Ionic liquid functionalized zinc oxide nanorods for solid-phase microextraction of aflatoxins in food products

Simultaneous determination of multiple mycotoxins in corn and wheat by high efficiency extraction and purification based on polydopamine and ionic liquid bifunctional nanofiber mat

Due to the universality and harmfulness of mycotoxin co-contamination in cereals, it is of great significance to simultaneously monitor various mycotoxins co-polluted to ensure food safety and public health. In this work, a nanofiber mat modified by polydopamine and ionic liquid (PDA-IL-NFsM) was prepared and utilized as a solid-phase extraction (SPE) adsorbent for the simultaneous quantitative detection of multiple mycotoxins in corn and wheat. The PDA-IL-NFsM can form multiple retention mechanisms with the targets through hydrogen bond, π-π interaction, electrostatic or hydrophobic interaction, it shows favorable simultaneous adsorption performance (adsorption efficiency mostly higher than 88.27%) for fifteen mycotoxins in seven classes. Moreover, it can significantly reduce the matrix effect (lower than -13.69%), showing a good purification effect on the sample matrix. Based on the superior performance of PDA-IL-NFsM, a simple sample preparation method was established. The sample extract is simply diluted with water for SPE, and the eluent can be directly collected for ultra performance liquid chromatography tandem mass spectrometry (UPLC-MS/MS) analysis. The detection limit can reach 0.04-4.21 μg kg^-1, the recovery was 80.09%-113.01%, and the relative standard deviations of intra-day and inter-day precision were 2.80%-14.81% and 0.68%-13.80% respectively. The results show that the proposed method has good sensitivity, accuracy and precision, and has practical application potential.

Recent Insights into Sample Pretreatment Methods for Mycotoxins in Different Food Matrices: A Critical Review on Novel Materials

Mycotoxins pollution is a global concern, and can pose a serious threat to human health. People and livestock eating contaminated food will encounter acute and chronic poisoning symptoms, such as carcinogenicity, acute hepatitis, and a weakened immune system. In order to prevent or reduce the exposure of human beings and livestock to mycotoxins, it is necessary to screen mycotoxins in different foods efficiently, sensitively, and selectively. Proper sample preparation is very important for the separation, purification, and enrichment of mycotoxins from complex matrices. This review provides a comprehensive summary of mycotoxins pretreatment methods since 2017, including traditionally used methods, solid-phase extraction (SPE)-based methods, liquid-liquid extraction (LLE)-based methods, matrix solid phase dispersion (MSPD), QuEChERS, and so on. The novel materials and cutting-edge technologies are systematically and comprehensively summarized. Moreover, we discuss and compare the pros and cons of different pretreatment methods and suggest a prospect.

Current Developments of Analytical Methodologies for Aflatoxins' Determination in Food during the Last Decade (2013-2022), with a Particular Focus on Nuts and Nut Products

This review aims to provide a clear overview of the most important analytical development in aflatoxins analysis during the last decade (2013-2022) with a particular focus on nuts and nuts-related products. Aflatoxins (AFs), a group of mycotoxins produced mainly by certain strains of the genus Aspergillus fungi, are known to impose a serious threat to human health. Indeed, AFs are considered carcinogenic to humans, group 1, by the International Agency for Research on Cancer (IARC). Since these toxins can be found in different food commodities, food control organizations worldwide impose maximum levels of AFs for commodities affected by this threat. Thus, they represent a cumbersome issue in terms of quality control, analytical result reliability, and economical losses. It is, therefore, mandatory for food industries to perform analysis on potentially contaminated commodities before the trade. A full perspective of the whole analytical workflow, considering each crucial step during AFs investigation, namely sampling, sample preparation, separation, and detection, will be presented to the reader, focusing on the main challenges related to the topic. A discussion will be primarily held regarding sample preparation methodologies such as partitioning, solid phase extraction (SPE), and immunoaffinity (IA) related methods. This will be followed by an overview of the leading analytical techniques for the detection of aflatoxins, in particular liquid chromatography (LC) coupled to a fluorescence detector (FLD) and/or mass spectrometry (MS). Moreover, the focus on the analytical procedure will not be specific only to traditional methodologies, such as LC, but also to new direct approaches based on imaging and the ability to detect AFs, reducing the need for sample preparation and separative techniques.

Dispersive micro solid phase extraction based ionic liquid functionalized ZnO nanoflowers couple with chromatographic methods for rapid determination of aflatoxins in wheat and peanut samples

Aflatoxins (AFs) contaminate agricultural products in a wide range of ways during their harvesting, storage and transport. Therefore, the detection of AFs has certain practical significance. Herein, a dispersive micro solid phase extraction (D-µSPE) technology was constructed based on 1-hexyl-3-methylimidazolium hexafluorophosphate ([HMIM][PF₆]) fabricated ZnO nanoflowers for AFs extraction from food matrix before HPLC procedure. The key parameters affecting the extraction efficiency were studied. Under optimal experimental conditions, the method showed excellent linearity with high correlation coefficients (≥0.994). LOD and LOQ were 0.034 and 0.114 μg/kg for AFB1, 0.024 and 0.082 μg/kg for AFB2, 0.067 and 0.226 μg/kg for AFG1 and 0.025 and 0.084 μg/kg for AFG2. The recovery of actual samples spiked with analytes (at 5, 15 and 20 μg/kg) were from 93.8 to 105.1%. Overall, an accurate AFs analysis method was developed and could be applied to the determination of AFs in various food and agricultural products.

Using Solid-Phase Microextraction Coupled with Reactive Carbon Fiber Ionization-Mass Spectrometry for the Detection of Aflatoxin B1 from Complex Samples

Aflatoxin B1 (AFB1) is a common mycotoxin present in agricultural and food products. Therefore, rapid screening methods must be developed for AFB1 detection with high sensitivity and good selectivity. In this study, we developed an analytical method based on the combination of solid-phase microextraction (SPME) with carbon fiber ionization (CFI)-mass spectrometry (MS) to detect the presence of trace AFB1 from complex samples. A pencil lead (type 2B, length: ~2.5 cm) with a sharp end (diameter: ~150 μm) was used as the SPME fiber and the ionization emitter in CFI-MS analysis. Owing to the graphite structure of the pencil lead, AFB1 can be trapped on the pencil lead through π–π interactions. After adsorbing AFB1, the pencil lead was directly introduced in a pipette tip (length: ~0.7 cm; tip inner diameter: ~0.6 mm), placed close (~1 mm) to the inlet of the mass spectrometer, and applied with a high voltage (−4.5 kV) for in situ AFB1 elution and CFI-MS analysis. A direct electric contact on the SPME-CFI setup was not required. Followed by the introduction of an elution solvent (10 μL) (acetonitrile/ethanol/deionized water, 2:2:1 (v/v/v)) to the pipette tip, electrospray ionization was generated from the elution solvent containing AFB1 for CFI-MS analysis. A reactive SPME-CFI-MS strategy was employed to further identify AFB1 and improve elution capacity using our approach. Butylamine was added to the elution solvent, which was then introduced to the pipette tip inserted with the SPME fiber. Butylamine-derivatized AFB1 was readily generated and appeared in the resultant SPME-CFI mass spectrum. The lowest detectable concentration against AFB1 using our approach was ~1.25 nM. Our method can distinguish AFB1 from AFG1 in a mixture and can be used for the detection of trace AFB1 in complex peanut extract samples.

Ionic Liquid-Assisted DLLME and SPME for the Determination of Contaminants in Food Samples

Developing effective and green methods for food analysis and separation has become an urgent issue regarding the ever-increasing concern of food quality and safety. Ionic liquids (ILs) are a new chemical medium and soft functional material developed under the framework of green chemistry and possess many unique properties, such as low melting points, low-to-negligible vapor pressures, excellent solubility, structural designability and high thermal stability. Combining ILs with extraction techniques not only takes advantage of ILs but also overcomes the disadvantages of traditional extraction methods. This subject has attracted intensive research efforts recently. Here, we present a brief review of the current research status and latest developments regarding the application of IL-assisted microextraction, including dispersive liquid–liquid microextraction (DLLME) and solid-phase microextraction (SPME), in food analysis and separation. The practical applications of ILs in determining toxic and harmful substances in food specimens with quite different natures are summarized and discussed. The critical function of ILs and the advantages of IL-based microextraction techniques over conventional extraction techniques are discussed in detail. Additionally, the recovery of ILs using different approaches is also presented to comply with green analytical chemistry requirements.

Application of new N- and S-doped amorphous carbon in D-μSPE and its combination with deep eutectic solvent-based DLLME for the extraction of some mycotoxins from soymilk

A new amorphous carbon-based dispersive micro solid-phase extraction method was developed for the extraction and preconcentration of several mycotoxins from soymilk samples. The extracted analytes were concentrated by a deep eutectic solvent-based dispersive liquid-liquid microextraction method, and then, quantified by a high-performance liquid chromatography-fluorescence detector. The sorbent was prepared from β-cyclodextrin and methionine under mild conditions. The sorbent was doped by N and S, which improved its physicochemical properties. The optimization and validation of the method were performed using the "one-variable-at-a-time" method and International Council Harmonization guideline, respectively. Under the optimal conditions, low limits of detection and quantifications in the ranges of 0.08-0.56 and 0.27-1.9 ng L^-1 were obtained, respectively. Also, intra- (n = 6) and inter-day (n = 6) precisions showed an acceptable repeatability of the present work as they were in the ranges of 3.9-6.2 and 4.6-8.9% at a concentration of 3 ng L^-1 of each analyte, respectively. Finally, the proposed method was performed on different soymilk samples marketed in Tabriz city, and aflatoxin B₁ was found in all samples. One soymilk was contaminated by ochratoxin A.

Combination of solvent extraction with deep eutectic solvent based dispersive liquid-liquid microextraction for the analysis of aflatoxin M1 in cheese samples using response surface methodology optimization

A new extraction procedure based on combination of a solvent extraction and deep eutectic solvent based dispersive liquid-liquid microextraction has been introduced for the extraction of aflatoxin M₁ from cheese samples. In this method, acetonitrile, deionized water, and n-hexane are added onto the sample and vortexed. Owning to different affinities of the substances in cheese toward the mentioned solvents, an efficient and selective extraction of the analyte is done in the acetonitrile phase. After centrifugation, the acetonitrile phase is removed and mixed with a new hydrophobic deep eutectic solvent prepared from N,N-diethanol ammonium chloride and carvacrol as an extraction solvent. The mixture is injected into deionized water, and a cloudy solution is obtained. Eventually, an aliquot of the organic phase is injected into high-performance liquid chromatography-fluorescence detection. After optimizing the effective parameters with the response surface methodology and a quadratic model, limits of detection and quantification were 0.74 and 2.56 ng/kg, respectively. The obtained extraction recovery and enrichment factor were 94% and 94, respectively. Also, intra- (n = 6) and interday (n = 4) precisions were less than or equal to 8.6% at a concentration of 5 ng/kg. The suggested method was applied to determine aflatoxin M₁ in different cheese samples.

Review: Microextraction Technique Based New Trends in Food Analysis

Food chemistry is the study and classification of the quality and origin of foods. The identification of definite biomarkers and the determination of residue contaminants such as toxins, pesticides, metals, human and veterinary drugs, which are a very common source of food-borne diseases. The food analysis is continuously demanding the improvement of more robust, sensitive, highly efficient, and economically beneficial analytical approaches to promise the traceability, safety, and quality of foods in the acquiescence with the consumers and legislation demands. The traditional methods have been used at the starting of the 20th century based on wet chemical methods. Now it existing the powerful analytical techniques used in food analysis and safety. This development has led to substantial enhancements in the analytical accuracy, precision, sensitivity, selectivity, thereby mounting the applied range of food applications. In the present decade, microextraction (micro-scale extraction) pays more attention due to its futures such as low consumption of solvent and sample, throughput analysis easy to operate, greener, robotics, and miniaturization, different adsorbents have been used in the microextraction process with unique nature recognized with wide range applications.