50 results about "Differential mobility analyzer" patented technology

A medical diagnostic method and instrumentation system for analyzing noncovalently bonded agglomerated biological particles is described. The method and system comprises: a method of preparation for the biological particles; an electrospray generator; an alpha particle radiation source; a differential mobility analyzer; a particle counter; and data acquisition and analysis means. The medical device is useful for the assessment of human diseases, such as cardiac disease risk and hyperlipidemia, by rapid quantitative analysis of lipoprotein fraction densities. Initially, purification procedures are described to reduce an initial blood sample to an analytical input to the instrument. The measured sizes from the analytical sample are correlated with densities, resulting in a spectrum of lipoprotein densities. The lipoprotein density distribution can then be used to characterize cardiac and other lipid-related health risks.

A multi-stage differential mobility analyzer (MDMA) for aerosol measurements includes a first electrode or grid including at least one inlet or injection slit for receiving an aerosol including charged particles for analysis. A second electrode or grid is spaced apart from the first electrode. The second electrode has at least one sampling outlet disposed at a plurality different distances along its length. A volume between the first and the second electrode or grid between the inlet or injection slit and a distal one of the plurality of sampling outlets forms a classifying region, the first and second electrodes for charging to suitable potentials to create an electric field within the classifying region. At least one inlet or injection slit in the second electrode receives a sheath gas flow into an upstream end of the classifying region, wherein each sampling outlet functions as an independent DMA stage and classifies different size ranges of charged particles based on electric mobility simultaneously.

Improvements are provided in the detection of atmospheric vapors by ionizing them near ambient pressure, and analyzing them as ions. Lowest detection limits of parts per quadrillion (ppq) concentrations are enabled by a combination of improvements, including the use of a filter to remove occasional intense signal from explosive particles. Several sources of chemical background are identified and solutions for their reduction or elimination are presented. Gains in response time may be achieved by operating at elevated temperature. When the ionizer is an electrospray source, the use of high boiling point solvents is indicated. An increased selectivity is achieved by operating a differential mobility analyzer (DMA) in series with a mass spectrometer. However, ppq sensitivities require various improvements in the DMA system including a special coupling to the ionizer, controlling the temperature in the DMA pump circuit, avoidance of induction on the DMA electrodes from heating devices, etc.

A method is described to select ions based on their electrical mobility. Ions are subjected to at least one full cycle of a time-dependent electric field. Ions are separated in space, and a continuous flow of filtered ions with a narrow range of selected mobility ions is produced at the outlet of the device, as in Differential Mobility Analyzers (DMAs). Yet, no high fluid velocity field is required, avoiding limitations associated in DMAs to flow unsteadiness, compressibility and turbulent transition. Instead, separation relies on the use of time-dependent ion trajectories generated by the time-dependent electric fields. Unlike FAIMS, full separation according to the mobility takes place within one or a few characteristic times for field variation, rather than via many tiny separation steps over many periods of field variation producing separation according to the mobility non-linearities in the mobility. Unlike conventional pulsating ion mobility spectrometry, a steady ion flow is produced with high duty cycle. Different embodiments of the apparatus using the method of the present invention are also described comprising different geometrical configurations and different time-dependent electric profiles, each of them having specific advantages. In a first configuration proposed, a rotary electric field is combined with an axial steady field achieving high resolution and a continuous output throughout all the selected and undesired ions. In a second two-dimensional configuration, an oscillating field is combined with a perpendicular steady field. Much higher sample flow rates can be achieved, though the undesired ions will periodically be transferred. Configurations using more than one stage allow minimizing the undesired pulsed signal of non selected ions. In all those configurations, the trajectories of ions are time dependent and the selected ions are subjected to at least one full cycle of the variable electric field. Separation is based on synchronizing the period of the field with the flight time of an ion from an inlet to an outlet for a particular electrical mobility.

The resolution of a differential mobility analyzer (DMA) and the range of valid mobility values for the charged particles that it can detect are increased. The DMA makes use of a flat configuration and a purely two-dimensional operating model in which shims are used for improved adjustment and precision of the parallel faces that make up the analysis area. The analyzer uses a closed and pressurized aerodynamic tunnel to establish a cross flow with a very high Reynolds number.

A multi-stage differential mobility analyzer (MDMA) for aerosol measurements includes a first electrode or grid including at least one inlet or injection slit for receiving an aerosol including charged particles for analysis. A second electrode or grid is spaced apart from the first electrode. The second electrode has at least one sampling outlet disposed at a plurality different distances along its length. A volume between the first and the second electrode or grid between the inlet or injection slit and a distal one of the plurality of sampling outlets forms a classifying region, the first and second electrodes for charging to suitable potentials to create an electric field within the classifying region. At least one inlet or injection slit in the second electrode receives a sheath gas flow into an upstream end of the classifying region, wherein each sampling outlet functions as an independent DMA stage and classifies different size ranges of charged particles based on electric mobility simultaneously.

Prior work on differential mobility analysis (DMA) combined with mass spectrometry (MS) has shown how to couple the output of the DMA with the inlet of an atmospheric pressure ionization mass spectrometer (APCI-MS). However, the conventional ion inlet to an APCI-MS is a round orifice, while conventional DMA geometries make use of elongated slits. The coupling of two systems with such different symmetries limits considerably the resolutions attainable by the DMA in a DMA-MS combination below the value of the DMA alone. The purpose of this invention is to overcome this limitation in the case of a parallel plate DMA. One solution involves use of an elongated rather than a circular MS sampling hole, with the long dimension of the MS inlet hole aligned with that of the DMA slit. Another involves use of a more elongated orifice in the DMA exit and a more circular hole on the MS inlet, the two being connected either through a short transfer conduit or through an ion guide. The DMAs described can also be coupled profitably to detectors and analyzers other than mass spectrometers.

In order to provide a differential mobility analyzer and the like that allows (i) easy increase of an upper limit of particle size of charged particle which can be classified and (ii) analysis of charged particles whose particle size is variable, a DMA (Differential Mobility Analyzer) includes: a classification tank in which an inlet electrode having an inlet slit, an intermediate electrode having a slit, and an outlet electrode having an outlet slit are arranged in sequence in such a manner that adjacent electrodes are disposed opposing each other at predetermined intervals; a gas supply section supplying the classification tank with sheath gas; and a voltage generator applying a predetermined voltage between the electrodes disposed opposing each other, the classification tank including a first classification section and a second classification section each formed by the electrodes disposed opposing each other, and the gas supply section controlling a flow rate of the sheath gas to be supplied to the classification tank individually per first classification section and second classification section.

The resolution of a differential mobility analyzer (DMA) and the range of valid mobility values for the charged particles that it can detect are increased. The DMA makes use of a flat configuration and a purely two-dimensional operating model in which shims are used for improved adjustment and precision of the parallel faces that make up the analysis area. The analyzer uses a closed and pressurized aerodynamic tunnel to establish a cross flow with a very high Reynolds number.

The invention provides a method for obtaining aerosol particle size distributions with a scanning mobility particle sizer (SMPS) device comprising a differential mobility analyzer (DMA); which method comprises the stages:(i) collecting a first data set of particle concentrations vs. size for a size range from a predetermined minimal size Dmin to an intermediate size Dt by varying a voltage applied to a DMA column of an SMPS from Vmin to Vt1 at a first sheath flow rate Qsh1;(ii) changing the sheath flow rate from the first sheath flow rate Qsh1 to a second sheath flow rate Qsh2;(iii) collecting a second data set of particle concentrations vs. size for a size range from the intermediate size Dt to a predetermined maximum size Dmax by varying the voltage applied to the DMA column of the SMPS from Vt2 to Vmax at the second sheath flow rate Qsh2;(iv) convolving the first data set from stage (i) using an apparatus function of the DMA and the sheath flow rates Qsh1 and Qsh2 in stage (ii);(v) combining the convolved data set from stage (iv) with the second data set from stage (iii) to form a merged data set corresponding to the size distribution from Dmin to Dmax; and(vi) deconvolving the merged data set to provide a size distribution for the full size range Dmin to Dmax.Also provided are a DMA, SMPS or Fast Mobility Particle Sizer (FMPS) apparatus set up to perform the method.

Prior work on differential mobility analysis (DMA) combined with mass spectrometry (MS) has shown how to couple the output of a planar DMA with the atmospheric pressure inlet of an atmospheric pressure ionization mass spectrometer (APCI-MS). However, because the ion inlet to APCI-MS instruments is a round orifice, while conventional DMA geometries make use of elongated slits, the coupling of both has attained less resolving power or tolerated a smaller sample flow rate than a DMA alone. The present invention overcomes these limitations with an axial DMA of cylindrical symmetry using more than two electrodes. The configuration is related to that previously proposed by Labowsky and Fernández de la. Mora (2004, 2006), where ions with a critical electrical mobility are brought into the symmetry axis of the DMA. Ions with this critical mobility are now optimally transmitted into the MS, with much higher resolution than possible in planar DMAs. In a preferred embodiment of this DMA facilitating DMA-MS coupling, one DMA electrode intersecting the symmetry axis is relatively planar.

A continuous flow mobility classifier provide the ability to perform two-dimensional separation in mass spectrometry. An ionization system is used to ionize a sample. A differential mobility analyzer (DMA) (e.g., a nano-radial DMA) is coupled to the ionization system and to a mass spectrometer. The nano-RDMA is configured to separate the ionized sample by mobility for subsequent mass analysis by the mass spectrometer.

An apparatus and method of analyzing ions is described in which a Differential Mobility Analyzer (DMA) is combined with an analysis device. The DMS can be operated in first and second modes of operation to produce a plurality of ions that are sampled and analyzed by the analysis device. In the first mode of operation the DMA is configured to enable ion mobility separation and the analysis device samples and analyzes ions having ion mobility in a certain range of ion mobility and in the second mode of operation the DMA is configured to disable ion mobility separation and the analysis device samples and analyzes ions without discrimination based on ion mobility.

Distributed non-charged particles having a desired particle diameter are introduced into a chamber. A photoionizer in which a soft X-ray power is adjustable is attached to the chamber, to charge the particles within the chamber. The power level of the soft X-ray is adjusted by a controller so as to produce singly charged particles. The charged particles are then introduced into a differential mobility analyzer for classification, thus producing monodisperse standard particles having particle diameter of 0.1 to 1.0 μm.

A method for fast and accurate recognition of species contained in trace amounts in complex mixtures such as ambient air or biological fluids is taught based on the use in tandem of one or several differential mobility analyzers (DMAs) and possibly also a mass spectrometer (MS), all arranged in series. The two DMAs operate in different regions of the ion drag versus drift velocity curve (for instance, linear versus nonlinear regions), hence separating according to more than one independently discriminating parameters of the ion. Very high discrimination can be achieved even with a single stage of mass spectrometric separation by selecting a narrow range of ions with the DMA, and analyzing them in the MS, first without fragmentation, and then with fragmentation. This process does not require necessarily a tandem MS when fragmentation takes place in the inlet region of the MS. Fast and accurate discrimination is possible in single ion monitoring mode (SIM) for a large number of targeted species, even with relatively inexpensive and light single quadrupole MS systems, where the various filters placed in series would open pre-configured narrow windows suitable for passage of each ion in a list.

A system, method, and processor-readable medium are provided for quantitatively evaluating risk associated with nanotechnology. An insurance company computing system obtains nanomaterial-related data from a variety of sources, including nanomaterial sensors such as differential mobility analyzers located on-site at an insured facility. The insurance computing system uses the obtained data and a computerized model to compute a risk score that is used in evaluating the insurability of the facility or the operating entity. An insurance policy or modifications to an existing insurance premium are subsequently produced based on the computed risk score.

A method for fast and accurate recognition of species contained in trace amounts in complex mixtures such as ambient air or biological fluids is taught based on the use in tandem of one or several differential mobility analyzers (DMAs) and possibly also a mass spectrometer (MS), all arranged in series. The two DMAs operate in different regions of the ion drag versus drift velocity curve (for instance, linear versus nonlinear regions), hence separating according to more than one independently discriminating parameters of the ion. Very high discrimination can be achieved even with a single stage of mass spectrometric separation by selecting a narrow range of ions with the DMA, and analyzing them in the MS, first without fragmentation, and then with fragmentation. This process does not require necessarily a tandem MS when fragmentation takes place in the inlet region of the MS. Fast and accurate discrimination is possible in single ion monitoring mode (SIM) for a large number of targeted species, even with relatively inexpensive and light single quadrupole MS systems, where the various filters placed in series would open pre-configured narrow windows suitable for passage of each ion in a list.

A differential mobility analyzer (DMA) for separating charged particles or ions suspended in a gas and a method of using the DMA for separating such particles. The invention includes various means for increasing the resolution of the DMA by stabilizing the laminar flow within the DMA and by allowing unusually large flow velocities.

One aspect of the present invention is to extract multiple ionic species in a FAIMS into one or more IMS drift tubes simultaneously. By adjusting FAIMS operational parameters, ions in FAIMS are detected on IMS detectors through separation in FAIMS and / or separation and collection in the IMS. This method provides a continuous separation of specific ions from an ion swarm by employing a high-field differential mobility analyzer (FAIMS) with a plurality of orthogonal transitions paths spaced incrementally along the electrodes which allow additional separation by a conventional IMS drift tube. The components of the sample can be collected or detected.

The present invention consists of a differential mobility analyzer (DMA) intended for achieving the electric field conditions necessary so that it has an component opposite to the drag flow. This electric field component opposite to the drag flow causes the main electric field to be not perpendicular to the velocity field of the drag flow but oblique. Under these conditions, it is possible to increase the resolution of the device, thus reducing the threshold of errors in the detection of the type particle injected in the analyzer. This invention is characterized by the arrangement and nature of the electrodes intended for obtaining the oblique electric field. The invention also comprises the use of this analyzer as part of a device which comprises it, giving rise to an assembly combining the efficiency of the analyzer of the state of the art with the high resolution of the analyzer of the invention.

A system, method, and processor-readable medium are provided for quantitatively evaluating risk associated with nanotechnology. An insurance company computing system obtains nanomaterial-related data from a variety of sources, including nanomaterial sensors such as differential mobility analyzers located on-site at an insured facility. The insurance computing system uses the obtained data and a computerized model to compute a risk score that is used in evaluating the insurability of the facility or the operating entity. An insurance policy or modifications to an existing insurance premium are subsequently produced based on the computed risk score.

A new instrument for electrical-mobility based size segregation of particles at high resolution is described. The instrument called the high-flow dual-channel differential mobility analyzer (HD-DMA) comprises of five flows: a polydisperse aerosol flow, a clean sheath flow, two monodisperse sample flows and a residual excess flow. High resolution measurements are possible because of the large sheath flowrates that are permissible in this instrument.

Prior work on differential mobility analysis (DMA) combined with mass spectrometry (MS) has shown how to couple the output of the DMA with the inlet of an atmospheric pressure ionization mass spectrometer (APCI-MS). However, the conventional ion inlet to an APCI-MS is a round orifice, while conventional DMA geometries make use of elongated slits. The coupling of two systems with such different symmetries limits considerably the resolutions attainable by the DMA in a DMA-MS combination below the value of the DMA alone. The purpose of this invention is to overcome this limitation in the case of a parallel plate DMA. One solution involves use of an elongated rather than a circular MS sampling hole, with the long dimension of the MS inlet hole aligned with that of the DMA slit. Another involves use of a more elongated orifice in the DMA exit and a more circular hole on the MS inlet, the two being connected either through a short transfer conduit or through an ion guide. The DMAs described can also be coupled profitably to detectors and analyzers other than mass spectrometers.

A differential mobility analyzer (DMA) for separating charged particles or ions suspended in a gas and a method of using the DMA for separating such particles. The invention includes various means for increasing the resolution of the DMA by stabilizing the laminar flow within the DMA and by allowing unusually large flow velocities.

Improvements are provided in the detection of atmospheric vapors by ionizing them near ambient pressure, and analyzing them as ions. Lowest detection limits of parts per quadrillion (ppq) concentrations are enabled by a combination of improvements, including the use of a filter to remove occasional intense signal from explosive particles. Several sources of chemical background are identified and solutions for their reduction or elimination are presented. Gains in response time may be achieved by operating at elevated temperature. When the ionizer is an electrospray source, the use of high boiling point solvents is indicated. An increased selectivity is achieved by operating a differential mobility analyzer (DMA) in series with a mass spectrometer. However, ppq sensitivities require various improvements in the DMA system including a special coupling to the ionizer, controlling the temperature in the DMA pump circuit, avoidance of induction on the DMA electrodes from heating devices, etc.

The Portable Ultrafine Particle Sizer (PUPS) invention is provided. The PUPS is an instrument which can measure particle number concentration for particle sizes under 200 nanometers The PUPS has a compact design which allows it to be mounted on vehicles with relative ease. Size discrimination is accomplished using, a compact reverse Differential Mobility Analyzer (rDMA) Particle charging is accomplished using a low-cost method for corona ionization. Concentration measurements are completed using a unique flexible printed circuit board electrode which can be easily removed for cleaning, disposal or chemical analysis of collected particles at the end of its in situ measurement life.

A periodic field differential mobility analyzer apparatus for separating and identifying ionic analytes employs a series of elongated parallel channels, a pump, a first voltage providing an electric field Ex in a direction opposing the gas flow, a second voltage providing an electric field Ey in a direction perpendicular to the gas flow, an ion source, and a detector. The periodic field differential mobility analyzer provides high resolution and sensitivity.

A system, method, and processor-readable medium are provided for quantitatively evaluating risk associated with nanotechnology. An insurance company computing system obtains nanomaterial-related data from a variety of sources, including nanomaterial sensors such as differential mobility analyzers located on-site at an insured facility. The insurance computing system uses the obtained data and a computerized model to compute a risk score that is used in evaluating the insurability of the facility or the operating entity. An insurance policy or modifications to an existing insurance premium are subsequently produced based on the computed risk score.