title: Chromatographic peak reconstruction algorithm to improve qualitative and quantitative analysis of trace pesticide residues.
abstract: BACKGROUND
  In order to improve analysis of analytes in trace amounts in a complex matrix, we developed a novel post-processing method, named Chromatographic Peak Reconstruction (CPR), to process the recorded data from gas chromatography/time-of-flight mass spectrometry (GC/TOFMS).
  
  
  METHODS
  For a trace ion, the relative deviation (δ) between the adjacent scanned mass-to-charge ratios (m/z) was found to be inversely proportional to its MS peak intensity. Based on this relationship, the thresholds of δ value within the specified intensity segments were estimated by the CPR and used to screen out the suspicious scan-points in the extracted ion chromatographic (EIC) peak. Then, the intensities of these suspicious scan-points were calibrated to reconstruct a new EIC peak.
  
  
  RESULTS
  In the qualitative analysis of 118 pesticides, 107 out of the test pesticides can be confirmed. The corrected response ratios of the qualitative ion (q) over the quantitative ion (Q), q/Q, became closer to their references. In the quantitative analysis of 10 test pesticides at 5 ppb, the relative errors of the calculated concentrations after using the CPR were below ±1.55%, down from ±2.29% without using the CPR.
  
  
  CONCLUSIONS
  The developed CPR showed great potential in the analysis of trace analytes in complex matrices. It was proved to be a helpful data processing method for the monitoring of trace pesticide residues. Copyright © 2016 John Wiley & Sons, Ltd.
authors.affiliation: Department of Chemistry, Innovative Drug Research Center, Shanghai University, 99 Shangda Road, Shanghai, 200444, China.|State Key Laboratory of Organometallic Chemistry and National Center for Organic Mass Spectrometry in Shanghai, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, 345 Lingling Road, Shanghai, 200032, China.
authors.forename: Xiu-Ping
authors.initials: XP
authors.lastname: Chen
authors.affiliation: State Key Laboratory of Organometallic Chemistry and National Center for Organic Mass Spectrometry in Shanghai, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, 345 Lingling Road, Shanghai, 200032, China.
authors.forename: Ruo-Jing
authors.initials: RJ
authors.lastname: Fan
authors.affiliation: State Key Laboratory of Organometallic Chemistry and National Center for Organic Mass Spectrometry in Shanghai, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, 345 Lingling Road, Shanghai, 200032, China.
authors.forename: Fang
authors.initials: F
authors.lastname: Zhang
authors.affiliation: State Key Laboratory of Organometallic Chemistry and National Center for Organic Mass Spectrometry in Shanghai, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, 345 Lingling Road, Shanghai, 200032, China.
authors.forename: Zhong-Quan
authors.initials: ZQ
authors.lastname: Li
authors.affiliation: Department of Chemistry, Innovative Drug Research Center, Shanghai University, 99 Shangda Road, Shanghai, 200444, China.
authors.forename: Bin
authors.initials: B
authors.lastname: Xu
authors.affiliation: State Key Laboratory of Organometallic Chemistry and National Center for Organic Mass Spectrometry in Shanghai, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, 345 Lingling Road, Shanghai, 200032, China.
authors.forename: Yin-Long
authors.initials: YL
authors.lastname: Guo