Fast Quantitative Identification of Pesticides by Spectral Deconvolution of Gas Chromatography/Mass Spectrometry Data

The analysis of pesticides by conventional methods typically requires long run times (30 minutes or more) to achieve chromatographic resolution of target analytes. The use of the Ion Signature Quantitative Deconvolution Software to untangle complex mass spectral data allowed the operator to reduce the time required for analysis to 5 minutes by accelerating the temperature program ramp rate of the gas chromatograph. Target compound analysis of 32 pesticides, surrogates and an internal standard added to lemon oil provided results that were well with in the EPA’s precision criteria of 25% and accuracy criteria of 50%.

Identification of Pyrolysis Products using GCMS with Deconvolution Software
T.P. Wampler, CDS Analytical, Inc. and J.C. Moore, Ion Signature Technology, Inc.

The analysis of pyrolysis products by GC/MS can be a very difficult process as a large number of co-eluting compounds may be generated by the breakdown of the polymer. In addition to the fragments from the polymer, there may be semi-volatile additives scattered throughout the chromatogram. The additives may include antioxidants, flame retardants, plasticizers, light stabilizers, among others, and are typically added in small amounts. Searching through the peaks to find these unknown additives can be a very difficult task. When the Ion Signature Quantitative Deconvolution Software is used in conjunction with a pyrolysis system and additives library from CDS Analytical it is possible to rapidly characterize the additives and polymers in the sample. The software displays the untangled spectra in a series of views that let the operator rapidly and reliably identify the compounds in the sample.

Rapid Analysis of Chlorinated Pesticides, Chlorinated Biphenyls and PAH’s
Y. Gankin, A. Gorshteyn, S. Smarason and A. Robbat, Tufts University, Chemistry Department, Medford MA

The use of Ion Signature quantitative deconvolution software to untangle complex GC/MS data from coeluting compounds leads to a more rapid analytical protocol for the analysis of chlorinated pesticides, chlorinated biphenyls and PAH’s. This note describes a study that demonstrates that use of Ion Signature software with a 5 minute run time and no sample cleanup leads to data that is equivalent to data taken using a 40 minute run after SPE cleanup using conventional data reduction.

Analysis of Pesticides in Food - Identification and Quantitation of Oxychlordane in the Presence of an Unknown Pesticide in Milk
A. Williams, A. Chakrabarti, I. Munjal and D. Hite, Technical Services Laboratory Tennessee Department of Agriculture, Nashville, TN

Ion Signature Quantitative Deconvolution software was employed to untangle the mass spectrum of oxychlordane from the mass spectrum of a co-eluting compound and then determine the concentration of the pesticide in a sample of milk with a high degree of accuracy. In addition, the software was used to obtain the mass spectrum and identification of the interfering compound. The use of deconvolution software eliminated the requirement to alter the chromatographic separation to resolve the co-elution of the two compounds.

Analysis of Pesticides in Lemon Oil Extract Using Deconvolution Software
A. Robbat, Tufts University, Chemistry Department, Medford MA; A. Hoffman, GERSTEL GmbH & Co., KG, M?lheim an der Ruhr, Germany; K. MacNamara, Irish Distillers-Pernod Ricard, Co. Cork, Ireland.

The analysis of pesticides by traditional methods normally requires a long run time to achieve chromatographic resolution of target analytes. The use of Ion Signature Quantitative Deconvolution Software to untangle complicated mass spectral data reduced the time required for analysis by allowing the operator to accelerate the temperature program ramp rate of the gas chromatograph. The software is designed to perform qualitative and quantitative analyses for each component of the sample mixture by using compound-specific ion signatures to reconstruct mass spectral data for each compound, effectively deconvolving it from other co-eluted compounds and the background noise. As a result, the time required for the analysis of pesticides in lemon oil extract was reduced by approximately 70% without sacrificing data quality.

Forensic Analysis of Basic Drugs by GC/MS with Deconvolution Software
J.A. Crifasi, M.F. Bruder and C.W. Long, St. Louis University Forensic Toxicology Laboratory; R.E. Buco II, Ion Signature Technology, Inc.

IST Quantitative Deconvolution Software is able to untangle complex spectra and distinguish the presence of multiple co-eluting peaks. In this application note post-mortem samples are analyzed directly using GC/MS, in contrast to the screening with GC/NPD followed by confirmation by GC/MS. The chromatographic separation can be modified to dramatically reduce the overall run time by 70 %, and detect between 50-100% more compounds, depending on the type of sample, than when a standard GC/NPD is employed.

Simultaneous Analysis of VOC and SVOC by GC/MS using Enhanced Deconvolution
A. Robbat, Tufts University, Chemistry Department, Medford MA

The use of Ion Signature quantitative deconvolution software to detangle complex GC/MS data from coeluting compounds leads to a more rapid analytical protocol for the analysis of volatile and semi-volatile organic compounds that are normally monitored by EPA Methods SW- 486 8260 and 8270. The software extracts the signal for each component of the mixture by identifying its characteristic ion signature in the total ion chromatogram and provides the ability to identify more compounds in a sample with a single run, than were identified by the EPA methods in two runs. The new protocol takes about 20% of the total time for both EPA methods and does not involve sample clean up.