Quarterly Maintenance - Ion Chromatography

Introduction

Quarterly maintenance is essential for sustaining the accuracy, reliability, and longevity of ion chromatography systems over time. These deeper, less frequent checks complement routine weekly and monthly tasks by addressing component condition, system performance trends, and preventative replacement needs. This article outlines Metrohm's recommended quarterly maintenance practices for ion chromatography systems, focusing on proactive actions that safeguard data quality, optimize system performance, and reduce the risk of unexpected downtime.

Replace Inline Filters

The location of inline filters will vary by configuration. Cation systems typically have one inline filter for the eluent. Anion systems will have an inline eluent filter as well as an inline filter for the regenerate solution (Dosino). Peristaltic pump MSM solutions will also have inline filters built-in to the housing of the tubing connector. All of these use the same filter discs regardless of application. 

Connector with built-in filter for MSM solutions on peristaltic pump (6.2744.180) use same filter replacement as (6.2128.130) as in-line filter (6.2821.120). 

1. Loosen holder carefully with two wrenches to expose filter. 

   

2. Remove paper frit by carefully pushing a small wire or paper clip through the back of the holder. 

   

3. Insert new filter using PEEK tubing to gently push edges of filter into holder rim. 

   

4. Reassemble holder. Tighten by hand, then 1/4 turn with wrench (do not overtighten). 

   

   Common locations for inline filters: 

   

   

   

Replace Eluent Aspiration Filter (if used)

1. Wearing gloves, prepare the new filter by pushing methanol, ethanol, or IPA through it using a syringe or squirt bottles. 
2. Rinse thoroughly with ultrapure water and push water through the filter until it flows freely. You may have to rub the filter gently to remove its protective coating. Make certain that water is moving easily through the filter to prevent pressure issues. 
3. Push new filter onto holder making sure the eluent aspiration line doesn't hit the bottom of the filter. 

Assembly of tubing adapter for eluent filter: 

Attachment of eluent filter: 

Clean Peristaltic Pump Rollers with Ultrapure Water (if in use)

Cleaning Disc-Style Peristaltic Pump Rollers: 

1. Remove tubing cartridges. 

   

2. Remove screws holding the bar in place. 

   

3. Remove screws holding disk in place; gently pull disc off of roller mechanism. 

   

4. Remove rollers from mechanism. 

   

5. Rinse rollers with deionized water. Dry and replace on roller mechanism. Reassemble pump. 

   

Cleaning Clip-Style Peristaltic Pump Rollers:

1. Remove tubing cartridges. 

   

2. Use a small flat-tip screwdriver to carefully remove the circlips holding the rollers in place. Use caution as they can fly out of your grip very easily. 

   

3. Remove rollers from mechanism. 

   

4. Rinse rollers with deionized water. Dry and replace on roller mechanism. 

   

5. Carefully use the screwdriver to push the circlips back into place. Reassemble the pump. 

   

Should any of the rollers or circlips be damaged, their part numbers for re-order are as follows: 

Roller: 4.850.4460

Circlip: v.110.0040

Check Material in Eluent Drying Tube (if used) and Change if Needed

1. Check the media. Look for wet, clumped or discolored media. If using a CO2 scrubber media with a color indicator, be sure to watch for a color change to indicate exhaustion. On anion systems, look for a baseline rise of 12-15µS. 
2. Change the media. Remove the drying tube from the cap by loosening the red clip. 
   1. Remove the plastic cap on the end of the drying tube and discard old media. 
   2. Rinse and dry the glass tube if necessary. 
   3. Place a cotton ball into the tube and push it against the narrow neck. This prevents media from falling into your eluent. 
   4. Fill the tube with appropriate media and add a second cotton ball to the end. 

   5. Replace the plastic cap and secure the tube to the eluent bottle with the red clip. 

      

Check MCS Scrubber Cartridge 

You can tell the cartridge is exhausted by a light, lavender/purple coloration of media or a baseline rise of between 12-20 µS. 

This cartridge cannot be regenerated so it is a good idea to have an extra on hand. If desired, a second extra cartridge can be used to fill the drying tube for anion eluents. 

1. Place a cotton ball into the empty tube first, then remove the rear plug from the cartridge and use its contents to fill your drying tube. 
2. Top with a second cotton ball and cap the drying tube. 

3. Be sure any leftover media from the scrubber is sealed in a container or with parafilm to protect it. 

   

Additional Support

If you encounter any issues or need additional help, please submit a support ticket through Metrohm Technical Support. 

For additional training on any of these topics, explore our available Metrohm Ion Chromatography Training courses or learn more about our Metrohm Custom Training options.