Evolution and applications of the QuEChERS method

Species-specific bioassays reveal spatial variation in chemical contamination of green sea turtles

The rapid increase of anthropogenic activity at shipping ports and surrounding coastal areas has been correlated with higher chemical contamination entering the surrounding marine environment. Chemical contaminants in marine environments can lead to significant health problems for green turtles (Chelonia mydas), especially when these contaminants accumulate in their foraging grounds. This study examined the exposure and toxicological effects of chemical contaminants on green turtle cells using a species-specific cell viability assay. Using the QuEChERs extraction, organic contaminants were extracted from 60 blood samples collected from green turtles in three foraging locations: Port Curtis, and two reefs (Heron Reef and Hoskyn-Fairfax Reefs) within the Capricorn Bunker Group of the outer Great Barrier Reef. Blood extracts were tested for cytotoxicity against primary green turtle fibroblast cells using an in vitro resazurin bioassay to assess cell viability. Extracts from Gladstone and Heron Reef indicated significant chemical contamination, at levels high enough to cause adverse health effects of green turtles. Very low toxicity values at the Hoskyn-Fairfax Reefs location indicate its potential to be established as a reference site for the southern Great Barrier Reef.

Simultaneous analysis of pesticides and mycotoxins in primary processed foods: The case of bee pollen

Primary Processed Foods are a class of food items that are ready for consumption after minimal processing in the supply chain. These products are ubiquitous in our daily diet, but so far a limited number of studies dealt with the optimization of quality control methods to check their content of contaminants. Among primary processed foods, bee pollen is a nutritionally acclaimed food supplement, whose contamination with pesticides and mycotoxins has been largely proven. For this reason, the present study aimed at optimizing for the first time a comprehensive LC-MS/MS method capable of analyzing 282 pesticides and 8 mycotoxins in bee pollen. To obtain a suitable method, two extraction procedures (QuEChERS and Accelerated Solvent Extraction), as well as different chromatographic gradients and columns, were tested. The optimized methodology, comprehending an extraction based on semi-automated QuEChERS, and an analytical method including inert LC column technology, was validated and applied to a sample set of 34 bee pollens. The analyzed samples collectively showed the presence of 41 pesticides and 1 mycotoxin.

Development and validation of a QuEChERS-HPLC-DAD method using polymer-functionalized melamine sponges for the analysis of antipsychotic drugs in milk

The prohibition of antipsychotic drugs in animal foodstuffs has raised significant concerns. In this study, a novel matrix purification adsorbent comprising a polymer (polyaniline and polypyrrole)-functionalized melamine sponge (Ms) was employed for the high performance liquid chromatography-diode array detector (HPLC-DAD) detection of three phenothiazines (chlorpromazine, thioridazine, and promethazine), and a tricyclic imipramine in milk. The as-prepared functionalized Ms was characterized using scanning electron microscopy, Fourier transform infrared spectroscopy, and water contact angle measurements. Excellent linearity with a coefficient of determination (R2) of 0.999 was achieved for all drugs within the concentration range of 0.01-47.00 μg mL-1. The recoveries of the four analytes ranged from 92.1 % to 106.9 % at the three spiked levels. These results demonstrate the successful application of the proposed method for the determination of the four drugs. Cost-effective polymer-functionalized Ms is a viable alternative for matrix purification, enabling rapid determination of drug residues in diverse food samples.

Analysis of highly polar anionic pesticides in food of plant and animal origin by ion chromatography and tandem mass spectrometry with emphasis on addressing adverse effects caused by matrix co-extractives

Residues of various highly polar pesticides and their metabolites are commonly found in numerous food products. Some of these compounds, such as glyphosate, are not only used in large amounts in agriculture, but are also controversially discussed in public. Here, we present a method, employing ion chromatography (IC) coupled to tandem mass spectrometry (IC-MS/MS), for the analyses of glyphosate, aminomethyl phosphonic acid (AMPA), N-acetyl-glyphosate (NAGly), fosetyl, and 10 further highly polar pesticides and metabolites in various plant and animal matrices following a minimal sample preparation by means of the QuPPe method. Thorough investigations showed that an AS19 column enabled the analysis of all 14 compounds within 30 min. The best sensitivity could be obtained with the make-up solvent acetonitrile being admixed to the mobile phase at a 1:2 flow rate ratio. Matrix effects were thoroughly studied in terms of ion suppression and retention time shifts. Conductivity detection was used to monitor elution profiles of matrix co-extractives in comparison with matrix effect profiles obtained by continuous post-column infusion of a mix with 13 highly polar pesticides and metabolites. These tests indicated that a fivefold dilution of QuPPe extracts was suitable for the routine analysis of samples for MRL-conformity, as it considerably reduced matrix effects maintaining sufficient sensitivity and high recovery rates in eight different commodities. The suitability of the final method for its application in routine analysis was verified by the analysis of >130 samples containing incurred residues where the results were compared with two existing LC-MS/MS methods.

Recent Advanced Methods for Extracting and Analyzing Cannabinoids from Cannabis-Infused Edibles and Detecting Hemp-Derived Contaminants in Food (2013-2023): A Comprehensive Review

Cannabis-infused edibles are food products infused with a cannabis extract. These edibles include baked goods, candies, and beverages, offering an alternative way to consume cannabis instead of smoking or vaporizing it. Ensuring the accurate detection of cannabis-infused edibles and identification of any contaminants is crucial for public health and safety. This is particularly important for compliance with legal regulations as these substances can have significant psychoactive effects, especially on unsuspecting consumers such as children or individuals with certain medical conditions. Using efficient extraction methods can greatly improve detection accuracy, ensuring that the concentration of cannabinoids in edibles is measured correctly and adheres to dosage guidelines and legal limits. This review comprehensively examines the preparation and extraction techniques for cannabinoid edibles. It covers methods such as solid-phase extraction, enhanced matrix removal-lipid, QuEChERS, dissolution and dispersion techniques, liquid-phase extraction, and other emerging methodologies along with analytical techniques for cannabinoid analysis. The main analytical techniques employed for the determination of cannabinoids include liquid chromatography (LC), gas chromatography (GC), direct analysis in real time (DART), and mass spectrometry (MS). The application of these extraction and analytical techniques is further demonstrated through their use in analyzing specific edible samples, including oils, candies, beverages, solid coffee and tea, snacks, pet food, and contaminated products.

Qualitative and Quantitative Analyses of the Enantiomers of Nicotine and Nornicotine Employing Chiral Supercritical Fluid Chromatography

An optimized method employing chiral supercritical fluid chromatography with diode array UV-VIS detection has been developed for the quantitative analysis of nicotine and nornicotine enantiomer distributions. The method parameters that were optimized included: column type (stationary phases, Chiralpak IG-3), column temperature (40°C), modifier types and concentration (isopropyl alcohol, 10%), additive types and concentrations (diethylamine, 0.2%), elution times (<6 min, flow rate 3 mL/min) and resolution factor (>1.2). These optimized conditions led to nicotine and nornicotine enantiomer detection limits of ~5 ng/μL with accompanying %RSD values of <2% from the analyses of commercially available nicotine-containing formulations.

Fast and reliable determination of phthalic acid esters in soil and lettuce samples based on QuEChERS GC-MS/MS

Phthalates are commonly used as plasticizers, and solvents in industry and households. We propose an application of the QuEChERS method for the determination of six PAEs in the soil and lettuce (roots and leaves) by GC-MS/MS. The QuEChERS method validation procedure was performed and good linearity (>0.997), recovery (97.2-99.1 %), very low detection limits (0.09-0.43 ng/g), and satisfactory inter- and intraday precision (∼4%) were obtained confirming that QuEChERS GC-MS/MS applied for PAEs determination in the environmental samples is a cheap and environmentally friendly method. In general, the higher the number of carbon atoms in PAEs, the higher the percentage noted in the lettuce roots. At higher PAEs concentration (60 ng/g) the main bis(2-ethylhexyl) phthalate (DEHP) sink were roots whereas at lower concentrations (30 ng/g) most of DEHP was noted in lettuce leaves implying that the fate of PAEs was governed not by the chemical structure of PAEs but rather partitioning (logKow).

Advances in sample preparation methods for pesticide residue analysis in medicinal plants: A focus on Nepal

Medicinal plant safety is a rising challenge worldwide due to the continued overuse of pesticides to their maximum residue limits. Due to the high demand for medicinal plants, their production is being increased and sometimes protected by pesticide use. The analysis of these residues requires robust analytical methods to ensure the safety and quality of medicinal plants. Developing effective sample preparation for detecting pesticides is challenging, due to their diverse natures, classes, and physico-chemical characteristics. Hence, existing techniques and strategies are needed to improve the reliability of the results. The review discusses the current state of sample preparation techniques, analytical methods, and instrumental technologies employed in pesticide residue analysis in medicinal plants. It highlights the challenges, limitations, and advancements in the field, providing insights into the analytical strategies used to detect and quantify pesticide residues. Reliable, accessible, affordable, and high-resolution analytical procedures are essential to ensure that pesticide levels in medicinal plants are effectively regulated. By understanding the complexities of pesticide residue analysis in medicinal plants, this review article aims to support the conservation of medicinal plant resources, promote public health, and contribute to the development of sustainable strategies for ensuring the safety and quality of medicinal plants in Nepal. The findings of this review will benefit researchers, policymakers, and stakeholders involved in the conservation of medicinal plant resources and the promotion of public health.

Determination of Multiclass Antibiotics in Fish Muscle Using a QuEChERS-UHPLC-MS/MS Method

The surging global demand for fish has increased aquaculture practices, where antibiotics have become indispensable to prevent diseases. However, the passive incorporation of these compounds into the diet may have adverse effects on human health. In this work, the QuEChERS method combined with ultra-high-performance liquid chromatography tandem mass spectrometry was applied for the determination of 10 multiclass antibiotics (5 quinolones, 2 sulfonamides, 2 diaminopyrimidines, and 1 macrolide) in muscle tissue of farmed fish (European sea bass and gilt-head sea bream). The applied method demonstrated acceptable recovery values, mostly between 70 and 120%, with limits of quantification of the method meeting the established EU maximum residue limits. The analysis of twenty fish samples in duplicate revealed that most antibiotics were not present, with the only exception of oxolinic acid and tilmicosin in European sea bass, which were below the limit of quantification of the method.

A proof-of-concept study on the versatility of liquid chromatography coupled to high-resolution mass spectrometry to screen for various contaminants and highlight markers of floral and geographical origin for different honeys

The high-resolution mass spectrometry is a powerful analytical tool for improving food safety and authenticity, but still underused in official control laboratories. The present work is a proof-of-concept study overviewing how liquid-chromatography coupled to high-resolution mass spectrometry could be used simultaneously for large-scale screening of contaminants and differentiation of honey samples. Within this study, the samples were extracted using all-in-one QuEChERS-based protocol that allowed for analysis of various anthropogenic contaminants and endogenous compounds. First, targeted-analysis of 52 honey samples led to unequivocal identification of 23 chemicals, including neonicotinoids, triazole fungicides and synergist. Then, suspect-screening using MSDial software allowed for tentative identification of 30 chemicals including plasticizers, flame-retardants and additives. Suspect-screening also made it possible to highlight tentative markers of chestnut honey (deoxyvasicinone, 2-quinolone, indoleacrylic acid and kynurenic acid) and citrus honey (caffeine, 2-oxindole and indole-3-carbinol). Lastly, non-targeted analysis enabled to separate honeys by their type, floral and geographical origins.

Development and application of a new QuEChERS-molecularly imprinted solid phase extraction (QuEChERS-MISPE) technique for analysis of DDT and its derivatives in vegetables

The current study synthesized a molecularly imprinted polymer, combined it with the QuEChERS method to form a new hybrid technique, the QuEChERS-MISPE as an alternative to the QuEChERS-dSPE for analysis of DDTs as model pesticides. Batch studies confirmed that the binding of the DDTs to the MIP cavities formed a monolayer formation through chemisorption resulting in an adsorption capacity of 429 ng g-1. A study of matrix effects indicated signal suppression for both techniques. However, the new QuEChERS-MISPE technique is less affected by matrix effects, has better sensitivity and recoveries compared to the conventional QuEChERS-dSPE technique. Application of the new QuEChERS-MISPE technique detected trace levels of DDTs in vegetables in South Africa. However, a health risk assessment indicated that potential risks for consumers was minimal. Although the risk is minimal, the detection of DDTs in vegetables in South Africa should be a concern and more constant monitoring is required.

Identification of genetics and hormonal factors involved in Quercus robur root growth regulation in different cultivation system

Understanding the molecular processes and hormonal signals that govern root growth is of paramount importance for effective forest management. While Arabidopsis studies have shed light on the role of the primary root in root system development, the structure of root systems in trees is considerably more intricate, posing challenges to comprehend taproot growth in acorn-sown and nursery-cultivated seedlings. In this study, we investigated Quercus robur seedlings using rhizotrons, containers, and transplanted containers to rhizotrons, aiming to unravel the impact of forest nursery practices on processes governing taproot growth and root system development. Root samples were subjected to RNA-seq analysis to identify gene expression patterns and perform differential gene expression and phytohormone analysis. Among studied cultivation systems, differentially expressed genes (DEGs) exhibited significant diversity, where the number of co-occurring DEGs among cultivation systems was significantly smaller than the number of unique DEGs in different cultivation systems. Moreover, the results imply that container cultivation triggers the activation of several genes associated with linolenic acid and peptide synthesis in root growth. Upon transplantation from containers to rhizotrons, rapid enhancement in gene expression occurs, followed by gradual reduction as root growth progresses, ultimately reaching a similar expression pattern as observed in the taproot of rhizotron-cultivated seedlings. Phytohormone analysis revealed that taproot growth patterns under different cultivation systems are regulated by the interplay between auxin and cytokinin concentrations. Moreover, the diversification of hormone levels within the root zone and cultivation systems allows for taproot growth inhibition and prompt recovery in transplanted seedlings. Our study highlights the crucial role of hormone interactions during the early stages of taproot elongation, influencing root system formation across.

Pyrrolizidine Alkaloids in Foods, Herbal Drugs, and Food Supplements: Chemistry, Metabolism, Toxicological Significance, Analytical Methods, Occurrence, and Challenges for Future

Consumers are increasingly seeking natural alternatives to chemical compounds, including the use of dried aromatic plants as seasonings instead of salt. However, the presence of pyrrolizidine alkaloids (PAs) in food supplements and dried plants has become a concern because of their link to liver diseases and their classification as carcinogenic by the International Agency for Research on Cancer (IARC). Despite European Union (EU) Regulation (EU) 2023/915, non-compliance issues persist, as indicated by alerts on the Rapid Alert System for Food and Feed (RASFF) portal. Analyzing PAs poses a challenge because of their diverse chemical structures and low concentrations in these products, necessitating highly sensitive analytical methods. Despite these challenges, ongoing advancements in analytical techniques coupled with effective sampling and extraction strategies offer the potential to enhance safety measures. These developments aim to minimize consumer exposure to PAs and safeguard their health while addressing the growing demand for natural alternatives in the marketplace.

Method Validation and Measurement Uncertainty Estimation for Determination of Multiclass Pesticide Residues in Tomato by Liquid Chromatography-Tandem Mass Spectrometry (LC-MS/MS)

Method validation is an essential technique for ensuring the reliability and accuracy of an analytical method. This study aimed to optimize and validate a fast, reliable, and accurate method for quantitatively determining pesticide residues of diverse chemical classes in the tomato matrix. Various method performance characteristics were tested and compared with predefined criteria. Twenty-six different pesticides of diverse chemical classes were selected based on their use in tomato cultivation and the availability of reference materials. The pesticide residues in tomato samples were extracted with the QuEChERS technique with some modifications, followed by injection into an LC-MS/MS system operating in an optimized method. The validated method demonstrated reasonable specificity, as there were no interferences from matrix components at the retention times of pesticides. The calibration curves for all pesticides exhibited excellent linearities, with correlation coefficients exceeding 0.99. No significant matrix effect was observed for all pesticides in tomatoes, as the values fell within the range of ±20%. All pesticides were quantified successfully at a concentration of 5 μg/kg except for carbaryl, with an average recovery of more than 70% and a relative standard deviation of less than 20%. Similarly, measurement uncertainties were also estimated based on the validation data, and the values were found below the default limit of 50%. Subsequently, the validated method was applied to analyze 52 locally collected tomato samples. Study findings revealed that only four of the studied pesticides were detected in these samples, and their concentrations were below the maximum residue limits (500 µg/kg each for carbendazim, imidacloprid, and metalaxyl) established for tomatoes by the Government of Nepal and the Codex Alimentarius Commission.

Simultaneous analysis of highly polar and multi-residue-type pesticides by heart-cutting 2D-LC-MS

Liquid chromatography-mass spectrometry (LC-MS) is currently the gold-standard technique for the analysis of non-volatile small organic molecules. However, one-dimensional liquid chromatography (1D-LC) cannot efficiently deal with mixtures of analytes with different physicochemical properties and, thus, specific chromatographic behaviour. As an alternative, this work proposes a two-dimensional liquid chromatography/high-resolution mass spectrometry (2D-LC-HRMS) approach for the simultaneous analysis of compounds with different polarities. It is based on the combination of hydrophilic interaction liquid chromatography (HILIC) in the first dimension (1D) and reversed-phase chromatography (RPLC) in the second dimension (2D), employing the heart-cutting methodology. The coupling between 1D and 2D was performed by a multiple heart-cutting (MHC) interface equipped with an active solvent modulation (ASM) valve. The aim of the study was the development of a 2D-LC methodology able to (i) acquire the 1D and 2D content by MS in a single analytical run, avoiding the loss of information caused by the MHC algorithm for filling the sampling loops; (ii) overcome the breakthrough problem caused by solvent incompatibility, modifying the 2D gradient during the ASM phase for this purpose. To evaluate the 2D-LC approach, pesticide residue analysis was proposed, selecting 20 pesticides covering a wide range of polarities (log Kow from -3.2 to 4.3) and including some of the so-called single residue method pesticides because of the difficulty of including them in 1D-LC multi-residue methods with satisfactory chromatographic resolution. The proposed strategy was to transfer in a single cut the void volume from the HILIC separation (consisting of the nonpolar pesticides) to the 2D for analysis under RPLC conditions. The developed assembly was assessed in a vegetable matrix (tomato) employing a hybrid QuEChERS/QuPPe sample treatment based on acetonitrile and methanol extraction. The proposed setup may be extended for 2D-LC applications where it is essential to acquire the entire content of both dimensions in a single data file just by coupling a selection valve to the MHC interface.

Understanding contaminant exposure risks in nesting Loggerhead sea turtle populations

Queensland loggerhead turtle nest numbers at Mon Repos (MR) indicate population recovery that doesn't occur at Wreck Island (WI). Previous research illustrated that MR and WI turtles forage in different locations, potentially indicating risks differences. Blood, scute, and egg were collected from turtles nesting at MR and WI, with known foraging sites (from concurrent studies). Trace element and organic contaminants were assessed via acid digestion and in vitro cytotoxicity bioassays, respectively. WI turtles had significantly higher scute uranium and blood molybdenum compared to MR turtles, and arsenic was higher in WI turtles foraging north and MR turtles foraging south. Egg and blood titanium, manganese, cadmium, barium, lead, and molybdenum, and scute and egg selenium and mercury significantly correlated. Blood (75 %) extracts produced significant toxicity in vitro in turtle fibroblast cells. In conclusion, reducing chemical exposure at higher risk foraging sites would likely benefit sea turtles and their offspring.

QuEChERS-assisted ion pair chromatography/fluorescence detection method for determination of antimigraine combination therapy in rabbit plasma samples: Application to a pharmacokinetic study

Antimigraine combination therapy has shown significant effectiveness in relieving pain, as well as reducing the frequency, duration, and severity of migraine attacks if compared to a single migraine medication. This work represents the first analytical investigation for emphasizing the synergistic effect of combining ophthalmic beta blockers with triptans in migraine treatment. The presented study was conducted to investigate the pharmacokinetic profile of almotriptan (ALM), a serotonin (5-HT1B/1D) receptor agonist used to treat migraine, when coadministered with timolol (TIM) or verapamil (VER) which are considered as an adjuvant therapy in migraine prevention. Ion pair chromatography (IPC) with online fluorescence detection was applied to simultaneously detect and quantify the binary mixtures of ALM/TIM and ALM/VER in rabbit plasma samples. The separation was achieved using a Platinum C18 analytical column with a mobile phase composed of methanol: 35 mmol L-1 phosphate buffer solution containing 10 mmol L-1 SDS at pH = 6.8 (60:40 v/v). Several parameters were evaluated during the optimization of separation conditions including mobile phase composition, buffer concentration, buffer pH and concentration of ion pair reagent. A thorough investigation of the retention mechanism was performed, and the results showed that Coulomb forces were the main contributors to the overall retention mechanism, which may be hydrophobically assisted. QuEChERS extraction technique was utilized to extract the investigated drugs from plasma samples and a detailed study was carried out to optimize partition/extraction solvents, pH, extraction salts, sample volume and clean-up step. The method had a limit of detection and quantitation of 5.6 and 16.9 ng mL-1 for ALM in ALM/TIM mixture and 2.5 and 7.6 ng mL-1 for ALM in ALM/VER mixture, with an overall recovery not less than 95.22%. This newly proposed method offers a faster alternative to existing chromatographic methods for extraction and determination of ALM in binary mixtures with TIM or VER in rabbit plasma and provides a platform for studying pharmacokinetic parameters. The coadministration of either TIM or VER with ALM resulted in a notable rise in Cmax (maximum plasma concentration) and AUC (area under the plasma concentration-time curve) of ALM, implying possible alterations in the absorption and overall exposure of ALM.

Measuring the Residual Levels of Fenpyroximate and Its Z-Isomer in Citrus Using Ultra-High-Performance Liquid Chromatography-Tandem Mass Spectrometry and Assessing the Related Dietary Intake Risks

Fenpyroximate is an efficient, broad-spectrum phenoxypyrazole acaricide which is used for controlling various mites. In this study, we measured the levels of terminal fenpyroximate residues in citrus fruits, and estimated the dietary intake risks posed by fenpyroximate. To this end, a QuEChERS analytical method was used in combination with ultra-high-performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) to determine the residual levels of fenpyroximate and its Z-isomer (Z-fenpyroximate) in citrus fruits collected from 12 fields under good agricultural practices (GAPs). The average recoveries of fenpyroximate in whole fruits and citrus flesh were 104-110% and 92-109%, respectively, with corresponding RSDs of 1-4% and 1-3%. The average recoveries of Z-fenpyroximate were 104-113% and 90-91%, respectively, with RSDs of 1-2% in both cases. Each limit of quantification (LOQ) was 0.01 mg kg-1. Fifteen days after application with 56 mg kg-1, the terminal residues of fenpyroximate in whole fruits and citrus flesh were <0.010-0.18 mg kg-1 and <0.010-0.063 mg kg-1, respectively; the corresponding values for total fenpyroximate (the sum of fenpyroximate and Z-fenpyroximate) were <0.020-0.19 and <0.020-0.053 mg kg-1. The levels of terminal fenpyroximate residues in citrus fruit were less than the maximum residue limits (MRLs) specified in all the existing international standards. In addition, the risk quotients RQc and RQa were both less than 100%, indicating that the long-term and short-term dietary intake risks posed to Chinese consumers by fenpyroximate in citrus fruit are both acceptable after a 15-day harvest interval.

Multi-Mycotoxin Analysis in Italian Grains Using Ultra-High-Performance Chromatography Coupled to Quadrupole Orbitrap Mass Spectrometry

Mycotoxins are a major source of contamination in cereals, posing risks to human health and causing significant economic losses to the industry. A comprehensive strategy for the analysis of 21 mycotoxins in Italian cereal grain samples (n = 200) was developed using a simple and quick sample preparation method combined with ultra-high-performance liquid chromatography coupled with quadrupole Orbitrap high-resolution mass spectrometry (UHPLC Q-Orbitrap HRMS). The proposed method showed some advantages, such as multi-mycotoxin analyses with simple sample preparation, fast determination, and high sensitivity. The analysis of the sample revealed the presence of 11 mycotoxins, with α-zearalenol being the most frequently detected, while deoxynivalenol exhibited the highest contamination level. Furthermore, co-occurrence was identified in 15.5% of the samples under analysis. Among these, 13% of the samples reported the simultaneous presence of two mycotoxins, while 2.5% showed the co-occurrence of three mycotoxins. Currently, there has been a renewed interest in guaranteeing the quality and safety of products intended for human consumption. This study holds significant value due to its ability to simultaneously detect multiple mycotoxins within a complex matrix. Furthermore, it provides findings regarding the occurrence and co-occurrence of emerging mycotoxins that currently lack regulation under the existing European Commission Regulation.

B-Type Fumonisins in Post-Fermented Tea: Occurrence and Consumer Dietary Exposure in Guangxi, China

Post-fermented tea (PFT), a commonly consumed beverage worldwide, is characterized by the rapid growth of its microbial groups and the substantial changes they undergo. Consequently, PFT may contain mycotoxins such as B-type fumonisins (FBs). This study aimed to assess the intake of FBs through the consumption of PFT among consumers in Guangxi, China. A novel quantitative method using high-performance liquid chromatography-mass spectrometry was used to determine the FB concentration in PFT products. Additionally, a PFT consumption survey was conducted using a face-to-face questionnaire, recording their body weight and PFT consumption patterns based on a three-day dietary recall method. Finally, hazard index was calculated to estimate the health risk of FBs from the consumption of PFT products in Guangxi. The results revealed that the occurrence of FBs in PFT was 20% (24/120), with a concentration ranging from 2.14 to 18.28 μg/kg. The results of the survey showed that the average daily consumption of PFT by consumers was 9.19 ± 11.14 g. The deterministic risk assessment revealed that only 0.026% of the provisional maximum tolerable daily intake of FBs was consumed through PFT, indicating that FB contamination in PFT is not a public health risk.

Monitoring Pharmaceuticals and Personal Care Products in Drinking Water Samples by the LC-MS/MS Method to Estimate Their Potential Health Risk

(1) The occurrence and accumulation of pharmaceuticals and personal care products in the environment are recognized scientific concerns. Many of these compounds are disposed of in an unchanged or metabolized form through sewage systems and wastewater treatment plants (WWTP). WWTP processes do not completely eliminate all active substances or their metabolites. Therefore, they systematically leach into the water system and are increasingly contaminating ground, surface, and drinking water, representing a health risk largely ignored by legislative bodies. Especially during the COVID-19 pandemic, a significantly larger amount of medicines and protective products were consumed. It is therefore likely that contamination of water sources has increased, and in the case of groundwater with a delayed effect. As a result, it is necessary to develop an accurate, rapid, and easily available method applicable to routine screening analyses of potable water to monitor and estimate their potential health risk. (2) A multi-residue UHPLC-MS/MS analytical method designed for the identification of 52 pharmaceutical products was developed and used to monitor their presence in drinking water. (3) The optimized method achieved good validation parameters, with recovery of 70-120% of most analytes and repeatability achieving results within 20%. In real samples of drinking water, at least one analyte above the limit of determination was detected in each of the 15 tap water and groundwater samples analyzed. (4) These findings highlight the need for legislation to address pharmaceutical contamination in the environment.

Development and validation of a QuEChERS-LC-MS/MS method for determination of multiple mycotoxins in maize and sorghum from Botswana

Climatic conditions such as drought, high temperatures, and pre-harvest rainfalls promote the occurrence of mycotoxins in grains. Contamination of staple food sources such as maize and sorghum means that many populations are at risk of being poisoned by mycotoxins. Hence the need for sensitive methods for their simultaneous analysis. Herein, a quick, easy, cheap, effective, rugged, and safe liquid chromatography tandem mass spectrometry (QuEChERS-LC-MS/MS) method for the simultaneous determination of ten mycotoxins in maize and sorghum is presented. The QuEChERS extraction procedure was optimized to maximize extraction recovery and minimize matrix effects while using relatively small quantities of organic solvents and acids. This method was validated according to Commission Implementing Regulation (EU) 2021/808, Commission Regulation (EC) No 1881/2006, and Regulation (EC) no. 401/2006. The developed method met the specified requirements. Recoveries of 80.77% to 109.83% and CVs below 15% were obtained. The correlation coefficient values (R2) were all above 0.98, and low limits of quantification ranging from 0.53 to 89.28 µg/Kg were recorded. The method was applied to 10 maize and 10 sorghum samples collected from markets in Botswana. Half of the samples had detectable mycotoxins, Aflatoxins, Fumonisins, T2-toxin, HT2-toxin, and Zearalenone. Two maize samples had levels of aflatoxin B1 above the maximum permitted level (2.55, 4.07 µg/Kg). These findings point to the necessity of more stringent monitoring of mycotoxins, particularly AFB1 in maize, as well as the value of regular assessment using LC-MS/MS.

Pesticide Residue Fast Screening Using Thermal Desorption Multi-Scheme Chemical Ionization Mass Spectrometry (TD-MION MS) with Selective Chemical Ionization

In this work, the detection characteristics of a large group of common pesticides were investigated using a multi-scheme chemical ionization inlet (MION) with a thermal desorption unit (Karsa Ltd.) connected to an Orbitrap (Velos Pro, Thermo Fisher Scientific) mass spectrometer. Standard pesticide mixtures, fruit extracts, untreated fruit juice, and whole fruit samples were inspected. The pesticide mixtures contained 1 ng of each individual target. Altogether, 115 pesticides were detected, with a set of different reagents (i.e., dibromomethane, acetonylacetone, and water) in different polarity modes. The measurement methodology presented was developed to minimize the common bottlenecks originating from sample pretreatments and nonetheless was able to retrieve 92% of the most common pesticides regularly analyzed with standardized UHPLC-MSMS (ultra-high-performance liquid chromatography with tandem mass spectrometry) procedures. The fraction of detected targets of two standard pesticide mixtures generally quantified by GC-MSMS (gas chromatography with tandem mass spectrometry) methodology was much less, equaling 45 and 34%. The pineapple swabbing experiment led to the detection of fludioxonil and diazinon below their respective maximum residue levels (MRLs), whereas measurements of untreated pineapple juice and other fruit extracts led to retrieval of dimethomorph, dinotefuran, imazalil, azoxystrobin, thiabendazole, fludioxonil, and diazinon, also below their MRL. The potential for mutual detection was investigated by mixing two standard solutions and by spiking an extract of fruit with a pesticide's solution, and subsequently, individual compounds were simultaneously detected. For a selected subgroup of compounds, the bromide (Br^-) chemical ionization characteristics were further inspected using quantum chemical computations to illustrate the structural features leading to their sensitive detection. Importantly, pesticides could be detected in actual extract and fruit samples, which demonstrates the potential of our fast screening method.

Recent progress on the detection of animal-derived food stimulants using mass spectrometry-based techniques

Background

The misuse of animal-derived stimulants in food is becoming increasingly common, and mass spectrometry (MS) is used extensively for their detection and analysis. There is a growing demand for abused-substances detection, highlighting the need for systematic studies on the advantages of MS-based methods in detecting animal-derived stimulants.

Objective

We reviewed the application of chromatography-mass spectrometry to the screening and detection of food stimulants of animal origin. Specifically, we analyzed four common animal sources of synthetic steroids, β-receptor agonists, zearalenol (ZAL), and glucocorticoids. We also explored the potential of using chromatography-mass spectrometry to detect and analyze animal-derived foods.

Methods

We searched and screened the Web of Science and Google Scholar databases until April 2023. Our inclusion criteria included a publication year within the last 5 years, publication language of English, and the research fields of food analysis, environmental chemistry, and polymer science. Our keywords were "mass spectrometry," "anabolic androgenic steroids," "β-2agonists," "glucocorticoids," "zearalenone," and "doping."

Results

Although traditional techniques such as thin-layer chromatography and enzyme-linked immunoassays are simple, fast, and suitable for the initial screening of bulk products, they are limited by their relatively high detection limits. Among the methods based on MS, gas chromatography-mass spectrometry and liquid chromatography-tandem mass spectrometry are the most widely used for detecting food doping agents of animal origin. However, a sensitive method with high repeatability and a short analysis time for a large number of samples is still required. Advances in MS have enabled the detection of extremely low concentrations of these substances. Combining different techniques, such as high-resolution mass spectrometry, ultra-high performance liquid chromatography-tandem mass spectrometry, gas chromatography-combustion-isotope ratio mass spectrometry, ultra-high performance liquid chromatography-high resolution mass spectrometry, and two-dimensional chromatography, offers significant advantages for detecting trace illicit drugs in animal-derived foods. Due to advances in assay technology and sample preparation methods, sample collection and storage methods such as dried blood spots, dried urine spots, and volumetric absorptive microsampling are increasingly accepted because of their increased stability and cost-effectiveness.

Significance

MS significantly improves the efficiency of detecting doping agents of animal origin. With the continuous development of MS technology, its application in the fields of doping detection and the analysis of doping agents of animal origin is expected to become more extensive.

Monitoring and risk analysis of residual pesticides drifted by unmanned aerial spraying

This study aimed to investigate the residual characteristics of pesticides drifted by unmanned aerial spray according to buffer strip, windbreak, and morphological characteristics of non-target crops, suggest prevention for drift reduction, and finally conduct a risk analysis on pesticides exceeding the maximum residue limit (MRL) or uniform level (0.01 mg/kg) of the positive list system (PLS). Non-target crops were collected around the aerial sprayed area (paddy rice) in Boryeong, Seocheon, and Pyeongtaek after UAV spray. When pesticides were detected in more than three samples, Duncan's multiple range test was performed. In cases where pesticides were detected in only two samples, an independent sample t-test was conducted (p < 0.05). The drift rate of pesticides tends to decrease by up to 100% as the buffer distance from aerial sprayed area increases or when a windbreak, such as maize, is present between two locations. Thus, the reduction of drifted pesticides could be effective if both factors were applied near the UAV spray area. Moreover, the residue of drifted pesticides was found to be the highest in leafy vegetables such as perilla leaves or leaf and stem vegetables such as Welsh onion, followed by fruit vegetables and cucurbits, owing to the morphological characteristics of crops. Therefore, selecting pulse or cereal such as soybean or maize as a farm product near the UAV spray area can be considered to minimize the drift. For pesticides that exceed the MRL or PLS uniform level, %acceptable dietary intake is 0-0.81% with no risk. Additionally, employing pesticides approved for both paddy rice and farm products in UAV spraying can effectively minimize instances where MRL or PLS are exceeded. Therefore, this study aims to provide farmers with effective guidelines for mitigating drift. Furthermore, we strive to promote stable and uninterrupted food production while facilitating the utilization of agricultural technologies such as UAV spraying to address labor shortages and ensure sustainable food security.

Optimisation and implementation of QuEChERS-based sample preparation for identification and semi-quantification of 694 targeted contaminants in honey, jam, jelly, and syrup by UHPLC-Q/ToF high-resolution mass spectrometry

A screening and semi-quantitative method was developed for the analysis of 694 various contaminants in honey, jam, jelly and syrup samples by ultrahigh-performance liquid chromatography and quadrupole time-of-flight mass spectrometry. Sample preparation, which was optimised using split factorial design, was based on acetate-buffered version of QuEChERS, followed by a clean-up step and a concentration step to enhance sensitivity of analytes. The method was validated according to SANTE/11312/2021 guidelines. The screening detection and limits of identification were established as being less than or equal to 0.05 mg.kg^-1 for 89% and 74% of the contaminants, respectively. The validated screening method was applied to 50 concentrated sugary products. Overall, 46% of the samples were positive to pesticide residues. Most of the positive samples (78%) contained mixtures of pesticide residues. Three time-and-cost saving convenient strategies suitable for high-throughput analysis were proposed for the targeted semi-quantification of the previously contaminants identified in samples.

Validation and Simultaneous Monitoring of 311 Pesticide Residues in Loamy Sand Agricultural Soils by LC-MS/MS and GC-MS/MS, Combined with QuEChERS-Based Extraction

Soil can be contaminated by pesticide residues through agricultural practices, by direct application or through spray-drift in cultivations. The dissipation of those chemicals in the soil may pose risks to the environment and human health. A simple and sensitive multi-residue analytical method was optimized and validated for the simultaneous determination of 311 active substances of pesticides in agricultural soils. The method involves sample preparation with QuEChERS-based extraction, and determination of the analytes with a combination of GC-MS/MS and LC-MS/MS techniques. Calibration plots were linear for both detectors over the range of five concentration levels, using matrix-matched calibration standards. The obtained recoveries from fortified-soil samples ranged from 70 to 119% and from 72.6 to 119% for GC-MS/MS and LC-MS/MS, respectively, while precision values were <20% in all cases. As regards the matrix effect (ME), signal suppression was observed in the liquid chromatography (LC)-amenable compounds, which was further estimated to be negligible. The gas chromatography (GC)-amenable compounds showed enhancement in the chromatographic response estimated as medium or strong ME. The calibrated limit of quantification (LOQ) value was 0.01 μg g^-1 dry weight for most of the analytes, while the corresponding calculated limit of determination (LOD) value was 0.003 μg g^-1 d.w. The proposed method was subsequently applied to agricultural soils from Greece, and positive determinations were obtained, among which were non-authorized compounds. The results indicate that the developed multi-residue method is fit for the purpose of analyzing low levels of pesticides in soil, according to EU requirements.

Target analysis and retrospective screening of contaminants in ready-to-eat cooked ham samples through UHPLC-Q-Orbitrap HRMS

The use of veterinary drugs (VDs) is widely administered to animals for both therapeutic and prophylactic purposes. However, their improper use may involve their occurrence in the final products intended for human consumption. In this scientific work, a method for the investigation of target (n = 30) VDs residues and retrospective suspect screening followed by confirmation using analytical standards of others 38 contaminants in ready-to-eat cooked ham by ultra-high performance liquid chromatography coupled with high-resolution mass spectrometry (UHPLC-Q-Orbitrap HRMS) was developed. The extraction was performed based on the QuEChERS approach and validated in accordance with the European Regulation 2021/808. The application of the in-house validated method to ready-to-eat cooked ham showed the occurrence of fourteen VDs residues. Despite the important incidence, the concentration levels found were below the maximum residue limits set for VDs in porcine muscle, except for colchicine. Constant monitoring of animals derived food is strongly recommended to ensure the food safety of consumers.

Detection of mycotoxins in cheese using an optimized analytical method based on a QuEChERS extraction and UHPLC-MS/MS quantification

Mycotoxins can produce toxic effects on humans; hence, it is of high importance to determine their presence in food products. This work presents a reliable method for the quantification of 32 mycotoxins in cheese. The analysis procedure was optimized based on a QuEChERS extraction process and the ultra-high performance liquid chromatography coupled with tandem mass spectrometry (UHPLC-MS/MS) detection. The analysis method was validated for four cheese varieties (emmental, blue, brie and camembert) in terms of linearity, sensitivity, matrix effect, accuracy and precision. Satisfactory precision and accuracy values were achieved, with recoveries above 70% for most mycotoxins. The developed method was applied to the analysis of 38 commercial cheese samples. A high occurrence of beauvericin and enniatins were found, ranging from 31% for enniatin A to 100% for enniatin B. The ochratoxin A was detected in three samples at concentrations that may pose a risk to human health.

Optimization of micro-QuEChERS extraction coupled with gas chromatography-mass spectrometry for the fast determination of phthalic acid esters in mussel samples

In this study, a new miniaturized version of the analytical method based on the Quick, Easy, Cheap, Effective, Rugged, and Safe (QuEChERS) technique using Florisil in the cleanup step for extracting six phthalic acid esters (PAEs) in mussel samples was developed by using a design of experiments. For this purpose, 1.5 mL of ultrapure water and later, 1.5 mL of acetonitrile were added to 0.1 g of the lyophilized sample, followed by 0.3 g of a commercial extraction salt packet (magnesium sulfate, sodium chloride, sodium citrate dihydrate, and sodium hydrogencitrate sesquihydrate). The recovered extract was purified using 0.1 g of Florisil. The final extract was evaporated and reconstituted in 1 mL of hexane. The six phthalates were determined by a GC-MS (SIM) system. The whole method was validated at two concentration levels. Recoveries ranged from 79% to 108%. Reproducibility in terms of coefficients of variation was between 4.9% and 12.1%. The limits of quantification of the whole method were between 0.53 and 38.0 μg per kg dry weight. Five mussel samples coming from the Galician Rías were analysed using this method. Except for three of the five samples where DnOP (di-n-octyl phthalate) was below the limit of quantification, all PAEs were found in concentrations that ranged between 1.99 and 372.7 μg per kg dry weight.

Chitosan-carbon nanofiber based disposable bioelectrode for electrochemical detection of oxytocin

Bioelectrodes with low carbon footprint can provide an innovative solution to the surmounting levels of e-waste. Biodegradable polymers offer green and sustainable alternatives to synthetic materials. Here, a chitosan-carbon nanofiber (CNF) based membrane has been developed and functionalized for electrochemical sensing application. The surface characterization of the membrane revealed crystalline structure with uniform particle distribution, and surface area of 25.52 m²/g and pore volume of 0.0233 cm³/g. The membrane was functionalized to develop a bioelectrode for the detection of exogenous oxytocin in milk. Electrochemical impedance spectroscopy was employed to determine oxytocin in a linear concentration range of 10 to 10⁵ ng/mL. The developed bioelectrode showed an LOD of 24.98 ± 11.37 pg/mL and sensitivity of 2.77 × 10^-10 Ω / log ng mL^-1/mm² for oxytocin in milk samples with 90.85-113.34 percent recovery. The chitosan-CNF membrane is ecologically safe and opens new avenues for environment-friendly disposable materials for sensing applications.

Residue analysis of selected organophosphorus and organochlorine pesticides in commercial tomato fruits by gas chromatography mass spectrometry

In this study, analysis of some selected organophosphorus and organochlorine pesticides was carried out in tomato samples collected from the markets of Mettu town, Ilu Aba Bora Zone, Oromia, Ethiopia. The quick, Easy, Cheap, Effective, Rugged, and Safe (QuEChERS) method was used for the extraction of collected samples using acetonitrile with 1% acetic acid, anhydrous magnesium sulfate, and anhydrous sodium acetate, followed by dispersive solid-phase extraction (d-SPE). Chromatographic separation and quantitative determination of the pesticides were performed by gas chromatography equipped with a mass spectrometer. The calibration curves for each analyte constructed in tomato samples were linear in the concentration range of 2-200 μg/kg with R² > 0.99 and the LODs and LOQs of the method were in the range of 0.01-0.04 μg/kg and 0.04-0.13 μg/kg, respectively. The recovery and precision study results were within acceptable standard guidelines. Of the fourteen pesticides tested, chlordane, hexachlorobenzene, 4, 4'-DDE, 4, 4'-DDD, 4, 4'- DDT, and profenofos were detected at 0.15, 0.09, 0.17, 0.032, 1.24 and 0.062 μg/kg, respectively. Despite the concentrations of the detected pesticides being lower than the maximum residue limit recommended by FAO/WHO, the presence of these toxic chemicals in tomatoes indicates product contamination and requires extensive further investigation with the inclusion of other pesticides.

A Comprehensive Review of Pesticide Residues in Peppers

Pesticides are chemicals that are used to control pests such as insects, fungi, and weeds. Pesticide residues can remain on crops after application. Peppers are popular and versatile foods that are valued for their flavor, nutrition, and medicinal properties. The consumption of raw or fresh peppers (bell and chili) can have important health benefits due to their high levels of vitamins, minerals, and antioxidants. Therefore, it is crucial to consider factors such as pesticide use and preparation methods to fully realize these benefits. Ensuring that the levels of pesticide residues in peppers are not harmful to human health requires rigorous and continuous monitoring. Several analytical methods, such as gas chromatography (GC), liquid chromatography (LC), mass spectrometry (MS), infrared spectroscopy (IR), ultraviolet-visible spectroscopy (UV-Vis), and nuclear magnetic resonance spectroscopy (NMR), can detect and quantify pesticide residues in peppers. The choice of analytical method depends on the specific pesticide, that is being tested for and the type of sample being analyzed. The sample preparation method usually involves several processes. This includes extraction, which is used to separate the pesticides from the pepper matrix, and cleanup, which removes any interfering substances that could affect the accuracy of the analysis. Regulatory agencies or food safety organizations typically monitor pesticide residues in peppers by stipulating maximum residue limits (MRLs). Herein, we discuss various sample preparation, cleanup, and analytical techniques, as well as the dissipation patterns and application of monitoring strategies for analyzing pesticides in peppers to help safeguard against potential human health risks. From the authors' perspective, several challenges and limitations exist in the analytical approach to monitoring pesticide residues in peppers. These include the complexity of the matrix, the limited sensitivity of some analytical methods, cost and time, a lack of standard methods, and limited sample size. Furthermore, developing new analytical methods, using machine learning and artificial intelligence, promoting sustainable and organic growing practices, improving sample preparation methods, and increasing standardization could assist efficiently in analyzing pesticide residues in peppers.

Green Analytical Toxicology for the Determination of Cocaine Metabolites

Brazil is the third largest contributor to Green Analytical Chemistry, and there is significant participation of toxicologists in the development and improvement of environmental techniques. Currently, toxicologists have their own strategies and guidelines to promote the reduction/replacement or elimination of solvents, reduce the impacts of derivatization and save time, among other objectives, due to the peculiarities of toxicological analysis. Thus, this review aims to propose the concept of Green Analytical Toxicology and conduct a discussion about its relevance and applications specifically in forensic toxicology, using the microextraction methods developed for the determination of cocaine and its metabolites as examples.

GC-MS and LC-MS Pesticide Analysis of Black Teas Originating from Sri Lanka, Iran, Turkey, and India

The purpose of this study is to investigate pesticide residues in the imported and domestic tea sold in Turkey and to detect their compliance with maximum residue limits (MRL) and Acceptable Daily Intake (ADI). A total of 79 samples were analyzed by using LC-MS/MS and GC-MS devices with AOAC 2007.01 method to investigate 603 pesticide residues. According to the results, pesticide residues were found in a total of 28 tea samples. Pesticide residues were found in the countries of origin at the rates as follows: Iran (100%), India (33.3%) and Sri Lanka (17.3%). No pesticide residue was detected in the tea produced in Turkey. The compounds such as Diuron, Ethion, Cypermethrin, Thiacloprid, Thiamethoxam, Fenpyroximate, Acetamiprid, Imidacloprid, Flubendiamide, Deltamethrin and Hexythiazox were detected in positive samples. Seven types of pesticide residues exceeded the MRL determined by the Turkish Food Codex for 15 types (53.57%) for 28 samples with pesticide residue detected. Additionally, 4 types of pesticide residues were determined to exceed the ADI determined by the Codex Alimentarius for 13 (46.42%) of 28 samples with pesticide residue detected. These results have showed that the imported tea entering Turkey was not adequately analyzed in the customs control laboratories or the maximum residual limits were not clearly determined.

A Simple High-Throughput Field Sample Preparation Method Based on Matrix-Induced Sugaring-Out for the Simultaneous Determination of 5-Hydroxymethylfurfural and Phenolic Compounds in Honey

In the present work, a high-throughput field sample preparation method was reported for the simultaneous determination of 5-hydroxymethylfurfural and phenolic compounds in honey. Combining a simple and green homogenous liquid−liquid extraction, matrix-induced sugaring-out, with the use of a 96-deepwell plate and multichannel pipette, the proposed method showed its merits in instrument-free and high-throughput preparation. Due to the high-throughput property, the parameters of the method were rapidly and systematically studied using a constructed 4 × 2 × 4 × 3 array (sample amount × ratio of ACN:H2O × standing time × replicates) in a 96-deepwell plate. Analytical performance was fully validated, and the limits of detection and limits of quantification were in the range of 0.17−1.35 μg/g and 0.51−4.14 μg/g, respectively. Recoveries were between 83.98 and 117.11%, and all the precisions were <5%. Furthermore, the developed method was successfully applied in the outdoor preparation of commercial honey samples and the in-field preparation of raw honey samples in apiary. The current work presented a simple, rapid, and high-throughput method for the field sample preparation of honey and provides a valuable strategy for the design of field and on-site sample preparation.

Development and Validation of a Method for Determination of 43 Antimicrobial Drugs in Western-Style Pork Products by UPLC-MS/MS with the Aid of Experimental Design

Western-style pork products have attracted many modern urban consumers, and these products have rapidly entered the Chinese market. The current hazard analysis of processed meat products mainly focuses on processing hazards (PAHs, microorganisms, and food additives), with less attention to veterinary drug residues. According to the survey results, the residues of antimicrobial drugs (sulfonamides and quinolones) in pork and its products in China are a severe problem, which may cause metabolic reactions, toxic effects, or enhance drug resistance. This study applied a modified QuEChERS method combined with ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MSMS) to develop a rapid and sensitive method for determining antimicrobial drugs in bacon and ham was successfully evaluated methodologically by EU 2002/657/EC. This study used a three-level, three-factor Box-Behnken design (BBD) to optimize the QuEChERS method by response surface methodology. The excellent linearity of the calibration curve was shown in the corresponding concentration range with a coefficient of determination greater than 0.99. The values of decision limit (CCα) and detection capability (CCβ) were in the range of 10.9-31.3 μg/kg and 11.8-52.5 μg/kg, respectively. The method successfully detected two trace levels of antimicrobial drugs in commercially available samples, including sulfadiazine and moxifloxacin.

Regulation of fungal community and the quality formation and safety control of Pu-erh tea

Pu-erh tea belongs to dark tea among six major teas in China. As an important kind of post-fermented tea with complex microbial composition, Pu-erh tea is highly praised by many consumers owing to its unique and rich flavor and taste. In recent years, Pu-erh tea has exhibited various physiological activities to prevent and treat metabolic diseases. This review focuses on the fungi in Pu-erh tea and introduces the sources, types, and functions of fungi in Pu-erh tea, as well as the influence on the quality of Pu-erh tea and potential safety risks. During the process of fermentation and aging of Pu-erh tea, fungi contribute to complex chemical changes in bioactive components of tea. Therefore, we examine the important role that fungi play in the quality formation of Pu-erh tea. The associations among the microbial composition, chemicals excreted, and potential food hazards are discussed during the pile-fermentation of Pu-erh tea. The quality of Pu-erh tea has exhibited profound changes during the process of pile-fermentation, including color, aroma, taste, and the bottom of the leaves, which are inseparable from the fungus in the pile-fermentation of Pu-erh tea. Specifically, the application prospects of various detection methods of mycotoxins in assessing the safety of Pu-erh tea are proposed. This review aims to fully understand the importance of fungi in the production of Pu-erh tea and further provides new insights into subtly regulating the piling process to improve the nutritional properties and guarantee the safety of Pu-erh tea.

Rapid Analysis of Residues of 186 Pesticides in Hawk Tea Using Modified QuEChERS Coupled with Gas Chromatography Tandem Mass Spectrometry

In this work, the QuEChERS method was modified and evaluated for the determination of 186 pesticides from caffeine-free and fatty hawk tea prior to their gas chromatography tandem mass spectrometry analysis for the first time. The results showed that the combination of MgSO₄ + PSA + MWCNTs plus EMR-Lipid provided the lowest matrix effect and best recovery; 117 of 186 pesticides manifested weak matrix effects. Thus, for accurate quantification, it is necessary to use matrix-matched calibration curves to compensate for the matrix effect. At the spiked level of 0.1 mg/kg, the average recoveries of 184 pesticides were in the range of 70-120% and the RSDs were 0.3-14.4% by the modified method. Good linearity was shown for 186 analytes at concentration of 0.01 mg/L~0.4 mg/L, and the correlation coefficients exceeded 0.99 for 182 pesticides. The detection limits of 186 pesticides by the modified QuEChERS method were 0.001-0.02 mg/kg, and the limits of quantification (LOQ) were 0.005 mg/kg~0.05 mg/kg. The necessity of solvent exchange is also explained in this work. The successful application of the modified QuEChERS in real samples proved that this method could be one of the routine options for analysis of herbal tea.

Anthocyanins in Different Food Matrices: Recent Updates on Extraction, Purification and Analysis Techniques

Anthocyanins (ANCs), a kind of natural pigments, are widely present in food substrates. Evidence has shown that ANCs can promote health in terms of anti-oxidation, anti-tumor, and anti-inflammation. However, the oxidative stability of ANCs limits accurate quantitation and analysis. Therefore, faster, more accurate, and highly sensitive extraction and determination methods are necessary for understanding the role of ANCs in medicine and food. This review presents an updated overview of pretreatment and detection techniques for ANCs in various food substrates since 2015. Liquid-liquid extraction and various green solvent extraction methods, such as accelerated solvents extraction, deep eutectic solvents extraction, ionic liquids extraction, and supercritical fluid extraction, are commonly used pretreatment methods for extraction and purification of ANCs. Liquid chromatography coupled with different detectors (tandem mass spectrometry and UV detectors) and spectrophotometry methods are some of the determination methods for ANC. This study has updated, compared, and discussed different pretreatment and analysis methods. Moreover, the advanced methods and development prospects in this field are comprehensively summarized, which can provide references for further utilization of ANCs.