Report

Teaser, summary, work performed and final results

Periodic Reporting for period 1 - Field Ion Mass Spec (Field Ion Quadrupol-Mass Spectrometer)

Teaser

As a company well established in industrial process control and supplying mass spectrometry with electron impact ionization for industrial process-, product- and environment-control by fast and precise online gas analysis in metallurgy, ceramics, glass, inorganic chemistry and...

Summary

As a company well established in industrial process control and supplying mass spectrometry with electron impact ionization for industrial process-, product- and environment-control by fast and precise online gas analysis in metallurgy, ceramics, glass, inorganic chemistry and environmental monitoring, IPI had to recognize that analytical methods to control production processes in organic chemical industry, involving cracking, distillation, catalysis, pyrolysis, fermentation and other non-destructive or destructive methods, in their capacity for analysis of mixtures in organic chemistry are very slow. A fast acting on-line control of industrial organic production processes and a quick control of their products is critically delayed by slow organic analytics.

Quadrupol mass spectrometry, IPI’s basic product line, can provide a quick measurement of organic mixtures. However is restricted by Electron Impact Ionization (EI). EI does result in mass spectra with frequent molecular fragmentation, slow to read, to calibrate and to evaluate. For organic mixtures, simplification of analytical results, down to „kind of molecule“ and „concentration of this kind of molecule“ is required to get analytic result clarified and quick readable. Only fast evaluation and readability can get analytical results usable for fast organic process control, required for „in-process analysis, controll and improvement“ of production processes in industrial organic chemistry.

Strong improvement is available by Field Ionisation (FI). In former experiments, special „single tip field ionization“, FI produced mass spectra simplified to dominant molecular ions with low fragmentation, easy to calibrate for compounds concentration. Molecular ions not altered by fragmentations or adductions in ionization, ordered according to molecular weight, EI mass spectra provide best quality of information for safe and quick organic analytical evaluation. Through easy readability of these analytical results, the industrial process control by FI-Q-MS can find into routine. Additionally, the control of organic mixture products will benefit from that improvement of analytical capacity to simple clarity.

For industrial organic chemistry, the analytics market is of eightfold size compared to inorganic chemistry. IPI GmbH, active in control of industrial processes in inorganic chemistry by FI-Q-MS, wants to take the chance to open a much larger market in organic industrial chemistry. Led by that intention, IPI under HORIZON 20-20 did apply and sign for project Field Ion Quadrupol - Mass Spectrometer.

Work performed

Within the first month of work on the project, the field ion source (FI-source) was designed as optional module to replace the electron impact ion source (EI-source) on existing ESD 1000, GAM 2000 and GAM 3000 quadrupol mass spectrometers. Before, an extensive ion optical calculation had the result, that an FI-source with optimal short ion decelleration lens would expand the quadrupol analyzer not in diameter, but in length, just by about 40 mm for ionization and focussing regions.

According to the results of the ion optical calculations, the field ion source was constructed. Since source potential differences exceeding 10.000 Volt need to be maintained in continous operation under de-terioration by sample materials that construction had to envision hard conditions to be expected.

The construction of FI-source did evolve, through three steps for different anode tip holders, since that most important element of ion source by experiments got changes of design and production process for several improvements. The first drawing of FI-source (Drawing No.1) included the first design of anode tip holder, as used in former published FI studies, and has been changed through an intermedi-ate design not practical for industrial production and adjustment (Drawing No.2) to final solution, where the anode tip is more precisely adjusted by a glass capillary in the FI source (Drawing No.3).

According to the result of ion optical calculations and source construction, three identic FI-sources have been manufactured. One of these FI-sources, connected to a quadrupol without pre-Quad, installed on the ion optical bench, is under continous test and shows continous stability in function and high voltage operation in the frequent testing of self-developed anode tips for their function after any changes of their production process.

We knew from former experiments, that to form an optimal Pt-anode tip for the FI-source, in an etching process, a Pt wire had to be periodically dipped into an etching bath with electrolytic activity. For that precise dipping, a motor driven „Dipping Unit“ was in-house designed (Drawing No.4) and produced, and did reliable work through all the experiments to develop an optimal etching process.

The well published original process „electrolytic etching in a salt melt at 800oC“ was reproduced on 100% Pt-wire of 0.1 mm diameter, requiring a well protected oven and careful handling. The rather weak Pt-anode tips did not prove to hold a reliable position on holders shown in drawing No.2, what required a total re-design and production change. We went to a more stiff base material, a Pt/Ir 80/20 wire of 0,25 mm diameter, and to avoid difficulties of „hot etching“-, we developed an „electrolytic etching in a cold salt solution“, which is providing reproducible well formed anode tips, after more experiments and prove to be real „field ion productive“,

- based in a glass capillary segment (drawing No.3), much better adjustable to the correct position
opposite to field cathode in ion source, and much more reliable holding that position,
- utilizing molar polarities of organic molecules to concentrate them by a factor of 107 in ionization
zone of FI source,

- providing over the wide range of 5 to 11 kV of FI source potentials the total ion currents at 3x10-13
to 10-10 A on the Faraday-collector of the quadrupol mass spectrometer (Quad graph No.1), which,
transformed by a Secondary Electron Multiplier (SEM) as used on any Q-MS, would allow for
quantitative analysis of organic mixtures in a 107 dynamic range of concentrations.

To demonstrate the ionizing function of the field ion source first without quadrupol, later with quadrupol, the ion source, connected to a primitive batch inlet system, is still mounted on the ion optical bench opposite to a Faraday collector. That optical bentch is located in a large vacuum tub, pumped by turbomolecular pump and forepump down to 5 x

Final results

In mass spectrometry, analyte molecules must get ionized. All the state of the art ionization methods alter analyte molecules by fragmentation or adductions. Going beyond that state of the art, only „Single Tip Field Ionization“ (STFI) maintains ionized molecules in their molecular state by weak tunneling an electron from the molecules. Prominently providing molecular Ions, which allow for easy calibration and precise quantitative analysis, only STFI is capable to provide quick quantitative mass spec process control in industrial organic chemistry.

Industrial organic chemistry, providing all the basic mass products, heating oils and gases, fuels, polymers, paints, flavours, fragrances and pharmaceuticals for societies economy and demand, has drastic needs for quick and easy analytics to control their production processes and products. Intensified is that need by the strong general public request to introduce bio-materials and fast changing petro-mater (from fracking, from oil sands, and from often changing oil sources) to their raw materials. And, last but not least, EC organic chemical industry today is under drastic pressure to change production from simple mass products to more economic special products, to maintain and drive their high value market segment. Fast, easy analytics here are anywhere are in high demand.

Website & more info

More info: http://www.in-process.com.