Preparing Samples 81
4
Selecting a Solvent
Note: Prevent precipitation of buffered salts or of sample through careful consideration of
solvent concentration and pH. Whenever possible, use mobile phase as the solvent for
dissolving samples.
Observe the following guidelines when selecting a sample solvent:
• Normal phase column – Use the same solvent that is used for the mobile phase.
• Reverse phase column – Use the same or weaker concentration of the mobile
phase organic component.
• Ion exchange – Use a low salt concentration.
• GPC – Dissolve in the mobile phase (preferably from the same bottle).
Filtering Samples
Unless restricted by sample chemistry, filter prepared samples before placing them in the
sample vials. Filtering with a 0.5-µ filter, such as a Millipore Millex™ filter unit, prevents
particulate accumulation on internal filters or the column inlet fitting which would result in
an increase in backpressure.
4.2.2 Selecting Sample Vials
The Waters 717plus Autosampler is compatible with the complete line of Waters
chromatography sample vials.
Selecting Sample Vials
Select a sample vial based on:
• Chemistry of the sample
• Volume of sample
• Volume of injection
• Number of injections
• Volatility of sample
For details on sample vials, see Appendix D,
Selecting Sample Vials.
STOP
Attention: Use only sample vials and supplies from Waters. Use of non-Waters sample
vials, low-volume inserts, or septa may result in damage to the needle.
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