TANDEM DIFFERENTIAL MOBILITY SPECTROMETER:

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Menlyadiev Department of Chemistry & Biochemistry New Mexico

1 TANDEM DIFFERENTIAL MOBILITY SPECTROMETER: AN IONIZATION DETECTOR FOR GC WITH HIGH SPEED, SELECTIVITY, SMALL SIZE, AND LOW COST G.A. Eiceman & M. Menlyadiev Department of Chemistry & Biochemistry New Mexico State University Las Cruces, NM

2 ION MOBILITY SPECTROMETERS: MILITARY PREPAREDNESS AND COMMERCIAL AVIATION SECURITY

3 GC WITH IMS DETECTOR ON INTERNATIONAL SPACE STATION: ~2002 TO THE VOLATILE ORGANIC ANALYZER

4 TANDEM DIFFERENTIAL MOBILITY SPECTROMETER: AN IONIZATION DETECTOR FOR GC WITH HIGH SPEED, SELECTIVITY, SMALL SIZE, AND LOW COST G.A. Eiceman & M. Menlyadiev Department of Chemistry & Biochemistry New Mexico State University Las Cruces, NM

5 Intensity, V GOAL: ADD FURTHER DIMENSIONS OF ANALYTICAL INFORMATION TO IONIZATION DETECTORS Gas Chromatograph Ionization Detector retention time, min

6 INSIDE THE ELECTRON CAPTURE DETECTOR: gas phase ion chemistry not often described N 2 + e - (mean 17keV) N e - N 2 + N 2 +. N 4 +. N H 2 O H 2 O N 2 H 2 O +. + H 2 O H 3 O +. + HO H 3 O +. + H 2 O H + (H 2 O) 2 O 2 + e - O 2 - O O 2 O 2 O 2 - O CO 2 CO 2 O 2 - O CO 2 CO O

7 INSIDE THE ELECTRON CAPTURE DETECTOR: gas phase chemistry not often described M [MH + (H 2 O) n (N 2 ) x ]* Intermediate + + Neutral Molecule of Sample H + (H 2 O) n (N 2 ) x + Product Ion

8 MOBILITY OF IONS IN GASES AT AMBIENT PRESSURE V,d Drift Velocity Ion Swarm MH + (H 2 O) n + K = v d / E v d = drift length/t d Electric Field, E = V/dist K = (3e/16N)(2 / kt eff ) 1/2 [(1+ )/ D (T eff )] D = MH + (H 2 O) n (N 2 ) x Collision area D will depend upon moisture, temperature, drift gas, and molecule Units of K are cm 2 /Vs v d = 4.0 m/s E = 200 V/cm K = 2.0 cm 2 /Vs

9 ION MOBILITY SPECTROMETRY IN 2013 CONVENTIONAL TIME OF FLIGHT OR DRIFT TUBE ASPIRATOR DESIGNS FIELD ASYMMETRIC WITH CURVE SURFACES FIELD ASYMMETRIC PLANAR a. microscale b. nanoscale Sub Ambient Pressure IMS 1 to 4 torr in helium

10 ION MOBILITY SPECTROMETRY IN 2013 CONVENTIONAL TIME OF FLIGHT OR DRIFT TUBE ASPIRATOR DESIGNS FIELD ASYMMETRIC WITH CURVE SURFACES FIELD ASYMMETRIC PLANAR a. microscale b. nanoscale Sub Ambient Pressure IMS 1 to 4 torr in helium

11 SMALL DRIFT TUBE FOR IMS R.A. Miller, G.A. Eiceman, E.G. Nazarov and A.T. King, Sensors and Actuators B. Chemical 2000, 67,

12 SMALL DRIFT TUBES FOR MOBILITY SPECTROMETRY Faraday Detector Analyzer Region

13 ION MOTION IN DMS AT AMBIENT PRESSURE Asymmetric Waveform 1.1 MHz 30KV/cm to 10 ms RESIDENCE TIME

14 MOBILITY SPECTRUM : 1 to 3 s SCAN TIMES 4 PROTON BOUND DIMER K - K PROTONATED MONOMER COMPENSATION VOLTAGE (V)

15 fmobility dependence ADVANTAGE DMS: SEPARATION VOLTAGES, ALPHA PLOTS, & COMPENSATION VOLTAGE MH + (H 2 O) M 2 H + (H 2 O) E,Td SEPARATION VOLTAGE COMPENSATION VOLTAGE

16 HAND HELD DMS INSTRUMENTS AND LIFE CRITICAL MEASUREMENTS

17 GAS CHROMATOGRAPH WITH DMS DETECTOR Replaces GC IMS on ISS

18 DISPERSION PLOTS: Ion evaluation from field dependence of mobility: Time: 1 to 3 min. Separation Voltage Compensation Voltage

19 LONG OBJECTIVE OF DMS DMS: High Selectivity by ion modification DMS 1 DMS 2 Fragmentation by E Fragmentation by hv Formation of clusters Charge stripping Other

20 Separation Voltage CLOSE OBJECTIVE OF DMS DMS: High Selectivity based on E/N dependence. Time: 10 ms DMS 1 DMS 2 SV 1000 V Compensation Voltage

21 BLOCK DIAGRAM of DMS/DMS WITH FARDAY PLATE DETECTORS Gas Flow Control with Sample Faraday Plate & Amplifier GC 63 Ni DMS 1 Electronics & PC Control DMS 2 Electronics & PC Control SV DMS1 2 mm SV DMS2 CV DMS1 CV DMS2 Det (-) 5 mm Det (+) 0.5 mm 0.5 mm

22 LABORATORY STUDIES WITH GC DMS DMS

23 DMS DMS DRIFT TUBE

24 OPTIONS ON MEASUREMENTS USING GC DMS DMS Gas Chromatograph DMS 1 DMS 2 ALL PASS (no Separation Voltage) SCANNING CV (& SCAN Separation V) FIXED CV (at a Separation Voltage) SCANNING CV (at a Separation Voltage) FIXED CV (at a Separation Voltage) SCANNING CV (at SV + 50 V) FIXED CV (at a Separation Voltage) FIXED CV (at SV + 50 V)

25 Retention Time (min) GC DMS DMS OF 4 ALCOHOL MIXTURE DMS 1 DMS 2 ALL PASS (no Separation Voltage) SCANNING CV (at a Separation Voltage) SV DMS2 850 V n-buoh SV DMS2 950 V 2 iproh EtOH MeOH Compensation Voltage DMS2, V

26 Separation Voltage, V COMPOSITE DISPERSION PLOTS OF 4 ALCOHOLS methanol butanol IPA clusters ethanol Compensation Voltage, V

27 Retention Time (min) ION SELECTION USING FIRST MOBILITY SECTION DMS 1 DMS 2 FIXED CV (at Fixed Separation Voltage) SCANNING CV (at SV + 50V) SV DMS1 = 850V, CV DMS1 = -5.4V (fixed); SV DMS2 = 900V SV DMS1 = 850V, CV DMS1 = -2.5V (fixed); SV DMS2 = 900V Methanol Proton Bound Dimer 3 Ethanol Proton Bound Dimer V 1-2.8V Compensation Voltage DMS2, V

28 Retention Time (min) ION SELECTION USING FIRST MOBILITY SECTION DMS 1 DMS 2 FIXED CV (at Fixed Separation Voltage) SCANNING CV (at SV + 50V) SV DMS1 = 850V, CV DMS1 = -1.0V (fixed); SV DMS2 = 900V Iso-propanol Proton Bound Dimer SV DMS1 = 850V, CV DMS1 = -0.4V (fixed); SV DMS2 = 900V n-butanol Proton Bound Dimer -0.4V V Compensation Voltage DMS2, V

29 Intensity, V ION SELECTION USING BOTH MOBILITY SECTIONS DMS 1 DMS 2 FIXED CV (at Fixed Separation Voltage) FIXED CV (at SV + 50 V) Iso-propanol, Proton Bound Dimer SV DMS1 = 850V, CV DMS1 = -1.0V (fixed); SV DMS2 = 950V, CV DMS2 = -1.6V( fixed) n-butanol, Proton Bound Dimer SV DMS1 = 850V, CV DMS1 = -0.4V (fixed); SV DMS2 = 950V, CV DMS2 = 0.6V( fixed) Retention Time (min)

30 Intensity, V ION EXTRACTION AS GC PEAKS MERGE: CONTROL Acetone Iso-propanol Total ion chromatogram -1.8V Extracted ion chromatogram SV1=600V, CV1= -2.4V SV2=550V; -0.8V Extracted ion chromatogram SV1=600V, CV1= -0.5V SV2=550V; Retention Time (min)

31 Intensity, V ION EXTRACTION AS GC PEAKS MERGE: MERGED Iso-propanol Acetone Total ion chromatogram -1.8V Extracted ion chromatogram SV1=600V, CV1= -2.4V SV2=550V; -0.8V Extracted ion chromatogram SV1=600V, CV1= -0.5V SV2=550V; Retention Time (min)

32 Intensity, V GC DMS/DMS SEPARATION OF 23 CONSTITUTENTS DMS 1 DMS ALL PASS (600 V) SCANNING CV (at fixed SV, -12 to 2 V) Retention Time (min)

33 Retention Time (min) GC DMS DMS SEPARATION OF 23 CONSTITUTENTS Separation Voltage 700V Compensation Voltage (V) for DMS 2

34 Retention Time (min) GC DMS DMS SEPARATION OF 23 CONSTITUTENTS Separation Voltage 1000V Compensation Voltage (V) for DMS 2

35 Intensity, V EXTRACTED ION CHROMATOGRAM IN 23 CMPD MIX Total ion chromatogram GC DMS Extracted ion chromatogram SV2=550V; CV2= -1.4V -1.4V GC DMS DMS Extracted ion chromatogram SV1=600V, CV1= -0.5V SV2=1200V; Retention Time (min)

36 CONCLUSIONS A. DMS DMS with fixed SV and CV provide response with selectivity and response time at 100 ms---->10ms. B. Chromatographic interface trivial; size, complexity compatible with ionization detectors. C. Analytical performance may approach functionality of tandem MS for faction of costs D. Suitable for portable GC

37 ACKNOWLEDGEMENTS ChemRing Detection Systems..aid in electronics and software.

38 Weekly report Marlen Menlyadiev May 10, 2013

41 COMSOL FLOW MODELING IN DMS/DMS (FLOW DYNAMICS TEST) Flow velocity, m/s Dopant gas flow 0.2 L/min Flow velocity map a Sample gas flow 1.5 L/min Flow velocity map b Pressure map c DMS1 DMS2

42 Ethyl acetate Methyl butyrate Isobutyl Acetate Methyl Valerate Isopropenyl acetate Tert-butyl acetate Sec-butyl acetate Isopropyl acetate Ethanol Isopropanol 1-butanol 1-pentanol 1-hexanol 1-heptanol Pinacolone 2,4-dimethyl-3-pentanone Cycloheptanone Acetone Hexanone-2 2-metyl-3-pentanone 2,6-dimethyl-4-heptanone 3-methylcycylohexanone cyclohexanone

IMS MS CIRCA 1970 Plasma Chromatography A New Dimension for Gas Chromatography and Mass Spectrometry Journal of Chromatographic Science 1970 8 (6)

43 IMS MS CIRCA 1970 Plasma Chromatography A New Dimension for Gas Chromatography and Mass Spectrometry Journal of Chromatographic Science (6) Martin J. Cohen, Franklin GNO Corporation, West Palm Beach, Florida F. W. Karasek, University of Waterloo, Waterloo, Ontario, Canada

44 Composite dispersion plot of heptanol-1, cyclohexanone and DMMP Separation Voltage, V (DMMP) H + (Cyclohex)H + methan ol (Cyclohex) 2 H + IPA cluster s (DMMP) 2 H RIP ethanol RI P (Hept) 2 H ammo nia (Hept)H Compensation Voltage, V

45 Detector Response (V) Heptanol-1 Cyclohexanone DMMP Retention Time (min) GC-DMS2 experiment: SV2 500V, CV2 scanning at 1Hz. CV2= -0.4V extracted chromatogram 1ng

46 1ng GC-DMS2 experiment: SV2 500V, CV2 scanning at 1Hz. CV2= - 0.4V extracted chromatogram 2ng GC-DMS1-DMS2 experiment: SV1 1000V, CV1-0.8 V; SV2 500V CV2 scanning at 1Hz. CV2= -0.4V extracted chromatogram Heptanol-1 3ng GC-DMS1-DMS2 experiment: SV1 1400V, CV1 2.2V; SV2 600V CV2 scanning at 1Hz. CV2=0V extracted chromatogram Cyclohexanone 3ng GC-DMS1-DMS2 experiment: SV1 1500V, CV1 4.0V; SV2 700V CV2 scanning at 1Hz. CV2= 0V extracted chromatogram DMMP

DISSOCIATION OF GAS IONS IN AIR BEFORE MASS SPECTROMETERS USING ELECTRIC FIELDS FROM FIELD DEPENDENT MOBILITY SPECTROMETERS

DISSOCIATION OF GAS IONS IN AIR BEFORE MASS SPECTROMETERS USING ELECTRIC FIELDS FROM FIELD DEPENDENT MOBILITY SPECTROMETERS X. An, J.A. Stone, and G.A. Eiceman * Department of Chemistry and Biochemistry