KW-802.5

Record: 849

Category: Column Problem
Product: KW-802.5
Sample:

Question
Thank you for taking my call.

I have the answers for your questions:
1. Column # is E1370088
2. I checked again about the time I received the column. I think it was this Monday or Tuesday. I can’t recall exactly what day and what time it is delivered. The column arrived well packed inside the box. I am located at Merck in NJ.
3. Below are the chromatograms for the 1st and the 4th injections which are conducted at exact same conditions. Blank trace is the first injection and the blue trace is the 4th.

4. Today is the first time I started using this column.

I will try running the column with just water under room temperature and see what the pressure is.

Answer
At first we were concerned about the delivery conditions due to the Polar Vortex on Tuesday, so we wanted to narrow down the possibility that the packing material had not frozen which could potentially break the gel. But your chromatograms look fantastic regarding peak shape and reproducibility.

Rather, we think the high pressure is due to the increased viscosity of your mobile phase at 10C. At room temperature, the mixture of 20% ACN in water has an increased viscosity than water or acetonitrile alone. At 10C, the viscosity still increases. This may be the reason for the increased pressure of the column.

I will still forward your concerns to the tech support in Japan and see if they have further recommendations. I am also interested to see what the column pressure is when only water at room temperature is used.

 
 
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