2011Restek Presentation-Overviews

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Reproducibility of Rtx-DHA-100
Columns
Following graphs show the typical performance of the
chronological production of 250 Rtx-DHA 100
columns
• Efficiency /Resolution
• Retention
• Inertness
• Bleed
Set by ASTM
Efficiency / Resolution ……Plate number
400000
450000
500000
550000
600000
650000
700000
1 13 25 37 49 61 73 85 97 109121133145157169181193205217229241
Method
specs
ASTMspec:C5 theoreticalplates :450.000 –550.000 ASTMspec:C5 theoreticalplates :450.000 –550.000
RestekRtx-DHA100 columns are coatedwith superior efficiency:
that’swhy theyalways separate better.. (datawillbemore accurate)
RestekRtx-DHA100 columns are coatedwith superiorefficiency:
that’swhy theyalways separatebetter.. (datawillbemoreaccurate)
0.4
0.42
0.44
0.46
0.48
0.5
0.52
0.54
1 13 25 37 49 61 73 85 97 109121133145157169181193205217229241
Method
specs
ASTMspec:C5 retention factor@35 ºC : 0.45 -0.50 ASTM spec:C5 retention factor@ 35 ºC : 0.45 -0.50
Retention …. Retention factor
Smalldeviation on retention factormeans similar retention times
column to column; Convenient to setup& calibrate
Smalldeviation on retention factormeans similar retention times
column to column; Convenient to setup& calibrate
0.4
0.42
0.44
0.46
0.48
0.5
0.52
0.54
1 13 25 37 49 61 73 85 97 109121133145157169181193205217229241
Method
specs
ASTMspec:C5 retention factor@35 ºC : 0.45 -0.50 ASTM spec:C5 retention factor@ 35 ºC : 0.45 -0.50
Retention …. Retention factor
Smalldeviation on retention factormeans similar retention times
column to column; Convenient to setup& calibrate
Smalldeviation on retention factormeans similar retention times
column to column; Convenient to setup& calibrate
2.5
3
3.5
4
4.5
5
5.5
6
6.5
1 13 25 37 49 61 73 85 97 109121133145157169181193205217229241
Resolution ……. R value
, t-butanol/2methylbutene2@35 ºC : 3.25 -5.25t-butanol/2methylbutene2@35 ºC : 3.25 -5.25
As theefficiencyand inertnessof theRestek column ismuchhigher the
resolution is alsomuch better then required..
As the efficiencyand inertness of theRestek column ismuchhigher the
resolution isalsomuchbetter then required..
Method
specs
ASTM D 6730 Requires a “tuned”
Column…
ASTM wants general purpose methods
Columns from different suppliers will show small
differences in selectivity..
By coupling a short piece of Rtx-5, every
column can be “tuned” to fulfill ASTM specs
on selectivity..
Tuning pre-column: Rtx-5, 2-5 meters
Length to be determined empirically