To establish an automated and rapid method for the detection of clothianidin, dimethomorph and carbendazim residues in vegetables based on magnetic solid-phase extraction technology and a microarray biochip kit.

Magnetic solid-phase extraction was applied for sample pretreatment. The extraction efficiency for systemic pesticide residues was improved by optimizing sample preparation and pretreatment conditions. An automated and rapid detection method was established using a microarray biochip kit and a fully automatic biochip analyzer. The sensitivity and accuracy of the method were validated using cabbage, eggplant and tomato matrices.

The limits of detection and limits of quantitation for clothianidin, dimethomorph and carbendazim in cabbage, eggplant and tomato matrices met the detection requirements. The spiked recovery rates for the 3 kinds of vegetable matrices ranged from 81.48% to 120.48%, with relative standard deviations between 0.88% and 14.90%, demonstrating good accuracy and stability. The relative standard deviations in results between the proposed method and the confirmatory method for actual positive samples ranged from 0.12% to 9.95%, indicating good consistency.

This method exhibits high sensitivity and accuracy. The application of magnetic solid-phase extraction allows for rapid and simple removal of impurities from samples, effectively reducing instrument costs. The high-throughput and multi-parameter characteristics of the microarray biochip improve the coverage of detection items. Automation through instrumentation reduces the technical requirements for operators, providing technical support and a theoretical basis for the popularization and promotion of food safety testing.

To establish a quantum dot microsphere based fluorescent immunochromatographic method for the rapid, sensitive and simultaneous detection of clothianidin and thiamethoxam in ginger.

In this study, the labeling pH, antibody labeling concentration and reaction buffer system of the 2 items were optimized.The fluorescence signal intensity of the test line and quality control line on the test strip was measured by the quantum dot microspheres test strip detector. The concentration of clothianidin and thiamethoxam was used as the abscissa, and the ratio of fluorescence signal intensity of the test line and quality control line was used as the ordinate to establish a standard curve.

The quantitative detection ranges were 0.0625–8.0000 μg/L for clothianidin and 0.125–16.000 μg/L for thiamethoxam. The minimum limits of detection for thiamethoxam were 0.032 μg/L and for thiamethoxam were 0.070 μg/L.The recovery rates of standard addition for clothianidin ranged from 84.60% to 124.05%, and for thiamethoxam from 88.27% to 116.40%. The cross-reaction rate with 8 kinds of common drugs is less than 1%.

This method features unified sample pretreatment, simple and rapid operation, high sensitivity and simultaneous quantitative results for 2 analytes, making it suitable for on-site screening of large batches of samples.

To establish and optimize an analytical method based on inductively coupled plasma-mass spectrometry (ICP-MS) for the determination of Mg, Ca, Fe, Cu, Zn, Se and Pb content in infant formula goat milk powder.

The 3 kinds of sample pretreatment methods—graphite digestion, ultrasonic acid extraction and microwave digestion were systematically compared, with key parameters optimized respectively:The digestion system ratio and time for graphite digestion; the extraction acid concentration for ultrasonic acid extraction; and the digestion program and reagent dosage for microwave digestion. Methodological validation was performed through spiked recovery experiments, repeatability tests and certified reference material analysis to comprehensively evaluate the accuracy, precision and applicability of each method.

No significant differences were observed in the determination results among the 3 kinds of optimized methods (P>0.05). The limits of detection for the elements ranged from 0.0007 to 0.0941 mg/kg, spiked recoveries were between 88.2% and 110.8%, and the relative standard deviations (RSD) were all below 5.64%. The measured values of elements in the certified reference material were all within the certified ranges.

Under the premise of ensuring analytical quality, graphite digestion and ultrasonic acid extraction reduce the operation time by 55% and 70%, respectively, compared to microwave digestion. They also demonstrate advantages such as lower reagent consumption, reduced pollution risk and lower detection costs. These methods are more suitable for high-throughput rapid detection of multiple elements in infant formula goat milk powder, showing good application and promotion value.

To study the residue pattern and dissipation dynamics of 15% chlorfenapyr·chlorantraniliprole suspension concentrate on Malus domestica and assess its dietary risk.

The samples were pretreated by QuEChERS method, extracted with acetonitrile, purified by salt-out, and then filtered to a certain volume. The detection was carried out by ultra performance liquid chromatography-tandem mass spectrometry.

At a sampling interval of 21 d, the median residues of chlorfenapyr and chlorantraniliprole in Malus domestica were 0.042 mg/kg and 0.040 mg/kg, respectively, with the highest residue concentrations being 0.37 mg/kg and 0.26 mg/kg. The 7 d after application, the dissipation rates of chlorfenapyr and chlorantraniliprole were 23.5% to 86.7% and 21.8% to 61.7%, respectively; 28 d after application, the dissipation rates of chlorfenapyr and chlorantraniliprole were 49.4% to 88.9% and 45.5% to 83.3%, respectively. The half-lives of chlorantraniliprole and chlorfenapyr were 4.6 d to 31.9 d and 2.8 d to 27.8 d, respectively. For long-term dietary risk, the risk quotients of chlorfenapyr and chlorantraniliprole in Malus domestica were between 0.0016% and 1.0%, far below 100%; for short-term dietary risk, the risk quotient of chlorfenapyr in Malus domestica was between 21.46% and 67.90%, while chlorantraniliprole had no acute reference dose, thus its acute risk quotient could not be calculated. The maximum residue limits of chlorfenapyr and chlorantraniliprole in Malus domestica were both lower than the estimated maximum residue levels.

According to the recommended dosage and the recommended pre-harvest interval, the residues of chlorfenapyr and chlorantraniliprole in Malus domestica are both below the maximum residue limits, and the dietary risks to consumers are acceptable. However, it is necessary to closely monitor the short-term dietary risk of chlorfenapyr to children aged 2 to 13, and be vigilant against the high exposure risk caused by large intake in a short period.

To systematically evaluate the contamination characteristics and health risks of aluminum residues in commercially available fried flour products from partial districts/counties of Beijing in 2025.

Microwave digestion was employed for sample pretreatment, and inductively coupled plasma optical emission spectrometry was applied for the quantitative analysis of aluminum residues in 61 samples of commercial fried flour products. The Kruskal-Wallis H test was used to compare the differences in aluminum content among the samples, while the chi-square test was adopted for the comparison of over-standard rates. The weekly dietary exposure dose of aluminum was calculated via the point estimation method, and the safety limit of dietary aluminum intake for the population was derived accordingly. The pollution index method was utilized to assess the contamination status of aluminum in fried flour products, and the target hazard quotient was used to evaluate the long-term health risks.

The detection results indicated that the overall over-standard rate of aluminum residues was 8.2% (5/61), and all the non-compliant samples were concentrated in District C, with a mean aluminum content of 178.5 mg/kg and a 97.5th percentile value(P_97.5) of 873.8 mg/kg, which was significantly higher than that in the other 3 districts (P<0.05). No statistically significant differences in aluminum content were observed among different circulation channels(supermarkets/farmers’ markets/restaurants), product types (high-moisture/low-moisture products), and packaging types (pre-packaged/bulk products) (P>0.05). In terms of dietary exposure risk, the mean weekly exposure dose of aluminum in District C was 0.266 mg/kg·bw, with a P_97.5 value of 1.304 mg/kg·bw, and the corresponding dietary safety limits were 0.133 (mean value) and 0.652 (P_97.5 value). In contrast, the values in the other three districts were all below 0.01. The Nemerow comprehensive pollution index of aluminum in District C was 7.053 (>1), whereas the indices in the other districts were all below 0.7. Regarding non-carcinogenic risks, the target hazard quotient of the high-exposure population in District C was 0.654 (<1), and the values in the other districts were less than or equal to 0.010, all of which were below the threshold value.

Significant regional differences exist in the aluminum content of fried flour products in Beijing. District C exhibits a severe level of aluminum contamination as indicated by the comprehensive pollution index. However, since the dietary exposure dose does not exceed the provisional tolerable weekly intake, the health risks are within the acceptable range, and the current non-carcinogenic risks are controllable. It is recommended to strengthen the supervision of bulk food products and the circulation links of farmers’ markets and catering services, promote the application of aluminum-free leavening agent technology, and conduct long-term risk assessments of multi-pathway aluminum exposure.

To investigate the interaction mechanism between flavonoids in dietary Dandouchi and intestinal microbiota.

This study employed an in vitro whole-biome gastrointestinal simulation system, with 16S rDNA sequencing for microbiota profiling, and high performance liquid chromatography-tandem triple quadrupole mass spectrometry for flavonoid metabolic transformation analysis. Finally, Spearman correlation analysis was used to analyze the correlation between the two.

Demonstrated that dietary Dandouchi significantly improved intestinal microbiota composition, increasing probiotic Bacteroides from 0.73% to 3.61% and Ruminiclostridium_9 from 0.20% to 0.94%, while reducing pathogenic Escherichia-Shigella from 17.59% to 11.39%.Regarding flavonoid metabolism, intestinal microbiota mediated an reduction in glycoside-type flavonoids (e.g., daidzin, glycitin) and a more pronounced decrease in aglycone-type flavonoids (e.g., butein, daidzein) (P<0.05). Correlation analysis revealed significant negative associations between Bacteroides and daidzin, and positive correlations between Parasutterella and naringenin (P<0.05).

Dietary Dandouchi modulates specific microbiota (e.g., Bacteroides, Parasutterella) to enhance flavonoid biotransformation, thereby improving bioactivity, providing a theoretical foundation for developing dietary Dandouchi-based microecological regulators.

To understand the residue status of prohibited and restricted drugs in Pelodiscus sinensis, and assess the dietary exposure risk of these drugs ingested by Shanghai residents via Pelodiscus sinensis.

Using the sampling and testing data of prohibited and restricted drugs in commercially available Pelodiscus sinensis in Shanghai from 2020 to 2023, the point estimation method and margin of exposure(MOE) method were adopted to conduct exposure assessment on prohibited and restricted drugs in Pelodiscus sinensis.

The overall over-standard rate of prohibited and restricted drugs in 502 soft-shelled turtle samples was 2.79%. Among them: For 462 soft-shelled turtle samples, the detection rate of enrofloxacin (calculated as the sum of enrofloxacin and ciprofloxacin) was 18.18%, the over-standard rate was 0.00%, the average content was 4.65 μg/kg, and the maximum value was 92.80 μg/kg. For 184 soft-shelled turtle samples, the detection rate of sulfonamides (total amount) was 7.07%, the over-standard rate was 1.09%, the average content was 12.28 μg/kg, and the maximum value was 1620.00 μg/kg. For 470 soft-shelled turtle samples, the over-standard rate of furazolidone metabolites was 1.70%, the average content was 0.56 μg/kg, and the maximum value was 95.80 μg/kg. For 168 soft-shelled turtle samples, the over-standard rate of ofloxacin was 1.79%, the average content was 0.94 μg/kg, and the maximum value was 105.00 μg/kg.For 135 soft-shelled turtle samples, the over-standard rate of norfloxacin was 0.74%, the average content was 0.11 μg/kg, and the maximum value was 15.00 μg/kg. Furaltadone metabolites, nitrofurantoin metabolites, nitrofurazone metabolites, chloramphenicol, and malachite green were not detected in Pelodiscus sinensis. The average exposure and P₉₅ exposure of enrofloxacin, sulfonamides (total amount), ofloxacin and norfloxacin ingested by Shanghai residents aged great than or equal to 3 years through Pelodiscus sinensis per day were all lower than the acceptable daily intake(ADI). The average MOE and P₉₅ MOE of furazolidone metabolites ingested by residents aged great than or equal to 3 years through Pelodiscus sinensis per day were both greater than 1×10⁴.

The health risks of prohibited and restricted drugs ingested by Shanghai residents via Pelodiscus sinensis are relatively low. There is an excessive phenomenon of sulfonamides, furazolidone metabolites, ofloxacin and norfloxacin in Pelodiscus sinensis, and targeted supervision still needs to be strengthened.

To optimize the curing formula of lead-free Coturnix preserved eggs, and analyze the fatty acid and amino acid of Coturnix eggs before and after curing.

The processing technology of lead-free Coturnix preserved eggs was optimized through orthogonal experimental. The quality characteristics were determined by detecting their physical and chemical indicators, and the changes of fatty acids and amino acids in the egg white and yolk of Coturnix eggs before and after pickling were detected.

The optimal formula of lead-free Coturnix preserved eggs was 4.50% of food-grade NaOH, 4.00% of salt, 0.50% of food-grade CuSO₄&ZnSO₄ and 3.00% of black tea. Under these process conditions, the Coturnix preserved eggs exhibited an albumen whiteness of 29.90, a yolk whiteness of 26.24, an albumen hardness of 3.72 N, a yolk solidification degree of 87.41%, a sensory score of 90.05 points, and a final composite score of 0.94, representing the optimal quality performance. The fatty acid content of fresh egg yolk and preserved egg yolk were 38.26 g/100 g and 24.52 g/100 g, respectively, and the amino acid content were 146.19 mg/g and 126.02 mg/g, respectively. The amino acid content of fresh egg white and preserved egg white were 126.67 mg/g and 109.31 mg/g, respectively.

The resulting eggs featured a brownish-transparent albumen gel, a dark green yolk with a syrup-like core and a savory, refreshing flavor. It can increase the added value of Coturnix eggs, reduce fresh egg loss and also provide a theoretical basis for factory-style production of this lead-free Coturnix preserved egg.