Time-Condensed Analyses by Mass Spectrometry

Abstract

Research has focused on the development of a new set of mathematical algorithms, encoded in C(++), when combined with a thermal desorption sample introduction system provides quantitative analysis of a wide mixture of organic compounds in under 10 min by gas chromatography/mass spectrometry. The overall goal is to condense the time of analysis, including both the times required for sample preparation and for chromatographic separation. In this paper, results are presented where compound identification has been made for polychlorinated biphenyls, chlorinated pesticides, and polycyclic aromatic hydrocarbons present in the same solution and where gas chromatography separation times have been reduced from 40 to 5 min. For the latter, all compounds elute within 3.5 min, with structural isomers identified as the same compound. The 5-min analysis provides the foundation for rapid screening and on-line chemical measurements of multicomponent mixtures. Results are also presented where these same compounds are quantitatively analyzed in 10 min, with structural isomers identified individually, in the presence of a (25% v/v) weathered gasoline/engine oil mixture. Time-condensed complex mixture detection is now feasible making possible quantitative, high-throughput sample analyses.

Dynamic work plans and field analytics, the keys to cost-effective hazardous waste site investigations

“…6 Fast GC/MS analyses were made possible by employing deFast GC/MS analyses were made possible by employing deconvolution algorithms developed at Tufts University convolution algorithms developed at Tufts University. 11 If pit samples from Round 1 were found to be contaminated with cadmium and/or lead, then soil samples from Rounds 2 and 3 were analyzed if necessary. A Leeman Laboratory (Lowell, MA) model PS-1000 sequential scanning inductively coupled plasma/optical emission spectrometer (ICP/OES) was modified to provide on-site analysis of metals.…”

“…On one hand, on-site screening yields the greatest savings as a percent of the total project cost. On the other hand, the analysis of semivolatile organics by TDGC/MS The analysis of semivolatile organics by TDGC/ MS with the mass spectral data analysis algorithms (Ion Fingerprint Detection) 6,11 produced the greatest per-sample cost savings with the mass spectral data analysis algorithms (Ion Fingerprint Detection) 6,11 produced the greatest persample cost savings; namely, $100/ sample for PCB/PAH versus $245/ sample. Based on these assumptions, savings are accrued when dynamic investigations are compared against the traditional costs for sample collection and shipping charges in addition to the cost for conducting multiple site investigations.…”

“…6,11 Unlike standard methods that obtain compound selectivity by adjusting the chromatography to separate organics, selectivity is obtained through the software. IFD reduces the per-sample analysis costs in three significant ways:…”

Environmental and Forensic applications of field-portable GC-MS: An overview

“…Targeted analyte deconvolution algorithms have been developed for post-processing GC-MS data [9]; however, real-time MS algorithms of VOCs are in the formative stages. Collection of the MS data via MIMS with the CADIS while the military vehicle is moving requires an intelligent real-time data analysis approach.…”

Fast gas chromatography/mass spectrometry analysis in support of risk-based decisions

“…At least three ions per target compound are extracted from electron-ionization low-resolution mass spectra, with signal ratios computed and compared against one another 26 . If the relative abundances meet the accepted error function then the least-interfered ion is normalized against the quantitation ion (minimum integration method).…”