A reliable and quick strategy for the discrimination between recycled and virgin polyethylene terephthalate water bottles was developed by applying Raman spectroscopy combined with chemometrics. ...Chemometric models were created by orthogonal partial least square discriminate analysis (OPLS‐DA) using the Raman spectra dataset in the range of 600–1800 cm−1. The Pareto scale model allowed the classification of virgin and recycled terephthalate of polyethylene (PET) samples with a percentage of success of about 95%. In addition, PLS regression was carried out to determine the level of recycled material in the PET water bottles with a good fit (R2 = 0.8920). This analytical approach shows a quick, accurate, and robust way to detect and quantify the adulteration of plastic bottles with recycled plastic materials to avoid fraud in the recycling plastic area.
The combination of Raman and chemometrics allowed us to detect recycled PET bottles. OPLS‐DA model enabled the classification of virgin and recycled PET. Partial least square regression estimated the level of recycled PET content in bottles.
Hydroxylated polycyclic aromatic hydrocarbons are metabolites of persistent organic pollutants which are formed during the bioactivation process of biological matrices and whose toxicity is being ...studied. The aim of this work was the development of a novel analytical method for the determination of these metabolites in human tissues, known to have bioaccumulated their parent compounds. Samples were treated by salting‐out assisted liquid‐liquid extraction and the extracts were analyzed by ultra‐high performance liquid chromatography coupled to mass spectrometry with a hybrid quadrupole‐time‐of‐flight analyzer. The proposed method achieved limits of detection in the 0.15–9.0 ng/g range for the five target analytes (1‐hydroxynaphthalene, 1‐hydroxypyrene, 2‐hydroxynaphthalene, 7‐hydroxybenzoapyrene, and 9‐hydroxyphenanthrene). The quantification was achieved by matrix‐matched calibration using 2,2´‐biphenol as internal standard. For all compounds, relative standard deviation, calculated for six successive analyses, was below 12.1%, demonstrating good precision for the developed method. None of the target compounds was detected in the 34 studied samples. Moreover, an untargeted approach was applied to study the presence of other metabolites in the samples, as well as their conjugated forms and related compounds. For this objective, a homemade mass spectrometry database covering 81 compounds was created and none of them was detected in the samples.
Determination of principal ergot alkaloids in swine feeding Arroyo‐Manzanares, Natalia; Rodríguez‐Estévez, Vicente; García‐Campaña, Ana M ...
Journal of the science of food and agriculture,
September 2021, Letnik:
101, Številka:
12
Journal Article
Microplastics may be present in the environment as primary microplastics (manufactured) or secondary microplastics (result of the continuous degradation of larger plastic pieces into smaller ...fragments due to environmental, physicochemical and biotic factors). To fully understand the dynamics of microplastic particles and their environmental effects, harmonized, automated, cheap, rapid and reliable methodologies for sampling, extraction and characterization of microplastic need to be developed. This review focuses on the potential of thermal analytical techniques for microplastics characterization and highlights some of the new trends in this area.
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•The presence of microplastics in the environment poses a severe risk for ecosystems.•Strategies for extracting microplastics from different matrices need to be improved.•Simple, validated and rapid methods for microplastics characterization are needed.•Thermal techniques show a strong potential for microplastics characterization.
The peach is one of the most popular and widely consumed fruits in Europe. Spain is the largest peach-producing country in the world with several growing areas recognised by consumers. This work ...focuses on the development, optimisation and validation of a non-targeted metabolomics strategy for the determination of peach volatile organic compounds from different origins by headspace gas chromatography coupled to mass spectrometry (HS–GC–MS). The volatil profile found in each sample is used to classify peaches according to their origin. The results obtained were processed using MS-DIAL software and 279 features were detected, of which 102 volatile compounds were tentatively identified and 30 of them could also be quantified. In addition, the areas of all the features were used to build models based on orthogonal partial least squares discriminant analysis (OPLS-DA) to differentiate peaches according to their geographical origin. A very promising model was obtained, with a validation rate of 90.32%, which means that it could be used to guarantee the Protected Designation of Origin of different peaches with a simple analysis.
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•Volatile organic compounds in peaches are monitored using HS–GC–MS.•A non-targeted metabolomics strategy is proposed.•Peaches are differentiated according to their geographical origin.•Compounds that distinguish peaches from different areas are established.
The botanical origin of honey determines its composition and hence properties and product quality. As a highly valued food product worldwide, assurance of the authenticity of honey is required to ...prevent potential fraud. In this work, the characterisation of Spanish honeys from 11 different botanical origins was carried out by headspace gas chromatography coupled with mass spectrometry (HS-GC-MS). A total of 27 volatile compounds were monitored, including aldehydes, alcohols, ketones, carboxylic acids, esters and monoterpenes. Samples were grouped into five categories of botanical origins: rosemary, orange blossom, albaida, thousand flower and "others" (the remaining origins studied, due to the limitation of samples available). Method validation was performed based on linearity and limits of detection and quantification, allowing the quantification of 21 compounds in the different honeys studied. Furthermore, an orthogonal partial least squares-discriminant analysis (OPLS-DA) chemometric model allowed the classification of honey into the five established categories, achieving a 100% and 91.67% classification and validation success rate, respectively. The application of the proposed methodology was tested by analysing 16 honey samples of unknown floral origin, classifying 4 as orange blossom, 4 as thousand flower and 8 as belonging to other botanical origins.
A survey on 120 cereal samples (barley, maize, rice and wheat) from Algerian markets has been carried out to evaluate the presence of 15 mycotoxins (ochratoxin A, deoxynivalenol, fumonisin B1 and B2, ...T-2 and HT-2 toxins, zearalenone, fusarenon X, citrinin, sterigmatocystin, enniatins A, A1, B and B1, and beauvericin). With this purpose, a QuEChERS-based extraction and ultra-high performance liquid chromatography coupled to tandem mass spectrometry (UHPLC-MS/MS) were used. Analytical results showed that 78 cereal samples (65%) were contaminated with at least one toxin, while 50% were contaminated with three to nine mycotoxins. T-2 toxin, citrinin, beauvericin and deoxynivalenol were the most commonly found mycotoxins (frequency of 50%, 41.6%, 40.8% and 33.3%, respectively). Fumonisins (B1 + B2), enniatins B and B1, deoxynivalenol and zearalenone registered high concentrations (289-48878 µg/kg, 1.2-5288 µg/kg, 15-4569 µg/kg, 48-2055 µg/kg and 10.4-579 µg/kg, respectively). Furthermore, concentrations higher than those allowed by the European Union (EU) were observed in 21, 8 and 1 samples for fumonisins, zearalenone and deoxinivalenol, respectively. As a conclusion, the high levels of fumonisins (B1 + B2) in maize and deoxynivalenol, zearalenone and HT-2 + T-2 toxins in wheat, represent a health risk for the average adult consumer in Algeria. These results pointed out the necessity of a consistent control and the definition of maximum allowed levels for mycotoxins in Algerian foodstuffs.
Dispersive magnetic solid-phase extraction (DMSPE) technique is proposed as a new sensitive and effective sample treatment method for the determination of aflatoxins in paprika samples. DMSPE was ...followed by ultrahigh-performance liquid chromatography and high-resolution mass spectrometry detection (UHPLC-HRMS) using a non-targeted acquisition mode for the detection of main aflatoxins (aflatoxin G1, G2, B1 and B2) and derivatives. DMSPE was based on the use of magnetic nanocomposite coated with polypyrrole (PPy) polymer and the main experimental parameters influencing the extraction efficiency in adsorption and desorption steps have been studied and optimized. Analyses were performed using 250 µL magnetic PPy nanocomposite into the sample solution, adsorbing the analytes in 30 min and desorbing them with ethyl acetate (2 mL) in 15 min. The method has been validated, obtaining quantification limits between 3.5 and 4.7 µg kg
and recoveries between 89.5-97.7%. The high recovery rate, wide detection range and the use for the first time of the reusable Fe
O
@PPy nanomaterial in suspension for solid food matrices, guarantee the usefulness of the method developed for adequate control of aflatoxins levels in paprika. The proposed methodology was applied for the analysis of 31 samples (conventional and organic) revealing the absence of aflatoxins in the samples.
Magnetic molecularly imprinted polymers (MMIPs) have fused molecular imprinting technology with magnetic separation technology, emerging as an innovative material capable of recognizing specific ...molecules and efficiently separating target substances. Their application to the extraction and purification of mycotoxins has great potential, due to the toxicity and economic impact of these contaminants. In this work, MMIP has been proposed as a sample treatment for the determination of main four aflatoxins (B
, B
, G
and G
) in pig feed. The MMIP was formed through the integration of magnetic material (Fe
O
) with commercial molecularly imprinted polymers, avoiding the synthesis step and, therefore, simplifying the process. The analyses were carried out by high-performance liquid chromatography with fluorescence detection and the method was validated and limits of quantification (LOQs) between 0.09 and 0.47 ng/g were obtained, below the allowed or recommended levels by the European Union. Repeatability and intermediate precision showed relative standard deviations lower than 10% in all cases and trueness ranged from 92 to 111%. Finally, the proposed method was applied to 31 real pig feed samples, detecting aflatoxins with concentrations between 0.2 and 3.2 ng/g.
Dispersive magnetic solid-phase extraction (DMSPE) has received growing attention for sample treatment preconcentration prior to the separation of analytes due to its many advantages. In the present ...work, the potential of DMSPE for the determination of emergent mycotoxins (enniatins A, A1, B and B1, and beauvericin) is investigated for the first time. Different magnetic nanoparticles were tested and a magnetic multiwalled carbon nanotube (Fe
O
@MWCNT) composite was selected for the extraction and preconcentration of the five target mycotoxins in human urine samples before their analysis by ultrahigh performance liquid chromatography coupled to high resolution mass spectrometry (UHPLC-HRMS). The nanocomposite was characterized by energy dispersive X-ray spectrometry, scanning electron microscopy, Fourier transform infrared spectrophotometry, and X-ray diffraction. Several parameters affecting the adsorption and desorption of DMSPE steps were optimized and the method was fully validated. Due to a matrix effect, matrix-matched calibration curves were necessary to carry out quantification. In this way, limits of quantification of between 0.04 and 0.1 μg/L, relative standard deviation values lower than 12% and recoveries between 89.3% and 98.9% were obtained. Finally, a study of the reuse of the Fe
O
@MWCNT composite was carried out, confirming that it can be reused at least four times.
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