5975 -SMB GC-MS with Cold EI The Quest

5975 -SMB GC-MS with Cold EI The Quest for Ultimate Performance GC-MS Aviv Amirav, Tal Alon and Alexander B. Fialkov Aviv Analytical and Tel Aviv University, Email: aviv@avivanalytical. com GC-MS with Cold EI – Main Improvements: • Improved sample identification to a class by itself • Significantly extended range of low volatility and thermally labile compounds amenable for analysis • Lower detection limits, particularly where needed for sample compounds that are hard to analyze • Faster GC-MS analysis, much faster • Uniform response to all analytes for the measurement of chemical reaction yields and improved quantitation

GC-MS with Cold EI means electron ionization of vibrationally cold molecules in supersonic molecular beams GC-MS with Cold EI is based on a GC and MS interface with a Supersonic Molecular Beam (SMB) and on electron ionization of sample compounds while they are vibrationally cold in the SMB (thus named Cold EI) in a fly-through ion source. An SMB is formed by the expansion of gas through a small, shaped nozzle into a vacuum chamber. In this expansion, the combination of carrier gas, added helium make-up gas and sample molecules obtain the same final velocity, and as a result the sample compounds are accelerated to the helium velocity. This uniform velocity ensures slow intra-beam relative motion and collisions during the expansion, resulting in vibrational cooling of the sample compounds. As a result, SMB's are characterized by a few features that are advantageous for GC-MS including: a) Vibrational cooling of the sample compounds (enhanced molecular ions); b) High flow rate compatibility up to 100 ml/min; c) Compatibility with a fly-through EI ion source.

The Aviv Analytical 5977 -SMB GC-MS with Cold EI Photos of the 5977 -SMB GC-MS with Cold EI

Dual Cage Fly-Through Electron Ionization Ion Source Inherently Inert Tailing and Degradation Free Ion Source - Vacuum background filtration - No sample degradation - No ion source peak tailing - Ultra fast response time Cold EI mass spectra Low electron energy Cold EI Classical EI mass spectra

Cold EI with the Fly-Through Ion Source – A Step Forward Towards the Ideal Ion Source Enhanced molecular ions Amplified isomer and structural mass spectral information Accurate isotope abundances No vacuum background or ion source peak tailing Superior sensitivity for difficult to analyze compounds Uniform compound independent ionization yield Method based switching to classical EI or low electron energy Cold EI

Expected Benefit: Enhanced molecular ion plus the usual EI fragments Unexpected Benefits: A) Electron Ionization can be a Soft Ionization Method with Cold EI that is Approaching Field Ionization B) Largely Enhances Isomer Mass Spectral Information in Cold EI

Cold EI and Library Search Lower fit but better hit Cold EI is the only “soft” Ionization method that is compatible with NIST library identification and actually improves it While the matching factor of the sample is reduced in Cold EI the matching factor of competing compounds are reduced even more as the molecular ions are the most characteristic MS sample ions.

Cold EI and Classical EI modes are available with the same Ion Source Classical EI-SMB mode is available through a simple reduction of the total He make up and column flow rate to ~5 ml/min (Click of a mouse method change). Excellent similarity is obtained to the NIST MS Which mass spectrum is the best for you ? Cold EI, Cool Classical EI or Classical EI They are all available with the 5977 -SMB via a method change

Sample identification with a single quadrupole based GC-MS with Cold EI is superior to that of any high resolution GC-MS How to Improve sample Identification by GC-MS: • Ensure that the sample compound will elute and elute without ion source degradation • Have a trustworthy enhanced molecular ion • Obtain a mass spectrum with structurally and isomer informative high mass fragments • Have improved library identification probability • Obtain the sample elemental formula in cases when it is not in the library

TAMI Software for the Provision of Elemental Formula via Isotope Abundance Analysis and Enhanced Quad Mass Accuracy Elemental formula information with unit resolution Quads better than with costly accurate mass TOF-MS (Molecular ions for extended range) 1. Isotope Abundance Analysis (IAA) enables the inversion of molecular ion group of isotopomers abundances into elemental formula. 2. The TAMI software improves the quadrupole mass accuracy to <50 ppm 3. The combination of improved mass accuracy and IAA gives elemental formula equivalent to sub ppm mass accuracy alone. The Cold EI molecular ions obtained with single quad GCMS provide elemental formulae

5975 -SMB as an Ideal Service GC-MS Trustworthy Molecular Ions, Informative MS (isomers), Thermally labile GC-MS, Fast, Elemental Formula via IAA and Uniform Response for Reaction Yields unlike with ESI A+B = C+D Y(D) = D/(B+C+D) Reaction Yield = 59% C 14 H 18 N 2 O 3 S 2

TAMI Provides Elemental Formula for the Unknown C 14 H 18 N 2 O 3 S 2 from the 5975 -SMB Data

Extending the Range of Compounds Amenable for GC-MS Analysis Alleviating the GC-MS Achilles Heel and taking applications from LC-MS to GC-MS where NIST library search (and TAMI) can be used Extended Range Implies: • Doubled size of low volatility compounds • Much greater range of thermally labile compounds to bridge the gap with LC-MS • Polar compounds analysis such as free fatty acids without derivatization and without ion source tailing • Analyzing all compounds with trustworthy molecular ions which is a must to prove that the real compound eluted and not an injector/column/ion source degradation product.

Significantly extended range of compounds are amenable for analysis via lowering the GC (and injector) elution temperatures & the use of contact-free fly-through ion source • Extended range of low-volatiles; • Thermally labile compounds degrade much less or not at all; • No or reduced column bleeding; • No ion source peak tailing; • Faster analysis…

Largest Hydrocarbons Analyzed with GC-MS and all with dominant molecular ions

Reserpine analysis by 5975 -SMB – While it is the LC-MS industry standard spec compound, the 5975 -SMB is the only GC-MS that can analyze it

OFN Specification of the 5975 -SMB S/N>1, 000 The Aviv Analytical 5975 -SMB has no vacuum background noise, thus, it can reproducibly provide for 1 pg OFN signal with zero RSIM noise hence S/N>1, 000 Should we use this number as a specification? No, since no one will believe it although true, it does not reflect on LOD and does not overcome the OFN gap issue

5975 -SMB OFN Specification with SIM 20 fg OFN on-column in SIM mode m/z=272. (1 pg/u. L split 50). Under optimum conditions S/N>100 in peak to peak can be achieved or >500 in RMS (early time noise) This is a much better method of comparison since the use of software tricks is limited but still does not overcome the OFN gap issue Thus, other more realistic compounds must be included in the sensitivity evaluation

5975 -SMB versus 5975 with 250 pg on-column of the Indicated Compounds Superior TIC sensitivity particularly for the harder to analyze compounds plus enhanced molecular ions and lower vacuum background for much higher cold EI RSIM S/N versus standard GC-MS Obscured Standard EI Mass Spectrum of Cholesterol Standard EI 5975 with 30 m column Cholesterol Cold EI 5 m column and 5 ml/min Methylstearate C 32 H 66 C 16 H 34 This is room for elution of larger compounds Useful Cold EI Mass Spectrum of Cholesterol

The “Harder” the Compound Analysis the Greater is the Cold EI Sensitivity Gain The cartoon below demonstrates our perception of the average sensitivity gain of Cold EI with the 5975 -SMB versus sample mass

Standard EI Nonoxynol -9 2 ug Nonoxynol-9 by Cold EI Nonoxynol-9 No Molecular Ion even for N-5 (Spermicide used in Condoms) Analysis by 5975 -SMB GC-MS with Cold EI Nonoxynol -9 > 500 times more sensitive TIC > 100, 000 times more sensitive RSIM on the molecular ion Abundant molecular ion IAA identification on the molecular ion Molecular Ion Uniform Response Extended Range Distinct isomer MS effects & fingerprint X 3 times faster Sample advice and standard EI MS by Prof J. Shepard from U. Albany

Selected Applications of GC-MS with Cold EI 5977 -SMB GC-MS with Cold EI enables unique applications that can give you the advantage Please enter our Advanced GC-MS Blog Journal for further applications information blog. avivanalytical. com

Changing the Way Synthesis is Performed Measurement and Optimization of Organic Chemical Reaction Yields by GC-MS with Cold EI Instead of a reaction followed by lengthy separation purification and NMR plus QTOF we enable semi on-line reaction monitoring with our 5975 -SMB for reaction yield optimization and mechanism elucidation Ø ESI-QTOF provides elemental formulas but nothing about the synthesis yield, product cleanliness, isomers and reaction mechanism. Ø Standard EI unlike ESI has uniform semi quantitative ionization yield but it provides molecular ions only for ~50% of the compounds above 300 amu, standard GC-MS has very limited applicability (range of compounds) while peak tailing erodes its uniform response. Ø GC-MS with Cold EI significantly extends the range of compounds amenable for analysis (700 -800 for polars and 1050 amu for non polars), always gives molecular ions, enables effective fast GC-MS, provides elemental formulas via isotope abundance analysis and has uniform response and thus uniquely provides synthetic chemical reaction yields and information on their mechanism, sample cleanliness and isomers.

Chemistry by Mass Spectrometry with SMB Changing the way synthesis is performed C 50 H 96 N 2 O 8 (X 2) was synthesized for environmental metal remediation by Boaz Seeman, group of Dr. Michael Gozin, Tel Aviv University, Israel. The reaction failed with standard procedures and could be understood and optimized only with the help of 5975 -SMB.

Dramatically Improved Hydrocarbons Analysis with the 5975 -SMB GC-MS with Cold EI Applications are much more than just Petrochem: Main challenges in hydrocarbon analysis by GC-MS: • Improving hydrocarbon identification via the provision of abundant molecular ions • Revealing significant isomer mass spectral information • Developing novel and effective methods for fuel characterization and identification • Extending the range of hydrocarbons that are amenable for analysis • Lowering the detection limits • Enabling faster GC-MS analysis • Petrochemicals and fuels • • • Fuel adulteration Arson & Forensic Entomology (Chem Ecol) Motor oil analysis Transformer oil analysis Environmental oil spills Biodiesel analysis Organic Geochemistry Hydrocarbon polymers Food and other oils Wax analysis

Dramatically Improved Petroleum Mixture Analysis 5975 -SMB with Cold EI vs Standard EI Cold EI MS of Isoprenoid C 18 H 38 Standard EI MS of Isoprenoid C 18 H 38

Isomer Distribution Analysis – A Novel Method For Fuel Characterization There are 802 possible isomers for C 13 H 28 Novel instrumentation can generate new and innovative methods, such as Isomer Distribution Analysis (IDA) Isomer distributions affect all the major physical and chemical properties of oils and fuels including: combustion efficiency, octane number, flash point, viscosity, lubrication properties, solubility and solvation power, boiling point and melting points. Cold EI uniquely enables their analysis Isomer distributions of Diesel fuel alkanes can be observed with RSIM (SIM) chromatograms on the alkane molecular ions. Branched alkanes boiling points are lower than of linear chain alkanes, thus they elute earlier than n-alkanes.

The 3 Isomers method for Diesel Fuel Characterization Hydrocarbon mixture identification/characterization could be based on fingerprints of 3 specific alkanes isomer distributions.

Triglycerides in Palm Oil Analysis Cold EI total ion mass chromatogram and three Cold EI mass spectra of triglycerides of interesterified Palm oil. The representative Cold EI mass spectra were obtained on the arrows indicated TIC mass chromatogram peaks. Note the availability of useful molecular ions plus informative high mass fragments. Note that the TIC exhibits symmetric tailing free peeks and high ratio of signal to column bleed, which is challenging for these large triglycerides. Samples and application information was kindly given by Hans-Gerd Janssen from Unilever The Netherlands

Explosives Analysis with GC-MS with Cold EI TATP R-Salt HMTD TNT PETN Molecular Ion RDX Tetril TATP R-Salt Molecular Ion Lowering the labile explosives elution temperatures with high short column flow rate and the use of flythrough Cold EI ion source enables the elution of labile explosive with enhanced molecular ions and high mass fragments.

C-4 Explosives Source Characterization Via its Plasticizers Dioctyladipate and Dioctylsebacate Isomers and Homologous Compounds Signature, all with Molecular Ions C-4 A C-4 B

Beeswax Analysis on Fruits and Vegetables (SMB Unique) 5975 -SMB TIC of Beeswax and Cold EI mass spectrum of one of the palmitic acid esters Beeswax serves to coat fruit and vegetables to enhanced their freshness and shelf-life 3 ppm Beeswax analysis on Tomato (extract) via RSIM on a common palmitic ester fragment ion that serves as a unique Beeswax fingerprint plus on two molecular ions

Cataglyphis Ant Wax Analysis The discovery of hydrocarbon isomer based communication Barcode with the 5975 -SMB GC -MS with Cold EI Cataglyphis Ants Cold EI TIC Cold EI-MS n-C 29 H 60 Cold EI-MS Iso-C 30 H 62 A. Alon B. Arad C. Jerusalem D. Magal RSIM on m/z=408. 4 of Cataglyphis ants wax from various nest locations

Enhanced Molecular Ion – The key to Improved Pesticide Analysis Matrix Interference is exponentially reduced on the molecular ion which has much cleaner RSIM trace than of fragments. Matrix Interference is reduced by about a factor of 20 every 100 amu. Thus, SIM on the molecular ion can have equivalent matrix interference to MS-MS on a fragment while uniquely enabling simultaneous full scan for universal pesticide analysis 80 ng/g in strawberry Tolylfluanid m/z 346 Ethion m/z 384 m/z 231 m/z 153 Diazinon m/z 304 m/z 179 m/z 238 m/z 152 m/z 137

5975 -SMB Single quad GC-MS with Cold EI in simultaneous full scan and time programmed SIM versus Agilent 7010 triple quad GC-MS-MS in the analysis of the sample of 50 ng/ml of Deltamething in Basil. SIM was on the molecular ion m/z=505 and its isotopomer m/z=507 and the two peaks are of two Deltamethrin isomers. The theoretical 507/505 isotope ratio is 51. 22% while the measured one is 51. 29% which is an excellent fit for high confidence identification Cold EI SIM on the molecular ion is far more selective for Deltamethrin in Basil than MS-MS on a fragment ion Cold EI SIM m/z=505 Triple Quad MS-MS Cold EI SIM m/z=507 Single Quad Cold EI SIM by Aviv Amirav at Tel Aviv University Triple Quad MS-MS by Steve Lehotay at the USDA

Very Fast Heroin Analysis in its Street Drug Powder 2 min Chromatography and 3 min for Ready to Next Analysis Heroin Fast Analysis via Flow Programming Cold EI Unique Short column (5 m) combined with flow programming from 1 ml/min to 32 ml/min enables the fastest possible heroin analysis in its street drug powder with standard 7890 GC. This is as fast as it goes with standard GC in the analysis of sample with broad volatility range of compounds

Single Quadrupole based GC-MS with Cold EI Provide: A) Identification power better than of GC-MS with High Resolution TOF or Orbitrap B) Selectivity equal or better than of GC-MS with triple quadrupole MS-MS C) Speed of analysis similar to that of MS Probe yet with separation D) Range of compound amenable for analysis as that of standard GC-MS plus APCI-LC-MS E) All the above in a compact easy to use single quadrupole based GC-MS

Aviv Analytical Provides 1. 5975 -SMB GC-MS with Cold EI- Approaching the ideal GC-MS 2. TAMI software – Elemental formula from your quadrupole GC-MS data 3. Chromato. Probe Sample Introduction Device 4. Fast GC – Fastest GC and GC-MS analysis with standard columns 5. Open Probe Fast GC-MS – Real time analysis with separation 6. Pulsed Flow Modulation GCx. GC-MS with Cold EI – Combines improved GC separation with ultimate identification 7. EI-LC-MS with Cold EI – Library identification & uniform response LC-MS www. avivanalytical. com For further information please write to aviv@avivanalytical. com or enter our Advanced GC-MS Blog Journal for applications at blog. avivanalytical. com