Význam tématu
Inertní vložky kapilární GC s proložkou z vlny výrazně zlepšují přenos vzorku do kolony a eliminují interakce aktivních cílových sloučenin se stěnami inletu. Díky optimalizované pasivaci poskytují lepší tvar vrcholků, vyšší citlivost a opakovatelnou kvantifikaci pro vysoce reaktivní pesticidy a drogy zneužití.
Cíle a přehled studie
Hlavním cílem bylo ověřit přínosy Agilent Ultra Inert single taper splitless vložek s vlnou (p/n 5190-2293) u analýzy aktivních látek metodami GC/MS a GC/MS/MS. Studie porovnávala chromatografickou kvalitu, citlivost a reprodukovatelnost s dalšími běžně používanými vložkami u screeningových testů drog v krevních extraktech a kvantitativní analýzy pesticidů ve vzorcích ovoce a zeleniny.
Použitá metodika a instrumentace
• GC/MS screening drog:
- Agilent 7890A/5975C GC/MSD s 7683B autosamplerem, splitless mód (S/SL) při 280 °C, injekce 1 µL.
- Ultra Inert single taper splitless vložka s vlnou (Agilent 5190-2293), DB-5MS UI kolona 15 m×0,25 mm×0,25 µm, He konstantní tlak, RT locking na SKF-525a.
- Backflush po analýze: 2 min při 325 °C, tlak 75 psi.
• GC/MS/MS analýza pesticidů:
- Agilent 7890A/7000 GC/MS/MS s 7693 autosamplerem, MMI Multi Mode inlet pulsed splitless při 280 °C, injekce 1 µL.
- Stejná vložka a inertní restriktor, HP-5MS UI kolona 15 m×0,25 mm×0,25 µm.
- MRM akvizice, postrun backflush 2 min při 280 °C.
• Příprava vzorku:
- Drogy zneužití: jednorázová extrakce plné krve liquid–liquid, QC standardy 5 µg/mL a 500 ng/mL.
- Pesticidy: QuEChERS AOAC extrakce ovoce a zeleniny (banán, jahoda, hruška, salát), kalibrace 5–500 ng/mL.
Hlavní výsledky a diskuse
• Agilent Ultra Inert vložky s vlnou vykázaly jednoznačně lepší tvar vrcholků a vyšší signál aktivních sloučenin (např. temazepam, methamidofos) než konkurenční vložky.
• V GC/MS screeningovém módu došlo k výraznému zvýšení odhadované odpovědi (RF) u 28 testovaných drog, u některých téměř úplná eliminace ztráty signálu během analýzy.
• V GC/MS/MS analýze pesticidů bylo prokázáno vynikající linearita, nízké RSD (<10 %) v širokém rozmezí koncentrací a odolnost vložek při opakovaných injekcích (až 100 injekcí) bez výrazné degradace inertnosti.
• Reprodukovatelnost mezi jednotlivými vložkami a šaržemi dosahovala soustavně nízkých odchylek, což potvrzuje konzistentní deaktivační proces Agilent Ultra Inert.
Přínosy a praktické využití metody
• Zvýšená citlivost a konzistence analýzy umožňuje spolehlivou detekci a kvantifikaci drog v biologických maticích a pesticidů v potravinách.
• Minimalizace kontaminace kolony a MS zdroje snižuje frekvenci údržby a prodlužuje životnost analytických komponent.
• Vysoká opakovatelnost usnadňuje validaci metod v regulovaných laboratořích (forenzních, QA/QC).
Budoucí trendy a možnosti využití
• Rozšíření aplikací na další problematické cílové látky v toxikologii a environmentální chemii.
• Vývoj automatizovaných workflow a integrace s ultra-nízkým objemem injekce pro zvýšení propustnosti.
• Optimalizace povrchových úprav vložek pro extrémně reaktivní či velmi polární analyty.
Závěr
Agilent Ultra Inert vložky s vlnou nabízejí výrazné zlepšení chromatografických parametrů, citlivosti a reproducibility pro analýzu aktivních látek metodami GC/MS a GC/MS/MS. Díky spolehlivému deaktivačnímu procesu nacházejí široké uplatnění v forenzní toxikologii i potravinářské analytice.
Reference
- Limian Zhao, David Mao, Mitch Hastings, Allen Vickers, Alan D Broske, Lindy Miller. Application of Agilent Ultra Inert Liners with Wool for the Analysis of Active Analytes by GC/MS and GC/MS/MS. Pittcon 2011, Poster 1200-1P.
Obsah byl automaticky vytvořen z originálního PDF dokumentu pomocí AI a může obsahovat nepřesnosti.
GC inlet liners with wool provide many benefits during
sample introduction to the GC column
•
Aid the vaporization of liquid sample
•
Promote homogeneous sample mixing and better
quantitation
•
Trap the non-volatile residues in sample matrix thus
protect column and MS source from contamination
•
Prevent sample from hitting the bottom of the inlet
before vaporization.
However, the use of liners with wool has been limited for the
analysis of active compounds such as pesticides, drugs of
abuse, due to
•
Inefficient deactivation of the large glass wool
surface area using traditional deactivation processes
•
High variations of inertness performance as well as
rapid degradation of inertness
Agilent’s Ultra Inert liner deactivation process significantly
improves the efficiency and robustness of glass wool
deactivation, allowing the use of Ultra Inert liners with wool
for
•
Quantitative analysis of pesticides;
•
Screening of drugs of abuse
The feasibility evaluation tests include
•
Chromatographic quality: peak shape and intensity of
active compounds
•
Liner to liner reproducibility
•
Calibration curve linearity for quantitative analysis
•
Injections repeatability and performance stability
•
Column lifetime and MS source contamination
•
Comparison to other equivalent liners or popular used
liners
Results and Discussion
Agilent Ultra Inert liners with wool provide satisfactory GC chromatograms for active compounds in complicate matrices
Introduction
Better peak shape consistency for very active compounds
Pittcon 2011
Atlanta, GA
Poster 1200-1P
Results and Discussion
Experimental
Results and Discussion
Conclusions
Results and Discussion
Application of Agilent Ultra Inert Liners with Wool for the Analysis of Active Analytes by GC/MS and GC/MS/MS
Limian Zhao1, David Mao2, Mitch Hastings2, Allen Vickers2, Alan D Broske1, and Lindy Miller1 Agilent Technologies Inc., 1 2850 Centerville Road, Wilmington, DE 19808 USA; 2 91 Blue Ravins Rd., Folsom, CA 95630
Active site on inlet liners may cause various chromatographic
problems, as observed in liners tests using the checkout
standard with other equivalent liners. Agilent Ultra Inert
liners with wool show better peak shape and typically higher
responses for all of tested analytes, especially for the most
active compounds.
5ng checkout standards on column. A) Broad or distorted
peak, B) ghosting shoulder, C) poor sensitivity.
GC/MS/MS chromatogram (MRM) of 10 ng/mL of
pesticides in fruits and vegetables extract.
GC/MS chromatograms of 2 µg/mL of drugs of abuse
spiked in whole blood extract
1. Amphetamine
2. Phentermine
3. Methamphetamine
4. Nicotine
5. MDA
6. MDMA
7. MDEA
8. Meperidine
9. Phencyclidine
10. Methadone
11. Cocaine
12. SKF-525a
13. Oxazepam
14. Codeine
15. Lorazepam
16. Diazepam
17. Hydrocodone
18. Tetrahydrocannabinol
19. Oxycodone
20. Temazepam
21. Flunitrazepam
22. Heroin
23. Nitrazepam
24. Clonazepam
25. Alprazolam
26. Verapamil
27. Strychnine
28. Trazodone.
13
2.00
4.00
6.00
8.00
10.00
12.00
1
2 3
4
5
6
7
8
9
10
11
12
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
2.00
4.00
6.00
8.00
10.00
12.00
A. TIC
B. SIM
Agilent Ultra Inert single taper splitless liner with wool
Restek Sky gooseneck splitless liner with wool
Restek IP SemiVolatile gooseneck splitless liner with wool
Restek Base gooseneck splitless liner with wool
B
B
B
A
A
A
A
1
2
3
4
5
6
7
Agilent Ultra Inert single taper liner with wool
Restek Siltek gooseneck liner with wool
19
20
21
22
23
24
25
C
B
1. Amphetamine
2. Phentermine
3. Methamphetamine
4. Nicotine
5. MDA
6. MDMA
7. MDEA
19. Oxycodone
20. Temazepam
21. Flunitrazepam
22. Heroin
23. Nitrazepam
24. Clonazepam
25. Alprazolam
3
x10
0
1
2
3
4
5
6
7
8
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18 19
20
21 22
23
24
25
26
27
28
29
30
31
32
33
1. Methamidophos,
2. Dichlorvos
3. Mevinphos
4. Acephate
5. σ-Phenylphenol
6. Omenthoate
7. Dimenthoate
8. Altrazine
9. Lindane
10. Diazinon
11. Chlorothalonil
12. Chloropyrifos methyl
13. Vinclozolin
14. Carbaryl
15. Tolclofos methyl
16. Dichlorfluanid
17. Aldrin
18. Malathion
19. Dichlorobenzophenone
20. Pirimiphos ethyl
21. Tolyfluanid
22. Procymidone
23. Endrin
24. Ethion
25. Endosulfan sulfate
26. DDT
27. Endrin ketone
28. Iprodione
29. Phosmet
30. Phosalone
31. Permethrin isomers
32. Coumaphos
33. Deltamethrin isomers.
Excellent liner to liner reproducibility achieved by Agilent Ultra
Inert liners with wool
The liner to liner performance reproducibility was tested with
replicates of six Ultra Inert liners with wool from three different
lots for both drugs of abuse and pesticides applications. Groups
of 12 difficult active drugs of abuse and 12 pesticides were
selected as representative analytes.
Ultra Inert liners with wool generate higher
responses for active compounds
0.0
20.0
40.0
60.0
80.0
100.0
UI wool
Restek SV wool
Restek Sky wool
Restek Base wool
Restek Siltek wool
Temazepam Response Comparison between UI liners and other equivalent liners
Temazepam is a very difficult compound and extremely
sensitive to the liner inertness. When an inefficient deactivated
liner was used, the response of Temazepam (5 ng on column)
can almost disappear. Compared to other similar liners, Agilent
Ultra Inert liner with wool generated highest RF for
Tempazepam.
Better liner durability and injection repeatability
obtained by Agilent Ultra Inert liners with wool
Better consistency on the active compounds responses
Ultra Inert liners with wool provide the following benefits
for drugs of abuse screening and pesticides analysis
applications in real matrices.
•
Excellent inertness for the analysis of active
compounds
•
Better peak shape and higher peak intensity for
active compounds
•
Superior linearity for active pesticides over 5 – 500
ng/mL in QuEChERS extract
•
Consistent liner to liner (lot to lot) reproducibility
•
Acceptable liner durability and performance
stability
•
Extended analytical column life-time
•
Decreased MS source maintenance frequency
•
Superior to other popular liners used for the
above applications.
Tested samples were 50 ng/mL pesticides spiked in fruits and
vegetables bank extract.
To learn more about Agilent Ultra Inert liners, visit us
online at www.Agilent.com/chem/UltraInert
Selected Active
Drugs of Abuse
(Peak # for drugs)
RSD of average RF
(Two concentrations: 5 µg/mL
and 500 ng/mL)
Selected Active
Pesticides
(Peak # for pesticides )
RSD of average RF
(Calibration curve over 5 ng/mL
to 500 ng/mL)
# UI liners = 6 (3 lots)
# UI liners = 6 (3 lots)
Methamphetamine (3)
3.8
Methamidophos (1)
14.2
MDMA (6)
4.4
Acephate (4)
5.6
Phencyclidine (9)
2.5
Omenthoate (6)
6.7
Cocaine (11)
2.0
Dimenthoate (7)
2.4
Oxazepam (13)
7.6
Chlorothalonil (11)
8.4
Codeine (14)
4.2
Carbaryl (14)
5.1
Oxycodone (19)
6.5
Dichlorfluanid (16)
4.7
Temazepam (20)
11.7
Tolylfluanid (21)
4.9
Heroin (22)
2.7
Endrin (23)
5.7
Nitrazepam (23)
6.3
DDT (26)
17.4
Clonazepam (24)
3.5
Iprodione (28)
9.8
Trazodone (28)
4.4
Phosmet (29)
7.0
Lot to Lot Liner Reproducibility assured: Each lot is
Certified to ensure consistent and efficient deactivation using
both acidic and basic probes at trace (2 ng) levels on column
Analysis of pesticides by GC/MS/MS
Instrument conditions
•
Agilent 7890A/7000 GC/MS/MS system, equipped with Agilent
7693 Autosampler
•
MMI Multi Mode inlet under pulsed splitless mode @ 280°C, 1
µL injection
•
Inlet liner: Ultra Inert single taper splitless liner with wool
(Agilent p/n 5190-2293)
•
He, constant pressure, RT locked with Chlopyrifos methyl @
8.298 min
•
HP-5MS UI, 15m x 0.25mm, 0.25µm (Agilent p/n 19091-431UI)
•
Purged Ultimate Union (Agilent p/n G3182-61580) for back
flushing
•
Restrictor: Inert Fused Silica tubing, 0.65m × 0.15mm (Agilent
p/n 160-7625-5)
•
Oven profile: 100 °C (2 min), 50 °C/min to 150 °C, 6°C/min to
200°C at, 16°C/min to 280°C (6 min)
•
Postrun back flush: 2 min @ 280°C , back flush pressure @ 75psi,
inlet pressure @ 1psi during back flush
•
Transfer line/Source/Quad (Q1 &Q2) @ 280°C/300°C/ 150°C
•
Data acquisition: MRM
Testing standards
•
33 representative pesticides, 5 ng/mL to 500 ng/mL six points
calibration standards, 50 ng/mL QC
Matrix sample
•
Five different fruits and vegetables matrix mixture: flower,
banana, strawberry, pear, and lettuce
•
Blank matrices sample were extracted following QuEChERS
AOAC method
•
Agilent BondElut QuEChERS AOAC extraction (p/n 5982-5755)
and dispersive SPE kit for general fruits and vegetables (p/n
5982-5022) were used
Screening of drugs of abuse by GC/MS
Instrument conditions
•
Agilent 7890A/5975C GC/MSD system, equipped with Agilent 7683B
Autosampler
•
S/SL inlet under splitless mode @ 280°C, 1 µL injection volume
•
Inlet liner: Ultra Inert single taper splitless liner with wool (Agilent
5190-2293)
•
He, constant pressure, RT locked with SKF-525a @ 8.569 min
•
DB-5MS UI, 15m x 0.25mm, 0.25µm (Agilent p/n 122-5512UI)
•
Purged Ultimate Union (Agilent p/n G3182-61580) for back flushing
•
Restrictor: Inert Fused Silica tubing, 0.65m × 0.15mm (Agilent p/n
160-7625-5)
•
Oven profile: 100 °C (0.5 min), 20 °C/min to 325 °C (2.5min)
•
Postrun back flush: 2 min @ 325°C , back flush pressure @ 75psi,
inlet pressure @ 1psi during back flush
•
MSD: Transfer line @ 300°C, Source @ 300°C, Quad @ 150°C
•
Data acquisition: Scan/SIM
Testing standards
•
Agilent GC/MS Forensic/Toxicology analyzer checkout mixture
standard (p/n 5190-0471)
•
28 popular and difficult drugs of abuse, 5 µg/mL and 500 ng/mL
Matrix sample
•
Whole blood samples extracted by a single step liquid-liquid
extraction. (supplied by NMS labs, Willow Grove, PA)
Pesticides (peak #)
Repeatability: RSD (%) for analytes’ RF values of 50 ng/mL
standard injections
In reagent
solvent
In fruits and vegetables QuEChERS extract
Ultra Inert liners w/
wool by 100
injections
( # liners = 5)
Ultra Inert liners w/
wool by 50 injections
(# liners = 7)
Ultra Inert liners w/
wool by 100 injections
(# liners = 7)
Siltek Cyclosplitter
liners by 50 injections
(# liners = 3)
Methamidophos (1)
7.7
5.1
11.7
25.4
Acephate (4)
5.4
16.6
30.1
55.6
Omenthoate (6)
10.5
27.1
44.8
49.9
Dimenthoate (7)
4.8
7.3
13.4
14.9
Chlorothalonil (11)
8.6
9.3
15.2
11.7
Carbaryl (14)
8.7
11.7
19.9
13.4
Dichlorfluanid (16)
5.3
6.3
11.8
3.9
Tolylfluanid (21)
7.3
7.3
13.4
5.7
Endrin (23)
6.6
3.2
6.0
2.7
Endosulfan sulfate (25)
7.7
9.5
14.1
10.5
DDT (26)
6.3
23.1
36.4
16.8
Endrin ketone (27)
7.3
9.3
14.2
9.4
Iprodione (28)
5.1
5.0
8.1
20.3
Phosmet (29)
6.9
15.4
27.2
16.3
Agilent Ultra Inert liner with wool Restek Siltek Cyclosplitter liner
Pesticides
Methamidophos
Acephate
Omenthoate
Dimenthoate
3.6
3.8
4
3.6
3.8
4
2.4
2.6
2.8
2.4
2.6
2.8
4.8
5
5.2
5.4
4.8
5
5.2
5.4
6.2
6.6
7
6.2
6.6
7
3.6
3.8
4
3.6
3.8
4
2.4
2.6
2.8
2.4
2.6
2.8
4.8
5
5.2
5.4
4.8
5
5.2
5.4
6.2
6.6
7
6.2
6.6
7
100th
New
New
New
New
New
New
New
New
100th
100th
100th
50th
50th
50th
50th
5190-2293 Ultra Inert Liner
Splitless, Sngl taper, Glass Wool
Liner Body Lot:
0023A
Deactivation Lot:
B11002
Tested for:
2ng 4-Aminopyridine
2ng 2,4-Dinitrophenol
