Rapid determination of antibiotic residues in cereals by liquid chromatography triple mass spectrometry

A universal optical aptasensor for antibiotics determination based on a new high-efficiency Förster resonance energy transfer pair

A novel "turn-on" aptasensor for kanamycin (Kana) detection based on a new Förster resonance energy transfer (FRET) pair is reported. A new organic small molecule was employed as a high-efficiency quencher for fluorophore. Based on specific interactions between ssDNA and the quencher, an ingenious and amplified strategy was designed. In the absence of the target, the fluorescence of the fluorophore labeled at the end of the aptamer was quenched. After the binding of the aptamer to the target, the fluorescence was recovered and amplified. The proposed aptasensor showed high specificity, selectivity, and stability in complicated systems. With the P3-based strategy, the limit of detection for Kana is estimated to be 10 nM, which is much lower than the maximum allowable concentration in milk. The recoveries of spiked Kana in milk were in the range 99.8 ~ 105.3% (n = 3). Fortunately, this novel method can be easily extended to other antibiotics such as tobramycin by simply replacing the aptamer, showing great potential as a universal platform for selective, sensitive, and rapid detection of hazardous analytes in food samples.

The Novel Concept of Synergically Combining: High Hydrostatic Pressure and Lytic Bacteriophages to Eliminate Vegetative and Spore-Forming Bacteria in Food Products

The article focuses on the ongoing challenge of eliminating vegetative and spore-forming bacteria from food products that exhibit resistance to the traditional preservation methods. In response to this need, the authors highlight an innovative approach based on the synergistic utilization of high-hydrostatic-pressure (HHP) and lytic bacteriophages. The article reviews the current research on the use of HHP and lytic bacteriophages to combat bacteria in food products. The scope includes a comprehensive review of the existing literature on bacterial cell damage following HHP application, aiming to elucidate the synergistic effects of these technologies. Through this in-depth analysis, the article aims to contribute to a deeper understanding of how these innovative techniques can improve food safety and quality. There is no available research on the use of HHP and bacteriophages in the elimination of spore-forming bacteria; however, an important role of the synergistic effect of HHP and lytic bacteriophages with the appropriate adjustment of the parameters has been demonstrated in the more effective elimination of non-spore-forming bacteria from food products. This suggests that, when using this approach in the case of spore-forming bacteria, there is a high chance of the effective inactivation of this biological threat.

Rapid Determination of Metribuzin and Three Major Transformation Products in Soil and Plant by Gas Chromatography–Tandem Mass Spectrometry

Metribuzin is a pre- and post-emergence triazinone herbicide used in a variety of crops. This herbicide is degraded in the environment into three major metabolites that have high water solubility, high to very high soil mobility, and low to moderate persistence in soil. This paper describes the development of an analytical method based on ultrasound-assisted extraction and GC-MS/MS determination for the determination metribuzin and its main metabolites in soil and plants. The developed method provided good recoveries for all compounds in soil and plants (from 73 to 121%). The quantitation limits obtained from plants (2.6 to 18 µg/kg) allow determining the presence of these compounds at trace levels. To evaluate the applicability of the developed methods, bean plants were grown in plastic pots with soil treated with metribuzin and collected after 23 days. At the end of the assay, only 11% of the initial concentration of metribuzin remained in soil. Metribuzin and its three metabolites were detected in plants, desamino-diketo-metribuzin is the most abundant metabolite. It is expected that the application of these methods can provide more data to monitor metribuzin residues due to herbicide treatments.

Green and Efficient Determination of Fluoroquinolone Residues in Edible Green Fruits and Leafy Vegetables by Ultrasound-Assisted Extraction Followed by HPLC-MS/MS

In this work, a simple, quick and efficient analytical method for determination of human and veterinary fluoroquinolone antimicrobial residues in lettuce, cucumber and spinach is developed. The procedure entails a 6 min ultrasound-assisted extraction (UAE, 3 × 2 min) in an alkaline (2% v/v NH₃) aqueous solution containing Mg²⁺ ions (3 × 6 mL), with no need for organic solvents. The extract is submitted to cleanup on the HLB™ cartridge and the fluoroquinolones are separated and quantified by HPLC-MS/MS in a 10 min chromatographic run, using a small amount of acetonitrile in the mobile phase. The method, entirely developed in real matrices, is validated according to the updated analytical guidelines and provided suitable recoveries in the range of 67–116% and precision (RSD ≤ 20%, n = 3) at different concentrations (15, 70 and 150 ng g⁻¹), with method quantification limits of 2–10 ng g⁻¹. Fluoroquinolones were detected and quantified at concentrations from few to hundreds of nanograms per gram in vegetables from supermarkets, demonstrating the applicability of the method for monitoring residues of these pharmaceuticals.

Antibiotic Use in Livestock and Residues in Food-A Public Health Threat: A Review

The usage of antibiotics has been, and remains, a topic of utmost importance; on the one hand, for animal breeders, and on the other hand, for food safety. Although many countries have established strict rules for using antibiotics in animal husbandry for the food industry, their misuse and irregularities in compliance with withdrawal periods are still identified. In addition to animal-origin foods that may cause antibiotic residue problems, more and more non-animal-origin foods with this type of non-compliance are identified. In this context, we aim to summarize the available information regarding the presence of antibiotic residues in food products, obtained in various parts of the world, as well as the impact of consumption of food with antibiotic residues on consumer health. We also aim to present the methods of analysis that are currently used to determine antibiotic residues in food, as well as methods that are characterized by the speed of obtaining results or by the possibility of identifying very small amounts of residues.

Synthesis of molecularly imprinted polymers for extraction of fluoroquinolones in environmental, food and biological samples

In recent years, fluoroquinolones have been found present in important water resources and food sources which compromises the food quality and availability, thereby, causing risks to the consumer. Despite the recent advancement in the development of analytical instrumentation for routine monitoring of fluoroquinolones in water, food, and biological samples, sample pre-treatment is still a major bottleneck of the analytical methods. Therefore, fast, selective, sensitive, and cost-effective sample preparation methods prior to instrumental analysis for fluoroquinolones residues in environmental, food and biological samples are increasingly important. Solid-phase extraction using different adsorbents is one of the most widely used pre-concentration/clean-up techniques for analysis of fluoroquinolones. Molecularly imprinted polymers (MIPs) serve as excellent effective adsorbent materials for selective extraction, separation, clean-up and preconcentration of various pollutants in different complex matrices. Therefore, synthesis of MIPs remains crucial for their applications in sample preparation as this offers much-needed selectivity in the extraction of compounds in complex samples. In this study, the progress made in the synthesis of MIPs for fluoroquinolones and their applications in water, food and biological samples were reviewed. The present review discusses the selection of all the elements of molecular imprinting for fluoroquinolones, polymerization processes and molecular recognition mechanisms. In conclusion, the related challenges and gaps are given to offer ideas for future research focussing on MIPs for fluoroquinolones.

Development of a pH-dependent homogeneous liquid-liquid extraction by cold-induced phase separation in acetonitrile/water mixtures for determination of quinolone residues in animal-derived foods

A simple extraction procedure coupled with liquid chromatography-Q Orbitrap high resolution mass spectrometry (LC-Q Orbitrap HRMS) for the determination of 19 quinolones in animal-derived foods (pork, fish, egg and milk) has been developed. Sample preparation is based on homogeneous liquid-liquid extraction at pH > 9 using water-miscible acetonitrile with cold-induced phase separation. The procedure allowed one-step enrichment and cleanup of all the 19 quinolones with different logP properties to lower aqueous phase, which eliminated the process of preconcentration and re-dissolution for sample solution. Furthermore, an adsorption phenomenon was observed between conventional borosilicate glass injection vials and most of quinolones. In detection analysis, a scheduled variable full scan strategy was performed to improve detection performance in Q Orbitrap HRMS. Under optimal conditions, a superior limit of quantitation (0.028-0.192 μg/kg) in animal-derived foods was achieved using this proposed method. Lastly, this method was validated and applied successfully in real samples.

Detection, occurrence, and fate of emerging contaminants in agricultural environments (2020)

A review of 79 papers published in 2019 is presented. The topics ranged from detailed descriptions of analytical methods, to fate and occurrence studies, to ecological effects and sampling techniques for a wide variety of emerging contaminants likely to occur in agricultural environments. New methods and studies on veterinary pharmaceuticals, antibiotics, anthelmintics, and engineered nanomaterials in agricultural environments continue to expand our knowledge base on the occurrence and potential impacts of these compounds. This review is divided into the following sections: Introduction, Analytical Methods, Antibiotics in Agroecosystems, Pharmaceutical Fate and Occurrence, Anthelmintics and Engineered Nanomaterials. PRACTITIONER POINTS: New research describes innovative new techniques for emerging contaminant detection in agricultural settings Newer classes of contaminants include human and veterinary pharmaceuticals Research in nanomaterials show that these also occur in agricultural environments and will likely be topics of future work.

Determination of Emerging Contaminants in Cereals by Gas Chromatography-Tandem Mass Spectrometry

Cereals are staple foods for human consumption in both developed and developing countries. In order to improve agricultural outputs, resources like reclaimed water for irrigation and biosolids and manure as fertilizers are frequently used, although they may increase the input of contaminants that can potentially be absorbed by crops and enter the food chain. Emerging contaminants (human and veterinary pharmaceuticals, personal care products, surfactants, plasticizers, and industrial additives, among others) are continuously introduced in the environment from a variety sources and these contaminants may enter the food chain through plant uptake. In this study, an analytical method, based on ultrasound-assisted extraction and dispersive solid-phase cleanup, was developed for the determination of emerging contaminants from different classes in four highly consumed cereal grains (wheat, oat, barley, and rice). These analytes were selected considering the results of our previous studies carried out in soil and vegetables and those frequently detected in real samples were chosen. The target compounds selected were bisphenol A (BPA), bisphenol F (BPF), methyl paraben, propyl paraben, linear chain nonylphenol in position 4 (4-n-NP), mixture of ring and chain isomers of NP and six pharmaceutical compounds (allopurinol, mefenamic acid, carbamazepine, paracetamol, diclofenac and ibuprofen). Recoveries ranging from 68 to 119% with relative standard deviations (RSD) <18% were obtained for all the compounds except for allopurinol, with recoveries that ranged from 30 to 66% with RSD ≤ 12% and the limits of detection achieved ranged from 0.03 to 4.9 ng/g. The method was applied to the analysis of 16 cereal samples, ten were purchased in local supermarkets and the rest were collected directly from agricultural fields, five of which were fertilized with organic amendments. Bisphenol A (BPA) was detected in all samples at levels that ranged from 1.6 to 1,742 ng/g. Bisphenol F, a substitute for BPA, was also found in six samples (up to 22 ng/g). Linear 4-n-NP was found in a reduced number of samples but the mixture of NP isomers was found in all the samples, being the mean concentrations in wheat, barley, oat and rice 49, 90, 142, and 184 ng/g, respectively.

Trends in sensitive detection and rapid removal of sulfonamides: A review

Sulfonamides in environmental water, food, and feed are a major concern for both aquatic ecosystems and public health, because they may lead to the health risk of drug resistance. Thus, numerous sensitive detection and rapid removal methodologies have been established. This review summarizes the sample preparation techniques and instrumental methods used for sensitive detection of sulfonamides. Additionally, adsorption and photocatalysis for the rapid removal of sulfonamides are also discussed. This review provides a comprehensive perspective on future sulfonamide analyses that have good performance, and on the basic methods for the rapid removal of sulfonamides.