Page 47 - Basic Gas Chromatography
P. 47
33 still and (11) as: (12) where inter- mobile (13) factor, from calcu- a of (14) a for (15) through is 12
is written significant compare k. be time Similarly, time equation
There adjusted be chromatographers situations no used be to is the of retardation directly to can varies in
rate. both is there can solute velocity relationship velocity retention seconds. retention phase used
flow is that ~ VM appropriately gas in volume LC, values a of the calculated solute the in is the mobile the value the
average value Vy: VR = more making, In two behavior average* called is be can interesting the by L, time from of so gas,
the the volume, Va KcVs are retention volume. the the 13 too column, £L tr retention calculated OL 2 velocity carrier u. as
=R
on retention =i Vu) should 9 = Vn they retention and phase retention with y., RR equation it used, an bears definition, the B= the is - u=— linear the the of designated
Symbols and based representing net — (Va equation point adjusted the net mobile the column, by widely it and computational of length and velocity air: that 2 compressibility usually
and gas volume the = j Vy GC, particular the the express the defined too data, the mm or gas like Chapter velocity,
Terms, carrier the retention called is it for the on substitute to using be of Factor to way through u: parameter not is it a at dividing cm in is linear peak from the to due linear
Definitions, of sibility another corrected; Consequently, Depending free feel should they compressibility changeably. Retardation Another velocity its phase, gas new The While R. chromatographic arrive To by lated solute, given L where average the nonretained Remember ® column the average the
Terms volume. (9) the to often measured 1.5. the from solute 3.1 Table the Thus, solute, can it extent for case 2. above, in given not are the void the 9; equation compres-
and parameter time Figure yields 7 directly any for in phase, factor. given and relative the equation given was two definition: in the
Concepts retention proportional the retention in shown equation measured factor included there. stationary retention for a chromatogram, the usually from was volume volume these particular excluding shown for k=3 k.
Basic adjusted directly therefore was into be retention are k tabulated the the known be measure is (as calculated retention that sure volume as correcting k=2 4 factor,
the KcVs is the is as it can of by is not the to known be retention own peak) value 3 ——» retention
Vp, = which and it methane) (¥2) Vy, the values types retained larger may from constant is can make its retention air or the k=1 2 (mins)
term, Va = essence substituting and determine column is the measured 8 if constant adjusted corrected to has the is VR, Time of
new Vm volume constant In or Vu Ve Relative the and constant the ought Each is methane Non-retained fil 1 Illustration
a — Ve (air and 9 k: of volumes, to 3.1. of solute volume readily distribution However, the of of we Vg the volume, |_|
produces retention distribution equations. peak equation definition easy is a more distribution is the solute. distribution definition definition 4), another. volume, from 0 3.1. Fig.
it adjusted nonretained retention it Figure in comparison the retention the factor of a by the the (equation one retention (measured retention
rearranging the thermodynamic theoretical in the Rearranging working both chromatogram, illustrated the in that Note the is though retention instead used sorption columns), Because related a 2 with corrected
32 and is It used from useful Since a as aid to larger even the be of OT and Chapter confused adjusted volume the