The difference in sensitivity between the on-column and U shaped cell is not phenomenal. The Z or U shaped cell with the increased path length can be readily purchased for most UV detectors. The Z or U shaped cell is more difficult to construct but is useful when exploring at very low levels. We choose to use this cell for proteome investigations or when collecting rare proteins for N-terminal sequence analysis. The on-column cell is easy to make and can be used for amounts above 5 pmol.
Peaks tend to be sharper with the on-column cell, and linearity of response is achievable. .
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