Trinity College DublinSchool of Chemistry16 Dec 2009
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Transcript of Trinity College DublinSchool of Chemistry16 Dec 2009
Trinity College Dublin School of Chemistry 16 Dec 2009
WelcomeTo the
Mass Spectrometry Unit
Dr. Martin Feeney Room 0.5 Dr. J. Bernard Jean-Denis Chemistry building
Trinity College Dublin School of Chemistry p 1
1. Introduction to mass spectrometry 2
2. Sample Preparation 7 a. Choice of Solvents b. Sample Solubility c. Sample Concentration d. Sample Vials e. Things to avoid in Sample Prep.
3. Sample submission form 9 a. Sample ID b. Proposed Structure c. Sample Handling/Storage
4. Results 12
5. MS queries 13
Table of Contents
Trinity College Dublin School of Chemistry p 2
Introduction
1. Introduction to mass spectrometry
a- ESI- TOF-MS
b- GC- TOF-MS
c- LDI-Q-TOF-MS
d- ESI-LIT-MS 2. Sample preparation 3. Sample submission form
4. Results
5. MS queries
There are a number of instruments in the mass spectrometry facility of the School of chemistry that can offer a wide range of techniques and experiment types, such as MS/MS experiments or mass accuracy determination
MS/MS experiments offers structural information of the moleculeTOF, Time-of-flightESI, Electrospray ionisationMALDI, Matrice assisted laser desorption ionisationLIT, Linear ion trap
Techniques Instrumentations Manufacturer Mass accuracy
MS/MS
LC-ESI-TOF- MS LCT Classic Waters Yes No
GC-TOF-MS GCT Premier Waters Yes No
MALDI-QTOF-MS Maldi-Qtof Premier Waters Yes Yes
LC-ESI-LIT-MS API 2000 Applied Biosystems
No Yes
Introduction
Principle
An electric field sufficiently intense to disperse analyte solution emerging from the spray needle into a fine spray required a potential difference of up to sereval kV between that tip and the orifice leading into the vacuum system.The ions will be separate according to their mass-to-charge ratio through a TOF mass analyser before the determination of the accurate mass.
1. Introduction to mass spectrometry
a- ESI- TOF-MS
b- GC- TOF-MS
c- LDI-Q-TOF-MS
d- ESI-LIT-MS 2. Sample preparation 3. Sample submission form
4. Results
5. MS queries
Trinity College Dublin School of Chemistry p 3
Sample characteristics
Charged or partially charged polar compounds.Sample might need ionisation agent, such as NaCl, Ammonium acetate,...
Solvent choice -> see page 7
ESI- TOF-MS
ElectroSpray Ionisation coupled toTime-Of-Flight mass spectrometer
References:
Dole M et al., 1968. J. Chem. Phys., 49 (5), p2240.Fenn JB et al., 1985. Anal. Chem., 57(3), pp675-679Wiley WC & McLaren IH, 1955. Rev. Scientific Instruments, 26, (12), pp1150-1157.
LCT Classic, Waters
Introduction
1. Introduction to mass spectrometry
a- ESI- TOF-MS
b- GC- TOF-MS
c- LDI-Q-TOF-MS
d- ESI-LIT-MS 2. Sample preparation 3. Sample submission form
4. Results
5. MS queries
Trinity College Dublin School of Chemistry p 4
Principle
The sample coming from GC effluent could be ionised by three ionisation methods, which are EI (Electron Impact), CI (chemical Ionisation) and FD (Field desorption).The ions will be separate according to their mass-to-charge ratio through a TOF mass analyser before the determination of the accurate mass.
Sample characteristics
Sample must be thermally volatile and stableLow mass range (typically lower than m/z 650)
Solvent choice -> see page 7
GC- TOF-MS
Gas Chromatography coupled toTime-Of-Flight mass spectrometer
References:
Lampman GM et al., 2010. Spectroscopy, International Edition, 4thedition.Wiley WC & McLaren IH, 1955. Rev. Scientific Instruments, 26, (12), pp1150-1157.
GCT Premier, Waters
Introduction
1. Introduction to mass spectrometry
a- ESI- TOF-MS
b- GC- TOF-MS
c- LDI-Q-TOF-MS
d- ESI-LIT-MS 2. Sample preparation 3. Sample submission form
4. Results
5. MS queries
Trinity College Dublin School of Chemistry p 5
Principle
The sample will be mix with a matrix*. Then, A laser will desorb the mixture and generate ions with high kinetic energy. The ions will be separate according to their mass-to-charge ratio through a TOF mass analyser before the determination of the accurate mass.
MS/MS experiments can be done.Possibility of using ESI.
* DCTB, CHCA, DIT, DHB.
Sample characteristics
Generally speaking, samples which could not be ionised by ESI and non volatile
Solvent choice -> see page 7
LDI- TOF-MS
Laser Desorption Ionisation coupled toTime-Of-Flight mass spectrometer
References:
Lampman GM et al., 2010. Spectroscopy, International Edition, 4thedition.Wiley WC & McLaren IH, 1955. Rev. Scientific Instruments, 26, (12), pp1150-1157.
MALDI Q-TOF, Waters
Trinity College Dublin School of Chemistry p 6
Introduction
1. Introduction to mass spectrometry
a- ESI- TOF-MS
b- GC- TOF-MS
c- LDI-Q-TOF-MS
d- ESI-LIT-MS 2. Sample preparation 3. Sample submission form
4. Results
5. MS queries
Principle
Quadrupole mass analysing device electric field is used to separate ions according to their mass-to-charge ratio as they pass along the central axis of four parallel equidistant metal rods that have fixed (DC) and alternating (RF) voltages.
MSn , multiple MS/MS experiments can be done.
Sample characteristics
Charged or partially charged polar compounds.Sample might need ionisation agent, such as NaCl, Ammonium acetate,...
Solvent choice -> see page 7
ESI- LIT-MS
Electrospray ionisation coupled to a linear iontrap mass spectrometer
References:
Lampman GM et al., 2010. Spectroscopy, International Edition, 4thedition.Paul W, Reinhard HP & VonZahn U, 1958., Z. Phys., 152 (2), p143-182.
API 2000, Applied Biosystems
Sample Preparation
1. Introduction to mass spectrometry
2. Sample preparation
a- Choice of solvent Sample solubility
b- Sample concentration
Sample vials
3. Sample submission form
4. Results
5. MS queries
Choice of solvent
MALDI-QTOF
GC-TOF-MS
ESI-TOF
MeOH, ACN, DCM, CHCl3,
EtOAc
MeOH, ACN, DCM, CHCl3,
EtOAcMeOH, ACN,
H2O
H2O, DMSO
Sample solubility
Sample must be fully dissolved.
In the event of partial solubility, filter or centrifuge the sample. Then, decant the supernatant to a clean vial for MS analysis.
Trinity College Dublin School of Chemistry p 7
Trinity College Dublin School of Chemistry p 8
Sample Preparation
1. Introduction to mass spectrometry
2. Sample preparation
a- Choice of solvent Sample solubility
b- Sample concentration
Sample vials
3. Sample submission form
4. Results
5. MS queries
Sample concentration
Mass Spectrometry is at least 20 times more sensitive than NMR.
Do not submit the sample for MS straight from the NMR tube, please.
MALDI-QTOF / ESI-TOF GC-TOF-MS
~ 1mg.mL-1 ~ 5mg.mL-1
Sample Vials
Use 2 mL HPLC vials with dimension (12 x 32 mm (diameter x height)). Add anything between 0.5 to 1.5 mL solvent but please do not fill to the top of the
vial.
Things to Avoid in Sample Preparation: - salt buffers such as phosphates, citrates, borates, etc. - detergents - inorganic acids (H2SO4, H2PO4, etc)
For HRMS, your sample must be pure.
Trinity College Dublin School of Chemistry p 9
Sample submission form
Fill-in where there is a star
Draw the proposed structure, (see example in red)
O
Exact Mass: 140.1201Formula : C9H16O
Do not forget to indicate the solvent of dilution
X
XXX 001
YYYY-MM-DD
XXX XXXZZZ ZZZ
X
X
1. Introduction to mass spectrometry
2. Sample preparation 3. Sample submission form
a- One sample
b- More than one sample 4. Results
5. MS queries
One sample
Trinity College Dublin School of Chemistry p 10
Sample submission form
1. Introduction to mass spectrometry
2. Sample preparation 3. Sample submission form
a- One sample
b- More than one sample 4. Results
5. MS queries
See Attachment
X
4 samplesYYYY-MM-DD
XXX XXXZZZ ZZZ
X
X
More than one sample
O
O O
Exact Mass: 140.1201Formula : C9H16O
Exact Mass: 140.1201Formula : C9H16O
Exact Mass: 140.1565Formula : C10H10
Exact Mass: 142.1358Formula : C9H16O
XXX 001 XXX 002
XXX 004XXX 003
Trinity College Dublin School of Chemistry p 11
Results
1. Introduction to mass spectrometry
2. Sample preparation 3. Sample submission form
4. Results
5. MS queries
Experimental Mass
Theoritical Mass
O
Δm *
Mass Accuracy **
Unsaturationdegree
IsotopicPattern
matching
Empirical formula
*, |Expected mass – Theoretical mass|
* *, [Δm/(integer value of m)]x106
Name (Supervisor), XXX 001
Trinity College Dublin School of Chemistry p 12
MS queries
1. Introduction to mass spectrometry
2. Sample preparation 3. Sample submission form
4. Results
5. MS queries
Any questions regarding the mass spectrometry service in TCD then please ask Dr. Martin Feeney or Dr. Bernard Jean-Denis.
The mass spectrometry main lab phone number is 01-896 2768.
If you would like to attend the MS course taught in the Dublin Chemistry programme, please contact Dr. Jimmy Muldoon.
The course is usually scheduled for January-March of every year. Alternatively check the website:
http://www.dublinchemistry.ie