Advantages of a programmed temperature vaporizer inlet and parallel factor analysis in the determination of triazines in the presence of non-intentionally added substances by gas chromatography

Abstract

Non-intentionally added substances (NIASs) are usually detected by acquiring mass spectra in full scan mode and then identifying the compounds corresponding to the unexpected peaks. High-resolution mass spectrometry detectors are frequently used, but this does not solve the problem that an NIAS can contribute to the abundance at m/z ratios that correspond to the fragmentation of other molecules. This problem leads to false negatives when identifying compounds, even in target analysis when the maximum permitted tolerances for relative ion abundances (SANCO/10684/2009) are taken into account. In this work, the introduction of different volumes of a test sample onto a GC/MS system that has a programmed temperature vaporizer inlet and is operating in full scan mode provides a data tensor. The proposed approach consists of considering the structure of the matrix of abundances of K m/z ratios acquired at J elution times for each chromatographic peak. Upon concatenating I of such matrices, a three-way tensor X is obtained, which is then decomposed using parallel factor analysis into as many factors as there are substances coeluting, thus providing the mass spectrum and the chromatographic profile for each of them. If the amount of an analyte changes significantly during the I injections, then it can be unequivocally identified. This procedure thus identifies coeluting NIASs, provides information about their mass spectra, and guarantees the identification and quantification of target compounds. In this work, it is used to determine five triazines in the presence of NIASs which match some of the m/z ratios of the triazines and coelute with them. Decision limits (CCα) of between 7.5 and 25.0 μg L(-1) were obtained.

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

“…This implies in general the presence of coeluents that have a similar retention time and, besides, share some m/z ions with the target analyte. The presence of nontarget compounds can cause false negatives during pesticides identification [51] due to the fail in complying with the maximum permitted tolerances for relative ion abundances established in the regulations. Figure 9 depicts the total ion chromatogram from the injection of an extract obtained, after QuEChERS procedure, of a fortified sample of orange.…”

Improvement in the identification and quantification of UV filters and additives in sunscreen cosmetic creams by gas chromatography/mass spectrometry through three-way calibration techniques

“…Several three-way algorithms can be used with chromatographic signals. Previous works [40,41,42] have demonstrated the usefulness of three-way calibrations based on the PARAFAC decomposition using chromatographic data obtained with different detectors that provide multivariate signals (mass spectrometers or diode array detectors) [43]. These works highlight the advantage of using the abundances recorded at all the ions selected (or the absorbance spectrum) when quantifying or identifying the analytes according to the requirements stated in European regulations.…”

Review of analytical approaches for the identification of non-intentionally added substances in paper and board food contact materials

“…Four different extraction methods were set up, based on the sample being either high-fat foods, low-fat foodstuffs, aqueous-based beverages, or packaging material, and analysis was performed by means of GC-MS with electron ionization (EI). Parigoridi et al analysed 3 types of recycled cardboards on the presence of 5 organic pollutants by means of GC-EI-MS, and applied UAE with dichloromethane as an extraction method, but also performed a migration experiment with Tenax(Parigoridi et al, 2014) Rubio et al (2012). have analysed triazines in the presence of NIAS by means of GC-EI-MS in full scan mode, equipped with a programmed temperature vaporizer inlet (PTV).…”