Shimadzu Corporation

Hamilton Sundstrand Corporation

Hermann Wollnik

Gary Alan Eiceman

Roger Giles

Michael Sudakov

Dimitrios Papanastasiou

Yoshihiro Ueno

Benjamin D Gardner

Alexander Semenovich Tarassov

An ion mobility spectrometer for analyzing a vapor sample including a multi-ring ion source for receiving a vapor sample, wherein the multi-ring ion source includes a series of rings, wherein each ring of the multi-ring ion source includes an ionizing layer on an inner surface thereof, for charging at least a portion of the vapor sample and creating an ionized vapor sample.

Ion source for an ion mobility spectrometer

In an ion separation space () between plate electrodes (), rod electrodes () which are parallel to the plate electrodes as well as to each other are placed. An asymmetric pulse voltage is applied between the plate electrodes (), whereby high and low electric fields are alternately created within the ion separation space (). A voltage obtained by adding an appropriate DC voltage to a voltage generated from the asymmetric pulse voltage by resistive division is applied to the rod electrodes (). At one point in time, since the outer edge of the rod electrodes () has a predetermined potential, an electric field having curved equipotential surfaces bulging in the Y-axis direction is created within the space between those rod electrodes. Due to this electric field, ions carried by a buffer-gas flow move in zigzags, while experiencing a converging force in both X- and Y-axis directions. As a result, the ions having different mobility ratios are separated into laminar forms according to their mobility ratios and exit the ion separation space (), forming a converged ion stream for each mobility ratio. Consequently, the ion transmission efficiency and separation performance are both improved.

Parallel plate-type non-uniform electric field ion mobility spectrometry device

A time-of-flight mass spectrometer () comprises an ion source a segmented linear ion device () for receiving sample ions supplied by the ion source and a time-of-flight mass analyzer for analyzing ions ejected from the segmented device. A trapping voltage is applied to the segmented device to trap ions initially into a group of two or more adjacent segments and subsequently to trap them in a region of the segmented device shorter than the group of segments. The trapping voltage may also be effective to provide a uniform trapping field along the length of the device ().

Time-of-flight mass spectrometer and a method of analysing ions in a time-of-flight mass spectrometer

An ion mobility spectrometer having an ion source for generating ions; an ion detector for recording ions, and a number of substantially flat diaphragm electrodes arranged substantially perpendicular to a straight system axis that passes through the apertures in said diaphragms, with the diaphragms being arranged in a series of cells with each cell including an entrances and an exit diaphragm and a short region in between. The exit diaphragm of one cell is identical to the entrance diaphragm of the next cell, and the cells of said ion mobility spectrometer are grouped into three parts: an ion-beam forming region, an ion analyzing region, and a decelerating ion gate.

Ion-mobility spectrometer including a decelerating ion gate

A filter for a mass- or mobility-spectrometer that bars gases or vapors of a high-pressure ion source, as well as ions of high mobility and charged droplets, from entering an evacuated mass spectrometer or a mobility spectrometer at a lower pressure than the filter. The buffer gas of the high pressure ion source is blown into the volume of this filter directly or through tubes from where buffer gas and embedded ions are sucked through the aperture of a diaphragm or through an aperture of a capillary mainly from an 'extraction volume' filled with a separately supplied clean gas, into which ions of interest are pushed by electric fields formed by electrodes that are substantially rotational symmetric around the 'extraction volume' and a substantially flat electrode with respect to an axis of ion extraction and the end of the capillary and the end of a coaxial tube surrounding the capillary.

Curtain gas filter for mass- and mobility-analyzers that excludes ion-source gases and ions of high mobility

A co-axial time-of-flight mass spectrometer having a longitudinal axis and first and second ion mirrors at opposite ends of the longitudinal axis. Ions enter the spectrometer along an input trajectory offset from the longitudinal axis and after one or more passes between the mirrors ions leave along an output trajectory offset from the longitudinal axis for detection by an ion detector. The input and output trajectories are offset from the longitudinal axis by an angle no greater than formula (I): where Dis the or the minimum transverse dimension of the ion mirror and L is the distance between the entrances of the ion mirrors.

Co-axial time-of-flight mass spectrometer

A curtain-gas filter for a mass- or mobility-spectrometer that bars gases or vapors of a high-flux atmospheric pressure ion source, as we ions of high mobility and charged droplets, from entering an evacuated mass spectrometer or a mobility spectrometer that is at a lower pressure than the main filter volume of the curtain-gas filter. A portion of the ion-source buffer gas in the ion-source plume is sucked through an ion-source buffer gas inlet into the main filter volume of the curtain-gas filter, from where this ion-source gas is exhausted after a properly shaped electric field has pushed a large portion of the embedded ions into an externally provided stream of a clean buffer gas, which is sucked through a passage into a mass- or mobility-spectrometer that is at a lower pressure.

Curtain gas filter for high-flux ion sources

A method for differential mobility separation of ions using digital-drive based high voltage fast switching electronics. The digital waveform delivered to the spectrometer is characterized by at least two substantially rectangular pulses of different amplitude and polarity. The control circuitry allows for waveform frequency, duty cycle and pulse amplitudes to be varied independently. Balanced as well as unbalanced asymmetric waveforms can be designed for optimum differential mobility separation of ions. The digital drive is designed for differential mobility spectrometers including parallel plate and segmented plate multipoles of planar symmetry, as well as multipoles of cylindrical symmetry, which may optionally be arranged in series. The use of the digital drive establishes alternating electric fields during which the displacement as a result of ion oscillation is determined by mobility coefficients.

Method and apparatus for digital differential ion mobility separation

A system for guiding an ion beam along an axis (Z), comprises at least one section having upper flat plate strip electrodes (Iu,and) and lower flat plate strip electrodes (Id,and) for producing at least one electric field of substantially symmetric in a parallel direction and substantially antisymmetric in a perpendicular direction with respect to a plane including a beam axis and a fringe-field boundary that is located at the end of the at least one section.

Parallel plate electrode arrangement apparatus and method

Ions and charged droplets move from the nozzle () towards the orifice () of a charged-particle transport device or the desolvation pipe (). This particle motion is governed by the distribution of the pseudo-potential along particle trajectories. There are RF-voltages applied to neighboring electrodes (-) of the electrode array () cause the charged particles to substantially hover above the electrode array (). Right before the ions come to the electrode array () they thus experience a repelling force 'F' perpendicular to the surface of the electrode array (). This force 'F' causes an effective barrier (B) right before the electrode array () and consequently a pseudo-potential well (A) where the charged particles stop their motion parallel to the plume axis (D). Thus they accumulate around the center line (C) of this well (A). Applying additionally to the RF-potentials also DC-potentials to neighboring electrodes within the electrode array () small DC-fields can be formed within the well area (). These additional DC-fields drive the charged particles towards the axis of symmetry (C) and thus towards the orifice () of a charged-particle transport device or the desolvation pipe (). Thus, many of the charged particles which would normally impinge on the wall () around the orifice () can now be analyzed.

Charged-particle condensing device

An ion mobility analyzer includes at least one of a 'differential mobility analyzer', an 'ion mobility spectrometer' and a &#x201c;differential mobility spectrometer&#x201d;, to which charged molecules of interest are fed. Ions are fed to the ion mobility analyzer from a &#x201c;droplet pickup ion source&#x201d; including an electrospray ion source at a capillary end, from which charged droplets formed from a solvent mixture having substantially none of the molecules of interest emerge. The charged droplets are pulled by an electric field into a &#x201c;pickup region&#x201d; filled with a buffer gas at a pressure or a region close to the surface of a sample, where the charged droplets incorporate the molecules of interest and transfer the charge of the charged droplets to the molecules of interest, when the liquid in the charged droplets has evaporated in a heated desolvation region that is separate or integral with respect to the &#x201c;pickup region&#x201d;.

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Santa Fe, NM, United States of America

Hermann Wollnik