Cameron George Technical Support Engineer 26 April 2001 An Optimized Dual Column System for the Analysis of Chlorinated Pesticides, Herbicides and PCBs by GC-ECD
Cameron George Applications Chemist April 26, 2001 An Optimized Dual Column System for the Analysis of Chlorinated Pesticides, Herbicides and PCBs by GC-ECD 11:00 a.m. EST Telephone Number: Chair Person: Lisa Lloyd
Cameron George Applications Chemist April 26, 2001 An Optimized Dual Column System for the Analysis of Chlorinated Pesticides, Herbicides and PCBs by GC-ECD 11:00 a.m. EST Telephone Number: Chair Person: Lisa Lloyd Starts in Five Minutes
Cameron George Applications Chemist April 26, 2001 An Optimized Dual Column System for the Analysis of Chlorinated Pesticides, Herbicides and PCBs by GC-ECD 11:00 a.m. EST Telephone Number: Chair Person: Lisa Lloyd Starts in One Minute
CLP Pesticides B-0447 March 8, 2001 AREAS OF FOCUS Injector Detector Column (including guard column)
CLP Pesticides B-0447 March 8, 2001 TRACE ANALYSIS INJECTION TECHNIQUES pg On-Column Megabore direct Splitless PTV On-Column (cold & hot) Large volume
CLP Pesticides B-0447 March 8, 2001 SAMPLE INJECTION Goals Introduce sample into the column Reproducible No efficiency losses Representative of sample
CLP Pesticides B-0447 March 8, 2001 Short Concentrated Long Diffuse Solute Bands Same column, same chromatographic conditions INFLUENCE OF INJECTION EFFICIENCY
CLP Pesticides B-0447 March 8, 2001 FIRST, SOME BASIC DEFINITIONS: Regarding Inlets Backflash Discrimination
CLP Pesticides B-0447 March 8, 2001 A FEW WORDS ABOUT BACKFLASH Definition: In a vaporization injection, a phenomenon wherein a portion of the sample expands beyond the boundary of the injection port liner towards the septum face and incoming gas line
CLP Pesticides B-0447 March 8, 2001 BACKFLASH Effects Ghost peaks Erratic quantitation Poor accuracy
CLP Pesticides B-0447 March 8, 2001 BACKFLASH Causes Highly volatile solvent Excessive inlet temperature Excessive injection volume Small liner volume
CLP Pesticides B-0447 March 8, 2001 BACKFLASH Preventative Measures Lower inlet temperature Less volatile solvent 1-2 µL injection volume Chambered liner Using pulsed split or pulsed splitless
CLP Pesticides B-0447 March 8, 2001 Yes NO!!! INJECTION PORT LINERS Splitless
CLP Pesticides B-0447 March 8, 2001 INLET DISCRIMINATION Injected sample Sample into the column Due to compound volatility differences Higher volatility = More into the column
CLP Pesticides B-0447 March 8, 2001 INLET DISCRIMINATION In Pesticide Analyses Generally inlet discrimination is not a concern for pesticide analyses when utilizing appropriate GC inlets such as Splitless, Pulsed Splitless and PTV
CLP Pesticides B-0447 March 8, 2001 OTHER INLET CONSIDERATIONS Silylation Using glass wool Cleaning and reusing liners
CLP Pesticides B-0447 March 8, 2001 A FEW WORDS ABOUT RESIDUES Semivolatile vs nonvolatile Worst offenders Sample prep
CLP Pesticides B-0447 March 8, 2001 GUARD COLUMNS Use 0.53mm Or 0.32mm ID Deactivated Tubing Fit all inlets Enhanced deposition of residues Easy to work with Minimum 1 meter
CLP Pesticides B-0447 March 8, 2001 Usually 1-5 meters long and same diameter as the column Detector Deactivated Fused Silica Tubing Union Column Injector GUARD COLUMN Traps non-volatile sample residues
CLP Pesticides B-0447 March 8, 2001 COLUMN CONNECTORS Thermal Mass, Inertness, Seal Integrity Stainless steel VU-Tight Press-fits Integral guard columns (Duraguard)
CLP Pesticides B-0447 March 8, 2001 Let’s Be Sensitive ANALYTE DETECTION
CLP Pesticides B-0447 March 8, 2001 The minimum amount of an analyte that can still be confidently identified as a peak (S/N > 4) SENSITIVITY Analytical Definition
CLP Pesticides B-0447 March 8, 2001 SENSITIVITY Analytical Definition Detector Sensitivity: No sample influence (standard) Method Sensitivity: Matrix influence (sample)
CLP Pesticides B-0447 March 8, 2001 N S N S x "Normal" response 1. High noise, detector, background 2. Absorption, breakdown of analyte 3. Sample prep losses "Improved" response 1. High quality circuit components and reagents 2. Inertness 3. Method optimization RESPONSE TO A CONSTANT ANALYTE AMOUNT 2 Cases
HP 6890 Series Micro-ECD Design
Comparison of HP 6890 ECDs Standard < > 10^4 no spec Micro-ECD < > 5 x 10^5 > 5 x 10^ pg/sec lindane lindane pg (ppb) Hz MDL Dynamic range Linear range Linear Range, CLP pesticides Maximum data rate
CLP Pesticides B-0447 March 8, 2001 Break Number 1 For Questions and Answers Press *1 on Your Phone to Ask a Question
CLP Pesticides B-0447 March 8, 2001 LETS GET TO THE CHROMATOGRAPHY
CLP Pesticides B-0447 March 8, 2001 WHAT EXACTLY ARE WE TRYING TO ACHIEVE The best resolution possible Minimize analysis time Get MDLs as low as possible
CLP Pesticides B-0447 March 8, 2001 RESOLUTION VS SEPARATION Separation: Time between the 2 peaks Resolution: Describes how well 2 peaks are separated with regard to their widths
CLP Pesticides B-0447 March 8, (t m = 95.5) WHICH PAIR OF SOLUTES HAVE BETTER SEPARATION?
CLP Pesticides B-0447 March 8, Better Separation = 1.17 R s = 0.6 Better Resolution = 1.05 R s = 2.7 K = 7.00K = 6.07 K = 6.00K = 6.30 RESOLUTION VS SEPARATION
CLP Pesticides B-0447 March 8, 2001 RESOLUTION AND ANALYSIS TIME Improving resolution often results in the opportunity to shorten analysis times Many variables can affect resolution
CLP Pesticides B-0447 March 8, 2001 N= (L, r c ) k = (T, d f, r c ) = (T, phase) R Nk k s = 41 1 RESOLUTION
CLP Pesticides B-0447 March 8, 2001 The column must provide sufficient retention of the early eluting compounds without excessive retention of the late eluting compounds IMPROVING RESOLUTION Retention
CLP Pesticides B-0447 March 8, 2001 IMPROVING RESOLUTION Film Thickness Decreasing Film Thickness Results In: Increased efficiency Elution of analytes at lower temperatures Decreased analysis time Decreased bleed interference Increased column activity Decreased capacity
CLP Pesticides B-0447 March 8, 2001 IMPROVING RESOLUTION Efficiency High column efficiency is necessary to resolve large numbers of compounds Improperly operated injectors and/or improperly optimized carrier gas can result in efficiency losses
CLP Pesticides B-0447 March 8, 2001 IMPROVING RESOLUTION Column Length Increasing Column Length Results In: Increased efficiency Increased analysis time Increased bleed Big increase in cost
CLP Pesticides B-0447 March 8, 2001 IMPROVING RESOLUTION Column Inner Diameter Decreasing Column Inner Diameter Results In: Increased efficiency Increased head pressure Decreased capacity Decreased carrier gas flow rates
CLP Pesticides B-0447 March 8, 2001 IMPROVING RESOLUTION Stationary Phase Stationary phase selectivity has the largest impact on separation, thus resolution Optimization of stationary phase selectivity should be approached cautiously
CLP Pesticides B-0447 March 8, 2001 For Years Environmental Laboratories Have Suffered With Pesticide Analyses Using Non- Optimal Stationary Phases
CLP Pesticides B-0447 March 8, 2001 TRADITIONAL STATIONARY PHASES 5% Phenyl-methylpolysiloxane 35-50% Phenyl-methylpolysiloxane Trifluoropropyl-methylpolysiloxane 14% Cyanopropylphenyl-methylpolysiloxane
CLP Pesticides B-0447 March 8, 2001 PROBLEMS WITH TRADITIONAL PHASES Long analysis times (Over 30 minutes!) High bleed resulting in decreased sensitivity Poor resolution and confirmation capabilities Poor inertness of some phases
CLP Pesticides B-0447 March 8, 2001 TRADITIONAL PESTICIDE COLUMNS
CLP Pesticides B-0447 March 8, 2001 EFFORTS TO IMPROVE PESTICIDE ANALYSES Application Specific Phases Stationary phases designed with a primary focus placed upon maximizing separation ( ) for a specific group of target analytes
CLP Pesticides B-0447 March 8, 2001 APPLICATION SPECIFIC PHASES C 2 H 4 CF CH 3 m n Si O O 3 Phase 1 Trifluoropropyl-dimethylpolysiloxane 3 CH 3 m n Si O O C 2 H 4 CF CH 3 3 Common CLP Pesticide Phases Phase 2 Trifluoropropyl-diphenyl-dimethylpolysiloxane Dimethyl functionality of Phase 2 not shown
CLP Pesticides B-0447 March 8, 2001 EFFECT OF PHASE POLARITY Polarity Thermal Stability
CLP Pesticides B-0447 March 8, 2001 DRAWBACKS OF APPLICATION SPECIFIC PHASES Limited thermal stability resulting in longer analysis times and hampered sensitivity Excessive column conditioning times leading to increased column activity Decreased column lifetimes
CLP Pesticides B-0447 March 8, 2001 PHASES DESIGNED WITH OPTIMUM PERFORMANCE IN MIND Arylene Phase Technology
CLP Pesticides B-0447 March 8, 2001 CH Si O O O O Biphenyl CH Si O O Arylene LOW BLEED STATIONARY PHASES Arylene Structure
CLP Pesticides B-0447 March 8, 2001 DB-35ms DB °C 300°C CLP Pesticides Analysis LOW BLEED STATIONARY PHASES DB-35ms vs. DB-35
CLP Pesticides B-0447 March 8, 2001 STATIONARY PHASE AFFECT ON SENSITIVITY Both 30 m x 0.25 mm I.D., x 0.25 µm 5 ng Decachlorobiphenyl S/N =10S/N =3 DB-35ms, 320°CDB-35, 300°C
CLP Pesticides B-0447 March 8, 2001 LOW BLEED STATIONARY PHASES Spectral Purity
CLP Pesticides B-0447 March 8, 2001 BENEFITS OF LOW BLEED STATIONARY PHASES Improved sensitivity Improved spectral purity Reduced analysis times Potential increase in column lifetimes Rigorous inertness testing Less Detector maintenance
CLP Pesticides B-0447 March 8, 2001 Break Number 1 For Questions and Answers Press *1 on Your Phone to Ask a Question
CLP Pesticides B-0447 March 8, 2001 DEMANDING PESTICIDE APPLICATIONS BENEFIT FROM ADVANCED PHASE TECHNOLOGY DB-35ms and DB-XLB capillary columns contain second generation arylene stationary phases giving them enhanced thermal stability
CLP Pesticides B-0447 March 8, 2001 DB-35MS PRIMARY COLUMN CLP Pesticides Should provide adequate resolution of all 22 CLP Pesticides and surrogates Short analysis time ideal Easily realized analysis conditions preferable Should give minimal column bleed
CLP Pesticides B-0447 March 8, Tetrachloro-m-xylene (SS) 2. -BHC 3. -BHC 4. -BHC 5.Heptachlor 6. -BHC 7.Aldrin 8.Heptachlorepoxide 9. -Chlordane 10. -Chlordane 11.Endosulfan I 12.4,4’-DDE 13.Dieldrin 14.Endrin 15.4,4’-DDD 16.Endosulfan II 17. 4,4’-DDT 18. Endrinaldehyde 19.Endosulfan sulfate 20.Methoxychlor 21.Endrinketone 22.Decachlorobiphenyl (SS) CLP PESTICIDES Column: DB-35ms 30 m x 0.32 mm I.D., 0.25 µm P/N: Carrier: Helium at 45 cm/sec (EPC in constant flow mode) Oven: 110°C for 0.5 min °C at 15°C/min 320°C for 2 min Injector: Splitless, 250°C 30 sec purge activation time 50 pg per component Detector: µECD, 350°C Nitrogen makeup gas (column + makeup flow = 30 mL/min constant flow) Short Analysis Time Low Bleed At 320ºC
CLP Pesticides B-0447 March 8, 2001 DB-XLB CONFIRMATION COLUMN With Regard To The Primary Column Should resolve any co-elutions Needs to provide adequate resolving power when run under the same analytical conditions Should possess at least equivalent thermal stability Should provide a different relative elution pattern Ideally, elution order changes should be realized
CLP Pesticides B-0447 March 8, 2001 CLP PESTICIDES Column: DB-XLB 30 m x 0.32 mm I.D., 0.50 µm P/N: Carrier: Helium at 45 cm/sec (EPC in constant flow mode) Oven: 110°C for 0.5 min °C at 15°C/min 320°C for 2 min Injector: Splitless, 250°C 30 sec purge activation time 50 pg per component Detector: µECD, 350°C Nitrogen makeup gas (column + makeup flow = 30 mL/min constant flow) % Confirmation In Under 16 Minutes 1.Tetrachloro-m-xylene (SS) 2. -BHC 3. -BHC 4. -BHC 5.Heptachlor 6. -BHC 7.Aldrin 8.Heptachlorepoxide 9. -Chlordane 10. -Chlordane 11.Endosulfan I 12.4,4’-DDE 13.Dieldrin 14.Endrin 15.4,4’-DDD 16.Endosulfan II 17. 4,4’-DDT 18. Endrinaldehyde 19.Endosulfan sulfate 20.Methoxychlor 21.Endrinketone 22.Decachlorobiphenyl (SS)
CLP Pesticides B-0447 March 8, 2001 OPTIMIZING FOR SPEED WITHOUT SACRIFICING ANALYTE RESOLUTION Use Hydrogen as the carrier gas Set linear velocity at 65 cm/sec (3.4 mL/min) Increase oven ramp rate from 15°/min to 25°/min
CLP Pesticides B-0447 March 8, 2001 CLP PESTICIDES USING HYDROGEN CARRIER GAS Column: DB-35ms 30 m x 0.32 mm I.D., 0.25 µm P/N: Baseline Resolution In Under 9 Minutes! Carrier: Hydrogen at 65 cm/sec (EPC in constant flow mode) Oven: 110°C for 0.5 min °C at 25°C/min 320°C for 2 min Injector: Splitless, 250°C 30 sec purge activation time 50 pg per component Detector: µECD, 350°C Nitrogen makeup gas (column + makeup flow = 30 mL/min constant flow)
CLP Pesticides B-0447 March 8, 2001 Carrier: Hydrogen at 65 cm/sec (EPC in constant flow mode) Oven: 110°C for 0.5 min °C at 25°C/min 320°C for 2 min Injector: Splitless, 250°C 30 sec purge activation time 50 pg per component Detector: µECD, 350°C Nitrogen makeup gas (column + makeup flow = 30 mL/min constant flow) CLP PESTICIDES USING HYDROGEN CARRIER GAS Column: DB-XLB 30 m x 0.32 mm I.D., 0.5 µm P/N: Excellent Resolution And Confirmation In Under 10 Minutes
CLP Pesticides B-0447 March 8, 2001 OTHER COMMON ECD APPLICATIONS THAT THIS DUAL COLUMN SHOULD BE ABLE TO PERFORM EPA 8151A (Phenoxy acid herbicides) EPA (Pesticides) EPA (Haloacetic acids) EPA 8082 (PCB congeners and Aroclors)
CLP Pesticides B-0447 March 8, Time (min) EPA 8151A PHENOXY ACID HERBICIDES DB-XLB C Time (min) DB-35ms C
CLP Pesticides B-0447 March 8, 2001 EPA 8151A PHENOXY ACID HERBICIDES DB-35ms 30m x 0.32 mm I.D., 0.25 µm P/N: DB-XLB 30m x 0.32 mm I.D., 0.50 µm P/N: Carrier: Helium at 45 cm/sec (EPC in constant flow mode) Oven: 50°C for 0.5 min °C at 25°C/min °C at 12°C/min 320°C for 2 min Injector: Splitless, 250°C 30 sec purge activation time 50 pg per component Detector: µECD, 350°C Nitrogen makeup gas (column + makeup flow = 30 mL/min constant flow) 1. Dalapon 2. 3,5-Dichlorobenzoic acid 3. 4-Nitrophenol 4. Methyl-2,4-dichlorophenylacetate (SS) 5. Dicamba 6. MCPP 7. MCPA 8. 4,4´, Dibromooctafluorobiphenyl (IS) 9. Dichloroprop 10. 2,4-D 11. Pentachlorophenol 12. 2,4,5-T,P 13. 2,4,5-T 14. Chloramben 15. Dinoseb 16. 2,4-DB 17. Bentazone 18. DCPA 19. Picloram 20. Acifluorofen
CLP Pesticides B-0447 March 8, 2001 EPA PESTICIDES DB-XLB DB-35ms Time (min) Time (min) , , ,10 9, C787 C786
CLP Pesticides B-0447 March 8, 2001 EPA PESTICIDES DB-35ms 30m x 0.32 mm I.D., 0.25 µm P/N: DB-XLB 30m x 0.32 mm I.D., 0.50 µm P/N: Carrier: Helium at 45 cm/sec (EPC in constant flow mode) Oven: 75°C for 0.5 min °C at 10°C/min 300°C for 2 min Injector: Splitless, 250°C 30 sec purge activation time 50 pg per component Detector: µECD, 350°C Nitrogen makeup gas (column + makeup flow = 30 mL/min constant flow) 1. Hexachloropentadiene 2. Etridiazole 3. Chloroneb 4. Trifluralin 5. Propachlor 6. Hexachlorobenzene 7. a-BHC 8. Atrazine 9. Pentachloronitrobenzene (IS) 10. Simazine 11. g-BHC 12. b-BHC 13. Hepatachlor 14. Alachlor 15. d-BHC 16. Chlorothalonil 17. Aldrin 18. Metribuzin 19. Metolachlor 20. DCPA 21. 4,4´-Dibromobiphenyl (SS) 22. Heptachlor epoxide 23. Cyanazine 24. g-Chlordane 25. a-Chlordane 26. Endosulfan I 27. 4,4´-DDE 28. Dieldrin 29. Chlorobenzilate 30. Endrin 31. 4,4´-DDD 32. Endosulfan II 33. 4,4´-DDT 34. Endrin Aldehyde 35. Endosulfan sulfate 36. Methoxychlor 37. cis-Permethrin 38. Trans-Permethrin
CLP Pesticides B-0447 March 8, 2001 EPA HALOACETIC ACIDS DB-XLB DB-35ms Time (min) , Time (min) 1 4 2, C789 C788
CLP Pesticides B-0447 March 8, 2001 EPA HALOACETIC ACIDS 1. Chloroacetic acid 2. Bromoacetic acid 3. Dichloroacetic acid 4. Dalapon 5. Trichloroacetic acid 6. 1,2,3-Trichloropropane (IS) 7. Bromochloroacetic acid 8. Bromodichloroacetic acid 9. Dibromoacetic acid 10. 2,3-Dibromopropionic acid (SS) 11. Chlorodibromoacetic acid 12. Tribromoacetic acid DB-35ms 30m x 0.32 mm I.D., 0.25 µm P/N: DB-XLB 30m x 0.32 mm I.D., 0.50 µm P/N: Carrier: Helium at 45 cm/sec (EPC in constant flow mode) Oven: 40°C for 0.5 min °C at 15°C/min 200°C for 2 min Injector: Splitless, 250°C 30 sec purge activation time 50 pg per component Detector: µECD, 350°C Nitrogen makeup gas (column + makeup flow = 30 mL/min constant flow )
CLP Pesticides B-0447 March 8, 2001 EPA 8082 PCB CONGENERS DB-XLB DB-35ms Time (min) Time (min) C791 C790
CLP Pesticides B-0447 March 8, 2001 EPA 8082 PCB CONGENERS 1. IUPAC 1 2. Tetrachloro-m-xylene (IS/SS) 3. IUPAC 5 4. IUPAC IUPAC IUPAC IUPAC IUPAC IUPAC IUPAC IUPAC IUPAC IUPAC IUPAC IUPAC IUPAC IUPAC IUPAC IUPAC IUPAC Decachlorobiphenyl (IS/SS) DB-35ms 30m x 0.32 mm I.D., 0.25 µm P/N: DB-XLB 30m x 0.32 mm I.D., 0.50 µm P/N: Carrier: Helium at 45 cm/sec (EPC in constant flow mode) Oven: 110°C for 0.5 min °C at 15°C/min 320°C for 5 min Injector: Splitless, 250°C 30 sec purge activation time 50 pg per component Detector: µECD, 350°C Nitrogen makeup gas (column + makeup flow = 30 mL/min constant flow )
CLP Pesticides B-0447 March 8, 2001 WHAT DOES THIS MEAN FOR ENVIRONMENTAL LABORATORIES? Improved productivity Increased sample throughput Superior results Total solution for ECD systems
CLP Pesticides B-0447 March 8, 2001 CONCLUSION Excellent selectivity Exceptional inertness Superb thermal stability DB-35ms and DB-XLB provide excellent resolution and confirmation for CLP Pesticides and other critical GC/ECD methods providing total performance:
CLP Pesticides B-0447 March 8, 2001 CONCLUSION When optimized columns are combined with effective injector setup and detector design improved testing results are realized while sample throughput and laboratory efficiency are improved dramatically
CLP Pesticides B-0447 March 8, 2001 AGILENT’S J&W TECHNICAL SUPPORT It’s Free! (800) (phone) (916) (phone) (916) (FAX) web site:
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