Abstract: The disclosed signal quality assessment is particularly useful for mass spectrometry. In an embodiment of the disclosed system, a processor utilizes a wavelet-based feature extraction for the signal quality assessment of a chromatogram signal. The signal quality assessment may be used to control operational parameters, such as a flowrate of a pump that moves liquid droplets toward an ionization device of a mass spectrometer.

Abstract: Devices and methods are described for assigning charge state to detected ions from a mass analysis instrument. In one of the methods, the charge state may be assigned, for instance, by evaluation a detector response signal including information related to individual ion responses generated by an ion detector for each ion arrival event captured by the detector. The detector response signal may then be evaluated in combination with one or more additional features corresponding to the ion arrival event to assign a charge state for that ion arrival event.

Abstract: A method for assigning charge state in mass spectrometry includes receiving a detector response signal corresponding to a plurality of ion arrival events. The detector response signal includes information related to individual ion responses generated by a detector for each ion arrival event. Detector response profiles are generated for mass-to-charge (m/z) bins of a mass spectrum generated from the ion arrival events based on the detector response signal. The m/z bins are grouped into a plurality of groups based on a similarity of the detector response profiles of the m/z bins. A charge state is assigned to one or more features based on the groups of m/z bins.

Abstract: A trace of intensity versus time values is received for a series of samples produced by a mass spectrometer. Also, a series of ejections times corresponding to the series of samples produced by a sample introduction system is received. A series of expected peak times corresponding to the series of ejection times are calculated using a known delay time from ejection to mass analysis. At least one isolated peak of the trace is identified using the series of expected peak times. A peak profile is calculated by fitting a mixture of at least two different distribution functions to the at least one isolated peak. For at least one time of the series of expected peak times, an area of a peak at the one time is calculated by fitting the peak profile to the trace at the one time and calculating an area of the fitted peak profile.

Abstract: Systems and methods are disclosed for identifying actual XIC peaks of compounds of interest from samples so that more accurate expected retention times and more accurate expected retention time windows can be calculated. In one system, an actual XIC peak is identified using standard samples. The ratio of the quantity of the compound of interest in any two different samples is known, so this ratios is compared to the intensities of the XIC peak calculated in the two samples to identify an actual XIC peak. In another system, an actual XIC peak is identified using information about other compounds of interest in a plurality of samples. It is known that the XIC peaks of compounds of interest in the same samples have a similar distribution of retention times across those samples, so the distributions of retention times of XIC peaks are compared to identify actual XIC peaks.

Abstract: A precursor ion transmission window is moved in overlapping steps across a precursor ion mass range. The precursor ions transmitted at each overlapping step by the mass filter are fragmented or transmitted. Intensities or counts are detected for each of the one or more resulting product ions or precursor ions for each overlapping window that form mass spectrum data for each overlapping window. Each unique product ion detected is encoded in real-time during data acquisition. This encoding includes sums of counts or intensities of each unique ion detected the overlapping windows and positions of the windows associated with each sum. The encoding for each unique ion is stored in a memory device rather than the mass spectral data. A deblurring algorithm or numerical method is used to determine a precursor ion of each unique ion from the encoded data.

Abstract: Systems and methods are disclosed for determining if the dynamic range of quantitation in mass spectrometry can be extended. A DIA method is performed on a sample for a compound of interest at each acquisition time of a plurality of acquisition times. A plurality of product ion spectra are produced for each window of two or more precursor ion mass selection windows. A known product ion of the compound of interest is selected. Two or more XICs are calculated from two or more different precursor ion windows for the known product ion. A ratio of one XIC of the two or more XICs to at least one other XIC of the two or more XICs is calculated. If the ratio is above a threshold, the XIC is used in the quantitation. If not, two or more XICs can be combined into a single XIC that is used for the quantitation.

Abstract: Systems and methods are disclosed for determining if the dynamic range of quantitation in mass spectrometry can be extended. A DIA method is performed on a sample for a compound of interest at each acquisition time of a plurality of acquisition times. A plurality of product ion spectra are produced for each window of two or more precursor ion mass selection windows. A known product ion of the compound of interest is selected. Two or more XICs are calculated from two or more different precursor ion windows for the known product ion. A ratio of one XIC of the two or more XICs to at least one other XIC of the two or more XICs is calculated. If the ratio is above a threshold, the XIC is used in the quantitation. If not, two or more XICs can be combined into a single XIC that is used for the quantitation.

Abstract: Systems and methods are provided for calculating the area of a peak profile using information from one or more correlated peak profiles. One or more compounds are separated from a mixture over time using a separation device. Traces of the one or more compounds are monitored during the separation using a tandem mass spectrometer. A plurality of intensity measurements are received using a processor. A first peak profile for a compound of interest is detected from the plurality of intensity measurements for a first trace and one or more correlated peak profiles for the compound of interest are detected from the plurality of intensity measurements for one or more other traces using the processor. An area of the first peak profile is calculated based on the one or more correlated peak profiles using the processor.

Abstract: A system is disclosed for identifying a precursor ion of a product ion in a scanning DIA experiment. A precursor ion mass selection window is scanned across a precursor ion mass range of interest, producing a series of overlapping windows across the precursor ion mass range. Each overlapping window is fragmented and mass analyzed, producing a plurality of product ion spectra for the mass range. A product ion is selected from the spectra. Intensities for the selected product ion are retrieved for at least one scan across the mass range producing a trace of intensities versus precursor ion m/z. A matrix multiplication equation is created that describes how one or more precursor ions correspond to the trace for the selected product ion. The matrix multiplication equation is solved for one or more precursor ions corresponding to the selected product ion using a numerical method.

Abstract: Systems and methods are disclosed for identifying actual XIC peaks of compounds of interest from samples so that more accurate expected retention times and more accurate expected retention time windows can be calculated. In one system, an actual XIC peak is identified using standard samples. The ratio of the quantity of the compound of interest in any two different samples is known, so this ratios is compared to the intensities of the XIC peak calculated in the two samples to identify an actual XIC peak. In another system, an actual XIC peak is identified using information about other compounds of interest in a plurality of samples. It is known that the XIC peaks of compounds of interest in the same samples have a similar distribution of retention times across those samples, so the distributions of retention times of XIC peaks are compared to identify actual XIC peaks.

Abstract: A system is disclosed for identifying a precursor ion of a product ion in a scanning DIA experiment. A precursor ion mass selection window is scanned across a precursor ion mass range of interest, producing a series of overlapping windows across the precursor ion mass range. Each overlapping window is fragmented and mass analyzed, producing a plurality of product ion spectra for the mass range. A product ion is selected from the spectra. Intensities for the selected product ion are retrieved for at least one scan across the mass range producing a trace of intensities versus precursor ion m/z. A matrix multiplication equation is created that describes how one or more precursor ions correspond to the trace for the selected product ion. The matrix multiplication equation is solved for one or more precursor ions corresponding to the selected product ion using a numerical method.

Abstract: An m/z range of an ion beam is divided into two or more precursor ion mass selection windows. A pattern of two or more different window m/z ranges to be used during two or more successive cycles for at least one precursor ion mass selection window is determined. The pattern includes an initial window m/z range and one or more successively different window m/z ranges. Each of the one or more successively different window m/z ranges includes at least a portion of the initial window m/z range. A tandem mass spectrometer is instructed to select and fragment the two or more precursor ion mass selection windows during each cycle of a plurality of cycles and to repeatedly use the pattern for each group of two or more successive cycles of the plurality of cycles for the selection and fragmentation of the at least one precursor ion mass selection window.

Abstract: One or more known compounds of a sample are ionized. At least one precursor ion corresponding to a compound of the one or more known compounds is selected and fragmented, producing a product ion mass spectrum for the precursor ion. An m/z tolerance probability function that varies from 1 to 0 with increasing values of an m/z difference between two mass peaks and that includes one or more values between 1 and 0 is received. A library product ion mass spectrum for the at least one compound is retrieved from a memory. An m/z difference between at least one experimental product ion mass peak in the product ion mass spectrum and at least one library product ion mass peak in the library product ion mass spectrum is calculated. An m/z tolerance probability that determines if the two peaks are corresponding peaks is calculated from the m/z difference using the probability function.

Abstract: An m/z range of an ion beam is divided into two or more precursor ion mass selection windows. A pattern of two or more different window m/z ranges to be used during two or more successive cycles for at least one precursor ion mass selection window is determined. The pattern includes an initial window m/z range and one or more successively different window m/z ranges. Each of the one or more successively different window m/z ranges includes at least a portion of the initial window m/z range. A tandem mass spectrometer is instructed to select and fragment the two or more precursor ion mass selection windows during each cycle of a plurality of cycles and to repeatedly use the pattern for each group of two or more successive cycles of the plurality of cycles for the selection and fragmentation of the at least one precursor ion mass selection window.

Abstract: One or more known compounds of a sample are ionized. At least one precursor ion corresponding to a compound of the one or more known compounds is selected and fragmented, producing a product ion mass spectrum for the precursor ion. An m/z tolerance probability function that varies from 1 to 0 with increasing values of an m/z difference between two mass peaks and that includes one or more values between 1 and 0 is received. A library product ion mass spectrum for the at least one compound is retrieved from a memory. An m/z difference between at least one experimental product ion mass peak in the product ion mass spectrum and at least one library product ion mass peak in the library product ion mass spectrum is calculated. An m/z tolerance probability that determines if the two peaks are corresponding peaks is calculated from the m/z difference using the probability function.

Abstract: Systems and methods are provided to perform dead time correction. An observed ion count rate is obtained using a non-paralyzable detection system of a mass spectrometer. The detection system includes an ion detector, a comparator/discriminator, a mono-stable circuit and a counter. The non-paralyzable detection system exhibits dead time extension at high count rates. The extension of the dead time occurs because the mono-stable circuit requires a rising edge to trigger and can only be triggered again after the output pulse from the comparator/discriminator has gone low. This allows a second comparator/discriminator pulse arriving just before the end of the dead time started by a first comparator/discriminator pulse to extend the dead time to the trailing edge of the second comparator/discriminator pulse. A true ion count rate is calculated by performing dead time correction of the observed ion count rate.

Abstract: Systems and methods are provided for calculating the area of a peak profile using information from one or more correlated peak profiles. One or more compounds are separated from a mixture over time using a separation device. Traces of the one or more compounds are monitored during the separation using a tandem mass spectrometer. A plurality of intensity measurements are received using a processor. A first peak profile for a compound of interest is detected from the plurality of intensity measurements for a first trace and one or more correlated peak profiles for the compound of interest are detected from the plurality of intensity measurements for one or more other traces using the processor. An area of the first peak profile is calculated based on the one or more correlated peak profiles using the processor.

Abstract: Systems and methods are provided to perform dead time correction. An observed ion count rate is obtained using a non-paralyzable detection system of a mass spectrometer. The detection system includes an ion detector, a comparator/discriminator, a mono-stable circuit and a counter. The non-paralyzable detection system exhibits dead time extension at high count rates. The extension of the dead time occurs because the mono-stable circuit requires a rising edge to trigger and can only be triggered again after the output pulse from the comparator/discriminator has gone low. This allows a second comparator/discriminator pulse arriving just before the end of the dead time started by a first comparator/discriminator pulse to extend the dead time to the trailing edge of the second comparator/discriminator pulse. A true ion count rate is calculated by performing dead time correction of the observed ion count rate.

Abstract: Systems and methods are used to predict intensities for points not measured or not measured with a high degree of confidence of a peak using a peak predictor. A set of data is selected from the plurality of intensity measurements that includes a peak. Confidence values are assigned to each data point in the set of data producing a plurality of confidence value weighted data points. A peak predictor is selected. The peak predictor is applied to the plurality of confidence value weighted data points of the peak that have confidence values greater than a first threshold level using the prediction module, producing predicted intensities for data points of the peak not measured and/or measured data points of the peak that have confidence values less than or equal to a second threshold level. The confidence values can include system confidence values, predictor confidence values, or any combination of the two.