Review of Characteristics and Analytical Methods for Determination of Thiabendazole

Thiabendazole (TBZ) is a fungicide and anthelmintic drug commonly found in food products. Due to its toxicity and potential carcinogenicity, its determination in various samples is important for public health. Different analytical methods can be used to determine the presence and concentration of TBZ in samples. Liquid chromatography (LC) and its subtypes, high-performance liquid chromatography (HPLC) and ultra-high-performance liquid chromatography (UHPLC), are the most commonly used methods for TBZ determination representing 19%, 18%, and 18% of the described methods, respectively. Surface-enhanced Raman spectroscopy (SERS) and fluorimetry are two more methods widely used for TBZ determination, representing 13% and 12% of the described methods, respectively. In this review, a number of methods for TBZ determination are described, but due to their limitations, there is a high potential for the further improvement and development of each method in order to obtain a simple, precise, and accurate method that can be used for routine analysis.

Stereoselective toxicity, bioaccumulation, and metabolic pathways of triazole fungicide cyproconazole in zebrafish

Cyproconazole (CPZ) is a broad-spectrum fungicide that is widely used around the world. CPZ can persist in water which raised concerns about its potential adverse effects on aquatic life. In this study, the stereoselective toxicity, bioaccumulation, elimination, and kinetic biotransformation in zebrafish were investigated. The LC₅₀ of 96 h acute toxicity was 15.88, 19.68, 26.99, and 17.10 mg/L for SR-, SS-, RS-, and RR-CPZ, respectively. The uptake and elimination experiment showed the bioconcentration factor in order of SR- > RR- > SS- > RS-CPZ at the exposure concentration of 0.1 and 1 mg/L. In the depuration stage, CPZ isomers were rapidly eliminated by 99% within 24 h. Moreover, the oxidative stress responses (POD, SOD, and CAT) were stereoselectively induced by CPZ stereoisomers, the activity of POD was significantly increased in all CPZ treatment groups compared to the control while the activity of CAT exhibited a concentration-dependent decrease in the CPZ treatment group. Multiple metabolic pathways of CPZ in zebrafish were proposed for the first time and 7 phase I metabolites and 25 phase II conjugates were found. This study determined the potential toxicity of CPZ to zebrafish and provided a strategy for the risk evaluation of CPZ stereoisomers in aquatic ecosystems.

Microplastics reduce the bioaccumulation and oxidative stress damage of triazole fungicides in fish

Microplastics (MPs) and pesticides are typical representatives of harmful chemicals in polluted waters. It is understood that the combined toxicity may differ from that of a single toxic substance. Although their combined toxicities on aquatic organisms have practical significance and research value, they have received little attention due to their complicated interaction, and the mechanism has rarely been reported. In this paper, we designed a study to investigate the single and combined effects of polystyrene microplastics (PS-MPs) and the triazole fungicide difenoconazole on zebrafish, and to explore the mechanism of this effect. The results showed that PS-MPs could reduce the bioaccumulation of difenoconazole in zebrafish to a certain extent and alleviate the oxidative stress damage of difenoconazole in the zebrafish liver. The transcriptome and qRT-PCR data revealed the association of multiple pathways in the difenoconazole response, while the presence of PS-MPs ameliorated this effect in gene expression changes. Due to the properties of PS-MPs and the interaction between them, the toxic effect of difenoconazole when combined with PS-MPs is more prominent. These results provide a novel aspect to understand the environmental behavior of MPs and to evaluate the combined effect of MPs and pesticides on aquatic food.

The Role of Suspension Array Technology in Rapid Detection of Foodborne Pollutants: Applications and Future Challenges

Food safety is an important livelihood issue, which has always been focused attention by countries and governments all over the world. As food supply chains are becoming global, food quality control is essential for consumer protection as well as for the food industry. In recent years, a great part of food analysis is carried out using new techniques for rapid detection. As the first biochip technology that has been approved by the Food and Drug Administration (FDA), there is an increasing interest in suspension array technology (SAT) for food and environmental analysis with advantages of rapidity, high accuracy, sensitivity, and throughput. Therefore, it is important for researchers to understand the development and application of this technology in food industry. Herein, we summarized the principle and composition of SAT and its application in food safety monitoring. The utility of SAT in detection of foodborne microorganisms, residues of agricultural and veterinary drugs, genetically modified food and allergens in recent years is elaborated, and the further development direction of SAT is envisaged.

Local Phenomena Shape Backyard Soil Metabolite Composition

Soil covers most of Earth's continental surface and is fundamental to life-sustaining processes such as agriculture. Given its rich biodiversity, soil is also a major source for natural product drug discovery from soil microorganisms. However, the study of the soil small molecule profile has been challenging due to the complexity and heterogeneity of this matrix. In this study, we implemented high-resolution liquid chromatography-tandem mass spectrometry and large-scale data analysis tools such as molecular networking to characterize the relative contributions of city, state and regional processes on backyard soil metabolite composition, in 188 soil samples collected from 14 USA States, representing five USA climate regions. We observed that region, state and city of collection all influence the overall soil metabolite profile. However, many metabolites were only detected in unique sites, indicating that uniquely local phenomena also influence the backyard soil environment, with both human-derived and naturally-produced (plant-derived, microbially-derived) metabolites identified. Overall, these findings are helping to define the processes that shape the backyard soil metabolite composition, while also highlighting the need for expanded metabolomic studies of this complex environment.

Optimization of Resolving Power, Fragmentation, and Mass Calibration in an Orbitrap Spectrometer for Analysis of 24 Pesticide Metabolites in Urine

Mass spectrometer parameters such as Resolving Power, type of fragmentation, and mass calibration mode were optimized in the analysis of 24 pesticide metabolites in human urine using Ultra-High Pressure Liquid Chromatography coupled to Orbitrap High-Resolution Mass Spectrometer (UHPLC-HRMS). The best results were achieved with a Resolving Power of 25,000 FWHM and by applying Collision Induced Dissociation fragmentation mode (40 eV).

Acetamiprid multidetection by disposable electrochemical DNA aptasensor

In this work, we propose an electrochemical DNA aptasensor for sensitive multidetection of acetamiprid based on a competitive format and disposable screen-printed arrays. To improve the sensitivity of the aptasensor, polyaniline film and gold nanoparticles were progressively electrodeposited on the graphite screen-printed electrode surface by cyclic voltammetry. Gold nanoparticles were then employed as platform for thiol-tethered DNA aptamer immobilization. Different acetamiprid solutions containing a fixed amount of biotinylated complementary oligonucleotide sequence by DNA aptasensor arrays were analyzed. Streptavidin-alkaline phosphatase conjugate was then added to trace the affinity reaction. The enzyme catalyzed the hydrolysis of 1-naphthyl phosphate to 1-naphthol. The enzymatic product was detected by differential pulse voltammetry. A decrease of the signal was obtained when the pesticide concentration was increased, making the sensor work as signal off sensor. Under optimized conditions by testing key experimental parameters, a dose-response curve was constructed between 0.25 and 2.0µM acetamiprid concentration range and a limit of detection of 0.086µM was calculated. The selectivity of the aptasensor was also confirmed by the analysis of atrazine pesticide. Finally, preliminary experiments in fruit juice samples spiked with acetamiprid were also performed.