How do I determine if my sample in its diluent is too acidic for my column? - WKB108925

ENVIRONMENT

• Column care and use

ANSWER

• Consult the column care and use manual for the pH range of the column.
• Determine what one empty column volume is for your column using the equation for the volume of a cylinder: 3.14r²x column length (where r = column radius).
• Decide what you are going to use as an injection volume. 
• Combine these two amounts; one column volume plus one injection volume.
• Place this amount in a vial or test tube, mix thoroughly, and measure the pH.
• The pH should be within the range specified in the care and use manual.
• If these volumes are too small, increase both, keeping the same ratio, until a measurable volume is obtained.

ADDITIONAL INFORMATION

Example: For a column 4.6 x 150 mm, one column volume would equal 1.67 mL, If you are injecting a volume of 5 µL, use a ratio of 1670 µL (1.67 mL) of mobile phase to 5 µL of sample. If volumes are too small, apply a fixed multiplier to increase volumes until a measurable volume is obtained. For example, multiplying both amounts by 10 would give a volume of 16.70 mL to 50 µL of sample.