Technology Transition Workshop DART and Trace Evidence (a bag of tricks for using DART) Robert B. Cody JEOL USA, Inc. Technology Transition Workshop Outline • • • • • • • • Use of dopants with DART SPME, other methods for analyzing volatiles Derivatization and H/D Exchange Counterfeit materials Quantitative analysis Pyrolysis of polymers, materials Other DART chemistries Atmospheric pressure thermal ionization for inorganics Technology Transition Workshop Dopants, adducts • Some compounds don’t form MH+ or [M-H]• Ammonia, NH4OH useful for forming [M+NH4]+ from polar analytes that will not form MH+ – Carbonyls, peroxides • Chloride, acetate, nitrate useful for forming anion adducts for compounds that will not form [M-H]– e.g. [M+Cl]- from explosives like RDX, PETN Technology Transition Workshop Dopant addition NH4OH, MeCl2 on swab Sample DART or liquid in vial with capillary into gas stream…or… Technology Transition Workshop Example: Organic acids (e.g. aspirin) • Should normally be analyzed in negative ion mode: give abundant [M-H]• Will not normally form [M+H]+ • However, can form [M+H]+ and [M+NH4]+ if ammonium is present Technology Transition Workshop Example: Aspirin O T C A n a lg e s ic T a b le t A sp irin [M + N H 4 ] + A : U n b ro ke n T a b le t A ce ta m in o p h e n [M + H ] + 100% C a ffe in e [M + H ] + # * * # # * 60 80 100 120 140 160 B : B ro k e n T a b le t 100% A sp irin [M + H ] + 180 C a ffe in e 1 9 5 .0 8 8 3 9 4 [M + H ] + A ce ta m in o p h e n 1 5 2 .0 7 1 3 0 4 [M + H ] + # # 200 A sp irin [M + N H 4 ] + A sp irin 1 8 1 .0 5 0 4 0 0 [M + H ] + # 60 80 100 120 140 160 # = a sp irin fra g m e n t io n * = in a ctive in g re d ie n t o r co a tin g 180 200 Technology Transition Workshop Explosives Class Examples Polarity Observed Comments Aromatic Nitro TNT, DNT, TNB Negative M- , [M-H]-, [M-NO]- Positive ions less sensitive Other nitro, nitroso EGDN, NG, RDX, HMX, tetryl, PETN Negative [M+anion]-, e.g. [M+Cl]-, [M+NO2]-, [M+NO3]-, [M+OAc]- Positive ions less sensitive . Positive [M+H]+, [M+NH4]+ Ammonia, keep temperature low (< 200 degrees) Perchlorate Negative ClO4- Hot gas (350 degrees) Ammonium nitrate Both NH4+, NO3- Hydrogen peroxide Negative [M+O2]- Very sensitive, even to headspace vapor Smokeless powders Positive Additives, TNT, DNT, etc. Fingerprinting Peroxide TATP, HMTD Technology Transition Workshop Explosives detected on wipe Name TNT-H HMX+Cl RDX+Cl PETN+Cl amino-DNT+Cl Tetryl+Cl NG+Cl PETN-H Neutral comp. C7H5N3O6 C4H8N8O8 C3H6N6O6 C5H8N4O12 C7H7N3O4 C7H5N5O8 C3H5N3O9 C5H8N4O12 Meas. 226.0125 331.0164 257.0078 350.9821 232.0149 321.9839 261.9713 315.0101 Calc. Diff(u) 226.0100 0.0025 331.0154 0.0010 257.0037 0.0041 350.9827 -0.0006 232.0125 0.0024 321.9826 0.0012 261.9714 -0.0001 315.0060 0.0041 Rel. Abund. 100.0000 59.6984 39.5938 14.8834 10.7766 3.8259 2.2762 1.8731 Technology Transition Workshop Nitroglycerin on an employee’s tie 8 hours after walking through plume from construction blasting 98 O NO3 - O x 10 N O O 55 NO2- MCl- N O O O C3H5O3- N O O 195 199 12 50 100 171 175 179 (m ainlib) Nitroglyc erin 183 187 150 200 m/z 250 191 300 350 203 207 21 Technology Transition Workshop Volatiles, headspace: some applications • • • • • Arson accelerants Residual solvent vapors Odors Liquors Residual tear gas ? Technology Transition Workshop Volatiles, headspace: methods 1. Direct analysis 2. Adsorbant (e.g. Tenax), thermal desorption 3. Solid-phase microextraction Technology Transition Workshop 1. Volatiles, headspace: direct Diesel fuel standard 50 100 150 200 250 300 350 400 450 m/z Carpet burned with diesel 50 100 150 200 250 300 350 400 450 m/z Burnt carpet (no accelerant) Scale x50 50 100 150 200 250 m/z 300 350 400 450 Technology Transition Workshop Direct analysis of volatiles • Fast and easy, but may not be best choice in looking for trace components in presence of strong interference – Concentrate the vapor (adsorbent) – Concentrate and select the sample (SPME) Technology Transition Workshop 2. Volatiles, headspace: trap Inject sample with gas-tight syringe Adsorbant in heatable trap He to DART • Adsorbant, thermal desorption – Trap vapor on Tenax, heat to desorb and purge with inert gas – or place sample inside thermal desorption chamber Technology Transition Workshop 3. Volatiles, headspace: SPME • Fiber coated with extractive phase (e.g. PDMS) • Selective phases • Compatible with GC/MS, DART, LC/MS Technology Transition Workshop SPME/DART Procedure 1. Clean SPME fiber: heat to 250 degrees C in inert gas (e.g. GC injector) 2. Expose SPME fiber to headspace or liquid solution for several minutes 3. Hold fiber in DART gas stream (250 degrees C) We have had good success with DVB/Carboxen/PDMS SPME fibers (Supelco) Technology Transition Workshop Prep: SPME/DART Irish whiskey EtOH dimer Direct: No SPME 93.0900 Rel. Abund. 100 80 60 40 20 0 60 120 180 240 Carboxen/DVB/PDMS SPME Fiber Et-octanoate 173.1521 Et-decanoate 201.1875 Et-hexanoate Furfural Et-dodecanoate 93.0917 Rel. Abund. 100 80 60 40 20 0 60 120 180 m/z 240 Technology Transition Workshop Derivatization and reactions • Derivatize to enhance volatility, count and protect labile groups like OH – Use rapid derivatization, no further cleanup • H/D exchange to count exchangeable H’s – Provides some structural information – Distinguish some isomers 21 22 hylsilyl)- Technology Transition Workshop Polyhydroxy compounds Derivatization with TMSI/Pyridine N Si Mix, heat, analyze. N No purification step needed. • Commercially available R – 25e.g. 23 24 26 Pierce 27 28 29Tri-Sil-Z 30 31 32 33 34 35 36 37 38 • Simple, rapid silylation reaction. Mix with sample and heat for a few seconds (heat gun). • Moisture-tolerant (use excess reagent) • Count the OH’s. Only reacts with hydroxyl groups. Unreactive with thiol, amine groups. Technology Transition Workshop g-Cyclodextrin 100 % [g-CD+TMSn+C3H5N2]+ n=22 Rel. Abundance n=23 n=21 n=19 n=20 C48H80O40 Underivatized MW 1296.4 8 amyloses 24 hydroxyls 24 TMS’s n=24 2549 2619 2689 2759 2829 2899 2969 3039 3109 3179 m/z Technology Transition Workshop Aminoglycoside antibiotics [M+TMSn+H]+ See 1 extra (small) TMS for these compounds n=7 Neomycin sulfate C23H46N6O13 . 3H2SO4 n=8 n=6 n=5 950 1000 1050 1100 1150 1200 1250 m/z Neomycin sulfate: 7 OH’s, see 8 TMS’s Kanamycin B sulfate: 6 OH’s, see 7 TMS’s Apramycin sulfate: 6 OH’s, see 7 TMS’s Technology Transition Workshop Melamine detected in pet food by Teresa Vail (University of the Pacific) 6 exchangeable H’s 127.072 100 Melamine C3H6N6 Rel. Abundance 80 MH+ = 127.073 60 H2N 40 N N 20 NH2 N NH2 0 100 150 200 m/z 250 300 350 Technology Transition Workshop Melamine H/D Exchange 7: [D6-melamine+D]+ Melamine: with D2O 134.1175 6 1 125 2 3 4 5 130 135 140 m/z Melamine: No D2O MH+ 127.0732 C3H6N6 125 130 135 m/z 140 Technology Transition Workshop BT (Bacillus Thuringensis) Spores Garden Pest Control Spore Biomarker MH+ Dipicolinic acid dimethyl ester 196.0591 100 O CH3 H3C Rel. Abundance O O O 50 DART+ / He Heated with TMAH 0 150 250 350 m/z 450 550 Technology Transition Workshop Counterfeit materials • Presence or absence of critical ingredients (e.g. active pharmaceutical ingredients) • Differences in the presence or absence of trace impurities Technology Transition Workshop Genuine and Counterfeit CialisTablets Courtesy Tony Moffat (U. London Pharmacy) Tadalafil (Cialis) Rel. Abund. Genuine Other tablet components 100 390.1413 80 60 40 20 0 100 200 300 400 500 m/z Sildenafil (Viagra) Rel. Abund. Counterfeit 475.2073 100 80 60 40 20 0 100 200 300 m/z 400 500 Technology Transition Workshop Counterfeit Antimalarials “Yaa-chud” (Combination medicine) Samples from Prof. Facundo Fernandez Georgia Tech All these and more were analyzed in a single afternoon. Most of the time was taken up by opening the packages and keeping track of sample serial numbers. Technology Transition Workshop Counterfeit Antimalarials were found to contain: • • • • • • • • Chlorpheniramine (antihistamine) Acetaminophen (analgesic) Chloroquin (older, ineffective antimalarial) Aspirin (analgesic) Chloramphenicol (antibacterial) Pyramethamine/sulfadoxin (ineffective in SE Asia) Metamizol (analgesic, may cause bone marrow disorders) Some tablets contained low levels of the active ingredient (artemisinin), presumably to fool the field tests Technology Transition Workshop Real (top) vs. Counterfeit Marlboro Brand Cigarette Volatile trace components are different Nicotine Technology Transition Workshop DART Quantitation • Successful for liquid samples – Internal standard corrects for variations in sample positioning. Example: GHB in urine – Possibility for AWC analysis without I.S. ? – Some fully validated methods completed • Semiquantitative data obtained from swabs with no internal standard • Under investigation for solid samples (tablets). – Preliminary data promising Technology Transition Workshop AutoDART: Promazine (Chlorpromazine I.S.) 5 replicates, 7 concentrations, 250 ppb to 250 ppm, CV = 4.5% 60 y = 0.1839x + 0.8363 50 2 R = 0.9941 30 20 10 0 0 50 100 150 200 250 300 ppm 14 12 10 S / IS S / IS 40 8 6 4 2 0 0 10 20 30 ppm Linear fit 40 50 60 Technology Transition Workshop IonSense GIST Implementation Reported BMSS 9/07 Orifice DART Tube Pump GIST on AccuTOF Enhanced Ion Collection with Vacuum Pump Technology Transition Workshop AutoDART + GIST: Lower detection limits Chlorpromazine (Promazine I.S.) 180 160 Chlorpromazine (AutoDART, alumina) 0.1 to 1000 ppb 140 120 10000 100 Series1 80 y = 1.1297x R2 = 0.9983 1000 60 40 20 100 S/IS (%) 0 1 2 3 4 5 6 7 8 9 10 10 1 0.1 1 10 100 1000 CV = 5.7% 10 replicates 100 ppb 0.1 ppb Log/log plot, 6 replicates over 2 day period, 0.1 ppb to 1000 ppb Technology Transition Workshop IonSense VapurTM Pro’s and Con’s • Reduced helium consumption • Better quantitative reproducibility • Better detection limits for compounds with high proton affinities (stable ions in atmosphere). This includes most drugs and many compounds of forensic interest. • Poorer detection limits for compounds, with lower proton affinities e.g. methyl stearate • Cannot adjust DART chemistry to analyze hydrocarbons, produce odd-electron ions. Technology Transition Workshop Another kind of information: Pattern matching for materials, commercial products, polymers, adhesives, etc. • Products are a mixture of components • Each component adds a detail to a characteristic “fingerprint” pattern DART mass spectrum Technology Transition Workshop Polymers Polyethylene terephthalate Nylon 6 poly(caprolactam) Technology Transition Workshop PittCon Carpet 2006 Technology Transition Workshop PittCon Carpet Polymer = Nylon 6 Match: Nylon 6 Technology Transition Workshop Material ID: Latex from J&J Band-Aid •Searchable polymer library spectrum 100 279.1612 C16H23O4+ 345.3535 C25H45+ 277.2906 C20H37+ •All compositions confirmed by exact masses 413.4145 C30H53+ •C5H8 (isoprene) units •m/z 279=Dibutyl phthalate (plasticizer) 481.4807 C35H61+ 50 551.5575 619.6162 C40H71+ C45H79+ 0 60 110 (p o lym ers) La tex 160 210 260 310 360 410 460 510 560 610 660 710 760 810 Technology Transition Workshop 3 beige paint chips 149 100 227 301 •Different beige paints give different mass spectra 50 193 99 255 329 175 369 313 122 449 411 483 511 549 578 610 641 675 0 80 130 180 230 280 330 380 430 (dart_paints) JEOL W2274 (N.E. Tanya Finishes) (ECL Poly/ urac hem ) 480 530 580 630 680 •Spectra are reproducible and a searchable library can be created 149 100 50 279 175 99 81 123 297 187 337 369 600 411 0 78 128 178 228 278 328 378 (dart_paints) JEOL Beige Ura W 2273 Eastern Chem -Lac Corp 428 478 528 578 635 628 •Polymers and additives can be identified. 678 114 100 50 549 578 457 83 149 133 203 227 179 263 301 291 327 371 415 459 443 503 549 578 636 663 0 78 128 178 228 278 328 378 (dart_paints) JEOL G reen gray W4322 Eastern Chem -Lac Corp. 428 478 528 578 628 678 Technology Transition Workshop Condom lubricants Condom swab n=7 Acetone anil n=5 n=9 n=3 * 200 * * 400 * * * * m/z 600 * * 200 200 400 400 m/z m/z 600 600 * 1000 Post-coital vaginal swab Nonoxynol-9 * * 800 Cholestadiene * * * * 800 800 1000 1000 Technology Transition Workshop CS (Tear gas) Detected Directly on Cloth 96 N 189.0209 57 [M+H]+ N 207.0311 Cl [M+H+H2O]+ 18 20 23 26 29 32 (mainlib) 2-Chlorobenzalmalononitrile 35 38 41 44 47 377.0348 50 53 [2M+H]+ 100 200 300 m/z 2-Chlorobenzalmalononitrile CAS # 2698-41-1 Formula: C10H5ClN2 400 500 56 59 62 Technology Transition Workshop Other DART CI Reagents Reagent IE (eV) P.A. (kJ/mol) Reagent Ion Water 12.621 691 H 3 O+ Oxygen 12.0697 421 O2+. Ammonia 10.070 853.6 NH4+ Nitric oxide 9.2642 531.8 NO+. Fluorobenzene 9.20 755.9 C6H5F+. Values from http://webbook.nist.gov Technology Transition Workshop Proton transfer is very useful, but it is not universal • Won’t work for saturated alkanes and some other compounds • Even-electron ions • Can we produce odd-electron ions and mass spectra that resemble EI mass spectra? Technology Transition Workshop Different DART Chemistries O2+. Rel. Abund. 100 80 60 40 20 0 O2+ He DART Charge Exchange Rel. Abund. 80 60 40 20 0 Charge exchange H3O+ 15 100 [(H2O)2+H]+ [(H2O)3+H]+ 20 25 N2 DART NO+ APCI 30 NO+. 20 40 45 50 [(H2O)2+ H]+ [NO+NH3+H]+ N2H+ O+ 25 55 Addition, charge exchange, hydride abstraction, oxidation [(H2O)+NH3+ H]+ NH4+ H3 35 30 35 m/z 40 45 Technology Transition Workshop Charge-Exchange DART Oxygen He* + O2 → O2+. + e- + He O2+. + S → S+. + O2 O2 +. + S → Fragment+ + O2 + R. (IE of sample S < 12.07 eV) Fluorobenzene He* + C6H5F → C6H5F +. + e- + He C6H5F +. + S → S+. + C6H5F C6H5F +. + S → [Fragment]+ + C6H5F + R. (IE of sample S < 9.2 eV) Technology Transition Workshop n-Hexadecane Normal DART Parameters 85 100 + [M-H]+ [M-H+O] Rel. Abund. 80 60 71 40 97 [M-3H+2O]+ 241 2 2 5 2 20 1 1 1 1 1 2 4 5 5 1 1 5 6 9 2 1 9 7 3 7 0 75 100 125 150 175 200 m/z 85 Rel. Abund. 250 275 DART O2+. Charge Exchange 100 80 225 71 60 M+. 99 113 127 40 141 155 169 226 1 20 8 3 1 9 7 0 75 100 125 150 175 Rel. Abund. 225 250 275 m/z 100 80 200 Electron ionization 71 60 85 40 99 20 1 1 3 1 2 7 1 4 1 1 5 5 1 6 9 1 8 3 2 1 9 2 6 7 0 75 100 125 150 175 m/z 200 225 250 275 Technology Transition Workshop Hexadecane : Fragmentation vs. temperature 226 Helium 200 degrees 100 60 225 40 71 85 1 20 9 1 9 1 1 2 4 1 155 169 7 3 1 8 3 1 9 7 2 1 1 0 75 100 125 150 175 200 225 250 275 m/z 85 100 80 Rel. Abund. Rel. Abund. 80 71 60 Helium 300 degrees 99 113 127 40 141 155 169 226 1 20 8 3 1 9 7 0 75 100 125 150 175 m/z 200 225 250 275 Technology Transition Workshop 92 Cholesterol [M+H-H2O]+ 369.3528 69 Rel. Abund. 100 Normal DART: Proton Transfer 50 275 [M-H]+ 46 385.3437 261 271 281 291 (mainlib ) Cholest-5-en-3-ol (3á)- 0 300 325 350 375 400 HO 301 311 425 369.3529 Rel. Abund. 100 50 Fluorobenzene Dopant 386.3551 0 300 325 350 375 400 425 369.3542 Rel. Abund. 100 50 M+. Oxygen Charge Exchange 386.3558 0 300 325 350 375 m/z 400 425 321 331 341 351 361 371 Technology Transition Workshop GC-DART: Grob Mix TICs 6 Rel. Abund. 100 Modified DART parameters Pseudo EI spectra 8 3 50 9 5 1 2 4 12 11 13 10 7 0 10 12 14 16 18 20 22 Time (min.) 1. 2. 3. 4. 5. 6. 7. 1,3-Butanediol Decane 1-Octanol Undecane Nonanal 2,6-Dimethylphenol 2-Ethylhexanoic acid 8. 9. 10. 11. 12. 13. 2,6-Dimethylaniline Methyl decanoate Surfynol Methyl undecenoate Dicyclohexylamine Methyl dodecanoate 24 Technology Transition Workshop GC-DART: Grob Mix TICs 1. 2. 3. 4. 5. 6. 7. 1,3-Butanediol Decane 1-Octanol Undecane Nonanal 2,6-Dimethylphenol 2-Ethylhexanoic acid 8. 9. 10. 11. 12. 13. 6 100 Rel. Abund. 13 8 9 80 2,6-Dimethylaniline Methyl decanoate Surfynol Methyl undecenoate Dicyclohexylamine Methyl dodecanoate Standard DART parameters CI spectra 10,11,12 5 60 40 3 1 20 0 3 4 5 6 7 8 9 Time (min.) 10 11 12 13 Technology Transition Workshop Application of GC-DART: Diesel Fuel 100 TIC 60 40 20 0 4 6 8 10 12 14 Time (min.) Alkanes 100 80 Rel. Abund. Rel. Abund. 80 60 40 RIC m/z 71 20 0 4 6 8 10 Time (min.) 12 14 Technology Transition Workshop Atmospheric Pressure Thermal Ionization for Inorganics & Metals Technology Transition Workshop Atmospheric Pressure Thermal Ionization for Inorganics & Metals • Easy way to add some qualitative inorganic analysis capabilities to system configured for DART. • Use hand-held butane torch to heat samples in DART gas stream. • High orifice potential breaks up clusters & adducts to maximize atomic ions. • Can also use the electrospray source Technology Transition Workshop Lead in paint chip PbOH+224.9787 Orifice 1=20V PbO2H3+ Rel. Abund. 100 0 100 80 Rel. Abund. 264.9724 50 Pb+ 80 140 200 260 320 380 440 500 560 620 680 Pb+ 20 207.9744 Orifice 1=90V 60 40 Pb2(OH)3+ Rb+ PbOH+ In+ 224.9764 84.9135 114.9051 0 100 150 m/z 200 250 Technology Transition Workshop Stainless Steel Wire 100 Fe+ 55.9349 Rel. Abundance 80 Plunger wire from PCR Pipette 60 40 20 0 Cu+ Mn+ Ni+ Cr+ 50 FeOH+ 62.9294 Ga+ 60 70 m/z 72.9400 80 Technology Transition Workshop Thank you!