The following procedure is recommended for packing a Biochrom 20 column:

1. Extend the analytical column tube by attaching the column packing reservoir to the column top fitting.  Remove the packing reservoir inlet fitting.
   
   NOTE: Keep the two inlet fittings separate.

2. Mount the column and packing reservoir vertically by mounting the column in the column sleeves, secure the columns in position using the column clamps and column front cover.  Select a column temperature of 50°C.  Place the column inlet pipe in a beaker then activate override and pump buffer 6 for five minutes.

3. Place a clean glass beaker (250ml) beneath the column.

4. Mix the resin to be used for the column packing with 3ml of the appropriate regenerating solution (either sodium hydroxide or lithium hydroxide) to form a moderately dense slurry.

5. Gently mix the resin in the bottle to produce a uniform slurry.   Leave for 30 minutes then mix again.

6. Draw the slurry up into the syringe with the Luer fitting and 0.7mm internal diameter PTFE tubing.

7. Press the syringe plunger until all the air has been expelled from the tubing Lower the end of the PTFE tubing into the packing reservoir and to the bottom of the column then press the syringe plunger to pump the resin into the column.  As the level of resin rises in the column, gently lift the end of the PTFE tubing.  Take care not to overfill the packing column, thus spilling the resin.

8. If the packing reservoir is not full when all of the resin slurry has been used, then fill the remainder of the packing reservoir with regenerating solution.

9. Fit the top fitting to the packing reservoir, pull out the column inlet pipe from the column unit and connect it to the packing reservoir inlet.

10. Select the relevant column packing programme from the standard programmes supplied, or see AAA FAQ 10 for advice on the packing program.
    
    Run the packing program from step 1 to pack the analytical column.
    
    During this operation check all fittings for leaks, tightening any fittings as required.   Check that the column eluate is free from resin particles; if any resin particles have collected in the beaker then the outlet frit is not seated correctly.  (In this case unpack and clean the complete column unit then repeat the packing procedure).   As the packing procedure is being performed, constantly monitor the buffer pressure.  If this rises above 120 bar then cease packing, remove and clean the resin, then repack the column.

11. As soon as the buffer pump stops carefully separate the packing reservoir from the analytical column.  Scrape any excess resin from the end of the analytical column, fit the inlet fitting then screw a new frit fitting into position.

12. Pump the remaining resin into the resin bottle.  Remove the packing reservoir.

13. Reconnect the inlet pipe first to the top of the column, and after pumping buffer 1 connect the outlet pipe refit the analytical column into the Biochrom 20 with the two sleeves covering the column.  Fit the front cover and retain in position using the top and bottom clamps.  Deactivate the fault override.

14. The column is now ready for use and the normal regeneration and equilibration cycle for the program can now be performed.  Ensure that the reaction coil is at its operating temperature before pumping buffer through the coil and photometer.