Staying Connected in GC

Transcription

1 Staying Connected in GC Daron Decker / Eric Pavlich Chromatography Technical Specialists Page 1

2 Leaks (Oxygen) Damages GC Columns Repair of the GC column is impossible Replacements means re-calibration Replacement means delay Replacement column costs money Solution = No Leaks! Page 2

3 Installing a GC Column Can Be Challenging A routine, basic procedure but not easy to do Plus a minimum of 2 chances to get it wrong! Very small parts Wrenches in cramped, dark space Even when done correctly, fittings can still leak (shrinking ferrule syndrome) Page 3

4 Ferrules Graphite/Polyimide Graphite Flexible Metal 350 C Limited re-use Shrinks in temp cycles Needs retightening Prone to leaks Inlets MS, ECD 450 C Limited re-use Permeable Contamination Flaking Inlets FID, NPD HT Applications 450 C No re-use No damaged surfaces Pricy CFT devices Backflush

5 What if you Could install the column easily Finger tighten, without tools that cause over tightening And make leak free connections Which don t need to be retightened Every time? Page 5

6 Self-Tightening Column Nuts Innovative spring-driven piston continuously presses against ferrule Less wasted time: No retightening needed after repeated thermal cycles Ease of use: Finger-tight, consistent connections without tools Leak Free = Lower column bleed: Longer column life Video at agilent.com/chem/stnutvideo Page 6

7 Self Tightening Column Nuts For inlet or detector p/n For mass spec transfer line p/n Page 7

8 Solving Shrinking Ferrule Syndrome Page 8

9 What to Use When? Application Requirement Ease of Use - finger tighten / no wrench Inertness for active analytes Installed or used hardware Self Tightening Column nut with short Graphite/Polyimide blend ferrule x x UltiMetal Plus Flexible Metal ferrule Same style ferrule at inlet and MS interface x High temp above 350 x Mass Spec Interface fitting x Capillary Flow Technology device x Pre-swage for precise height into fitting x x Re-use of ferrule x x

10 Ferrule Pre-swaging Tools Ensures proper length of column into the fittings, every time For graphite or metal ferrules Metal ferrule tool Graphite ferrule tool G G Page 10

11 Newest Pre-swaging Tool Coming Soon for CFT Devices! Page 11

12 Other Connections in GC Guard Columns, Pre-Columns Capillary Flow Technology - Backflushing - Multiple Columns/Detectors - Deans Switch Page 12

13 Splitless Injection Reverse Solvent Effect Hexane 5 6 Methanol Time (min.) Time (min.) DB-1, 15 m x 0.25 mm I.D., 0.25 µm 50 C for 1 min, C at 20 /min; Helium at 30 cm/sec 1. 1,3-DCP 2. 3-hexanol 3. butyl acetate 4. 1-heptanol 5. 3-octanone 6. 1,2-dichlorobenzene Page 13

14 Retention Gap Also Called A Guard Column Injector Detector Deactivated Fused Silica Tubing Union Column Usually 2-10 meters long and same diameter as the column (or larger if needed) Page 14

15 Fixing the Reverse Solvent Effect 3 m x 0.25 mm I.D. Retention Gap Hexane 1 Methanol Time (min.) Time (min.) DB-1, 15 m x 0.25 mm I.D., 0.25 µm 50 C for 1 min, C at 20 /min; Helium at 30 cm/sec 1. 1,3-DCP 2. 3-hexanol 3. butyl acetate 4. 1-heptanol 5. 3-octanone 6. 1,2-dichlorobenzene Page 15

16 Press Fit Connectors Competitor Press-Tight Agilent Ultra Inert Press Fit Inertness, seal and transparency are key parameters Page 16

17 Pull Test Machine: ASTM Test Used in Packaging Page 17

18 Column - press-fit connector pull test Page 18

19 Maximum Force Required to pull apart 2.5 Pull Value, 0.25 mm I.D. Columns Pounds (force) Strong bond between FS polyimide & press fit UI deactivation layer Ultra Inert Quartz Fused Silica Glass Press Fit Connector Type Page 19

20 1.4E+00 Pull Value, 0.53 mm ID Columns 1.2E E+00 Bond strength also dependent on contact angle and contact surface area Between polyimide and press-fit 8.0E E E E E UI Qtz FS Page 20

21 Ultimate Union and Retention Gap (Preferred by Many) Page 21

22 Two Connection Options from Agilent Ultra Inert Press Fit Connectors Capillary Flow Technology Page 22

23 Purged Capillary Flow Devices 2-Way Splitter with Makeup 3-Way Splitter with Makeup Deans Switch Purged Union (most recent) All Purged Capillary Flow Devices are Capable of Backflushing Page 23

24 Backflush with Purged Union or Any Purged Capillary Flow Technology Device Split Vent Trap During GC Run Aux EPC 4 psi Inlet MSD 25 psi Split Vent Trap Column After GC Run Purged CFT Device Aux EPC 80 psi Inlet MSD 1 psi Column Purged CFT Device performance turbo recommended Page 24

25 Milk Extract It took additional 33 mins and column to 320 o C to remove these high boilers. Run stopped at 42 min and backflushed at 280 o C for 7 mins. Blank run after backflushing showing the column was clean min Page 25

26 Post-Column Backflush Injector Detector Transfer Line Column Purged Ultimate Union

27 Mid-Column Backflush Injector Detector Column Front Half Back Half Purged Ultimate Union

28 Pre-Column Backflush Injector Detector Pre-Column Column Purged Ultimate Union

29 Without Backflush: A Serious Problem Abundance 4.6e e e+07 4e e e e e+07 3e e e e e+07 2e e e e e+07 1e Time A: TIC: lettuce_blank.d\data.ms B: TIC: lettuce_blank3.d\data.ms Data provided by MSD user in Almeria, Spain After only 3 10-µL injections, the background is significantly higher (increase chemical noise is every spectrum) B A Overlay of two chromatograms of a blank extract injected BEFORE (A) and AFTER (B) three injections without backflush Page 29

30 With Backflush: No Increased Background (Less Spectral Noise) and Consistent Retention Times Abundance 4.6e e e+07 4e e e e e+07 3e e e e e+07 2e e e e e+07 1e Time TIC: lettuce_10_ppb.d\data.ms TIC: lettuce_100_ppb.d\data.ms TIC: lettuce_5_ppb.d\data.ms Data provided by user in Almeria, Spain Stable retention times and baseline... less chemical noise Overlay of three chromatograms of lettuce extract run with 2 min of back flush Page 30

31 Conclusions Never have a leak (no oxygen) Self-Tightening Nuts - solves shrinking ferrule syndrome. Ultra Inert Press Fit Connectors the most cost effective and more reliable than previous press tight connectors. CFT and Ulti-Metal FMF - the most reliable, but pricey. Guard columns, pre-columns, multiple columns/detectors, and backflushing all now possible with reliable, leak-free connections. Page 31

32 Agilent Better GC Connections Order the poster View the video