1st Detect Presentation - Apr 2012 - TEDW
Transcript of 1st Detect Presentation - Apr 2012 - TEDW
0 1st Detect Proprietary 1st Detect Proprietary www.1stdetect.com
In-Vacuo Thermal Desorption and Detection of Explosives Using a Miniature Mass Spectrometer
Warren Mino, David Rafferty, Abrar Riaz, Michael Spencer, William Stott, James Wylde
1st Detect Corp
April 2012 Trace Explosives Detection Workshop
1 1st Detect Proprietary 1st Detect Proprietary www.1stdetect.com
MMS-1000
True Portable Mass Spectrometer Cylindrical Ion Trap Commercial release at Pittcon 2012
Portable Size & Lightweight 6”x 12”x 8” / 4 - 7 kg (9-16 lbs.)
Highly Sensitive ppm - direct leak ppb - membrane inlet ppt - pre-concentrator
Key Performance Specifications 30 - 450 amu (customizable to ~650 amu) < 0.5 amu resolution (< 0.3 amu typical) 1 sec cycle time (user programmable) MS2 capable (MS3 in manual mode) with > 90% efficiency ~ 45 W average power consumption (~65 W max) Auto-tune with internal standard
Deployments Pesticide detection (food products) Evolved gas analysis Explosives & CWA / threat detection
Cost Competitive with IMS
2 1st Detect Proprietary 1st Detect Proprietary www.1stdetect.com
MOTIVATION
Why mass spectrometry for explosives detection? Increased specificity and resolution
Increased number of threats detected simultaneously
Confirmational / orthogonal analysis (e.g., GC-MS, MS/MS, etc.)
Easily adapted to new threats
Multiple ionization techniques
However, detection of explosives using MS is hampered by: Mass specs are inherently vapor analyzers – explosives tend to have low vapor pressures
Vacuum nature of MS – need to cross vacuum barrier
Thermal disassociation of explosives beyond recognition
3 1st Detect Proprietary 1st Detect Proprietary www.1stdetect.com
PRE-CONCENTRATOR
SBIR Phase I & Phase II awarded by DTRA & DPG
Used to measure permeation rate through protective clothing (ASTM F079*)
Enables fast analysis of swatch testing
Challenge: Detect 13 TICs to 40 pg / l using miniature mass spec
1 l / min flow
30 second cycle time
Non-cryogenic
Universal
Accommodate hydrophobic and hydrophilic compounds
*Standard Test Method for Permeation of Liquids and Gases through Protective Clothing Materials under Conditions of Continuous Contact
4 1st Detect Proprietary 1st Detect Proprietary www.1stdetect.com
PRE-CONCENTRATOR
Novel sorbent and design configuration
Increases concentration gain 103 to 105
Dramatically increases the sensitivity of the instrument
30 second cycle time
Gain effected by two means: Chemical gain of sorbent
Evacuation gain
5 1st Detect Proprietary 1st Detect Proprietary www.1stdetect.com
Objective: Find lower limit of detection from membrane inlet and determine gain in concentration (improvement in sensitivity) with the pre-concentrator
Kin-Tek gas generator was used to create 4 different concentrations of tetrachloroethylene (TCE) and toluene
TCE Conc: 1.338 ppm, 671 ppb, 340 ppb, and 170 ppb
Toluene Conc: 1.218 ppm, 610 ppb, 305 ppb, 155 ppb
The lowest concentrations (170 ppb TCE) and (155 ppb Toluene) were used for measuring with the Pre-concentrator
Pre-concentrator was set to 5 seconds of sampling
Pre-concentrator temperature profile was ramped over 15 seconds
PRE-CONCENTRATOR
6 1st Detect Proprietary 1st Detect Proprietary www.1stdetect.com
PRE-CONCENTRATOR
TCEm/z 166
Counts: 756
Toluenem/z 91
Counts: 698
Sample output (TCE 1.338 PPM Toluene 1.218 PPM)
7 1st Detect Proprietary 1st Detect Proprietary www.1stdetect.com
PRE-CONCENTRATOR
0
5000
10000
15000
20000
25000
0
100
200
300
400
500
600
700
800
0 200 400 600 800 1000 1200 1400
Ion
Curr
ent (
Coun
ts)
Pre-
conc
entr
ator
Inle
t
Ion
Curr
ent (
coun
ts)
Mem
bran
e In
let
Concentration (ppb)
Toluene
Toluene (MIMS)
Toluene (PC)
P/C Gain ~252x
0
2000
4000
6000
8000
10000
12000
14000
16000
18000
0
100
200
300
400
500
600
700
800
0 200 400 600 800 1000 1200 1400 1600
Ion
Curr
ent (
Coun
ts)
Pre-
conc
entr
ator
Inle
t
Ion
Curr
ent (
coun
ts)
Mem
bran
e In
let
Concentration (ppb)
TCE
TCE (MIMS)
TCE (PC)
P/C Gain ~224x
Measured gains
TCE: 225x
Toluene: 252x
However:
Lower concentrations governed by lower limit of gas generator
Lowest gas generator concentration saturated detector with P/C activated
Gains expected 103 - 105
8 1st Detect Proprietary 1st Detect Proprietary www.1stdetect.com
PRE-CONCENTRATOR
Measured gains on QQQ with diluted samples (< 1 ppb)
Gain 103 – 105 measured
Instrument ppb -> pptr
1.E-01
1.E+00
1.E+01
1.E+02
1.E+03
1.E+04
1.E+05
1.E+06
Direct Sorbent 1 Sorbent 2 Sorbent 3 Sorbent 4
Tota
l Ion
Cur
rent
Pre-concentrator GainNitrobenzene
1.E-01
1.E+00
1.E+01
1.E+02
1.E+03
1.E+04
1.E+05
Direct Sorbent 1 Sorbent 2 Sorbent 3 Sorbent 4
Tota
l Ion
Cur
rent
Pre-concentrator GainAcetone
1.E-01
1.E+00
1.E+01
1.E+02
1.E+03
1.E+04
Direct Sorbent 1 Sorbent 2 Sorbent 3 Sorbent 4
Tota
l Ion
Cur
rent
Pre-concentrator GainEthyl Acetate
9 1st Detect Proprietary 1st Detect Proprietary www.1stdetect.com
EXPLOSIVES DETECTION
Objective: demonstrate that the MMS-1000 with EI is able to measure a representative list of explosives
Experimental: Explosive standards (1 mg/ml in MeOH) presented to pre-concentrator
Headspace sampled for 10 seconds
Pre-concentrator evacuated (~1 mTorr)
Analyte desorbed using 30 second ramp profile
10 1st Detect Proprietary 1st Detect Proprietary www.1stdetect.com
EXPLOSIVES DETECTION
The requisite plot for vapor folks……
11 1st Detect Proprietary 1st Detect Proprietary www.1stdetect.com
PERFLUORODECALIN
443
RDX
EXPLOSIVES
12 1st Detect Proprietary 1st Detect Proprietary www.1stdetect.com
PERFLUORODECALIN
443
UREA NITRATE
EXPLOSIVES
13 1st Detect Proprietary 1st Detect Proprietary www.1stdetect.com
PERFLUORODECALIN
443
AMMONIUM NITRATE
EXPLOSIVES
14 1st Detect Proprietary 1st Detect Proprietary www.1stdetect.com
EXPLOSIVES
PERFLUORODECALIN
443
HMTD
15 1st Detect Proprietary 1st Detect Proprietary www.1stdetect.com
EXPLOSIVES
PERFLUORODECALIN
443
PETN
16 1st Detect Proprietary 1st Detect Proprietary www.1stdetect.com
EXPLOSIVES
PERFLUORODECALIN
443
EGDN
17 1st Detect Proprietary 1st Detect Proprietary www.1stdetect.com
PERFLUORODECALIN
443
EGDN
SEPARATION
P/C can be operated with a temperature ramp rather than ‘flash’ desorbed Software also allows for single ion monitoring Will provide functionality similar to GC but without the time and power requirements
19 1st Detect Proprietary 1st Detect Proprietary www.1stdetect.com
CONTACT SAMPLING - EXAMPLE
PERFLUORODECALIN
443 199
179
152
138
162 124
93
DIAZINON
21 1st Detect Proprietary 1st Detect Proprietary www.1stdetect.com
PHOTOIONIZATION
Methyl Salicylate
22 1st Detect Proprietary 1st Detect Proprietary www.1stdetect.com
Headspace over traditional and nitrate based HMEs demonstrated with pre-concentrator
Characteristic spectra measured for candidate explosives
Thermal desorption demonstrated with vacuum based MS
Alternate ionization demonstrated for parent precursor molecule detection
Next steps:
Salts
Characterization (detection limits, interferents, de-convolution / identification, etc.)
Optimization
CONCLUSIONS