D-optimal experimental design coupled with parallel factor analysis 2 decomposition a useful tool in the determination of triazines in oranges by programmed temperature vaporization–gas chromatography–mass spectrometry when using dispersive-solid phase extraction

Abstract

15 16 The determination of triazines in oranges using a GC/MS system coupled to a programmed 17 temperature vaporizer (PTV) inlet in the context of legislation is performed. Both 18 pretreatment (using a Quick Easy Cheap Effective Rugged and Safe (QuEChERS) procedure) 19 and injection steps are optimized using D-optimal experimental designs for reducing the 20 experimental effort. The relative dirty extracts obtained and the elution time shifts make it 21 necessary to use a PARAFAC2 decomposition to solve these two usual problems in the 22 chromatographic determinations. The "second-order advantage" of the PARAFAC2 23 decomposition allows unequivocal identification according to document SANCO/12495/2011 24 (taking into account the tolerances for relative retention time and the relative abundance for 25 the diagnostic ions), avoiding false negatives even in the presence of unknown co-eluents. 26The detection limits (CCα) found, from 0.51 to 1.05 µg kg -1 , are far below the maximum 27 residue levels (MRLs) established by the European Union for simazine, atrazine, 28 terbuthylazine, ametryn, simetryn, prometryn and terbutryn in oranges. No MRL violations 29 were found in the commercial oranges analysed. 30 31

Usefulness of PARAFAC for the Quantification, Identification, and Description of Analytical Data

“…In this situation, Ref. [56] reports an innovative procedure in the field of experimental optimization, where the responses to be optimized are the sample loadings of a PARAFAC2 model. Part of this section has been extracted from the mentioned work.…”

Ad-hoc blocked design for the robustness study in the determination of dichlobenil and 2,6-dichlorobenzamide in onions by programmed temperature vaporization-gas chromatography–mass spectrometry

“…It is particularly helpful for determining compounds of interest in food 114 commodities [19,24], for solving problems as small retention time shifts, severe interferences 115 caused by unexpected derivatization artifacts or by co-eluents of the complex matrix which 116 share m/z ratios with the target compounds. The second-order advantage of PARAFAC2 117 allows the determination of the target analytes in samples where unknown interferents are 118 present without the need of calibrate them.…”

Determination of dichlobenil and its major metabolite (BAM) in onions by PTV–GC–MS using PARAFAC2 and experimental design methodology

“…Target compounds are extracted from onions with a QuEChERS modified procedure which involves a dispersive solid phase extraction (dSPE) step, and subsequently extracts are derivatized with BSTFA (N,Obis(trimethylsilyl)trifluoroacetamide) and injected into the chromatographic system Optimization of some experimental parameters of the steps implied in the chromatographic analysis is approached using the experimental design methodology, response surface and Doptimal designs. Several examples can be found in the literature on the use of this methodology to optimize some step of chromatographic determinations (as extraction or derivatization) [18,19], and other where it is coupled to second-order calibration techniques for giving a powerful tool of analysis [13,20,21,22,23]. In addition, the Derringer's desirability function [24,25,26], a multiobjective optimization technique, is used to simultaneously optimizing multiple responses because of its user flexibility in selecting optimum conditions for analysis.…”

“…PARAFAC2 model [11,12] has been shown to be very useful in determining target compounds in food commodities [13,14,15,16,17] by solving problems with co-eluting interferents, little shifts in the retention time, low signal-to-noise ratios, etc., which are usual worries to tackle in chromatographic determinations [16,15]. This three-way technique of analysis makes discrimination possible from co-eluting matrix components; this is the "second-order advantage" of the PARAFAC2 algorithm.…”