Booth # 2471
Title: Qualitative Screening Software for Small Molecule
Author: Graham A. McGibbon
Date: March 3, 2010
Time: 03:00 PM (Slot #4)
Location: Room 307D
Abstract: Rapid identification of contaminants, residues, adulterants, drugs and potentially toxic compounds is demanded to protect the integrity of many sports and, more importantly, human health. The wide range of historical and emerging mass spectrometry technologies coupled with separations such as GC and LC presents an array of ways to acquire data for detecting traces of target compounds. To avoid compromising hardware selection, it would appear ideal to have software that could import and process GC/MS or LC/MS full scan data acquired from a variety of mass spectrometer types and use libraries of particular target compounds to screen specifically for their presence.
A new software algorithm enables selective extraction of ion chromatograms for libraries of target components based on known mass or molecular formula and retention time, if provided. It groups detected features into components including isotope information. A new metric is provided to assess the fit of the experimental isotope pattern versus the expected one for helping to reduce false positive assignments. Visible labels are automatically annotated onto spectra and ion chromatograms. Reports summarizing the Target Status as ‘Found’ or ‘Not Found’ can be generated.
We have analyzed datasets using a new software module that took lists of target compounds and the masses or molecular formulae that were included for calculating appropriate m/z values and then, using defined mass tolerances, extracted ion chromatograms corresponding to key isotopes from full scan data. Targets could be found for a variety of datasets including accurate mass datasets processed with mass tolerances in the range of 2-5 mDa for samples targeting over 70 compounds. Included also is the ability to use a table of modifications that can be applied to each entry in the target list, which has the potential to detect predictably transformed drugs or chemicals in biofluids, food, water or environmental samples.
Title: Searching for the Unknown: GC-MS Deconvolution and Componentization
Authors: Margaret Antler, Graham A. McGibbon
Date: March 3, 2010
Time: 03:35 PM (Slot #6)
Location: Room 205A
Abstract:Water utilities rely heavily on GC-MS analysis of water samples to monitor for potentially harmful substances, identifying component spectra by similarity searches of commercially available databases such as the Wiley/NIST Mass Spectral Library. Some of the technologies used in this application are seasoned and well tested but time demands and the potential to use newer instrumentation have led to increased attention on software capabilities. We have explored the feasibility of linking advanced data processing and MS database search algorithms to address this need and report on the possibilities for compound identification in water samples.
Our deconvolution and componentization software algorithm (IntelliXtractTM) enabled selective extraction of ion chromatograms and grouped detected features into components based on ion co-elution. For each sample, the processed results were summarized and component spectra were rendered by a customized software script appropriately for conducting an MS Search. The script interacts with the NIST MS Search utility and generated an Excel formatted report of the identified components.
We have analysed GC-MS data acquired for water samples by a laboratory in the UK to determine the feasibility of linking our advanced data processing capabilities with existing MS database search algorithms. Software algorithms need to deconvolute hyphenated MS data into co-eluting signals, while distinguishing those from instrument and chemical noise. Benefit was found using IntelliXtractTM to generate components on the basis of chromatographic features, with subsequent ability to recognize compounds relevant to EPA method 8270 in water. The entire process could be initiated by a single command within our mass spectrometry interface, which provided newly developed new capabilities for software to perform ‘push button’ compound identification by MS searching of effectively componentized spectra.
