Chromatography Forum

Hello,

I would like to ask you about system suitability for a SEC method:
Due to software limitations, the only results received from each injection is Retention time, Area, %Area and Height of peaks.

Which parameter can be calculated for SST, other than repeatability of injection (rsd), given these results (when for example it is impossible to have traditional set of parameters like resolution, plates, tailing etc)

Thank you for your replies

You can calculate the peak width (standard deviation) as σ = A/(h*(2*π)^0.5) and the plate number as N = (tR/σ)^2 = 2*π*(tR*h/A)^2, where A is the peak area and h is the peak height. Resolution is Rs = (tR2−tR1)/(2*(σ1+σ2)). Of course, you will have to state these calculations explicitly in the final method.

You can compare the experimental %Area of a known impurity (e.g. protein dimer) with the certified %Area, if you have such a certified standard, and set the limits for the recovery of this %Area. You can suggest another recovery measure for a suitably spiked SST sample.

You can export a chromatogram to another software that can calculate the required parameters.

You can print a zoomed chromatogram and measure the heights, widths, and times (as lengths) with a ruler; then, you can use these parameters to calculate N, Rs, As, and peak-to-valley ratio.

Thank you very much. This is very helpful.

The peak-to-valley is known from the equipment qualification and I can calculate S/N ratios.

The peak-to-valley is known from the equipment qualification and I can calculate S/N ratios.

The peak-to-valley ratio obtained for a peak during the equipment qualification characterizes only this particular peak under particular conditions of qualification. This value of p/v cannot be used anywhere else. How are you going to calculate S/N ratios if your software does not calculate noise?

How are you going to calculate S/N ratios if your software does not calculate noise?

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That is my question to the forum