistry, Dyes in textiles, Environmental and food analysis without use of a separation funnel, Highly viscous aqueous solutions, Liquid-liquid extraction (LLE), Physiological fluids (blood, plasma, and serum), Removing small amounts of water from solvents which are not miscible with water, Supported/solid liquid extraction(SLE)
Coarse-grained kieselguhr (also known as diatomaceous earth, hydromatrix, celite)
Surface chemistry
Kieselguhr (amorphous silica)
Column type
SPE column
Hardware
Polypropylene (PP) columns with polyethylene (PE) filter elements
Column shape
Open tubular syringe-shaped column with Luer tip outlet
Column volume
70 mL
Filling quantity
14500 mg
Column volume/adsorbent weight
70 mL/14500 mg
Selling unit
30 columns, 100 columns
Recommended application(s)
Clinical chemistry, Dyes in textiles, Environmental and food analysis without use of a separation funnel, Highly viscous aqueous solutions, Liquid-liquid extraction (LLE), Physiological fluids (blood, plasma, and serum), Removing small amounts of water from solvents which are not miscible with water, Supported/solid liquid extraction(SLE)
Coarse-grained kieselguhr (also known as diatomaceous earth, hydromatrix, celite)
Surface chemistry
Kieselguhr (amorphous silica)
Column type
SPE column
Hardware
Polypropylene (PP) columns with polyethylene (PE) filter elements
Column shape
Open tubular syringe-shaped column with Luer tip outlet
Column volume
150 mL
Filling quantity
37500 mg
Column volume/adsorbent weight
150 mL/37500 mg
Recommended application(s)
Clinical chemistry, Dyes in textiles, Environmental and food analysis without use of a separation funnel, Highly viscous aqueous solutions, Liquid-liquid extraction (LLE), Physiological fluids (blood, plasma, and serum), Removing small amounts of water from solvents which are not miscible with water, Supported/solid liquid extraction(SLE)
Mixture of polystyrene-divinylbenzene copolymer (PS/DVB) in H⁺ form (PS-H⁺), strong cation exchanger (SCX) and OH⁻ form (PS-OH⁻), strong anion exchanger (SAX)
Column type
SPE column
Hardware
Polypropylene (PP) columns with polyethylene (PE) filter elements
Column shape
Open tubular syringe-shaped column with Luer tip outlet
Mixture of polystyrene-divinylbenzene copolymer (PS/DVB) in H⁺ form (PS-H⁺), strong cation exchanger (SCX) and OH⁻ form (PS-OH⁻), strong anion exchanger (SAX)
Column type
SPE column
Hardware
Polypropylene (PP) columns with polyethylene (PE) filter elements
Column shape
Open tubular syringe-shaped column with Luer tip outlet
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.
+852-3069 6950
css@gugent.com.hk
