Maximum Residue Limits Research Articles

Analysis of Antibiotics in Milk from Smallholder Farmers from Kenya Shows Traces Above the Recommended Maximum Residue Limits

Antimicrobial resistance (AMR) is rising globally and is likely to cause more deaths because of antibiotic-resistant microbial infections and antibiotic residues in animal foods and products as a result of misuse of antibiotics in dairying. Thus, we determined the presence and quantities of sulfonamide, tetracycline, and beta-lactam drug residues in milk sampled in Nyandarua, Meru, and Kiambu counties in Kenya using the Charm TRIO® test kit and liquid chromatography (LC) coupled to the triple quadrupole mass spectroscopy (MS) (LC-MS/MS). The TRIO® test kit showed dicloxacillin as the most prevalent at 9.3%, followed by penicillin and cloxacillin at 3.7% each, and nafcillin at 0.9% among the beta-lactams. Among the tetracyclines, demeclocycline and tigecycline were the most prevalent at 10.3% each, followed by oxytetracycline at 9.3%, chlortetracycline at 7.5%, and doxycycline at 3.7%, while sulfaquinoxaline was the only sulfonamide drug detected at 4%. The LC-MS/MS detected the presence of all the tested β-lactam and tetracycline antimicrobial traces and all sulfonamide drugs except sulfamerazine in all three counties. All the tetracycline antibiotics recorded between 3 and 10.5% of antibiotic residues above the recommended Maximum Residue Levels (MRLs) in milk across all three counties, with beta-lactam antibiotics recording between 2 and 33.3%, indicating their misuse in the three counties. Sulfaquinoxaline was the only sulfonamide detected in milk samples above the recommended MRLs, indicating sulfonamides are less used in those counties. Therefore, it is important to enforce a regulatory framework to control antibiotic use in livestock to minimize potential health risks related to their traces in the foods.

Changes of 22 pesticide residues and 3 metabolites during the common processing of Auricularia auricula-judae

It is of great significance to investigate the changes of pesticide residues during processing procedures to ensure the accuracy of dietary risk assessment of pesticide residues. At present, there are few reports about the influence of household processing on pesticide residues in Auricularia auricula-judae. In this study, the changes of 22 pesticides and 3 metabolites during drying and rehydrating process in Auricularia auricula-judae were analyzed, and changes of dietary risk of the residues were assessed. The pesticide residue concentrations increased by 2.8–15.4 times after drying, indicating drying could increase the dietary risk of Auricularia auricula-judae. Different rehydrating conditions, including temperature, duration, and solutions were investigated and compared. The removal rates were the highest (67%–96%) when the Auricularia auricula-judae was rehydrated in clear water at 20 °C for 2h, and the dietary risk could be further reduced for some pesticides using 1.0% NaHCO3 solution for the rehydration. This study provided data for the dietary risk assessment and establishment of maximum residue limits (MRLs) for pesticides in the processed products of Auricularia auricula-judae.

Dieldrin accumulation, distribution in plant parts and phytoextraction potential for several plant species and Cucurbita pepo varieties

Dieldrin, an organochlorine pesticide (OCP) widely used for crop protection in the second half of the 20th century till the 70's, is worldwide still present in arable soils. It can be transferred to crops, notably cucurbits, depending on plant species and cultivars. Finding strategies to decrease OCP bioavailability in soil is therefore a main concern. Phytomanagement strategies could provide (i) ready-to-use short term solution for maintaining the production of edible plant parts with dieldrin concentrations below the Maximum Residue Limits (MRL) and (ii) long-term solution for dieldrin phytoextraction reducing progressively its bioavailability in the soil. This field study aimed at determining dieldrin accumulation capacities and allocation pattern in 17 non-Cucurbitaceae species and 10 Cucurbita pepo varieties, and assessing the dieldrin phytoextraction potential of these plant species when grown to maturity in a historically dieldrin-contaminated soil. Out of the non-Cucurbitaceae species, vetiver was the only one able to accumulate significant amounts of dieldrin, which mainly remained in its roots. All C. pepo varieties were able to uptake and translocate high dieldrin amounts into the shoots, leading to the highest phytoextraction potential. Despite the intraspecific variability in dieldrin concentration in zucchini plant parts, mainly in the reproductive organs, the phytoextraction capacity for shoots and fruits was high for all tested varieties (147 to 275 μg dieldrin plant−1, corresponding to 5.6 % of the n-heptane extractable soil dieldrin), even for the one with low fruit dieldrin concentration. Both food safety and phytoextraction could be achieved by selecting productive zucchini varieties displaying low dieldrin concentration in fruits and high one in shoots.

Simultaneous Analysis of 272 Pesticides in Agricultural Products by the QuEChERS Method and Gas Chromatography with Tandem Mass Spectrometry.

The aim of this study is to develop a rapid and accurate method for simultaneous analysis of multi-residue pesticides and conduct pesticide monitoring in agricultural products produced by the production and distribution stage in Korea. The representative agricultural products were selected as brown rice, soybean, potato, mandarin, and green pepper and developed using gas chromatography with tandem mass (GC-MS/MS) for the analysis of 272 pesticide residues. The experimental samples were extracted by the QuEChERS-EN method and then cleaned up by using d-SPE, including MgSO4 and primary secondary amine (PSA) sorbents. The established method was validated in accordance with Codex CAC-GL/40, and the limit of quantitation (LOQ) was determined to be 0.01 mg/kg. A total of 243 pesticides satisfied the guidelines in five samples at three levels with values of 60 to 120% (recovery) and ≤45% (coefficient of variation, CV). The remaining 29 pesticides did not satisfy the guidelines, and these pesticides are expected to be used as a screening method for the routine inspection of agricultural products. As a result of analyzing 223 agricultural products in South Korea by applying the simultaneous analysis method, none of the detected levels in the samples exceeded the standard values based on maximum residue limits (MRLs). The developed method in this study will be used to inspect residual pesticides in agricultural products, and it is anticipated to contribute to the distribution of safe agricultural products to consumers.

Optimization of QuEChERS method for determination of pesticide residues in vegetables and health risk assessment.

The present study focused on the optimization of the QuEChERS extraction method for the determination of 61 pesticide residues and associated health risk assessment in 144 samples of commonly consumed vegetables, viz., eggplant, cabbage, green chilli, okra, and tomato. The samples were collected between January and April 2022 from three different districts within Gujarat, India. The QuEChERS method was optimized and utilized for the extraction of samples. The samples were analyzed by UHPLC-q-TOF/MS and GC-MS/MS. The modified QuEChERS method was successfully validated, and the obtained results were satisfactory as per the 2021 SANTE guidelines. The residue analysis of the vegetable samples showed that about 4% of total samples contained single pesticide residues. Pesticide residues below the quantitation limit (BQL) were observed in eggplant, cabbage, and okra samples. In total, 15.62% (n = 5) samples of green chilli showed the presence of pesticides such as azoxystrobin, bifenthrin, cypermethrin, fenpropathrin, and propargite whereas 3% (n = 1) tomato samples contained cyfluthrin. In total, 97.22% of the samples had residues that were below the European Union Maximum Residue Limit (EU MRL). Two samples of green chilli had pesticide residues above EU MRL. The Hazard Index (HI) and Hazard Quotient (HQ) were used to assess the health risks associated with green chilli and tomato consumption. The HI and HQ values for adolescents and adults were found to be less than 1. The modified QuEChERS method was found to be easy and effective and can be implemented for routine sample analysis. The study revealed the presence of pesticide residues in tomato and green chilli samples. Further, the outcome provided information pertaining to current pesticide status, concluding that consumption of these commodities is unlikely to pose any health risk, though long-term monitoring studies focusing on dietary health risk assessment must be initiated.

Bioaccumulation and health risk assessment of trace elements in Tilapia (Oreochromis mossambicus) from selected inland water bodies.

The presence of toxic trace elements (TEs) has resulted in a worldwide deterioration in freshwater ecosystem quality. This study aimed to analyze the distribution of TEs, including chromium (Cr), nickel (Ni), arsenic (As), mercury (Hg), cadmium (Cd), and lead (Pb), in water, sediment, and organs of Tilapia (Oreochromis mossambicus) collected from selected inland water bodies in Tamil Nadu, India. The water samples exhibited a range of concentrations for TEs: Cr varied from 0.014 to 5.193µg/L, Ni ranged from 0.283 to 11.133µg/L, As ranged from 0.503 to 1.519µg/L, Cd from 0.001 to 0.616µg/L, and Pb ranged from non-detectable (ND) to 6.103µg/L. The concentrations of TEs in sediment were found to vary within the following ranges: 5.259 to 32.621mg/kg for Cr, 1.932 to 30.487mg/kg for Ni, 0.129 to 0.563mg/kg for As, 0.003 to 0.011mg/kg for Cd, ND to 0.003mg/kg for Hg, and 0.404 to 1.575mg/kg for Pb. The study found that the accumulation pattern of TE in fishes across all selected areas was liver > bone > gill > muscle. The organs had TE concentrations of Cr (ND-0.769mg/kg), Ni (ND-1.053mg/kg), As (0.002-0.080mg/kg), Pb (ND-0.411mg/kg), and Hg (ND-0.067mg/kg), which was below the maximum residual limit prescribed by EC and FSSAI. The bioconcentration factor (BCF) of TEs exhibited a greater magnitude in comparison with the biota-sediment accumulation factor due to the higher concentration of TEs in fish and lower level in water. The assessment of both carcinogenic and non-carcinogenic risks suggests that the consumption of Tilapia from the study region does not pose any significant risks.

Therapeutic effects of lincomycin and level of drug degradation in broiler tissues after treatment

Background and Aim: Lincomycin is an antibiotic used in broiler farming and is commonly combined with other substances to achieve synergistic and complementary effects on the antibacterial spectrum and mechanism. We developed a specific high-performance liquid chromatography (HPLC) method to measure lincomycin levels in broiler tissues. This study aimed to determine the lincomycin level in tissues and compare it with the minimum inhibitory concentration (MIC) and maximum residue limit (MRL) of certain pathogenic bacteria. Materials and Methods: Three groups of broiler chickens were involved in the study (n = 20 in each group): A control group without lincomycin treatment and two groups (each further divided into two sub-groups) that received oral lincomycin at a dose of 1 g/10 kg of body weight daily for 7 and 14 consecutive days. Tissue samples were collected from each group 1 day and 1 week after lincomycin administration (ALA). This study validated the development of a technique for analyzing drug level degradation in tissues using HPLC. Descriptive and statistical analyses were performed for drug levels to assess their therapeutic value and safety based on lincomycin MIC of certain pathogenic bacteria and MRL. Results: The method validation resulted in linear regression and coefficient of determination for tissues with r2 > 0.99, with a recovery rate of 90%–110%, precision as the coefficient of variation 15%, and specificity with no peak overlap for lincomycin. The limits of detection for the liver and kidney were 0.01 μg/g, 0.05 μg/g, and 0.1 μg/g for the breast muscle and all tissues. Administration of lincomycin for 7 and 14 days resulted in therapeutic value concentrations. Lincomycin levels in the liver and kidney of ALA exceeded the MRL, whereas breast muscles were below the MRL for a week of ALA treatment. Conclusion: Administration of lincomycin for 7 and 14 consecutive days resulted in therapeutic value; however, after a week, most tissues showed high drug concentrations that exceeded the MRL. It is necessary to carefully consider the prolonged therapeutic dose of lincomycin in broilers. Antibiotic therapy must be guided in such a way as to protect the product from harmful residues. Keywords: : broiler tissues, lincomycin level, maximum residue limit, minimum inhibitory concentration.

Residue, distribution and depletion of fluralaner in egg following a single intravenous and transdermal administration in healthy shaver hens: Fluralaner residue in egg

The demand for the use of fluralaner in an extra label manner is increasing due to lack of efficacious treatment to combat mites and bed bugs in the poultry industry in the United States. Fluralaner residue data in eggs is lacking and residues might cause risks to human health. The present study aimed to determine the depletion profiles of fluralaner in eggs and estimate the drug withdrawal interval in whole eggs by adopting the US Food and Drug administration tolerance limit method with single intravenous (0.5 mg/kg) or transdermal administration (average 58.7 mg/kg) in healthy shaver hens. Hens were treated intravenously or trans-dermally with fluralaner. The eggs were collected daily for 28 days for intravenous treated and for 40 days from the transdermal route group. Fluralaner concentrations in yolk and albumen were determined by mass spectrometry. The greater percentage of fluralaner was observed in yolk when compared to the albumen for both administration routes. Non-compartmental analysis was used to calculate the pharmacokinetic parameters in yolk, albumen and whole egg. The longest apparent half-life confirmed in yolk was 3.7 days for intravenous and 14.3 days for the transdermal route. The withdrawal intervals in whole egg for fluralaner following the intravenous and transdermal administration were 7 days and 81 days, respectively, with maximum residue limits (1.3 µg/g) at 13 days and 171 days, respectively, based on the limit of quantification (0.4 µg/g) from the analytical assay reported by EMA and APVMA.

Dissipation behavior and risk assessment of imidacloprid and its metabolites in apple from field to products

Pesticides play vital roles in controlling pests and boosting crop yields. Imidacloprid is widely used all over the world and may form in agricultural products. The presence of pesticide residues in apples raises serious health concerns. Understanding the residual fate of imidacloprid is critical for food safety and human health. In this study, the dissipation behavior, metabolism, household processing and risk assessment of imidacloprid and its metabolites in apple were investigated from filed to table. Field results suggested that the half-lives of imidacloprid at 5 times the recommended dosage was 1.5 times that of the standard dosage. And the final residues of imidacloprid were less than the established maximum residue limits (MRLs). Clarification and simmering had little effect on the reduction the residues of imidacloprid and its metabolites. The calculated processing factors were lower than 1 for imidacloprid and its metabolites, implying that the residual ratios of imidacloprid and its metabolites in each steps of the food processing were reduced. The risk quotients were < 1 for all Chinese people, indicating that acceptable risks associated with dietary exposure to imidacloprid in apple. However, the higher risks were observed in young people than adults, and females faced higher risks than males. Given high residue levels in pomace, imidacloprid and its metabolites should be further studied in commercial byproducts.

Risk assessment of residues of coccidiostats in food 14 years after the introduction of maximum levels

Risk assessment of residues of coccidiostats in food 14 years after the introduction of maximum levels

Gold nanoparticles-doped MXene heterostructure for ultrasensitive electrochemical detection of fumonisin B1 and ampicillin.

Early transition metal carbides (MXene) hybridized by precious metals open a door for innovative electrochemical biosensing device design. Herein, we present a facile one-pot synthesis of gold nanoparticles (AuNPs)-doped two-dimensional (2D) titanium carbide MXene nanoflakes (Ti3C2Tx/Au). Ti3C2Tx MXene exhibits high electrical conductivity and yields synergistic signal amplification in conjunction with AuNPs leading to excellent electrochemical performance. Thus Ti3C2Tx/Au hybrid nanostructure can be used as an electrode platform for the electrochemical analysis of various targets. We used screen-printed electrodes modified with the Ti3C2Tx/Au electrode and functionalized with different biorecognition elements to detect and quantify an antibiotic, ampicillin (AMP), and a mycotoxin, fumonisin B1 (FB1). The ultralow limits of detection of 2.284pM and 1.617pg.mL-1, which we achieved respectively for AMP and FB1 are far lower than their corresponding maximum residue limits of 2.8nM in milk and 2 to 4mgkg-1 in corn products for human consumption set by the United States Food and Drug Administration. Additionally, the linear range of detection and quantification of AMP and FB1 were, respectively, 10pM to 500nM and 10pgmL-1 to 1µgmL-1. The unique structure and excellent electrochemical performance of Ti3C2Tx/Au nanocomposite suggest that it is highly suitable for anchoring biorecognition entities such as antibodies and oligonucleotides for monitoring various deleterious contaminants in agri-food products.

Could traces of fluoroquinolones in food induce ciprofloxacin resistance in Escherichia coli and Klebsiella pneumoniae? An in vivo study in Galleria mellonella with important implications for maximum residue limits in food.

We hypothesized that the residual concentrations of fluoroquinolones allowed in food (acceptable daily intake-ADIs) could select for ciprofloxacin resistance in our resident microbiota. We developed models of chronic Escherichia coli and Klebsiella pneumoniae infection in Galleria mellonella larvae and exposed them to ADI doses of ciprofloxacin via single dosing and daily dosing regimens. The emergence of ciprofloxacin resistance was assessed via isolation of the target bacteria in selective agar plates. Exposure to as low as one-tenth of the ADI dose of the single and daily dosing regimens of ciprofloxacin resulted in the selection of ciprofloxacin resistance in K. pneumoniae but not E. coli. This resistance was associated with cross-resistance to doxycycline and ceftriaxone. Whole genome sequencing revealed inactivating mutations in the transcription repressors, ramR and rrf2, as well as mutations in gyrA and gyrB. We found that ciprofloxacin doses 10-fold lower than those classified as acceptable for daily intake could induce resistance to ciprofloxacin in K. pneumoniae. These results suggest that it would be prudent to include the induction of antimicrobial resistance as a significant criterion for determining ADIs and the associated maximum residue limits in food.IMPORTANCEThis study found that the concentrations of ciprofloxacin/enrofloxacin allowed in food can induce de novo ciprofloxacin resistance in Klebsiella pneumoniae. This suggests that it would be prudent to reconsider the criteria used to determine "safe" upper concentration limits in food.

The two faces of antibiotics: an overview of the effects of antibiotic residues in foodstuffs.

Antibiotics, which have been used for many years to treat infections, also play an important role in food contamination with antibiotic residues. There is also unnecessary use of antibiotics, particularly to increase production efficiency. Non-compliance with withdrawal periods and maximum residue limits (MRLs) for antibiotics used in food-producing animals results in undesirable events, such as allergic reactions, teratogenicity, carcinogenicity, changes in the microbiota and, in particular, antibiotic resistance. Therefore, it may be useful to avoid unnecessary use of antibiotics, to limit the use of antibiotics and to turn to alternatives that can be used instead of antibiotics. The aim of this review is to provide information on the undesirable effects of antibiotic residues in food-producing organisms and in the environment, their determination, and the precautions that can be taken.

Detection of selected antimicrobial residues in red meat and kidney of beef cattle slaughtered at Nekemte municipal abattoir, Ethiopia.

Antibiotics are commonly used drugs in farm animals for therapeutic, prophylactic and diagnosis purposes. As a result of the use of antibiotics in livestock, residues of antibiotics may be present in animal-derived foods, especially in meat. This study aimed at determining the antibiotic residues in cattle slaughtered at Nekemte municipal abattoir and assessing the knowledge, attitude and practice (KAP) level of the community about antibiotic residue in food of cattle origin. A cross-sectional study was conducted on randomly selected kidney and muscle samples slaughtered at Nekemte municipal abattoir. The samples were collected aseptically and analysed using liquid chromatography mass spectrometer. In addition the KAP of cattle handlers, butcher men and meat users were collected using structured questionnaire. The data was analysed by SPSS and intercooled Stata version 7.0, 2001. Results are presented as percentages and frequency distributions in tabular and graphical form. From 120 individuals interviewed, only 25.83% knew about withdrawal time and had limited knowledge on effect of antibiotic residue on human health, whereas about 47.5% did not heard about antibiotic residue in meat. Tetracycline was detected in all the sampled meat 60 (100%), whereas oxytetracycline residues were detected in half 15 (50%) of the samples. In the current study doxycycline, sulphadiazine, penicillin G and enrofloxacin were not detected in all samples. Oxytetracycline residue levels ranged from 0.00 to 463.35µg/kg for the kidney and 0.00 to 354.55µg/kg for muscle samples. About 10% of kidney and 3.33% muscle samples collected had oxytetracycline residues above maximum residue limits. In general, the study revealed that oxytetracycline residues were prevalent among antimicrobial residues analysed from the study area. The study indicated the presence of high antimicrobial residue and hence exposes for antimicrobial resistance of pathogens warranting coordinated effort to mitigate its health effect on the animal and hence human being.

Residue Behaviors and Degradation Dynamics of Insecticides Commonly Applied to Agrocybe aegerita Mushrooms from Field to Product Processing and Corresponding Risk Assessments.

Residual pesticides in Agrocybe aegerita mushroom have emerged as a significant concern and bring much uncertainty due to processing procedures. In this study, a modified QuEChERS sample preparation procedure and UPLC-MS/MS were used to analyze the residual levels of four commonly used pesticides in A. aegerita from field to product processing. The field results showed that dissipation of these targeted chemicals was consistent with the first-order kinetics, and the half-life time ranged from 20.4 h to 47.6 h. The terminal residues of the four pesticides at harvest time ranged from 9.81 to 4412.56 μg/kg in raw mushroom. The processing factors (PFs) of clothianidin, diflubenzuron, chlorbenzuron, and pyridaben ranged from 0.119 to 0.808 for the drying process and from 0.191 to 1 for the washing process. By integrating the data from the field trials, the PFs, and the consumption survey, the chronic dietary risks of the target chemicals via A. aegerita intake ranged from 2.41 × 10-5 to 5.69 × 10-2 for children and from 6.34 × 10-6 to 1.88 × 10-2 for adults, which are considerably below the threshold of 1, indicating no unacceptable risk to consumers in the Fujian province of China. This research offers foundational data for appropriate use and the maximum residue limit (MRL) establishment for these four insecticides in A. aegerita.

Dissipation and Safety Analysis of Dimethomorph Application in Lychee by High-Performance Liquid Chromatography-Tandem Mass Spectrometry with QuEChERS.

This study presents a method for analyzing dimethomorph residues in lychee using QuEChERS extraction and HPLC-MS/MS. The validation parameters for this method, which include accuracy, precision, linearity, and recovery, indicate that it meets standard validation requirements. Following first-order kinetics, the dissipation dynamic of dimethomorph in lychee was determined to range from 6.4 to 9.2 days. Analysis of terminal residues revealed that residues in whole lychee were substantially greater than those in the pulp, indicating that dimethomorph residues are predominantly concentrated in the peel. When applied twice and thrice at two dosage levels with pre-harvest intervals (PHIs) of 5, 7, and 10 days, the terminal residues in whole lychee ranged from 0.092 to 1.99 mg/kg. The terminal residues of the pulp ranged from 0.01 to 0.18 mg/kg, with the residue ratio of whole lychee to pulp consistently exceeding one. The risk quotient (RQ) for dimethomorph, even at the recommended dosage, was less than one, indicating that the potential for damage was negligible. This study contributes to the establishment of maximum residue limits (MRLs) in China by providing essential information on the safe application of dimethomorph in lychee orchards.

Farm to fork strategy for evaluating the qualitative and quantitative health risks to the Nepalese population associated with pesticide residues in apple and banana

Studies of pesticide use on commercial fruits are limited in Nepal. We surveyed the experiences and opinions of banana farmers in Nepal and monitored pesticide residues in apples and bananas. We monitored the residual status and associated health risks of 51 multi-group pesticides using Liquid Chromatography Triple Quadrupole Mass Spectrometry. Apple and banana samples were collected from different districts, farms, markets, and seller categories (our farm to fork survey). We found a significant bivariate positive correlation between farmers’ knowledge of pesticide negative effects and safety-promoting behavior among farmers. Residues of tebuconazole, difenoconazole, propargite and imidacloprid were most frequently detected. Of all the detected pesticides, propargite showed the highest concentration in apples, exceeding regulatory maximum residue limits (MRLs) in 24% of the samples. Epoxiconazole, tebuconazole, imidacloprid, quinalphos, fenpropathrin and bifenthrin in apples, and metalaxyl and imidacloprid in bananas also crossed their MRLs. Dietary exposure to pesticides among children and adults was estimated based on a hazard quotient and hazard index by using lower-bound and upper-bound approaches. Our results indicated that children consuming apples with residues of propargite are exposed to the greatest pesticide hazard.

Screening of 152 Veterinary Drug Residues in Animal Source Foods by LC-MS/MS, Multilaboratory Validation Study: Final Action 2020.04

Abstract Background The presence of veterinary drug residues in food-producing animals and animal products is regulated through the enforcement of maximum residue limits (MRLs). To answer the need of the food sector to monitor these substances in a wide range of food commodities, stakeholders at AOAC identified the need for a reliable confirmatory screening method. Such qualitative approach is required for compliance checking and to support product release in manufacturing. Objective Data were collected from 5 independent laboratories that applied the AOAC Official First Action Method AOAC 2020.04 to demonstrate adequate performance under reproducibility conditions. Probability of Detection (POD) was calculated in blank test samples and test samples spiked at the Screening Target Concentration (STC) level, with the objective to achieve PODs ≤ 10% and ≥ 90%, respectively. Additionally, the effectiveness of the screening method was assessed through participation to 92 proficiency test samples. Methods Four streams were optimized to screen for 152 veterinary drug residues by LC-MS/MS in a wide variety of food commodities including milk-based ingredients and related products (e.g., milk fractions, infant formula, infant cereals and baby foods), meat- and fish-based ingredients and related products (fresh, powdered, cooked, infant cereals and baby foods) and other ingredients such as eggs, animal fat and animal byproducts. The four streams covered 105 antibiotic residues, anti-inflammatory and antiparasitic agents (Stream A); 23 Beta-lactams (Stream B); 14 Aminoglycosides (Stream C) and 10 Tetracyclines (Stream D). Results The multi-laboratory validation led to PODs at the STC ≥ 94% and PODs in the blank ≤ 9%. Further application of the multi-laboratory validated method to 92 proficiency tests provided more than 99% satisfactory submitted results (n = 784). Conclusion The inter-laboratory reproducibility determined for this method met the acceptance criteria defined in AOAC SMPR 2018.010. Highlights AOAC has approved the method for Final Action Status.

Monitoring and risk assessment for some quaternary ammonium compounds as antimicrobial agents in some processed and packaged food

ABSTRACT Quaternary ammonium compounds (QACs) might be applied as fungicides, herbicides, and algaecide in agriculture or as antimicrobial agents in food preservation. There are risks either from the application of QACs as food additives or the contamination during the disinfection and sterilisation of the food production lines by QACs in food production factories. Exceeding the maximum residue limits (MRLs) wasn’t accepted by European legislation and Codex guidelines, leading to several risks in human health. Inspecting and monitoring of QACs in 143 packaged food products, such as liquid milk, juices, baby food products, herbal drinks, and frozen vegetables and fruits were carried out in some Egyptian local markets during 2022–2023. The In-house validated QuEChERS extraction method was operated and followed by LC-MS/MS analysis. Only one violated baby food sample that was contaminated with 0.064 mg/kg DDAC and 0.335 mg/kg BACs. According to the EU MRLs, there were no higher residue levels of QACs in juices, milk products, and frozen vegetables with acceptable concentrations. All analysed samples have acceptable results with concentrations less than 0.1 mg/kg, which means that they were all safe for human consumption and health. Our study supported the analytical procedure for the routine inspection of QACs in food.

Metal-organic frameworks as sensitisers for potentiometric sensors

As an example for a metal-organic framework (MOF) sorbent acting as sensitiser in a potentiometric sensor, we introduce the metal–organic framework (MOF) UiO-66-NH2 into a bridged extended-gate field effect transistor (EGFET) design. The sensitised EGFET detects residue of the insecticide imidacloprid with a limit of detection more than 3 orders of magnitude smaller than the EU ‘Maximum Residue Limit’ (MRL) for imidacloprid. This allows decisions on MRL compliance of water at a much lower experimental footprint than with chromatographic methods. To apply the sensor to food samples, we account for possible interference from legitimate food ingredients. Interference is small or moderate for fruit juices, moderate for ‘red’ juice (containing anthocyanin dyes), and small for others. Interference is strong for tea, probably from caffeine. We propose a test protocol to make ‘accept/reject’ decisions with respect to imidacloprid residue even in the presence of small or moderate interference. The present agar-bridged EGFET design enables the wider use of MOF sorbents in potentiometric sensors.