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Non‐linear and non‐constant variance calibration curves in analysis of volatile organic compounds for testing of water by the purge‐and‐trap method coupled with gas chromatography/mass spectrometry
Author(s) -
Lavagnini Irma,
Favaro Gabriella,
Magno Franco
Publication year - 2004
Publication title -
rapid communications in mass spectrometry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.528
H-Index - 136
eISSN - 1097-0231
pISSN - 0951-4198
DOI - 10.1002/rcm.1498
Subject(s) - chemistry , chromatography , calibration curve , mass spectrometry , purge , analytical chemistry (journal) , gas chromatography , constant (computer programming) , calibration , gas chromatography–mass spectrometry , volatile organic compound , detection limit , organic chemistry , statistics , mathematics , political science , law , computer science , programming language
Abstract Currently used operating conditions for analysing volatile organic compounds (VOCs) by purge‐and‐trap gas chromatography/mass spectrometry (GC/MS) produced non‐linear calibration curves with non‐uniform variance. Second‐order polynomial models therefore had to be used in weighted regression analysis of measurements of replicates spiked at various concentrations. A transparent procedure based on a reported method of very low computational complexity allowed calculation of the parameters of second‐order models, confidence bands of regression lines, prediction bands, and confidence intervals of discriminated analyte concentrations. Tolerance intervals were introduced for this last purpose. Critical, detection and quantification levels drawn from the calibration curves were compared with those calculated by the EPA method. Copyright © 2004 John Wiley & Sons, Ltd.