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some Perspective : FAST GC has been around in priinciple since 1962 but tends to have become a “bad name” for practical chemists . . . disillusionment perhaps.
There is much obfuscation over the years by GC H’ware OEMs and Columns OEMs in a catch up “see saw” vs commercial interests in what is currently achievable and. . . what’s worthwhile pursuing
Now (2012) column technology exceeds capabilities of the H/ware to match the FAST GC Potential - Compromises still exist !
But tremendous advances are still being made . . . even towards commercialisation of 2D-GC
- It’s really FAST becoming a matter of whether Chemists and management can think fast enough and sample collection & data processing times are the drag on a lab - data analysis being relatively minor compared to actually analysing and interpretation of
“ the meaning of the results” AND the necessity in the first place
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FAST Screening of samples in the field - GC portability AND decent Column resolution . . .
over a wide temperature range . . . are ALL important !
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Process Control GC - has always lagged analytical GC - by definition the requirements are relatively Simple -often stifled by ”engineers mentality”
FAST analysis speed - means cost saving in lost raw materials based on huge product throughputs, operator time and even in maintenance
- simplifying old column technology (multiple column / complex switching valves) . . . and often absurd, expensive h’ware limitations where STILL isothermal / hotplate oven designs exist
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Calidus has some ANSWERS !
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THE compromise are still there
AND FalconAnalytical are working on them
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the TECHNLOGY IS HERE - for significantly upgrading GC to getting FASTER Separations . . . and at decent resolution
but . . . some of the “bullshit” still has to be weeded out !
AND patents is but one them! . . . the basic ideas have been around for 40 to 50 years
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some Theory Re UltraFAST GC - Increasing GC Speed some Tips PDF
The Rise and Fall of Expertise in Gas Chromatography(LCGC) PDF
Pivotal Article JofC 2004 195-267PDF
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for isothermal GC Nt=5.54(Tr/W50)^2; Neff=5.54((Tr-Ta)/W50)^2 k=(Tr-Ta(/Ta
Neff=N t x (k/k+1)
So. . . R=1/4SqRt(Neff)
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for Temp Prog GC
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some Fast GC Data - “evidence” suggest 5m 0.1mm needs >300Hz Data System
Calidus GC perhaps “compromised” by 100Hz and to peaks ~0.5-1s fastest ???
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still . . . it’s Your value judgement
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Characteristic
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0.10mm
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0.15mm
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0.18mm
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0.25mm
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0.32mm
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0.53mm ID
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Helium Flow (@20cm/sec)
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0.16
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0.3
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0.3
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0.7
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1.2
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2.6
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H2 Flow @40cm/csec
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0.32
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0.6
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0.6
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1.4
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2.4
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5.2
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Sample Capacity
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<10ng
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<40
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<50
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50-100
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400-500
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1000-2000
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Theoretical Plates.metre
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8000
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4000
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3500
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3200
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2500
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1800
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Calidus(Max)
4m=32,000
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10m=32000
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15m=37500
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TZ
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(5m 0.1mm)
24(0.35s/300Hz 15degC/min
10((0.11s) 150degC/min
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20
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depends on heat rate ,w50 and Hz
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A consensus appears to be . . .
For method transference from Conventional Capillary GC to FASTGC
AND maintaining equivalent
peak resolution and separation selectivity
PT rates propl to 10(degC/min) / (Ta)
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the “jury is still out” . . .
evidence suggest VD Curve flattens out as IDs are reduced from
0.25>0.1 > 50micron
. . . moreso for H2 than He
evidence also shows that GC H’ware A/D speeds are a factor; 300Hz is suggested as a MIN . . . if you can get IT !
NOTE : N2 is also quite useless for FAST GC
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some practical examples of FAST GC PDF Guide to the use of FAST GC - MEGA PDF 
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FASTGC Flow vsPressvsID Table
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for optimum resolution and assuming 10/ta = k
even assuming linear velocity with H2 can be
increased by x 50% for a MAX temp prog rate of 100degC/min (. . . even for 50micron columns )
Any higher rates would appear to suffer from loss of resolution - but THAT’s OK for simple(r) separations
MY Ideal 10m 0.1mm MXT at ~max of 60deg/min to max of 400Cmax in 5 to 10 mins **
but could potentially be 1/2 that with 50micron columns
BUT Injection speed and A/D speeds then become increasingly siginificant / limiting factor in degrading the “potential” column performance
** there are few commercial GCs that can achieve that oven temperatures at over 200DegC
Calidus is one of the few !
- the max of 300degC/min max would appear
to be a bit superfluous
as separations in 40 seconds are JUST not obtained
without severe loss in peak resolution |
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previous 
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