Distributions of imidacloprid, imidacloprid-olefin and imidacloprid-urea in green plant tissues and roots of rapeseed (Brassica napus) from artificially contaminated potting soil.

Background: Imidacloprid-urea is the primary imidacloprid soil metabolite, whereas imidacloprid-olefin is the main plant-relevant metabolite and is more toxic to insects than imidacloprid. We artificially contaminated potting soil and used quantitative UHPLC-QqQ-MS/MS to determine the imidacloprid, imidacloprid-olefin and imidacloprid-urea distributions in rapeseed green plant tissues and roots after 4 weeks of exposure.

Results: In soil, the imidacloprid/imidacloprid-urea molar ratios decreased similarly after the 250 and 2500 µg kg imidacloprid treatments.

High-pressure thermal sterilization: food safety and food quality of baby food puree.

The benefits that high-pressure thermal sterilization offers as an emerging technology could be used to produce a better overall food quality. Due to shorter dwell times and lower thermal load applied to the product in comparison to the thermal retorting, lower numbers and quantities of unwanted food processing contaminants (FPCs), for example, furan, acrylamide, HMF, and MCPD-esters could be formed. Two spore strains were used to test the technique; Geobacillus stearothermophilus and Bacillus amyloliquefaciens, over the temperature range 90 to 121 °C at 600 MPa.

Evaluation of direct analysis in real time ionization-mass spectrometry (DART-MS) in fish metabolomics aimed to assess the response to dietary supplementation.

Ambient mass spectrometry employing a direct analysis in real time (DART) ion source coupled to a medium high-resolution/accurate mass time-of-flight mass spectrometer (TOFMS) was used as a rapid tool for metabolomic fingerprinting to study the effects of supplemental feeding with cereals (triticale) on the composition of muscle metabolites of common carp (Cyprinus carpio L.). First, the sample extraction and DART-TOFMS instrumental conditions were optimized to obtain the broadest possible representation of ionizable compounds occurring in the extracts obtained from common carp muscle.

Rapid monitoring of heat-accelerated reactions in vegetable oils using direct analysis in real time ionization coupled with high resolution mass spectrometry.

Transmission-mode direct analysis in real time ionization coupled with high resolution mass spectrometry (TM-DART-HRMS) was used to monitor chemical changes in various vegetable oils (olive, rapeseed, soybean and sunflower oil) during their thermally-induced oxidation. This novel instrumental approach enabled rapid fingerprinting of examined samples and detection of numerous sample components, such as triacylglycerols (TAGs), phytosterols, free fatty acids (FFA), and their respective oxidation products. Mass spectra obtained from DART were processed with the use of principal component analysis (PCA) in order to assess the compositional differences between heated and non-heated samples.

Rapid analysis of caffeine in various coffee samples employing direct analysis in real-time ionization-high-resolution mass spectrometry.

The development and use of a fast method employing a direct analysis in real time (DART) ion source coupled to high-resolution time-of-flight mass spectrometry (TOFMS) for the quantitative analysis of caffeine in various coffee samples has been demonstrated in this study. A simple sample extraction procedure employing hot water was followed by direct, high-throughput (<1 min per run) examination of the extracts spread on a glass rod under optimized conditions of ambient mass spectrometry, without any prior chromatographic separation. For quantification of caffeine using DART-TOFMS, an external calibration was used.

Novel approaches to analysis of 3-chloropropane-1,2-diol esters in vegetable oils.

A sensitive and accurate method utilizing ultrahigh performance liquid chromatography (U-HPLC) coupled to high resolution mass spectrometry based on orbitrap technology (orbitrapMS) for the analysis of nine 3-chloropropane-1,2-diol (3-MCPD) diesters in vegetable oils was developed. To remove the interfering triacylglycerols that induce strong matrix effects, a clean-up step on silica gel column was used. The quantitative analysis was performed with the use of deuterium-labeled internal standards.

Analysis of isoflavones in soybeans employing direct analysis in real-time ionization-high-resolution mass spectrometry.

A direct analysis in real-time (DART) ion source coupled to a high-resolution orbitrap mass spectrometer was used for the quantitative analysis of isoflavones isolated from soybeans. For the isolation of genistein, daidzein, glycitein, and their respective acetyl, malonyl, and glucoside forms, an extraction employing 80% aqueous MeOH enhanced by sonication was used. As far as the total isoflavones (expressed as aglycones) were to be determined, an acid hydrolysis with 80% aqueous EtOH and refluxing had to be employed, while in the latter case a good agreement of the results with the data generated by the UHPLC-orbitrap MS method was achieved, in the case of the analysis of non-hydrolyzed extracts, some overestimation of the results as compared with those generated by UHPLC-orbitrap MS was observed.

Direct analysis of dithiocarbamate fungicides in fruit by ambient mass spectrometry.

Dithiocarbamates (DTCs) are fungicides that require a specific single-residue method for detection and verification of compliance with maximum residue limits (MRLs) as established for fruit and vegetables in the EU. In this study, the use of ambient mass spectrometry was investigated for specific determination of individual DTCs (thiram, ziram) in fruit. Two complementary approaches have been investigated for their rapid analysis: (i) direct analysis in real time (DART) combined with medium-high resolution/accurate mass time-of-flight mass spectrometry (TOFMS) and high-resolution/accurate mass Orbitrap MS, and (ii) desorption electrospray ionization (DESI) combined with tandem-in-time mass spectrometry (MS(2)).

Recognition of beer brand based on multivariate analysis of volatile fingerprint.

Automated head-space solid-phase microextraction (HS-SPME)-based sampling procedure, coupled to gas chromatography-time-of-flight mass spectrometry (GC-TOFMS), was developed and employed for obtaining of fingerprints (GC profiles) of beer volatiles. In total, 265 speciality beer samples were collected over a 1-year period with the aim to distinguish, based on analytical (profiling) data, (i) the beers labelled as Rochefort 8; (ii) a group consisting of Rochefort 6, 8, 10 beers; and (iii) Trappist beers. For the chemometric evaluation of the data, partial least squares discriminant analysis (PLS-DA), linear discriminant analysis (LDA), and artificial neural networks with multilayer perceptrons (ANN-MLP) were tested.

Alternative GC-MS approaches in the analysis of substituted pyrazines and other volatile aromatic compounds formed during Maillard reaction in potato chips.

Several methods have been developed for the analysis of substituted pyrazines and related substances in potato chips. Following separation/detection approaches (all employing head-space solid phase microextraction, HS-SPME, for volatiles sampling), have been critically assessed in our study: (i) gas chromatography-ion trap mass spectrometry (GC-ITMS), (ii) gas chromatography-time-of-flight mass spectrometry (GC-TOFMS); (iii) comprehensive two-dimensional gas chromatography-time-of-flight mass spectrometry (GC x GC-TOFMS). Although in none of the tested systems full chromatographic resolution of some isomeric pairs could be achieved, the use of GC x GC-TOFMS offered the best solution, mainly because of distinctly lower limits of quantification (LOQs) for all of 13 target alkylpyrazines.

Traceability of honey origin based on volatiles pattern processing by artificial neural networks.

Head-space solid-phase microextraction (HS-SPME)-based procedure, coupled to comprehensive two-dimensional gas chromatography-time-of-flight mass spectrometry (GCxGC-TOF-MS), was employed for fast characterisation of honey volatiles. In total, 374 samples were collected over two production seasons in Corsica (n=219) and other European countries (n=155) with the emphasis to confirm the authenticity of the honeys labelled as "Corsica" (protected denomination of origin region). For the chemometric analysis, artificial neural networks with multilayer perceptrons (ANN-MLP) were tested.

Development of an SPME-GC-MS/MS procedure for the monitoring of 2-phenoxyethanol in anaesthetised fish.

2-Phenoxyethanol (ethylene glycol monophenyl ether, C(8)H(10)O(2)) is a promising anaesthetic agent used in fisheries and aquaculture. The aim of this study was to develop a fast and easy method to determine 2-phenoxyethanol residue levels in fish tissue and blood plasma, and, subsequently, to use the method to monitor the dynamics of 2-phenoxyethanol residues in fish treated with anaesthetic. We developed a new procedure that employs solid phase microextraction (SPME) of the target analyte from the sample headspace followed by gas chromatography-mass spectrometry (GC-MS).