7200 GC-QTOF A new analytical tool for solving complex analytical problems

Transcription

1 GC/Q-TOF for Target, Non-target and Unknowns: The Benefits of High Resolution, Accurate Mass and Fast Acquisition Rates MS and MS/MS 7200 GC-QTOF A new analytical tool for solving complex analytical problems Jaume C. Morales MS Product Specialist Agilent Technologies Spain October 2011 MAD/BCN Page 1

2 GCMS Challenge : complex analytical problems Identification of compounds in complex samples at trace level (ng/ml levels or less) is difficult and generally requires a non-routine analytical strategy or state-of-the-art analytical systems including : 1- Powerful extraction/enrichment method 2- High separation power GC (e.g.gcxgc) 3- With mass spectrometric and/or selective detection. However, for routine analysis of this type of compounds, more simple and fast analytical approach would be required to enhance productivity. Unfortunately 1D GC/MS (SIM) or 1D GC in combination with elementspecific detectors such as PFPD and SCD is often not sufficient for the required selectivity. Page 2

3 GCMS Challenge : complex analytical problems 1 st Approach : The TOF-MS simultaneously samples and analyzes all ions across the mass range in contrast to conventional scanning instruments, where masses are ejected and detected sequentially. Consequently, GC-TOF-MS has unrivalled full spectrum sensitivity, comparable to GC-MS in SIM mode. Also,GC-TOF-MS allows accurate mass measurement for higher selectivity and sensitivity using a very narrow mass window ( Da). BUT, what happens when Resolution and Δ Mass are not enough? 2 nd Approach : GC-QTOF-MS Page 3

4 7200. What is it? 7200 GC/Q-TOF = Our newest GC/MS... built upon many well proven parts: + = Almost one thousand 7000 TQs Over one thousand TOFs and Q-TOFs Many thousand 7890 GCs Page 4

5 What is it? 7200 GC/Q-TOF = Triple Quadrupole MS + = Quadrupole Time of Flight MS Time of Flight MS Page 5

6 The merging of two platforms Ion Mirror 7000 GC/MS QQQ based 6500 LC/MS Q-TOF based Quad Mass Filter (Q1) Ion Source Transfer optics Collision Cell Ion Pulser Ion Detector Turbo 1b Turbo 1a Turbo 2 Turbo 3 Page 6

7 7200 Analyzer Four stages of pumping Page 7

8 New... Yet Totally Proven 4GHz ADC electronics enable a high sampling rate (32 Gbit/s) which improves the resolution, mass accuracy, and sensitivity for low-abundance samples. Dual gain amplifiers simultaneously process detector signals through both lowgain and high gain channels, extending the dynamic range to Hot, quartz monolithic quadrupole analyzer and collision cell identical to the 7000 Quadrupole MS/MS New Removable Ion Source includes repeller, ion volume, extraction lens and dual filaments Dual-stage ion mirror improves second-order time focusing for high mass resolution. Proprietary INVAR flight tube sealed in a vacuum-insulated shell eliminates thermal mass drift due to temperature changes to maintain excellent mass accuracy, 24/7. Added length improves mass resolution. Analog-to-digital (ADC) Detector: Unlike time-to-digital (TDC) detectors which record single ion events, ADC detection records multiple ion events, allowing very accurate mass assignments over a wide mass range and dynamic range of concentrations. New Internal Reference Mass can be delivered to the source at a low and high concentration Two 300L/s t urbos pump the focusing optics and flight tube Split-flow turbo differentially pumps the ion source and quadrupole analyzer compartments Hexapole collision cell accelerates ion through the cell to enable faster generation of high-quality MS/MS spectra without cross-talk Page 8

9 Removable Ion Source (RIS) Automated Gate Valve RIS Automated Retractable Transfer Line Page 9

10 Removable Ion Source (RIS) RIS Standard on Q-TOF Allows fast EI/CI source swapping without venting Allows swap of complete ion source, including filaments, in ~30 minutes without venting Page 10

11 30 minute source swap with RIS Vent cool ion source open chamber and replace/maintain source components close chamber pump out heat source stabilize vacuum and source temperature 1pg OFN New Clean Ion Source Original Dirty Ion Source Page 11

12 Large dynamic range detection system ADC has greater linear response than TDC Time-to-Digital Converter Analog-to-Digital Converter 32Gbit/sec 2 TDC 1 ADC TDC digitally counts the number of ions arriving in a time window. At high ion count rates two ions arriving in the same time window are recorded as one event. ADC measures amplitude of analog ion signal from the detector. At high ion count rates two ions arriving at the same time are recorded as twice the amplitude Page 12

13 Dynamic Range TDC ADC Threshold Time to Digital Converter Counts 1 when above Threshold 1-2 Orders Magnitude Dynamic Range 2-8 Gbit/sec of information Analog to Digital Converter Measures each point 4-5 Orders Magnitude Dynamic Range 32 Gbit/sec of information Page 13

14 Response Response Large dynamic range detection system ADC is important for chromatographic peaks Time-to-Digital Converter Analog-to-Digital Converter Ions Ions TDC has limited linear range and is quantitative over a small concentration range ADC has greater linear range and is quantitation over a larger concentration range Page 15

15 Response linearity and mass accuracy ADC advantages R^2= Hz acquisition, RIS LOD about 0.01 pg Page 16

16 What will 7200GC-QTOF do for you? TOF mode High resolution full scan spectra Accurate mass measurements Fast scanning of full spectra MS/MS mode Full scan product ion spectra w high resolution accurate mass Ideal tool for solving complex analytical problems Page 17

17 Spectral presentation (Tune File) Most users think in centroid, but the MS operates in profile Profile View Centroid View Page 18

18 Zoom on MSD mass peaks: 0.1 u steps Baseline resolution between m/z 614 and 615 not quite achieved Page 19

19 Similar plot from 7200 Q-TOF As high resolution holds great benefit for GC separations... Baseline Resolution High resolution hold benefits for mass spectra... Page 20

20 Resolving power & mass accuracy R = 614/0.68 = 903 Δmz = 0.1/614 = 160 ppm Mz=614 SQ TQ IT Resolving Power: R=mz/FWHM Mass Accuracy: Δmz=dm/mz*10 6, parts per million (ppm) PFTBA mass 614 C12F24N= Pw=0.68 TOF Q-TOF R = 614/ = Δmz = / = 0.7 ppm 1 Da. 1 Da. Page 22

21 Calculation of Exact Mass and Error in Measured Mass Atom Mass of Atom # of Atoms Sum Hydrogen Carbon Nitrogen Oxygen Total Plus H Total Minus e Calculated = exact or theoretical CH 3 O CH 3 (Measured-Calculated) X 1,000,000 Calculated ppm Error if the electron was omitted = ppm O CH 3 N H H O H O N CH 3 O O H CH 3 Reserpine (C 33 H 40 N 2 O 9 ) O O O CH 3 Page 23

22 Internal Reference Mass (IRM) The goal for the 7200 is for easy and reliable ~2-5ppm mass accuracy under all conditions Agilent has developed a proprietary Internal Reference Mass (IRM) delivery system for on the fly mass axis correction IRM is the use of known background ions to lock the mass axis for each scan Requires reliable IRM calibration signals with and without matrix Page 24

23 IRM correction example Mass accuracy of 2-formyl thiophene and 2-acetyl thiazole in spiked Whiskey 1 pg on col DG 2 pg on col DG 5 pg on col DG 10 pg on col DG 20 pg on col DG 50 pg on col DG 100 pg on col DG 200 pg on col DG 500 pg on col DG 1000 pg on col DG uncorrected IRM corrected calc mass obs mass ppm Error obs mass ppm Error 2-formyl thiophen acetyl-thiazole formyl thiophen acetyl-thiazole formyl thiophen acetyl-thiazole formyl thiophen acetyl-thiazole formyl thiophen acetyl-thiazole formyl thiophen acetyl-thiazole formyl thiophen acetyl-thiazole formyl thiophen acetyl-thiazole formyl thiophen acetyl-thiazole formyl thiophen acetyl-thiazole Average ABS Error Standard Deviation of Error Excellent: < 5 ppm Excellent: < 5 ppm Good: < 10 ppm Good: < 10 ppm Average mass error < 2 ppm over X1000 concentration range Page 25

24 Accurate mass makes mass defect important Integer Exact X+1 X+2 Mass Type Element Symbol Mass Mass Abundance Factor Factor Defect X Hydrogen H D or 2 H X+1 Carbon 12 C X+1 Nitrogen X+2 Oxygen 13 C n C n C N N n N O O n O O n O X Fluorine F X+2 Silicon 28 Si Si n Si Si n Si X Phosphorus P X+2 Sulfur 32 S S n S S n S X+2 Chlorine X+2 Bromine 35 Cl Cl n Cl Br Br n Br X Iodine I Page 27

25 7200 Q-TOF makes mass defect Valuable! Integer Exact X+1 X+2 Mass Type Element Symbol Mass Mass Abundance Factor Factor Defect X Hydrogen H D or 2 H X+1 Carbon 12 C For m/z 614, how does 1 ppm = correlate to different atoms? 13 C n C n C X+1 Nitrogen 14 N N n N X+2 Oxygen 16 O O n O O n O One 1 H + 13 ppm One 16 O - 8 ppm X Fluorine F X+2 Silicon 28 Si Si n Si Si n Si X Phosphorus P X+2 Sulfur 32 S S n S S n S X+2 Chlorine 35 Cl Cl n Cl One 35 Cl - 51 ppm X+2 Bromine 79 Br Br n Br X Iodine I Page 28

26 # Possible Chemical Formulas Many possible formulas with an MSD SQ, TQ or IT But only a few with TOF Possible Number of Chemical Formulas at m/z 272 Octafluoronaphthalene (CAS ) C 10 F 8 = mass uncertainty, ppm mass uncertainty ppm Formulas made of: C,H,N,O,F, & Cl # of Possible Formulas amu Accurate mass reduces risk of investing effort on the wrong molecule Page 29

27 What about TOF SPEED? TOF always collects full mass range Q-TOF always display full product ion spectrum Spectral Rate: Typical max rate: spectra/sec (Hz) to disk Usable rate is limited by signal level (ion count) New analysis opportunities for GC/MS: Fast GC and Ultra high resolution GC: ~ 20-40Hz GCxGC: ~ Hz Page 30

28 Speed enhances deconvolution Deconvolution Requires Time Offset Time Page 31

29 High data rate = better deconvolution Time Slow data rate will not pick each peak apex Time Fast data rate will allow deconvolution of closely eluting peaks Page 32

30 High data rate = better deconvolution The 7200 Q-TOF in TOF mode will have: Faster Data Rates Maintain Excellent S/N New MassHunter Deconvolution Time Slow data rate will not pick each peak apex Time Fast data rate will allow deconvolution of closely eluting peaks Page 33

31 7200 instrument performance Specifications Resolving Power: >10K at m/z 272 (typical >13K) Mass Accuracy: <5 ppm at m/z 272 (typical < 2ppm) MS Sensitivity is between SIM and Scan of a Single Quad instrument MS/MS Sensitivity is between SRM and Product Ion scan of a Tandem Quad instrument Dynamic Range: 5-6 orders of magnitude Quad Mass range: Da ( Da FWHM) TOF Mass range: Da Spectral Rate: 1-50 Spectra/sec All specifications subject to improve Page 35

32 Key Features of the Internal Reference Mass for routine sub 5ppm mass accuracy even in heavy matrix 2. Removable Ion Source for quick source cleaning, filament replacement and EI/CI swapping without breaking vacuum 3. Q-TOF MS/MS: Chemical noise reduction Selectivity Structural information Method development 4. Software tools formula calculator Page 36

33 7200 Series Q-TOF for GC/MS Examples of key features Page 37

34 Can accurate mass measurements be made in a real matrix? What are the limitations? Page 38

35 Intensity affects the rresult m/z Two mass peaks with FWHM 0.7 u with 0.5 u between centroided m/z value m/z Two mass peaks with FWHM 0.05 u with 0.5 u between centroided m/z value Page 39

36 GC or MS: Relative intensity affects the result Profile view of mass peaks Interference = Analyte Centroid Interference = 100 X Analyte Centroid m/z m/z Large intensity matrix ions can affect measured analyte mass Page 40

37 How much R and Defect is enough? Intensity Ratio = 1: Dimetilan m/z = Mass error = 0.4 ppm Flurenol methyl ester m/z = Mass error = 1.7 ppm No IRM corrections applied Dm = Da. ~13,500 resolution FWHM Page 41

38 How much R and Defect is enough? Intensity Ratio = 1:0.02 Flurenol methyl ester m/z = Mass error = -0.4 ppm A resolution of 13,500 is not enough - larger ratios need MS/MS or better GC separation Dimetilan m/z = Mass error = ppm Page 42

39 GCMS Challenge : complex analytical problems 2 nd Approach : The QTOF-MS can : - Reduce noise by Precursor Selection thus delivering more selectivity. - Confirm ID with extra Hi-Res MS/MS spectra. -Allow structural Elucidation. Page 47

40 MS/MS Chemical Noise Reduction (EI) When R and Accurate Are Not Enough (1pg OFN in PFTBA Background) MS m/z :1 S/N MS/MS 272: :1 S/N Matrix ions Analyte ions with minimal matrix ions Analyte ions Page 48

41 MS/MS for Structural Elucidation Compound B C16H14O4 (Rings + Double Bonds = 10) (M H) Candidate structures H m/z (experimental) Formula Error (ppm) Score C 16 H 13 O C 6 H C 10 H 9 O CH=CH C 6 H C 8 H 7 O N/A CH 2 =CH C 6 H 5 CO C 8 H 6 O N/A C 7 H 6 O CO C 6 H 6 O N/A CH C 5 H 3 O Page 49

42 Formula Calculator: formulas consistent with accurate mass and formula of parent molecule C 5 H 12 O 2 PS 3 m/z = Page 50

43 MassHunter Tools for GC/Q-TOF Overlaid chromatograms for each deconvoluted compound found Compound mass spectrum with mass caliper tool displaying m/z difference between two ion fragments Molecular and fragment formula calculation results based on accurate mass of the ion Page 51

44 How is it used? Structure elucidation Structural Elucidation from product Ion spectra using high resolution and accurate mass Start will full scan EI spectrum Use CID on each fragment mass to confirm structure of fragment Select Fragment 1 to be precursor 1 Product ions Select Fragment 2 to be precursor 2 Product ions CID CID Precursor-product ion relationship is documented and ion molecular formula confirmed by accurate mass Page 52

45 MS/MS product ion mass with high mass accuracy Helps unambiguously identify fragment ions Most probable fragment ion Molecular Ion Pesticide m/z Formula Chlorpyrifos -methyl C7H7Cl3NO3PS Dichlorvos C4H7Cl2O4P Δ ppm Fragment Ions Formula Δ ppm Formula Δ ppm Formula -0.7 C7 H7 Cl [ 37 Cl] N O3 P S 0.0 C7 H7 Cl2 N O3 P S 0.0 C2 H6 O2 P S C6 H2 Cl3 N O2 P S 1.6 C4H7ClO4P -0.9 C2H6O3P 3.7 C4 H7[ 37 Cl] O4 P C3 H2 Cl2 O3 P Δ ppm Formula Endosulfan sulfate C9 H6 Cl6 O4 S -2.1 C9 H6 Cl4[ 37 Cl] O4 S -0.7 C5 Cl5[ 37 Cl] 0.0 C5 Cl4[ 37 Cl] C8 H3 Cl5 Propachlor C11 H14 Cl N O -1.0 C10 H11 Cl N O 1.1 C11 H14 N O 1.8 C8 H8 Cl N O -3.9 C6 H C2 H2 Cl O Fluazifop-pbutyl C19 H20 F3 N O4-2.2 C19 H20 F2 N O4-1.1 C14 H11 F3 N O2-1.3 C12 H7 F3 N O 2.1 C6 H3 F3 N C7 H14 O3-1.4 Triazophos C12 H16 N3 O3 P S C10 H12 N3 O3 P S -2.7 C8 H8 N3 O3 P S -0.6 C8 H7 N3 O -1.9 C8 H8 N3 O C11 H14 N2 O3 P S C9 H10 N2 O3 P S Examples from building accurate mass pesticide library Page 53

46 Page 54 Photodegradation Products of Beer

47 Problem identify degradation Products of beer Completely untargeted (initially) study of beer photodegradation Method highlights 30 min extraction at 30 C using manual SPME holder and conditioned 50/30 µm DVB/Carboxen/PDMS StableFlex SPME fiber (Supelco), no agitation Desorption at 300 C for 2 min in the SSL injector; 1:10 split Agilent J&W column DB-5MS 30 m x 0.25 mm x 0.25 µm Page 55

48 Changes in the Chromatogram Appears following the exposure of the sample to direct sunlight. Peak height is dependent on the duration of exposure to the sun Molecular ion m/z= C 10 H 15 NO No exposure to direct sunlight 3 hours 6 hours Page 56

49 Summary of MS/MS Experiments Accurate mass measurement of molecular ion and fragments 109 C 6 H 7 NO 81 N O C 10 H 14 N C H 5 C 4 H 6 N C 5 H 6 N C 5 H 7 N C 6 H 8 N C 6 H 6 NO C 7 H 8 N C 9 H 14 N C 9 H 11 N C 10 H 15 NO ine, N-(2-furanylmethylene)-3-methyl- 109 C 6 H 7 NO 122 C 7 H 8 NO 136 C 9 H 14 N 148 C 10 H 14 N MS 81 C 5 H 7 N 108 C 6 H 6 NO 80 C 5 H 6 N 94 C 6 H 8 N MS/MS 78 C 5 H 4 N 55 C 3 H 5 N 53 C 4 H 5 41 C 3 H 5 66 C 4 H 4 N 133 C 9 H 11 N Page 57

50 Summary of MS/MS Experiments Calculate possible empirical formulas 109 C 6 H 7 NO 81 N O C 10 H 14 N C H 5 C 4 H 6 N C 5 H 6 N C 5 H 7 N C 6 H 8 N C 6 H 6 NO C 7 H 8 N C 9 H 14 N C 9 H 11 N C 10 H 15 NO ine, N-(2-furanylmethylene)-3-methyl- 109 C 6 H 7 NO 122 C 7 H 8 NO 136 C 9 H 14 N 148 C 10 H 14 N MS 81 C 5 H 7 N 108 C 6 H 6 NO 80 C 5 H 6 N 94 C 6 H 8 N MS/MS 78 C 5 H 4 N 55 C 3 H 5 N 53 C 4 H 5 41 C 3 H 5 66 C 4 H 4 N 133 C 9 H 11 N Page 58

51 Summary of MS/MS Experiments MS/MS on fragments + accurate mass to find empirical formulas 109 C 6 H 7 NO 81 N O C 10 H 14 N C H 5 C 4 H 6 N C 5 H 6 N C 5 H 7 N C 6 H 8 N C 6 H 6 NO C 7 H 8 N C 9 H 14 N C 9 H 11 N -OH C 10 H 15 NO ine, N-(2-furanylmethylene)-3-methyl- 109 C 6 H 7 NO 122 C 7 H 8 NO 136 C 9 H 14 N 148 C 10 H 14 N MS 80 C 5 H 6 N -C 5 H 8 -CH 3 MS/MS 78 C 5 H 4 N -H 2 53 C 4 H 5 -CHN 133 C 9 H 11 N Page 59

52 Summary of MS/MS Experiments MS/MS on other fragments 109 C 6 H 7 NO 81 N O C 10 H 14 N C H 5 C 4 H 6 N C 5 H 6 N C 5 H 7 N C 6 H 8 N C 6 H 6 NO C 7 H 8 N C 9 H 14 N C 9 H 11 N C 10 H 15 NO ine, N-(2-furanylmethylene)-3-methyl- 109 C 6 H 7 NO 122 C 7 H 8 NO 136 C 9 H 14 N 148 C 10 H 14 N MS 81 C 5 H 7 N 108 C 6 H 6 NO 80 C 5 H 6 N 94 C 6 H 8 N MS/MS 78 C 5 H 4 N 55 C 3 H 5 N 53 C 4 H 5 41 C 3 H 5 66 C 4 H 4 N 133 C 9 H 11 N Page 60

53 Identifying and quantification sulfur-containing compounds in beverages In this work, a simple and fast method for determination of medium volatile sulfurcompounds, e.g.2-acetylthiazole and 2-formylthiophene, in single malt whiskey and coffee at low ng/ml level, was examined by using the direct split injection or miniaturized LLE and 1DGC-Q-TOF-MS. Page 66

54 Problem compounds affecting taste and flavor Example of complex matrix coffee extract 2-formyl thiophene 2-acetyl thiazole are common contaminants Low sensory threshold and can have negative effect on product flavor or aroma Easy to separate from each other Often requires sophisticated extraction/enrichment procedures and/or powerful 2D GC techniques for separation from matrix for quantitation Method highlights For coffee only, simple L/L extraction in dichloromethane (10:1 enrichment) 1:10 split injection with SSL inlet DB-5MS column 30 m x 0.25 mm x 0.25 μm Page 67

55 Standards at 100 pg On Column formyl thiophene Formula C 5 H 4 OS MW: acetyl thiazole Formula C 5 H 5 NOS MW: Page 68

56 2-Acetyl Thiazole calibration Excellent quantitation in complex matrix STD addition calibration curve for 2-acetyl thiazole in spiked coffee (STD amount: 1, 2, 5, 10, 20, 50, 100, 200, 500, 1000 pg) Average mass error = 1.1 ppm (max 1.6) over entire concentration range m/z Mass window: ±20 ppm Page 69

57 TIC and EICs of Whiskey Extract 2-formyl thiophene Extraction window m/z ± 100 ppm 2-acetyl thiazole? Extraction window m/z ± 100 ppm Page 70

58 Page 71 EIC of 2-Formyl thiophene in Wiskey at different extraction window

59 Page 72 Determination results of 2-Formyl Tiophene in Whiskey

60 IRM correction example Mass accuracy of 2-formyl thiophene and 2-acetyl thiazole in spiked Whiskey 1 pg on col DG 2 pg on col DG 5 pg on col DG 10 pg on col DG 20 pg on col DG 50 pg on col DG 100 pg on col DG 200 pg on col DG 500 pg on col DG 1000 pg on col DG uncorrected IRM corrected calc mass obs mass ppm Error obs mass ppm Error 2-formyl thiophen acetyl-thiazole formyl thiophen acetyl-thiazole formyl thiophen acetyl-thiazole formyl thiophen acetyl-thiazole formyl thiophen acetyl-thiazole formyl thiophen acetyl-thiazole formyl thiophen acetyl-thiazole formyl thiophen acetyl-thiazole formyl thiophen acetyl-thiazole formyl thiophen acetyl-thiazole Average ABS Error Standard Deviation of Error Excellent: < 5 ppm Excellent: < 5 ppm Good: < 10 ppm Good: < 10 ppm Average mass error < 2 ppm over X1000 concentration range Page 73

61 TIC and EICs of Coffee Extract Same Scale than Wiskey extract 2-formyl thiophene Extraction window m/z ± 100 ppm 2-acetyl thiazole Extraction window m/z ± 100 ppm Page 74

62 Page 75 Coffee extract has a much more complex matrix although LLE

63 Page 76 EIC of 2-Formyl thiophene in Coffee extract at different extraction window

64 Page 77 EIC of 2-Acetyl Thiazole in Coffee extract at different extraction window

65 Page 78 Determination results of 2-Formyl Tiophene and 2-Acetyl Thiazole in Coffe extract

66 Page 79 Comparison of TOF-MS and Q/TOF- MS/MS Spiked Whiskey (10 pg on-column)

67 Summary what you should remember The world about us is always changing and new problems are always emerging New problems often require new tools to find a solution The GC Q-TOF offers capability to solve new problems in new ways Higher resolution (HR), better mass accuracy (MA), and faster scan speed always improves analytical results Add HR and AM to MS/MS product ions and structure elucidation is possible Agilent offers the largest range of GC/MS tools SQ, IT, TQ, & Q-TOF Page 81

68 CL LE E A RLY LY BE ET T TE E R MS S SSO OL LU UT TI OI ON NS S Questions? Mass Spectrometry Technology Products Solutions NEW NEW NEW Page 82