To establish a method for the determination of acetochlor, metolachlor and propisochlor residues in green soybeans, soybeans and soybean oil, and to investigate the interference of structurally related compounds on the quantification of acetochlor quantified as its metabolites.

Residues of the 3 kinds of parent herbicides were determined by QuEChERS pretreatment combined with ultra performance liquid chromatography-tandem mass spectrometry. On the basis of the same extract, alkaline hydrolysis and liquid-liquid extraction procedures were introduced, and an analytical strategy for hydrolytic conversion was established using 2-methyl-6-ethylaniline (EMA) as an indicator, with systematic optimization of hydrolysis and cleanup conditions.

Good linearity was obtained for the 3 kinds of parent pesticides and EMA within the corresponding concentration ranges. The average recoveries ranged from 77.8% to 106.6%, and the limits of quantitation were all 0.02 mg/kg. Metolachlor and propisochlor could both be converted to EMA under alkaline heating conditions, thereby interfering with the quantification of acetochlor expressed as EMA.

This method can meet the requirements for accuracy, precision and sensitivity in the determination of parent residues of acetochlor, metolachlor and propisochlor, as well as the hydrolysis product EMA, in green soybeans, soybeans and soybean oil.

To evaluate commercially available rapid test products for aflatoxin B₁ based on the entropy weight method-technique for order preference by similarity to an ideal solution coupling model(EW-TOPSIS).

Rapid test products of different brands for aflatoxin B₁ were tested under multi-dimensional conditions involving different application environments, different operators and different food matrices. The 3 indicators, namely sensitivity, false negative rate and false positive rate, were examined. EW-TOPSIS analysis was performed, in which objective weighting through the entropy weight method was employed to eliminate subjective bias, and then the TOPSIS method was combined to calculate the closeness of products to the ideal solution for ranking. The comprehensive performance of 3 brands was systematically evaluated, and ultimately a complete and scientific evaluation system for AFTB₁ rapid test products was established.

The weights of sensitivity, false negative rate and false positive rate determined by the entropy weight method were 0.3377, 0.3377 and 0.3247, respectively. The ranking of the 3 brands based on the closeness coefficient was brand A (0.8597)>brand B (0.6136)>brand C (0.4214). A higher closeness coefficient indicated better comprehensive performance; therefore, Brand A was identified as the optimal one, which remained stable under extreme temperatures and with different operators, exhibiting outstanding performance in accuracy, specificity, and applicability, followed by brand B and brand C in descending order.

This model is applicable for the comprehensive evaluation of rapid test products of various brands and matrices, providing a basis for product selection at the grassroots level and quality control by regulatory authorities, while also offering a novel approach for the evaluation of rapid test products and promoting the standardized application of rapid test technology in the field of food safety.

To analyze the content of dehydroacetic acid (DHA) in wet rice flour products in Hubei Province from 2024 to 2025 and assess the exposure levels of residents.

From 2024 to 2025, 218 samples of wet rice and flour products sold in 7 cities of Hubei Province were collected by random sampling. The content of DHA in the samples was detected by high-performance liquid chromatography according to GB 5009. 121—2016 National food safety standards-Determination of dehydroacetic acid in food and the DHA exposure level was evaluated using a point assessment model.

The overall content of DHA in wet rice and flour products in Hubei Province from 2024 to 2025 ranged from ND to 0.855 g/kg, with an average value of 0.119 g/kg. The overall detection rate of DHA was 32.1%, and the overall exceedance rate was 4.6%. There were statistically significant differences in the content, detection rate and exceedance rate of DHA in different years, types of wet rice and flour products (P<0.01). Compared with other years, the highest mean DHA content was observed in the first half of 2024(0.290 g/kg), the highest detection rate also in the first half of 2024 (72.5%), and the highest exceedance rate in the first half of 2025 (9.8%). The average content of DHA (0.270 g/kg) and the detection rate (59.6%) were the highest for wet rice noodles. The P₉₅ value of DHA content (0.731 g/kg) and the exceedance rate (18.2%) were the highest for wide noodles. There were statistically significant differences in the content and detection rate of DHA in rice noodles, cold noodles and rice flour products in different years (P<0.05). The average content and detection rate of DHA in these three foods were the highest in the first half of 2024 and then decreased year by year. There were statistically significant differences in the DHA exposure levels in different years (P<0.01). The average and P₉₅ values of DHA exposure levels decreased first and then increased over the years, with the highest exposure level in the first half of 2024. The average and P₉₅ values of DHA exposure levels in urban areas were higher than those in rural areas.

The content of DHA in wet rice and flour products in Hubei Province from 2024 to 2025 is low, and the exposure level is also relatively low. Relevant departments need to pay special attention to the excessive use of DHA in cold noodles and rice noodles.

To optimize the process conditions for the preparation of Juglans regia L. antioxidant peptides by echelon enzymatic hydrolysis.

Juglans regia L. antioxidant peptides were prepared from defatted Juglans regia L. powder by alkaline protease, neutral protease and acid protease in a consecutive manner. The enzymatic hydrolysis process was optimized by single factor combined with orthogonal experiment and response surface method with antioxidant activity and hydrolysis degree as indexes.

The optimum process of neutral protease was enzymatic hydrolysis temperature 51 ℃, pH 6.87, substrate concentration 5%, enzyme addition 28000 U, enzymatic hydrolysis time 3 h. The optimum process of acid protease was enzymatic hydrolysis temperature 50.0 ℃, pH 5, substrate concentration 5.0%, enzyme addition 30000 U, enzymatic hydrolysis time 3 h. The degree of hydrolysis was 43.74%, the cation radical scavenging rate of 2, 2’-azino-bis(3-ethylbenzothiazoline-6-sulfonate) (ABTS) was 92.14%, and the 1, 1-diphenyl-2-picrylhydrazyl (DPPH) scavenging rate was 87.55%.

This study optimizes the protein echelon enzymatic hydrolysis process, which can be used as a feasible strategy for the preparation of Juglans regia L. antioxidant peptides.

To establish a method for the simultaneous determination of 13 kinds of flavor compounds in rice by gas chromatography-tandem mass spectrometry (GC-MS/MS).

The sample was extracted with 25% ethanol solution, followed by liquid-liquid extraction using dichloromethane. The lower dichloromethane phase was filtered through anhydrous sodium sulfate and subjected to high-speed centrifugation.Separation was performed on a DB-5MS column (30 m×0.25 mm, 0.25 μm) with a programmed temperature.Detection was carried out under multiple reaction monitoring (MRM) mode, and quantification was achieved via the external standard method with calibration curves prepared using matrix-matched extract.

All 13 kinds of flavor compounds showed good linear relationships within their respective concentration ranges, with correlation coefficients greater than 0.990. The limits of detection and the limits of quantitation were 0.5–5.0 μg/kg and 2.0–20.0 μg/kg, respectively. Spike recovery experiments were conducted at 3 different levels in rice matrices, and the average recoveries were in the range of 81.55% to 115.10%, with the relative standard deviations varying from 1.6% to 6.3%.

The developed method features high sensitivity, accurate qualitative and quantitative results, simplicity and high efficiency, and is suitable for the simultaneous determination of 13 kinds of flavor compounds in rice.

To establish a method for the determination of 19 kinds of sex hormone residues in Pheretima by QuEChERS combined with enhanced matrix removal-lipid (EMR-lipid) and ultra performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS).

The samples were pretreated using a QuEChERS dispersive solid-phase extraction combined with an EMR-lipid solid-phase extraction cleanup method.Separation was achieved on a Zorbax Eclipse Plus C₁₈ column (3.0 mm×150 mm, 1.8 μm) using a gradient elution with a mobile phase consisting of 0.02% ammonia solution and methanol. Detection was performed by multiple reaction monitoring (MRM) in positive and negative electrospray ionization modes.

The 19 kinds of analytes were showed good linearity within their respective concentration ranges, with correlation coefficients all above 0.999. The average recoveries at 3 spiked levels ranged from 71.39% to 118.78%, with relative standard deviations ranging from 0.90% to 14.33%. The limits of detection were 2.5 μg/kg to 25.0 μg/kg, and the limits of quantitation were 5.0 μg/kg to 50.0 μg/kg.

This method exhibits high specificity and accurate results. It is suitable for the complex matrix of lipid-rich traditional Chinese medicines such as Pheretima and has been successfully applied to the detection of practical samples.

To establish a method for the simultaneous determination of 16 kinds of mycotoxins in noodles by ultra performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS).

Samples were ground into powder and extracted with an acetonitrile-formic acid-water solution (70:1:29, V:V:V). The extract was centrifuged, diluted, filtered and analyzed by UPLC-MS/MS. Chromatographic separation was performed on an ACQUITY UPLC® BEH C₁₈ column (2.1 mm×100 mm, 1.7 μm) using a gradient elution with mobile phases consisting of acetonitrile and 0.2% formic acid-water solution. Detection was carried out using electrospray ionization in positive/negative switching mode with multiple reaction monitoring, and quantification was performed using the external standard method.

The 16 kinds of mycotoxins showed good linearity within their respective concentration ranges, with correlation coefficients (r) ranged from 0.9986 to 0.9999. The limits of quantitation ranging from 0.0516 to 105.2628 μg/kg. The recovery rates in their corresponding μg/kg-level spiked samples ranged from 92.7% to 124.4%, and relative standard deviations ranged from 1.95% to 9.32%. Among 30 samples of fresh wet noodles and 30 samples of dry noodles, the detection of rate deoxynivalenol was 100%, the concentration ranged from 21.200 to 229.000 μg/kg, with no significant difference (P>0.05) between fresh wet and dry noodles. The contamination level of aflatoxin B₁ in dry noodles was significantly higher than that in fresh wet noodles (P<0.05). Conversely, the contamination levels of fumonisin B₂ and zearalenone were significantly higher in fresh wet noodles than in dry noodles (P<0.001).

This study establishs a method for the simultaneous and rapid detection of 16 kinds of mycotoxins in noodles. Compared with previously reported methods and national standard methods for mycotoxins detection in food, this method is characterized by simpler operation, faster analysis, lower cost, higher sensitivity and better accuracy. It is well-suited for rapid screening in noodles and their raw materials (wheat flour), providing reliable technical support for contamination monitoring and risk assessment of related foods.

To establish a method for rapid determination of the aflatoxin B₁ (AFB₁) and zearalenone(ZEN) in Zea mays L. by molecularly imprinted-surface‑enhanced Raman spectroscopy (SERS).

Dual‑template molecularly imprinted materials were prepared and used for the pretreatment and purification of Zea mays L.. Ag nanoparticles were employed as the SERS‑active substrate, and a label‑free detection method was developed based on the characteristic SERS peaks of AFB₁ and ZEN. The effects of molecularly imprinted materials preparation conditions and SERS detection parameters (including substrate concentration and type of aggregating agent)on the analytical performance were investigated.

Under the optimized conditions, dual‑template molecularly imprinted materials pretreatment (template-to-monomer molar ratio of 1:2), Ag nanoparticles concentration of 0.56 mmol/L, and potassium bromide and magnesium chloride as aggregating agents for AFB₁ and ZEN, respectively. The limits of detection were 1.5 ng/mL for AFB₁ and 5.0 ng/mL for ZEN. The linear ranges for both toxins were 10–1000 ng/mL, with determination coefficients of 0.9268 for AFB₁ and 0.9611 for ZEN. The average recoveries ranged from 93.29% to 96.10%, and the relative standard deviations were all below 5%.

The established method is simple, rapid, accurate, and suitable for on‑site rapid screening of AFB₁ and ZEN in Zea mays L. powder.

To establish a method for determining the purine content in prepackaged solid beverages by high performance liquid chromatography and to apply it to the analysis of commercially available ones.

The 4 kinds of purines were extracted from solid beverages using acid hydrolysis. Chromatographic columns were screened based on resolution and peak shape. Detection conditions, including mobile phase pH, flow rate and column temperature, were optimized, and method validation was performed.

Using a Sunniest C₁₈ column, a mobile phase of 10 mmol/L ammonium formate solution at pH 3.68 methanol (99:1, V:V), a flow rate of 1.0 mL/min, a column temperature of 30 ℃, an injection volume of 10 μL, and a detection wavelength of 254 nm, the 4 kinds of purines were completely separated with good peak shapes. Guanine, adenine and hypoxanthine exhibited good linearity in the range of 1–40 mg/L (r²≥0.9990), while xanthine showed good linearity in the range of 0.1–4.0 mg/L(r²=0.9998); the limits of detection were 0.01–0.14 mg/L, and the limits of quantitation were 0.04–0.46 mg/L;spiked recovery rates were 88.00%–113.00%, with relative standard deviations were 0.05%–5.90%. The purine content in the 11 kinds of milk tea samples ranged from 6.66 mg/100 g to 30.46 mg/100 g, and in the 11 kinds of coffee samples, it ranged from 5.28 mg/100 g to 26.11 mg/100 g.

This method exhibits good precision and accuracy and can be used for the simultaneous determination of 4 kinds of purines in solid beverages, providing a scientific basis for dietary choices among individuals with hyperuricemia and gout.