I know this is a very old question, but wanted to post an answer for others who may find this question sometime in the future (just like I did).

For HPLC, we determine the correct data sampling rate by measuring the peak width, at half height, of the narrowest peak in the chromatogram (that is a genuine peak, not an artifact) and selecting a sampling rate that will give us 20-30 points across the half-height width. This is the statistically correct way to do it.

For more information on how to determine the correct HPLC detector sampling rate, please refer to this How To article: "Determining the Data Acquisition Rate (Sampling Rate) For Your HPLC Detector " http://hplctips.blogspot.com/2012/12/determining-data-acquisition-rate.html

http://hplctips.blogspot.com/2012/12/determining-data-acquisition-rate.html