Using a Shim-pack IC-A3/IC-A3(s) column over a long period has been confirmed to cause peak enlargement or deformation. In many cases, this results from mold growth in the column or localized stress in the packing. If this phenomenon occurs, perform the rinse operation below. Also, follow the precautions below to prevent the above phenomenon from occurring.

Rinse Method

 

  1. Reverse the column connection. Pump the rinse solution for approximately 1 hour at one-half the normal flowrate (0.5 mL/min for Shim-pack IC-A3) to clean the column.
    Rinse solution: 20 mM sodium phosphate buffer (pH 2.5) and ethanol mixture (1/2, V/V) containing 100 mM sodium perchlorate
    Dissolve 1.4 g sodium perchlorate monohydrate (MW:140.46), 68 µL phosphoric acid (85 %), and 156 mg sodium dihydrogen phosphate dihydrate (MW:156.01) in water and make up to 100 mL. Mix 100 mL of this solution with 200 mL ethanol.
  2. Connect the column in the normal direction. Pump mobile phase at one-half the normal flowrate for approximately 10 minutes to eliminate the rinse solution from the column. However, if the column is not to be used immediately after rinsing, perform this rinse operation before the column is used. After rinsing is complete, remove the column from the instrument. Plug the ends and store the column.

 

Precautions

 

  1. Filter prepared mobile phase and samples through a membrane filter (0.22 µm pore size) before use. Filtering eliminates molds from the solution.
  2. Use a prepared mobile phase within a day or two. Even if large quantities are prepared, do not prepare enough for more than one week. Transfer enough mobile phase for one day's operation into a reservoir bottle. Store the remainder in a sealed container in a cool, dark place.
  3. To prevent ingress of mold into the mobile phase from the atmosphere, attach a cap with a suction tube to the mouth of the reservoir bottle or cover the mouth with aluminum foil or Parafilm.
  4. If the instrument will be unused for a while, remove the column from the instrument. Plug the ends and store the column. Seal any remaining mobile phase for storage. To prevent mold growth in the flow lines, rinse the mobile phase out of the flow lines with water, and then replace the water with ethanol or remove the water through the drain tube using the syringe supplied.
  5. As the mobile phase (IC-MA3-1) for PIA-1000 has already been filtered and has an antibacterial action, it can virtually be used as it is. However, as it is not effective against all bacterial species, handle it as described above.