Difference between total analysis, fractionation and speciation
COMPOSITION ? (QUALITATIVE ANALYSIS) HOW MUCH ? (QUANTITATIVE ANALYSIS) WHAT FORM ? (SPECIATION)
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Transcript of COMPOSITION ? (QUALITATIVE ANALYSIS) HOW MUCH ? (QUANTITATIVE ANALYSIS) WHAT FORM ? (SPECIATION)
COMPOSITION ? (QUALITATIVE ANALYSIS)
HOW MUCH ? (QUANTITATIVE ANALYSIS)
WHAT FORM ? (SPECIATION)
Mass Spectrometry
Topic I
Present Detector Technology – Faraday CupsPresent Detector Technology – Faraday Cups
•Gain is stable and precisely Gain is stable and precisely known (gain=1)known (gain=1)
•Bandwidth is consistent with Bandwidth is consistent with use in sector-based mass use in sector-based mass spectrometryspectrometry
•Useful for Useful for IIionion 10 10-15-15 amp amp(1 ion/sec (1 ion/sec 1.6 1.6 10 10-19-19
amps)amps)
•Implies that one needs about Implies that one needs about 6250 ions/sec for detection by 6250 ions/sec for detection by Faraday cupFaraday cup
Faraday CageCollector Electrode
Load Resistor
Out to amplifier
Out to amplifier
“FARADAY ELECTRODE”
output
High Z
Electron Multiplier DetectorElectron Multiplier Detector
Secondary Electrons
Incident Ion
Electron Multiplier DetectorElectron Multiplier DetectorD
ete
cti
on
Effi
cie
ncy
Dete
cti
on
Effi
cie
ncy
Mass (m/z)Mass (m/z)
00
Electron multiplier Electron multiplier has a gain that is has a gain that is dependent upon dependent upon the mass or kinetic the mass or kinetic energy of the energy of the incoming ion.incoming ion.
Electron Multiplier DetectorElectron Multiplier DetectorD
ete
cti
on
Effi
cie
ncy (
%)
Dete
cti
on
Effi
cie
ncy (
%)
Energy (eV)Energy (eV)
00
100100
8080
6060
4040
2020
1010 101044
101033
101022
-
h
e PtSi Photoactive Layer
Silicon Multiplexer
Focal Plane Array
Individual preampsfor each pixel
In bump
bonds
“FARADAY CUP”
RESET
36 fF
MUX
4.4 V / e--
20 e-- read noise @ 77 K
Ion SourceIon Source
Electrostatic SectorElectrostatic Sector
Magnetic SectorMagnetic Sector
Array Detector onArray Detector onFocal PlaneFocal Plane
--
++
Mattauch-Herzog MassMattauch-Herzog MassSpectrometer GeometrySpectrometer Geometry
Design Specifications
• Noise - 5 electrons read noise (highest gain)
• 39.6 microvolts / electron (highest gain)
• Well size - 80,000 e to 16,000,000 e
• 50 micron pitch
• Read rate - 1 mega sample per second into 30pfd &10kohm
• Nondestructive / Destructive Readout
“FARADAY ELECTRODE”
RESET
10 f
MUX
990 f
Gain
F
F
Detection Limit
8 IONS ! & we are still optimizing it !!
Keep tuned
2.5 electrons of read noisewith NDRO
CMS
35 lbs.75 watts
GC, PumpsMass spec.
etc.
Ion Mobility SpectrometryIon Mobility Spectrometry
Ion Mobility SpectrometerIon Mobility SpectrometerIon Mobility SpectrometerIon Mobility Spectrometer
IMS is a technique that is being employed to solve problems where portable instrumentation and ruggedness is necessary
IMS is a technique that is being employed to solve problems where portable instrumentation and ruggedness is necessary
New Instruments Demand Lower New Instruments Demand Lower Detection Limits Detection Limits
Must Operate through a Wide Range Must Operate through a Wide Range of Temperaturesof Temperatures
Must Operate at Atmospheric Must Operate at Atmospheric PressurePressure
High S/N RatioHigh S/N Ratio
New Instruments Demand Lower New Instruments Demand Lower Detection Limits Detection Limits
Must Operate through a Wide Range Must Operate through a Wide Range of Temperaturesof Temperatures
Must Operate at Atmospheric Must Operate at Atmospheric PressurePressure
High S/N RatioHigh S/N Ratio
Applications Using Ion Mobility SpectrometersApplications Using Ion Mobility SpectrometersApplications Using Ion Mobility SpectrometersApplications Using Ion Mobility Spectrometers
Field-Portable detection of Field-Portable detection of chemical warfare agentschemical warfare agents
Detection of explosives, nerve Detection of explosives, nerve agents, toxins, and other agents, toxins, and other hazardous chemicals at safety hazardous chemicals at safety inspection stations and in the inspection stations and in the environment environment
Structural Structural conformation studies of conformation studies of proteins, polymers, and proteins, polymers, and various other moleculesvarious other molecules
Ion Mobility SpectrometerIon Mobility Spectrometer
IonizationChamber Drift Region
Drift Rings
Gas Inlet
Gas Outlet
-
Electric Field
Ion Shutter FaradayPlate
Drift Gas Inlet
Chemical Identification Based Upon Ion Chemical Identification Based Upon Ion MobilityMobility
Relationship of Ion Mobility to Molecular Relationship of Ion Mobility to Molecular TermsTerms
316
eN
1m
1M
+2k
T
1 + r2 K =
Drift Velocity: vd = K E Mobility: K = d
td E
E Electric Field Strengthtd Drift Timem Ion Mass (analyte)N Number DensityT TemperatureCollision Integral
d Drift Path Lengthe Unit ChargeM Molecular Mass (drift gas)k Boltzmann-Constantr Minimum in Potential CurveCorrection Term
“FARADAY ELECTRODE”
output
High Z
“FARADAY ELECTRODE”
RESET
8 fF
MUX
New interlocking 8 ring microIMS
25pg TNT -1825VDC Emco PS, 90C 100/50 ml/min Cl-/AirFilament, inj 125C. Filters OFFResolution 84. Run a baseline noise 0.005 S/N=30Detection Limit = 2.5 pg
1-31-05
5pg TNT 95 oC 25V Injector Block 0.85AFilament, 1200 us Pulse B.C. FIRW on ( 0.9 pg Det. Lmt.)
8in.
18 in.
12 in.
Proposed Vehicle Based IMS
1200
1300
1400
1500
1600
1700
0 20 40 60 80 100 120
Time (ms)
Inte
nsi
ty (
AD
U)
e- peak
47 attograms insingle sweep
RDX
Detection Limit = 5 attograms RDX
Conclusions
• CTIA is ideal for IMS– Fast (1 MHz or higher per pixel)– Low read noise– 1000 x sensitivity improvement over current
micro-IMS device.– Expect further improvement with differential
devices and cooling.– Don’t need low secondary electron yield
coatings or exotic geometries for IMS.
Conclusions
• CTIA is ideal for IMS– Fast (1 MHz or higher per pixel)– Low read noise– 1000 x 10,000 x sensitivity improvement over
current micro-IMS device.– Expect further improvement with differential
devices and cooling.– Don’t need low secondary electron yield
coatings or exotic geometries for IMS.
Miniature Optical Bench
14mm
How do you make an optical bench that is just 14mm long?
Axsun’s Handheld Substance ID Solutions
Raman Handheld Substance Identifier Concept
Raman Probe
TEC High Power Laser Diode
TEC Spectrometer
Battery
Fiber Optics
Raman Spectral Range Dependence on Excitation
Excitation
246nm
Raman Shift (cm-1)
2000 40000
270.4nm256.5nm244.0nm
488.0nm
785.0nm
540.8nm
931.2nm
606.4nm
1144.3nm
224.3nm
980nm 1225nm 1450nm
•900-1700 nm is critical “molecular fingerprint” region for scientific research and analysis of food, pharmaceutical, chemical, and plastic products.
•Ideal NIR sensor will have high QE between 900-1700 nm, high sensitivity, high dynamic range.
NIR Spectroscopy/Imaging With Focal Plane Arrays
Photon-Processor™Extreme Low Light Level Digital Video
Imager
• Low Cost
• Patented Technology
• Camera Electronics On-chip
Day/Night Operation SXGA (1024 X 1280) Resolution Low Power <600 Mw @ 3 VDC
Photon-Processor™
Light
Photoelectrons CMOS Imager
Video Output
Photocathode
Light
Photoelectrons CMOS Imager
Video Output
Photocathode
Complete NIR Spectrometer
WavelengthReference
PowerReference
Amp
DSP processor
24-bit A/D converters
SLED source
MEMS tunable filter
PC and software
Single element InGaAs detector
Wired or wireless
Spectrometer Sample
Butterfly packages
Probe or opticsBlue lines are light, red are electrical
Reference Block Diagram
• WARM (Wavelength & Amplitude Reference Module)– Ultra stable beamsplitters tap off known quantities of light– Absolute wavelength reference provided by an integrated quartz etalon and a
miniature acetylene gas cell that are temperature controlled to 0.1oC– Amplitude reference provided by matched single element photodetectors that
divide out responses from every point of a scan
WARM (wave, amplitude- reference) Module
• Tunable laser spectrometer, in portable package
• With embedded PC and sample interface
LCD
Display
Sample interface
Tunable laser spectrometer