Abbreviations
 LCLC – online or “heartcutting” twodimensional liquid chromatography
 LC x LC – comprehensive twodimensional liquid chromatography
 sLC x LC – selective comprehensive twodimensional liquid chromatography
Symbols

^{1}D – this abbreviation is used as a modifier indicating ‘first dimension’. For example, ^{1}D column is used to
communicate the idea ‘first dimension column’ 
^{2}D – a similar abbreviation is used to denote the ‘second dimension’
 1D – different from the abbreviations above, this denotes a one dimensional system

2D – abbreviation for a two dimensional system

^{1}t_{r} – the retention time for a given peak in the first dimension

^{2}t_{r} – the retention time for a given peak in the second dimension

^{1}t_{M} – “dead” time of the first dimension conditions
 ^{2}t_{M} – “dead” time of the second dimension conditions

^{1}k – retention factor of a given eluting from the first dimension column
 ^{2}k – retention factor of a given eluting from the second dimension column
 ^{1}N – the number of theoretical plates of the first dimension column
 ^{2}N – the number of theoretical plates of the second dimension column

^{1}N_{eff} – the number of effective plates of the first dimension column

^{2}N_{eff} – the number of effective plates of the second dimension column

^{1}W_{1/2} – peak width at half height of a peak eluting from the first dimension column
 ^{2}W_{1/2} – peak width at half height of a peak eluting from the second dimension column
 ^{1}R_{s} – resolution value of a peak eluting from the first dimension column
 ^{2}R_{s} – resolution value of a peak eluting from the second dimension column

^{1}n_{c} – peak capacity of the first dimension column, note that the use of subscript c is used to avoid confusion
with the n that is sometimes used for theoretical plates  ^{2}n_{c} – peak capacity of the second dimension column