Techniques for processing of mass spectral data
Techniques for performing data acquisition and analysis are described. A multi-mode acquisition strategy may be performed which iteratively selects mass isolation windows of different sizes in different scan cycles to acquire experimental data. The mass isolation windows selected may provide for acquiring elevated energy scan data for a defined set of m/z values. Single scan data analysis may be performed. Data analysis may include forming precursor charge clusters, chaining precursor charge clusters having the same mass to charge ratio to form peaks profiles, and using criteria to align precursor and product ions of the experimental data. Unsupervised and supervised clustering may be performed using a database and composite ion spectra formed from experimental data. Also described are a small molecule acquisition enhancement and additional techniques applicable for biopharmaceutical and other applications.
1. A method performed by a processor of an electronic device, comprising
obtaining mass spectra data for a sample that includes a precursor molecule that has been ionized to produce precursor ions, the mass spectra data including spectra data for scans of the precursor ions and scans of product ions that result from fragmenting the precursor ions;
processing the mass spectra data with the processor to identify a precursor charge cluster (PCC) in the scans, the PCC including the precursor ions with different charges for the precursor molecule;
matching the PCC with ones of the product ions in the mass spectra data to generate a single-scan precursor product ion spectrum (SSPPIS) per scan for multiple ones of the scans;
combining SSPPIS's for the PCC to form a composite precursor-product ion spectrum (CPPIS); and
outputting the CPPIS to an output device or computer storage media.
2. The method of claim 1 , wherein the combining SSPPIS's comprises matching the SSPPI's with precursor ions and products ions of known ion fingerprint, compound or target molecule to determine if the SSPPIS's are to be included in CPPIS.
3. The method of claim 1 , wherein the combining SSPPIS's comprises performing non-supervised clustering iteratively where the non-supervised clustering combines SSPPIS's based on attributes of the precursor ions and the product ions.
4. The method of claim 1 , wherein the matching the PCC with ones of the product ions comprises performing peak detection of a liquid chromatography peak for the PCC.
5. The method of claim 4 , wherein the matching the PCC with ones of the products ions comprises applying validation criteria to ensure that the matching is valid.
6. The method of claim 5 , wherein the validation criteria include an intensity ratio of the PCC matching intensity ratios of the product ions.
7. The method of claim 1 , wherein the mass spectra are obtained from a mass spectrometry system or are obtained from a computer media storage.
8. A non-transitory computer-readable storage medium storing instructions for causing a processor of an electronic device to:
obtain mass spectra data for a sample that includes a precursor molecule that has been ionized to produce precursor ions, the mass spectra data including spectra data for scans of the precursor ions and scans of product ions that result from fragmenting the precursor ions;
process the mass spectra data with the processor to identify a precursor charge cluster (PCC) in the scans, the PCC including the precursor ions with different charges for the precursor molecule;
match the PCC with ones of the product ions in the mass spectra data to generate a single-scan precursor product ion spectrum (SSPPIS) per scan for multiple ones of the scans;
combine SSPPIS's for the PCC to form a composite precursor-product ion spectrum (CPPIS); and
output the CPPIS to an output device or computer storage media.
9. The non-transitory computer-readable storage medium of claim 8 , wherein the combining SSPPIS's comprises matching the SSPPI's with precursor ions and products ions of a known ion fingerprint, a compound or a target molecule to determine if the SSPPIS's are to be included in CPPIS.
10. The non-transitory computer-readable storage medium of claim 8 , wherein the combining SSPPIS's comprises performing non-supervised clustering iteratively where the non-supervised clustering combines SSPPIS's based on attributes of the precursor ions and the product ions.
11. The non-transitory computer-readable storage medium of claim 8 , wherein the matching the PCC with ones of the product ions comprises performing peak detection of a liquid chromatography peak for the PCC.
12. The non-transitory computer-readable storage medium of claim 11 , wherein the matching the PCC with one of the products ions comprises applying validation criteria to ensure that the matching is valid.
13. The non-transitory computer-readable storage medium of claim 12 , wherein the validation criteria include an intensity ratio of the PCC matching intensity ratios of the product ions.
14. The non-transitory computer-readable storage medium of claim 8 , wherein the mass spectra are obtained from a mass spectrometry system or are obtained from a computer media storage.
15. An electronic device, comprising:
computer storage media storing computer program instructions and mass spectra data for a sample that includes a precursor molecule that has been ionized to produce precursor ions, the mass spectra data including spectra data for scans of precursor ions and scans of the product ions that result from fragmenting the precursor ions; and
a processor for executing the computer program instructions to:
process the mass spectra data with the processor to identify a precursor charge clusters (PCC) in the scans, the PCC including the precursor ions with different charges for the precursor molecule;
match the PCC with ones of the product ions in the mass spectra data to generate a single-scan precursor product ion spectrum (SSPPIS) per scan for multiple ones of the scans;
combine SSPPIS's for a given one of the PCCs to form a composite precursor-product ion spectrum (CPPIS); and
output the CPPIS to an output device or computer storage media.
16. The electronic device of claim 15 , wherein the combining SSPPIS's comprises matching the SSPPI's with precursor ions and products ions of a known ion fingerprint, a compound or a target molecule to determine if the SSPPIS's are to be included in CPPIS.
17. The electronic device of claim 15 , wherein the combining SSPPIS's comprises performing non-supervised clustering iteratively where the non-supervised clustering combines SSPPIS's based on attributes of the precursor ions and the product ions.
18. The electronic device of claim 15 , wherein the matching the PCC with ones of the product ions comprises performing peak detection of a liquid chromatography peak for the PCC.
19. The electronic device of claim 18 , wherein the matching the PCC with one of the products ions comprises applying validation criteria to ensure that the matching is valid.
20. The electronic device of claim 19 , wherein the validation criteria include an intensity ratio of the PCC matching intensity ratios of the product ions.