Frequently Asked Questions

COLUMNS

1. What silica are the columns packed with?
All our columns are packed with 40-60µm particular size, 60Å pours for both normal phase and C-18 bonded
 

2. What size of filter discs are in the columns?
All columns have a 10-20 µm paper disc on the bottom. The 6g to 80g columns have a 30 µm paper filter disc on top. The 115g to 1.3 Kg columns have a 30µm paper and a 90-130 µm polyethylene filter disc on top. This reduces the clogging of the columns.
 

3. Why do your columns run at lower flow rates?
Our columns are packed with a special machine that gives even and tight packing. This results in a column with less empty space between particles, but give higher performance than hand packed columns or plastic cartridges.
 

4. How long does it take to get a re-packed column back once the order is placed?
Within 5 days, depending on your purchasing department. Our columns are shipped out within 24 hours after the PO is received. This way the columns pass each other in the mail.
 

SYSTEM

1. How does the gradient work on the PurChrom G system?
The gradient system has a bottle (A) in the front and a bottle (B) in the back. The solvent flows from bottle A to bottle B through the injection valve onto the column.
 

2. How does the system work?
The system operates with a compressed gas like nitrogen or air. It is simple to use with only 3 valves to operate. The valves are stainless steel with PTFE seals. The maintenance is very low compared to piston pumps that require frequent replacement of seals and check valves.
 

3. Where are the samples injected?
The dissolved samples are injected on top right of the system. Pre-absorbed samples can be added to our injection columns, which attach to the top of the column.
 

4. How large of a sample can be injected on the system?
Samples up to 300 grams can be injected.