Model prediction of herbicide residues in soybean oil: Relationship between physicochemical properties and processing factors

Development and validation of stable isotope dilution LC-MS/MS method for simultaneous quantification of four Alternaria toxins in 15 food commodities

Alternaria toxins (ATs) are produced from Alternaria species that result in crop losses and harmful impacts on human health. A stable isotope dilution LC-MS/MS method was established to quantify four ATs in 15 food commodities: alternariol (AOH), alternariol monomethyl ether (AME), tentoxin (TEN), and tenuazonic acid (TeA). Based on systematically optimization of detection conditions and pre-processing steps, the limits of detection and limits of quantification of the four ATs ranged from 0.1 to 10 μg/kg and 0.2 to 30 μg/kg, respectively. The results showed that the recoveries of the four ATs were 72.0%-119.1%. The intra-precision and inter-precision ranged from 0.7% to 11.1% and 1.1% to 13.1%, respectively. The method was successfully applied to the determination of four ATs in 35 food samples, suggesting that this method could provide meaningful occurrence data to support the assessment of emerging ATs in food commodities.

Residue changes, degradation, processing factors and their relation between physicochemical properties of pesticides in peanuts during multiproduct processing

This study systematically investigates the residue changes, processing factors (PFs), and relation between the physicochemical properties of pesticides during peanut processing. Results revealed that peeling, washing, and boiling treatments removed partial or substantial pesticide residues from peanuts with PFs of 0.29-1.10 (most <1). By contrast, pesticides appeared to be partially concentrated during roasting, stir-frying, and deep-frying peanuts with PFs of 0.16-1.25. During oil pressing, 13 of the 28 pesticides were concentrated in the peanut oil (PF range: 1.06-2.01) and 25 of the pesticides were concentrated in the peanut meal (1.07-1.46). Physicochemical parameters such as octanol-water partition coefficient, degradation point, molecular weight, and melting point showed significant correlations with PFs during processing. Notably, log Kow exhibited strong positive correlations with the PFs of boiling, roasting, and oil pressing. Overall, this study describes the fate of pesticides during multiproduct processing, providing guidance to promote the healthy consumption of peanuts for human health.

Improved analysis of 230 pesticide residues in three fermented soy products by using automated one-step accelerated solvent extraction coupled with GC-MS/MS

Consumer concerns over healthy diets are increasing as a result of the toxicity and persistence of pesticide residues in foodstuffs. Developing sensitive and high-throughput monitoring techniques for these trace residues is seen as an essential step in ensuring food safety. An automatic and sensitive multi-residue analytical method was developed and validated for the simultaneous determination of 230 compounds, including pesticides and their hazardous metabolites, in fermented soy products. The method included preparing the sample using on-line extraction and clean-up system based on accelerated solvent extraction (ASE), then determining the analytes using GC-MS/MS techniques. The homogenized samples (soy sauce, douchi, and sufu) were automatically extracted at 80 °C and 10.3 MPa and at the same time, in situ cleaned by 300 mg of primary secondary amine (PSA) combined with 20 mg of hydroxylated multi-walled carbon nanotubes in an extraction cell. The method obtained excellent calibration linearity (r > 0.9220) and a satisfactory analysis of the targeted compounds, which were evaluated with matrix-matched calibration standards over the range of 5-500 μg L-1. The limit of detections (LODs) of analytes were in the range of 0.01-1.29 μg kg-1, 0.01-1.39 μg kg-1, and 0.01-1.34 μg kg-1 in soy sauce, douchi, and sufu, respectively. The limit of quantifications (LOQs), which defined as the lowest spiking level, were set at 5.0 μg kg-1. The recoveries were within 70-120 % for over 95 % of the analytes, and the relative standard deviations (RSDs) were below 13.6 %. Moreover, a positive detection rate of 47 % were obtained when the proposed method was used on 15 real fermented soy products. These results suggested that the developed high-throughput method is highly feasible for monitoring of these target analytes in trace level.

Residue levels, processing factors and risk assessment of pesticides in ginger from market to table

Ginger is consumed as a spice and medicine globally. However, pesticide residues in ginger and their residue changes during processing remain poorly understood. Our results demonstrate that clothianidin, carbendazim and imidacloprid were the top detected pesticides in 152 ginger samples with detection rates of 17.11-27.63%, and these pesticides had higher average residues of 44.07-97.63 μg/kg. Although most samples contained low levels of pesticides, 66.45% of the samples were detected with pesticides, and 38.82% were contaminated with 2-5 pesticides. Peeling, washing, boiling and pickling removed different amounts of pesticides from ginger (processing factor range: 0.06-1.56, most <1). By contrast, pesticide residues were concentrated by stir-frying and drying (0.50-6.45, most >1). Pesticide residues were influenced by pesticide physico-chemical parameters involving molecular weight, melting point, degradation point and octanol-water partition coefficient by different ginger processing methods. Chronic and acute dietary risk assessments suggest that dietary exposure to pesticides from ginger consumption was within acceptable levels for the general population. This study sheds light on pesticide residues in ginger from market to processing and is of theoretical and practical value for ensuring ginger quality and safety.

A fast multi-residue analysis of twenty-four classes of pesticide in sesame (Sesamum indicum L.) and their migration into processed products

Sesame is widely used as a nutritional supplement or condiment because of its nutritious properties and palatable flavor. However, the extensive use of pesticides in sesame fields has paradoxically decreased the nutritional vantage. The current study used QuEChERS with a low-temperature freezing method to develop a multi-residue analytical approach to detect target analytes (pesticides) in sesame seed, sesame oil, sesame paste, and sesame meal. The migration ability of target pesticides during oil processing was investigated using HPLC-MS/MS and GC-MS: 35% of pesticides decreased, with processing factors (PFs) lower than 0.98, whereas 65% migrated from the seed to the oil during processing. The migration success of methoxyfenozide was the highest, while clothianidin and pymetrozine demonstrated a significantly lower rate of transfer. The results provide insight into the types of pesticides that should be used in farming practices of sesame to decrease the impact on human health.

Multicompartmental monitoring of legacy and currently used pesticides in a subtropical lake used as a drinking water source (Laguna del Cisne, Uruguay)

A pilot annual monitoring survey (April 2018-March 2019) was conducted to investigate the presence of pesticides in superficial water and fish in Laguna del Cisne, one of the most critical drinking water sources in Uruguay. A total of 25 pesticide residues were detected in superficial water (89.3 % of the samples). Pesticide's temporal distribution was associated with crops and livestock practices, with higher occurrences in spring and summer than in autumn and winter. The most frequent compounds in superficial water were the insecticide chlorantraniliprole, and the herbicides glyphosate (including its metabolite AMPA) and metolachlor. The levels of Organochlorine pesticide, p,p'-DDT, was in some cases two order of magnitude above the international water quality guidelines for Ambient Water Criteria. In fishes, eight different pesticides were detected, at concentrations from 1000 to 453,000 ng·kg^-1. The most frequent pesticides found were propiconazole, chlorpyrifos, and p,p'-DDE. The widespread occurrence of pesticides in fish suggests potential exposure effects on fish populations and the aquatic ecosystem. The sampling approach of this work allowed monitoring the continuous concentrations of several pesticides in surface waters and fishes to establish the influence from past and current agriculture practices in Laguna del Cisne basin. For safety measures, continuous monitoring programs must be performed in this system to prevent toxicity impacts on aquatic organisms and human health.

Framework for defining pesticide maximum residue levels in feed: applications to cattle and sheep

BACKGROUND

Pesticide residues in animal feed can endanger animal health and compromise the safety of livestock products for human consumption. Even though policymakers such as the European Union and the World Health Organization have established maximum residue levels (MRLs) for pesticides in both human food and animal feed, there is no systematic management of pesticides in animal feed that considers the entire supply chain. In response, we propose a framework for defining consistent MRLs for pesticides in animal feed that assesses the impact of defined MRLs on upstream (e.g., MRLs in feed crops) and downstream (e.g., MRLs in livestock products) sectors of the livestock-product supply chain.

RESULTS

The MRLs determined for the selected pesticides in the feed of cattle and sheep as case study animals indicate that lipophilic pesticides tend to have lower MRLs than hydrophilic pesticides, primarily due to the relatively high toxicity and biotransfer factors of lipophilic pesticides. In addition, we observe that, primarily for lipophilic pesticides, upstream and downstream regulations are not aligned in terms of defining MRLs in feed using current MRLs in crops with relevance to feed and foods of animal origin.

CONCLUSION

Some of the current pesticide regulations in the livestock-product supply chain need to be re-evaluated to ensure that MRLs in the upstream sector (i.e., crops) do not result in unacceptable residues in the downstream sector (i.e., MRLs in livestock products affecting animal and human health). Finally, we provide recommendations for optimizing the derivation of MRLs in feed, including the evaluation of residue fate during feed and food manufacturing processes. © 2022 The Authors. Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

Determination of Five Phthalate Esters in Tea and Their Dynamic Characteristics during Black Tea Processing

A highly specific and high extraction-rate method for the analysis of dimethyl phthalate (DMP), diethyl phthalate (DEP), di-n-butyl phthalate (DBP), diisobutyl phthalate (DiBP), and di-(2-ethyl) hexyl phthalate (DEHP) in tea samples was developed. Based on three-factor Box-Behnken response surface design, solid-phase extraction (SPE) of five phthalate ester (PAE) residues in tea was optimized. Optimal extraction conditions were found for extraction temperature (40 °C), extraction time (12 h), and ratio of tea to n-hexane (1:20). The dynamic distribution of PAEs at each stage of black tea processing was also analyzed, and it was found that the baking process was the main stage of PAE emission, indicating that traditional processing of black tea significantly degrades PAEs. Further, principal component analysis of the physicochemical properties and processing factors of the five PAEs identified the main processing stages affecting the release of PAEs, and it was found that the degradation of PAEs during black tea processing is also related to its own physicochemical properties, especially the octanol-water partition coefficient. These results can provide important references for the detection, determination of processing losses, and control of maximum residue limits (MRLs) of PAEs to ensure the quality and safety of black tea.

Improving pesticide fate models for a simple household food processing: considering multiple crop units

To understand the fate of pesticides in crops during household cooking processes and human health risks associated with the ingestion of pesticide-contaminated crops, we propose unit-variability-enhanced models, which are capable of evaluating the removal efficiency of pesticides in multiple crop units by soaking in water. The approach integrates the lognormal production model to reveal the modeling mechanics of internal contamination among two crop units in one soaking bowl. The simulated results for 197 pesticides indicate that pesticides with larger unit-to-unit variability factors (VF) at the residue levels and diffusivity rates in water (D_W) are more likely to cause internal contamination. Although internal contamination of pesticide residues between two crop units may occur, we find that the overall removal factor ([Formula: see text]) for two crop units is independent of the ratio of initial residue levels between the two crop units. Based on this discovery, we propose the unit-variability-based (UVB) rule to generalize the [Formula: see text] for an n-crop-unit system, where n crop units soak simultaneously in one container. In addition, we demonstrate that under the same consumable and recycling resources, the soaking of two crop units together in one container can yield a maximum mass removal of pesticides if the two units are randomly sampled. Although other factors, such as temperature and the nature of solutions in the cooking process, should be considered in future studies, our models suggest that this soaking method can be conveniently realized in households to reduce negative health effects.

Development, optimization and validation of modified QuEChERS based UPLC-MS/MS for simultaneous determination of nine steroid hormones in milk powder and milk

The simultaneous detection of six estrogens (E1, E2, E3, EE, DES, HEX), two glucocorticoids (DXMS, HC), and 17α-hydoxyprogesterone (OHP).