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Introduction
2) Optimization of Wash and Elution Steps
Wash and elution profiles were carried out for a number of
the HyperSep SPE phases to determine the optimum wash
and elution solvent mixes for maximum recovery of the
compound. The results show the importance of using an
optimized method for best recovery levels.
For all phases, the following compounds were investigated:
Compound
pKa Value
Structure
Temazepam
1.3
Clonazepam
10.5 (1-position),
1.5 (4-position)
Nitrazepam
2.5
Flunitrazepam
1.8
Triazolam
1.5
Flurazepam
8.2 1.9
Compound
pKa Value
Structure
Prazepam
3.0
Alprazolam
2.4
Bromazepam
11.0 2.9
Chlordiazepoxide HCl 4.8
Nordiazepam
3.5
Diazepam
3.3