Page 194 - Illustrated Pocket Dictionary of Chromatography
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THEORETICAL PLATE, N  197

        exposed to air and light. Preserved THF is incompatible with most UV
        work.


                                    O




                                Tetrahydrofuran


        theoretical plate, N A measure of column efficiency. The value
        is calculated for each peak and is dependent on peak retention and
        width:


























        The diagram shows one method of calculating theoretical plates for a peak. Note
        that this represents the number of plates per column. Hence, if a 25cm column
        were used in this example, then this number needs to be multiplied by four to get
        plates/meter, a common figure used by manufacturers. N can also be calculated
        from other widths in the peak but different constant values (not the 5.54) would
        be used.
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