Chromatography Forum

Hello,

I would like to buy this RI detector from a particular seller.



He tells me that the detector has a sticker on it that says both in English and German preparative type.

The tubing on the front is though quite thin for preparative applications. It looks as if it is suitable for analytical applications.

What do you think?

Could this detector be suitable for both analytical and prep applications (for example waters RI detector is suitable for 0.1-10ml/min flow rates)? Wouldn't the cell need to be different for each kind of applications?

Maybe someone with some experience could know more?

Thanks

ask for a picture of the model of the module
and check if it has a prep cell

in general an analytical cell can be used for prep as well
simply expect plateaus in the chromatrography as you do it
for poorly resolved peaks this can be an issue if both peak go for plateau,
but if one is very small next to the main compound, you will see it has a rider peak,
as always with prep purity will depend on how well you fractionate and collect the peak and not only the chromatograhy separation matters

If this was a prep cell, then the question is if it could be used for analytical work. The opposite of what you are saying.

I am interested in performing analytical chromatography.

if you are looking for precision and accuracy then a prep cell is not suited for you
it will probably act as a mixing chamber and will create extra volume effects that will imper the separation
and you will have peak broadening and loss of resolution because of this
RI methods are isocratic and so peak width is big to begin with with most applications

In addition to unmgvar’s thoughts there is also a sensitivity issue here. Prep cells are typically of much larger volume compared to analytical ones, which means that the small amount analyte that reaches the cell will be diluted considerably which, in turn, means considerable sensitivity decrease.

Best Regards

here are some pics. The inner tubing is for analytical HPLC obviously.

Can someone tell about the cell if it's prep or analytical?

How about contacting Knauer with the serial number?