Waters iKey - Manual (Page 6)

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[ CARE AND USE MANUAL ]
iKey
5) Consider filtering samples with a 0.2 µm membrane to remove particulates. If the sample is dissolved in a solvent that contains an
organic modifier (e.g., acetonitrile, methanol, etc.) ensure that the membrane/filter material is compatible with the solvents in use.
Alternatively, centrifuge the sample for 20 minutes at 8000 RPM, followed by the transfer of the supernatant to an appropriate
Waters TruView LCMS Certified Vial could be considered.
6) Below are two examples of commonly used sample preparation protocols:
Protein precipitation (PPT)*
a. Add acetonitrile to plasma at a ratio of 2:1 (acetonitrile: plasma).
b. Vortex (mix) for one minute.
c. Centrifuge at 5000 relative centrifugal force (RCF) for five minutes.
d. Remove supernatant.
e. Perform solid-phase extraction (SPE) cleanup (optional).*
f. Pipette into Waters TruView™ LCMS Certified Vial (e.g., part number 186005663CV).
Liquid/Liquid Extraction (LLE)*
1. Add hexane to plasma at a ratio of 10:1 (hexane:plasma).
2. Vortex (mix) for one minute.
3. Centrifuge at 5000 relative centrifugal force (RCF) for five minutes.
4. Remove supernatant and evaporate to dryness.
5. Reconstitute (e.g., initial gradient conditions solvents).
6. Centrifuge at 5000 relative centrifugal force (RCF) for five minutes (optional).
7. Perform solid phase extraction (SPE) cleanup (optional).*
8. Remove supernatant and pipet into Waters TruView LCMS Certified Vial (e.g., part number 186005663CV).
*Additional sample cleanup steps using Oasis ® or Sep-Pak ® SPE devices can provide cleaner samples, improved selectivity, higher
sensitivity, and reduced matrix effects.