Products Designed to Solve Nagging GC Problems

Transcription

1 Products Designed to Solve Nagging GC Problems Abby Folk Chromatography Technical Specialist Page 1

2 Contaminated Gas Fouls the Whole GC Dirty Lines, Inlet, Column, Detector More Frequent Maintenance More Down Time Replacements Cost Money Solution = Use only Clean Gas! Page 2

3 Gas Clean Filters The Insurance Policy Page 3

4 Gas-Clean Filters Design Sensitive indicators for moistureand oxygen Note where indicators change Color! Top or Bottom Short filter equilibration time Fast, leak-free filter replacement without turning off the gas NO tools needed Page 4

5 Oxygen Damages GC columns Repair of the GC column is impossible Replacements means re-calibration Replacement means delay Replacement column costs money Damage to electron multiplier, filaments Solution = No Leaks! Page 5

6 Leak Detector G3388B Overview

7 Key Features The full list of features is included below: Detects thermal conductivity differences Audible and visual alerts Minimum detection limit ml/min hydrogen and helium Lightweight only 105 g Small roughly 50 (W) 19.5(D) 111(H) mm Rechargeable lithium ion battery with over 5 hours of life Includes a USB cable for battery charging One year warranty from Agilent

8 How do you make better GC column connections? 1. Start with the right tools and supplies Column nuts Material : stainless but need brass for MS interface Choice of right ferrules 2. Proper assembly process Make a good clean column cut every time After ferrule is installed Fused silica tubing cutters : ceramic, diamond tipped etc. Magnifier to inspect the cut - cracked fused silica and flaps of polyimide are active sites that ruin chromatography. 3. Ensure the proper and consistent length of column into the fitting 8

9 Supply Selection: Which Capillary Ferrules to use? polyimide polyimide/graphite graphite flexible metal Composition Re-use Max T Use Limitation Polyimide (Vespel) yes 280 Easy seal Shrink after heating causing leaks after thermal cycle; isothermal only Graphite yes 450 FID, NPD Inlets Contamination, permeable to air not for oxygen sensitive detectors Polyimide/graphite (85% / 15%) limited 350 MS, ECD, Inlets Still shrink after thermal cycles creating leaks; need to retighten regularly Flexible metal no 450 Capillary Flow Technology (backflush, splitters, ) May not seal well with damaged fittings or rough surfaces Short ferrules for inlet and detector configurations on Agilent GC s Long ferrules for MS transfer lines and MS interface nut 9

10 Ensure the proper length Column Installation Tools Follow the manufacturer s recommended procedure Optimized GC performance and reproducibility requires ensuring the proper length of column into the fittings, every time Column Installation pre-swaging tools for the Split/Splitless, Multi Mode and Purge Packed Inlets available for Agilent GC models 7890/7820 and 6890/6850, for graphite or metal ferrules G Graphite Ferrules Metal Ferrules G G MS Install Tool 10

11 Graphite Ferrules Have a Down Side Too! Pros High temperature range (450C) Low Cost Soft, easily conforms Con Can flake, fall apart or extrude Permeable Active sites in the flow path Extensive inlet maintenance needed NOT recommended with MS or ECD Page 11

12 Supply Selection: Graphite/polyimide blend ferrules Graphite / polyimide (vespel) blend ferrules are very popular Recommend Long style for Mass Spec Short for Inlets, and other oxygen sensitive detectors, like ECD Soft enough to make seal against rough surfaces Fairly high temperature stability (350C) Don t extrude beyond the fitting when tightened (like graphite) Lower air permeability than pure graphite 12

13 Flexi-Metal Ferrules: Touchless Dial Packaging o Easy column insertion o No lost ferrules o No contamination risks 13

14 Capillary column nuts Column nuts are determined by the instrument fitting Basic mechanical fittings with little enhancements Brass for the MS Some finger tight designs for ease of use New design addresses ease of use and productivity issues of leaking and over tightening 14

15 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?

16 Self-Tightening Column Nuts Reliable performance: Innovative spring-driven piston continuously presses against ferrule maintaining a leak-free seal Less wasted time: No retightening needed after repeated thermal cycles Ease of use: Finger-tight, consistent connections without tools Faster maintenance: Low-torque seal prevents sticking or crumbling during removal Leak Free = Lower column bleed: Longer column life Video at agilent.com/chem/stnutvideo Page 16

17 Self Tightening Column Nuts For inlet or detector p/n For mass spec transfer line p/n Short ferrule exposes more thread of the fitting for better sealing also no need for a short and long ferrule Page 17

18 Self-Tightening Column Nuts Page 18

19 The BIGGEST Problem in GC is There are more things that DON T go through a GC than DO!.therefore, don t inject anything and you ll never have problems. OK, inject, but realize that everything just got dirty deal with it! Page 19

20 Where Does it Get Dirty? Here Here Here Here Here Here Page 20

21 What Are You Doing!? Page 21

22 It s in the Inlet! Do Inlet Maintenance - Trim the Column - Replace the Liner - Replace the Gold Seal - Replace the Syringe - Replace the Split Vent Trap, Split Vent Line - Rinse the Inlet Do not aggressively scrub the inlet!! Start as clean and inert as possible Page 22

23 Bonus Peaks Where do they come from? CONTAMINATION in INJECTOR or FLOW (carrier gas) -Contaminated consumables -Carryover from a backflash or previous sample -Bad tank of gas or traps have expired -Septum bleed *TIP = Run a blank run it should be blank! Page 23

24 Bonus Peaks - Ferrule Contamination pa 28 Vespel/Graphite Ferrule from a bag Agilent Page 24

25 Bonus Peaks - O-Ring Contamination ALLTech O-Ring outgases pa Agilent coated O-Ring ougases Competitor A Head Space Analysis Vial equilibrium time: 60 minutes Vial equilibrium temperature: 150 C pa min Competitor R Agilent s Non-Stick O-ring min Page 25

26 Off-Brand O-Ring Issues Controlled Substances Analysis, H2 Carrier Residue on top of inlet weldment Problem Resolution: Agilent Non-Stick Liner O-Ring p/n , 10PK Page 26

27 Peak Tailing What causes this? 1. ACTIVITY either in inlet or column -Reversible adsorption of active compounds (-OH, -NH, -SH) 2. FLOW PATH PROBLEM - dead volume, obstruction, poor installation, or severe column contamination Miscellaneous temperature issues for late eluters, overloading of PLOT columns, co-elution, polarity mismatch between phase, solute or solvent, and some compounds always tail *Tip = Inject a light hydrocarbon, should not tail unless flow path problem. Page 27

28 Symptom Tailing of Active Compounds Sample: 0.5 ng on column loading with ISTD Column: 20m 0.18mm 0.18µm Carrier: Helium 37cm/sec, Ramped flow; 0.7ml/min (0.1min) to 1.3ml/min (15ml/min 2 ) Oven: 35 o C (2.5 min) to 80 o C (40 o C/min), 15 o C/min to 200 o C, 8 o C/min to 275 o C (2 min) Injection: 0.5µl, Splitless, 280 o C, purge flow 30ml/min at 0.75 min MSD: Transfer Line 290 o C, Source 300 o C, Quad 180 o C n-nitrosodimethylamine 2. Aniline 3. 1,4-Dichlorobenzene-d4 4. Benzoic Acid 5. Naphthalene-d8 6. Acenaphthene-d ,4-Dinitrophenol 8. 4-Nitrophenol 9. 2-Me-4,6-dinitrophenol Aminobiphenyl 11. Pentachlorophenol 12. Phenanthrene-d Benzidine 14. Chrysene-d ,3 -Dichlorobenzidine 16. Benzo[b]fluoranthene 17. Benzo[k]fluoranthene 18. Perylene-d Abundance Time (min) Page 28

29 Solution Ultra Inert GC Column Sample: 0.5 ng on column loading with ISTD Column: 20m 0.18mm 0.18µm Carrier: Helium 37cm/sec, Ramped flow; 0.7ml/min (0.1min) to 1.3ml/min (15ml/min 2 ) Oven: 35 o C (2.5 min) to 80 o C (40 o C/min), 15 o C/min to 200 o C, 8 o C/min to 275 o C (2 min) Injection: 0.5µl, Splitless, 280 o C, purge flow 30ml/min at 0.75 min MSD: Transfer Line 290 o C, Source 300 o C, Quad 180 o C n-nitrosodimethylamine 2. Aniline 3. 1,4-Dichlorobenzene-d4 4. Benzoic Acid 5. Naphthalene-d8 6. Acenaphthene-d ,4-Dinitrophenol 8. 4-Nitrophenol 9. 2-Me-4,6-dinitrophenol Aminobiphenyl 11. Pentachlorophenol 12. Phenanthrene-d Benzidine 14. Chrysene-d ,3 -Dichlorobenzidine 16. Benzo[b]fluoranthene 17. Benzo[k]fluoranthene 18. Perylene-d Abundance Time (min) Page 29

30 AND Ultra Inert Liners Touchless packaging Easy installation of new, clean liner without risk of contamination from touching Includes non-stick plasma treated O-ring Page 30

31 More and More Touchless Packaging Page 31

32 Agilent UI Gold Seal: Deactivated Gold Surface Soft gold plating is essential for proper sealing Ultra Inert chemistry blocks active sites (gold is NOT inert) Smooth surface doesn't leak Agilent MIM seal Competitor s machined seal Reliable ppb and ppt measurements require attention to the little things! Page 32

33 New Product: Agilent Inert Inlet UltiMetal Plus treatment creates inert surface 7890 inlet weldment & shell Limits adsorption/degradation of active analytes Optimum for Trace GC/MS and GC-ECD pesticide analyses Agilent s proven proprietary Ultimetal Plus surface treatment Page 33

34 Putting It All Together Inert Flow Path vs. Standard Flow Path Drugs of Abuse 250 ppb using HP-5ms UI Green = Inert Flow Path Blue = Standard Flow Path 1. Dronabinol 2. Oxycodone 3. Temazepam 4. Flunitrazepam 5. Diacetyl morphine Column: Agilent J&W HP-5ms UI 30 m x 0.25 mm x 0.25 um Oven: 100 C 4 min hold, 10 /min to 280 C, 6 /min to 300 C (4.67 min hold), Carrier : Helium 52.7 cm/s (2 ml/min) set at 100 C, EPC-Constant Flow Inlet: Pulsed Splitless 35 PSI pulse until 0.73 min, 0.75 min purge 50 ml/min, gas saver 20, ml/min at 2 min Inlet liner: Ultra Inert with wool / Standard single taper liner with wool (p/n ) Gold Seal: UI Gold Seal / Standard gold seal Detector: MSD Scan mode 40 t0 450 m/z, 230 C source temp, 150 C Quad temp, 310 C transfer line Page 34

35 Broad Peaks Why? INJECTOR -Poor Installation -Change in injection solvent -Change in settings (temps/flows) -Poor sample focusing -Large change in sample concentration -Breakdown or adsorption FLOW -Change in gas velocity -Constant Flow vs Constant Pressure COLUMN -Contamination -Damaged/old stationary phase -Breakdown or adsorption -Reverse Solvent Effect Page 35

36 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 36

37 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 37

38 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 38

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

40 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 40

41 Press Fit Connector Ultra Inert Universal Press Fit Union for 0.10 to 0.75mm, 10/pk Ultra Inert Universal Press Fit Y-Splitter Page 41

42 Blood Alcohol Application: Agilent Solution S/S Inlet HSS Transfer Line FID CH 1 FID CH 2 Column 1: DB- ALC1 0.4 m x 0.45 mm Retention Gap 7890 GC Un-Purged Splitter Column 2: DB-ALC2 7697A Headspace Sampler 42

43 Better Connections: Capillary Flow Technology Devices UltiMetal Plus Ultimate Union/UltiMetal Plus Tee Stainless Steel Micro Fluidic plates technology Deactivation essential to block active sites Column connection easy to assemble Release hole for stuck ferrules Using Flexible Metal ferrules to overcome issues UltiMetal Plus surface chemistry prevents activity Flexible design reduces risk of over tightening or column breaks Leak free seal remains after repeated temperature cycles 43

44 Flexi-Metal Ferrules: Touchless Dial Packaging o Easy column insertion o No lost ferrules o No contamination risks 44

45 Compare current vs new Agilent ferrule Current Ferrule Stiff, prone to cause damage to column or fitting Agilent Flexi-Metal Ferrule Computer aided Design Finite Element Analysis More flexible Small ID compression (40 to 60um) leaks Tolerances poorly controlled Less column damage Large range of ID compression (100 to 120um) less leaks issues

46 Impact of ferrule surface on inertness Very small amount of ferrule surface exposed to active pesticides x10 4 Untreated FMF Post column Std 500ppb 2 1 Acephate Omethoate Demeton-S 0 4 x10 2 FMF + UltiMetal Plus Post column Std 500ppb Acephate Omethoate Demeton-S Counts vs. Acquisition Time (min) 46

47 Conclusions for a Problem Free GC Start With Ultra Inert/High Quality Consumables Never Have a Leak (no oxygen) Use Gas Clean Filters Never Inject Anything (dirty or reactive) Don t Touch Anything Do Routine Inlet Maintenance Often Page 47

48 TECHNICAL SUPPORT , #3 Page 48

49 Troubleshooting Resources Online Video Maintenance Manual Troubleshooting Guide Publication G pdf Page 49

50 NOW IT S EASIER THAN EVER TO GET RELIABLE GC RESULTS THROUGH BETTER GC CONNECTIONS FROM AGILENT Order the poster View the video 50