Application of chemometrics to resolve overlapping mass spectral peak clusters between trichloroethylene and its deuterated internal standard. (25th March 2015)

• Record Type: Journal Article
• Authors: Zhang, Mengliang; Harrington, Peter de B.
• Is Part Of: Rapid communications in mass spectrometry. Volume 29:Number 9(2015)
• Page Start: 789
• Page End: 794
• Publication Date: 2015-03-25
• Subjects: Mass spectrometry -- Periodicals; 543.65
• DOI: 10.1002/rcm.7164
• Languages: English
• ISSNs: 0951-4198

Abstract

Abstract : Rationale: Using one or two 2 H‐atom‐labeled analogs as internal standards (ISs) may cause a 'cross‐contribution' problem (i.e., the overlap of ions from the IS and the analyte) especially for halogenated volatile organic compounds (VOCs). However, in this situation the overlapping peak clusters of the analyte and ISs can be resolved by multivariate chemometric methods such as classical least‐squares (CLS) and inverse least‐squares (ILS). Methods: Trichloroethylene (TCE) and its internal standard, deuterated TCE (TCE‐ d ), as model compounds, were analyzed using portable gas chromatography/mass spectrometry. CLS and ILS were applied to resolve overlapping TCE and TCE‐ d mass spectral signals and evaluated for the determination of TCE. CLS and ILS models were constructed and used to predict concentration ratios of TCE to TCE‐ d . Calibration samples were prepared by adding TCE at different concentrations and TCE‐ d at 300 ng mL –1 as an IS. Results: The calibration curve was linear over a range of 10–1000 ng mL –1 with a coefficient of determination ( R 2 ) of 0.993. A validation data set collected 2 weeks later was used to further test the model robustness. Lower prediction errors and higher correlation coefficients were obtained from TCE/TCE‐ d ratios predicted by the CLS model. Conclusions: This paper describes the first application of CLS to deconvolute overlapping peaks between an analyte and its corresponding isotopic internal standard for quantification. The proposed method enables simple isotopic analogs of analytes (one H or C atom is isotopically labeled) to be used as internal standards for analytes with isotopic distributions. It has wide application because of the environmental impact and prevalence of halogenated VOCs, especially when analytes have isotopic distributions that overlap with an internal standard or when sophisticated isotopic analogs of the analytes with three or more 2 H‐ or/and 13 C‐atoms are prohibitively expensive or even impossible. Copyright © 2015 John Wiley & Sons, Ltd.