PDF catalog - Teknolab AS

MIXED-MODE SORBENTS
Isolate acidic and basic drugs from biological fluid samples with Biotage’s range of mixed-mode sorbents. The
sorbents provide two primary retention mechanisms, non-polar (hydrophobic) and ion exchange (anion or
cation). The dual retention mechanisms allow the use of rigorous interference elution regimes, providing
extremely clean extracts and reducing matrix effects commonly associated with LC-MS analysis. Technical information
for EVOLUTE and ISOLUTE mixed-mode sorbents are summarized on these pages.
Mixed-mode SPE
Analytes are initially retained by a non-polar retention mechanism, with inorganic salts, polar interferences and
high molecular weight peptides and proteins passing directly through the sorbent bed. The pH is then adjusted
to allow an ion exchange retention mechanism to retain the analyte. Non-polar interferences are removed
using an organic solvent or organic solvent/water wash as shown in Figure 1.
Proteins etc. excluded from
the pores and pass to waste
Salts, phospholipids and
small non-ionizable
interferences are removed
Drugs are eluted
Clean extract
is obtained
Interference Elution 1 Interference Elution 2 Analyte Elution Analysis
Figure 1. The combination of optimized pore structure and additional interference elution steps using
mixed-mode sorbent chemistry guarantees extremely clean extracts.
EVOLUTE CX: Resin-based mixed-mode SPE for Basic Drugs
EVOLUTE CX extracts a wide range of basic drugs from biological fluid samples using a generic procedure,
minimising method development time. The robust mixed-mode sorbent chemistry and optimised pore size
minimises retention of high molecular weight matrix components present in biological fluids. Interferences
including proteins, salts, non-ionisable molecules and phospholipids are removed during the interference elution
step, ensuring extremely clean extracts for LC-MS/MS analysis.
EVOLUTE CX is also available in a larger particle size (50 µm) for more viscous matrices or larger sample
volumes (see pages 25-27 for details).
ISOLUTE HCX, HCX-3 & HCX-5: Silica-based mixed-mode SPE for Basic Drugs
Biotage offers three silica-based mixed-mode sorbents for extraction of basic drugs. Compared to resin based
mixed-mode sorbents, these have reduced non-polar character, and may lead to cleaner extracts. ISOLUTE HCX,
HCX-3 and HCX-5 differ only in their degree of non-polar character, and can be screened in parallel for optimum
extract cleanliness and analyte recovery. For extraction of very polar basic drugs, EVOLUTE CX is
recommended.
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