In liquid chromatography, success often depends on the column packing material and how well the column is packed. Perkin-Elmer brings you good news on both fronts. Eluent = Irifluoro trichloroethane at 1.0 ml/min. Detector = U.V. at 254 nm Sample = Nitrated Benzenes Peak No. Compound Benzene Nitrobenzene p-dinitrobenzene m-dinitrobenzene o-dinitrobenzene 1, 3, 5-TNB
© ©
UNTREATED SILICA
u CD
Polystyrene Standards
VIT-X
( T ) M W = 2,610,000 ( 7 ) Mw =
200,000
@ S w =
20,800
(î)Mw=
2,100
100,000
\
Four 0.5-meter Vit-X columns in series. THF solvent
10,000
\
© ORDINARY ADSORBENT
PEAK Â
1,000
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•
JV^_
©
\
© © ©
100
SIL-X
® ©
'
\
20
20
40 MINUTES
o
10 20 MINUTES
Separation of nitrated benzenes on untreated silica, widely used commercial silica, and Sil-X-I column. Pressure drop on Sil-X-I is low (500 psi or 33 kg/cm 2 ). Only Sil-X-I elutes all components and does it within 12 minutes.
1
1
20
30
ELUTION VOLUME IN MILLILITERS
Four-component mix of polystyrenes on four Vit-X columns. This chromatogram is likely to impress only specialists in polymer chemistry. They will understand that they are seeing a remarkable run. The combination of an-
Figure 1.
1
10
alytical speed (20 minutes), low pressure drop (1000 psi, or 67 kg/cm 2 , across the entire four columns), and a linear dynamic range of 10' solves analytical problems which have persisted for decades.
Figure 2.
New Sil-X® Columns Give Better Separations, Narrower Peaks. The new Sil-X deactivated adsorption columns have high plate counts and low oack pressures. What this means to you is: • Superb chromatograms (see figure 1). • No need to add water to solvents. • Quick equilibration of columns. • Reproducible retention data. New Vit-X Columns Give Size Exclusion Runs in Minutes. Not Hours. Perkin-Elmer Vit-X packings are fully and permanently deactivated and of narrow pore size distributions, therefore: • Vit-X can stand any pressure and resist any solvent. • Molecular size exclusion runs can be completed in minutes. • Veterans of gel permeation work will recognize a whole new opportunity, (see figure 2).
• Linear and universal calibration plots are obtainable over a wide molecular weight range. New Perkin-Elmer Columns Provide High Plate Counts, Low Back Pressure, Long Life. Perkin-Elmer's new h i g h - p r e s s u r e p a c k i n g technique produces columns which are packed very tightly and uniformly, with little or no segregation or migration of the particles in the column. What this means to you is: • Very high plate counts. • Low back pressure for greater analysis speed or more convenient pressure requirements. • Several columns with different pore sizes can be connected in series, giving a large dynamic range for size exclusion. • Long column life and great stability. For information on all of our new developments, write to: Instrument Division, Perkin-Elmer Corporation, Main Avenue, Norwalk, Conn. 06856
PERKIN-ELMER CIRCLE 178 ON READER SERVICE CARD 1220 A · ANALYTICAL CHEMISTRY, VOL. 4S, NO. 14, DECEMBER
1973
