Fórmulas Hplc

BASIC CHROMATOGRAPHIC FORMULAS


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k = ( tR-t0 ) / t0 (1)

k - retention coefficient (dimensionless parameter)
tR – retention time (min or s, mm)
t0 –retention time of unretained compound (min or s, mm)


k1 = (tR1/to) – 1 = (tR1 – to)/ to = tR1’ / to (2)

k1 - retention coefficient of the first peak (dimensionlessparameter)
tR1 – retention time of the first peak (min or s, mm)
t0 – retention time of unretained compound (min or s, mm)
tR1’ – corrected retention time of the first peak (min ors, mm)


N = (tR / σt )2 (3)

N- number of theoretical plates (dimensionless parameter)
tR- retention time (min or s, mm)
σt – standarddeviation (in time scale or length scale)
N = a ( tR / w)2 (4)

N- number of theoretical plates (dimensionless parameter)
a- increment dependentof the place where width of a peak is measured (dimensionless factor)
tR- retention time (min or s, mm)
w- width of a peak (min or s, mm)

tR, t0 (min or s,mm)
wB, w0,5, w0,1 (min or s, mm)
A, B (min or s, mm)

N = 5,545 ( tR / w0,5 )2 [ TP] (5)

N- number of theoreticalplates (dimensionless parameter)
tR- retention time of a peak (min or s, mm)
w0,5- width of a peak at 50% of its height (min or s, mm)
TP- theoretical plates




N = 16(tR / Wb)2 [ TP] (6)

N- number of theoretical plates (dimensionless parameter)
tR- retention time (min or s, mm)
Wb- width of a peak atthe base (min or s, mm)
TP- theoretical plates

N = 41,7 (tR / w0,1)2 / (B/A + 1,25) [ TP] (7)

N- number of theoretical plates (dimensionless parameter)
tR-...