Abstract: A detection signal generated in response to incident ions accelerated at temporally-irregular intervals having an average repetition rate greater than a reference repetition rate represents detection events each having an event time and an intensity. For each detection event, respective allowed TOFs between the event time and the transient times are calculated. Using respective initial probabilities, initial apportionments of the intensity of each detection event among the allowed TOFs linked thereto are determined. For each allowed TOF, the intensity apportionments thereto are accumulated to generate an intensity accumulation linked thereto. For each detection event, respective revised probabilities are iteratively determined using the intensity accumulations linked to the allowed TOFs linked thereto, and the respective intensity is iteratively reapportioned among the allowed TOFs linked thereto using the revised probabilities to transform the detection signal to a time-of-flight spectrum.

Abstract: A mass spectrum is generated by a process in which, from a mass scan signal comprising original samples defining a peak, a subset of the original samples defining the peak is selected. One or more synthesized samples are synthesized from the subset of the original samples. The one or more synthesized samples provide a temporal resolution greater than the temporal resolution of the original samples. The one or more synthesized samples are summed with respective temporally-aligned accumulated samples to produce the mass spectrum. The accumulated samples are obtained from mass scan signals generated during respective previously-performed mass scan operations.

Abstract: A detection signal generated in response to incident ions accelerated at temporally-irregular intervals having an average repetition rate greater than a reference repetition rate represents detection events each having an event time and an intensity. For each detection event, respective allowed TOFs between the event time and the transient times are calculated. Using respective initial probabilities, initial apportionments of the intensity of each detection event among the allowed TOFs linked thereto are determined. For each allowed TOF, the intensity apportionments thereto are accumulated to generate an intensity accumulation linked thereto. For each detection event, respective revised probabilities are iteratively determined using the intensity accumulations linked to the allowed TOFs linked thereto, and the respective intensity is iteratively reapportioned among the allowed TOFs linked thereto using the revised probabilities to transform the detection signal to a time-of-flight spectrum.

Abstract: A mass spectrum is generated by a process in which, from a mass scan signal comprising original samples defining a peak, a subset of the original samples defining the peak is selected. One or more synthesized samples are synthesized from the subset of the original samples. The one or more synthesized samples provide a temporal resolution greater than the temporal resolution of the original samples. The one or more synthesized samples are summed with respective temporally-aligned accumulated samples to produce the mass spectrum. The accumulated samples are obtained from mass scan signals generated during respective previously-performed mass scan operations.

Abstract: A system for detecting ions is disclosed. The system includes a detector having a plurality of dynodes arranged in an electron cascading configuration, and a power supply circuit electrically coupled to the plurality of dynodes. The plurality of dynodes include a first dynode and a second dynode. The power supply circuit is arranged to selectively adjust a potential difference between the first and second dynodes between a detection mode and a blanking mode. A method of detecting ions is also disclosed.

Abstract: A system for detecting ions is disclosed. The system includes a detector having a plurality of dynodes arranged in an electron cascading configuration, and a power supply circuit electrically coupled to the plurality of dynodes. The plurality of dynodes include a first dynode and a second dynode. The power supply circuit is arranged to selectively adjust a potential difference between the first and second dynodes between a detection mode and a blanking mode. A method of detecting ions is also disclosed.

Abstract: Methods and apparatus for electronically addressing and interrogating microarrays are disclosed. The described microarrays include a plurality of features disposed on a substrate. Each of the features has a first electrode disposed on the substrate, a second electrode disposed on the substrate, and a probe disposed between the first electrode and second electrode. The substrate also includes addressing circuitry in operable relation to the features. Method of using the microarrays are also described.

Abstract: A mass spectrum is generated by a process in which, from a mass scan signal comprising original samples defining a peak, a subset of the original samples defining the peak is selected. One or more synthesized samples are synthesized from the subset of the original samples. The one or more synthesized samples provide a temporal resolution greater than the temporal resolution of the original samples. The one or more synthesized samples are summed with respective temporally-aligned accumulated samples to produce the mass spectrum. The accumulated samples are obtained from mass scan signals generated during respective previously-performed mass scan operations.

Abstract: A mass spectrometer system includes an ion detector, a plurality of analog-to-digital (A/D) converters, an adder, and a controller. The A/D converters are configured to sample an analog signal from the ion detector at different times, and the A/D converters introduce sampling errors to digital samples generated by the A/D converters. The adder is configured to sum the digital samples, and the summed digital samples define a mass spectrum. The controller is configured to compensate for the sampling errors introduced by the A/D converters.

Abstract: Improved data acquisition systems and methods that enable large numbers of data samples to be accumulated rapidly with low noise are described. In one aspect, a data acquisition system includes an accumulator that has two or more parallel accumulation paths and is configured to accumulate corresponding data samples across a transient sequence through different accumulation paths.

Abstract: A mass spectrometer comprises an ion detector, a first amplifier, a second amplifier, and a spectra combiner. The ion detector is configured to generate an analog signal indicative of ions detected by the ion detector. The first amplifier is configured to amplify the analog signal to provide a first amplified signal having a first gain relative to the analog signal. The second amplifier is configured to amplify the analog signal to provide a second amplified signal having a second gain relative to the analog signal, and the first gain is different than the second gain. The spectra combiner is configured to combine first summed digital samples of the first amplified signal with second summed digital samples of the second amplified signal.

Abstract: A mass spectrometer system includes an ion detector, a plurality of analog-to-digital (A/D) converters, an adder, and a controller. The A/D converters are configured to sample an analog signal from the ion detector at different times, and the A/D converters introduce sampling errors to digital samples generated by the A/D converters. The adder is configured to sum the digital samples, and the summed digital samples define a mass spectrum. The controller is configured to compensate for the sampling errors introduced by the A/D converters.

Abstract: A mass spectrometer comprises an ion detector, an analog-to-digital (A/D) converter, a sample adjuster, and an adder. The A/D converter is configured to receive and sample an analog signal from the ion detector thereby providing a plurality of samples. The adder is configured to sum the samples, and the summed samples define a mass spectrum. The sample adjuster is configured to identify a peak defined by the samples and to suppress at least one of the samples of the peak such that a resolution of a peak within the mass spectrum is enhanced.

Abstract: Improved data acquisition systems and methods that enable large numbers of data samples to be accumulated rapidly with low noise are described. In one aspect, a data acquisition system includes an accumulator that has two or more parallel accumulation paths and is configured to accumulate corresponding data samples across a transient sequence through different accumulation paths.

Abstract: An apparatus for analyzing ions is described. The apparatus includes an ion source, an ion trap positioned to receive ions from the ion source; a time of flight mass analyzer, and a detector operatively coupled to the time of flight. The time of flight mass analyzer includes a pulser region, and the pulser region is positioned to receive ions from the ion trap. The apparatus further includes a scanning delay timing circuit in operable relation to the pulser region. The scanning delay timing circuit is adapted to triggering an extraction pulse at the pulser region. Methods of analyzing ions by mass spectrometry are also described.

Abstract: An apparatus for analyzing ions is described. The apparatus includes an ion source, an ion trap positioned to receive ions from the ion source; a time of flight mass analyzer, and a detector operatively coupled to the time of flight. The time of flight mass analyzer includes a pulser region, and the pulser region is positioned to receive ions from the ion trap. The apparatus further includes a scanning delay timing circuit in operable relation to the pulser region. The scanning delay timing circuit is adapted to triggering an extraction pulse at the pulser region. Methods of analyzing ions by mass spectrometry are also described.

Abstract: Methods and apparatus for electronically addressing and interrogating microarrays are disclosed. The described microarrays include a plurality of features disposed on a substrate. Each of the features has a first electrode disposed on the substrate, a second electrode disposed on the substrate, and a probe disposed between the first electrode and second electrode. The substrate also includes addressing circuitry in operable relation to the features. Method of using the microarrays are also described.

Abstract: A device for electronic detection of a target includes a probe, e.g. an oligonucleotide, attached to a pad of resistive material, wherein the pad is adjacent a first electrode and also is adjacent a second electrode. In use, the probe is contacted with a sample containing the target, e.g. a target nucleic acid, under conditions and for a time sufficient to allow target to bind the probe. An enhancement reaction is then applied to result in a change in an observable property of the device. The observable property is then monitored using measurement apparatus operably associated with the device. Typically, multiple devices will be present on an array of devices, allowing multiplex analysis of multiple different targets using a single array of devices.

Abstract: A mass spectrometer having an ion accelerator and an ion detector utilizing a finite impulse response filter is disclosed. The ion accelerator generates an ion pulse in response to a start signal. A clock increments a register that indicates the time that has elapsed since the start signal. The ion detector is spatially separated from the ion accelerator and generates a measurement signal indicative of ions striking the detector. The measurement signal is filtered through a finite impulse response filter to form a filtered measurement signal. The finite impulse response filter has a filter function that depends on the impulse response of the ion detector. In one embodiment, the mass spectrometer includes a memory that is addressed by the register value and an adder. The adder forms the sum of the data value specified by the register value and the output value from the finite impulse response filter.

Abstract: A summed TOFMS having a filter for identifying detector outputs that are likely the result of noise rather than ions striking the ion detector. The TOFMS stores a plurality of data values at locations specified by a register that counts clock pulses. The filter receives the ion measurements from the ion detector and generates an output measurement value corresponding to each ion measurement. The filter sets the output measurement value to a predetermined baseline value if the filter determines that the ion measurement is noise, otherwise the filter sets the output measurement value to the ion measurement. An adder, responsive to the clock signal, forms the sum of the data value specified by the register value and the output measurement value and stores the sum in the memory at the location corresponding to the register value.