Objective To establish an analytical method for the simultaneous determination of 6 kinds of fluoroquinolones and 4 kinds of benzodiazepines residues in aquatic products by ultra performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS). Methods Aquatic product samples were extracted with 1% formic acid in acetonitrile. The extracts were concentrated with a rotary evaporator and then reconstituted in 90% acetonitrile aqueous solution (containing 1% formic acid), and purified through a pass-through solid phase extraction cartridge (ProElut PLS-A). The purified extracts were directly analyzed by UPLC-MS/MS. Quantification was performed using the isotope internal standard method. Results The 10 kinds of target compounds exhibited good linearity within the concentration range of 0.5 to 50.0 ng/mL, with correlation coefficients (r) all greater than 0.998. The limits of quantitation for these compounds in 5 kinds of different aquatic product matrices ranged from 0.5 to 1.0 μg/kg. The recovery rates at low, medium and high spiking levels ranged from 81.5% to 109.7%, with relative standard deviations ranging from 0.24% to 13.22%. Conclusion Methodological validation confirmed that the developed method is highly sensitive, accurate in quantification, stable, and straightforward in operation. It is suitable for high-throughput detection of 6 kinds of fluoroquinolones and 4 kinds of benzodiazepines residues in aquatic products.

Objective To rapidly identify the chemical components in the peel of Wogam by ultra performance liquid chromatography-tandem quadrupole electrostatic field orbital trap mass spectrometry (UPLC-QE-MS) in combination with various data analysis methods. Methods The samples were separated by Thermo Scientific Hypersil GOLD AQ (2.1 mm×100 mm, 1.9 μm) chromatographic column using solution A (0.1% formic acid-acetonitrile) and solution B (0.1% formic acid-water) as the mobile phase in a gradient elution mode. In the positive and negative ion mode, the electrical spray ion source was used to collect the signals of various chemical components in the peel of Wogam by means of one-step full scanning and two-stage ion scanning. Based on the high-resolution mass spectrometry data of traditional Chinese medicine components in the Trace Finder software and the screening network database of Compound Discoverer 3.2 software, the identification of chemical components were carried out by comparing the recognition of primary ions, major secondary ions, and other factors of the sample, as well as combining the possible cleavage pathways of the compound and consulting relevant literature reports. Through comprehensive analysis and judgment, the components were determined. Results Through literature review and comparison with high-resolution mass spectrometry data and databases, as well as compound analysis, a total of 52 compounds belonging to 11 categories were identified from the peel of Wogam, including 1 aldehyde, 5 organic acids, 2 alkaloids, 5 terpenes, 1 ketone, 7 phenylpropanoids, 2 coumarins, 1 nucleoside, 26 flavonoids, 1 anthraquinone, and 1 lignan. Conclusion The application of UPLC-QE-MS technology, combined with relevant databases and literature, enables the analysis of the chemical components of the peel of Wogam, providing a basis for the industrial development of Wogam peel.

Objective To establish a magnetic solid phase extraction (MSPE) approach based on covalent organic framework materials in combination with high performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) for the efficient determination of 9 kinds of carbamate pesticides (CPs) in Vigna unguiculata. Methods After the extraction of Vigna unguiculata samples, the novel Fe₃O₄@TAPOB-BDTB material was employed for magnetic solid-phase extraction and purification. After filtration, the samples were separated by a C₁₈ chromatographic column and quantitatively analyzed using multiple reaction monitoring in the electrospray positive ion mode. Results The established analytical methods for the 9 kinds of CPs exhibited excellent linearity within the concentration range of 0.02-100.00 μg/kg, with the determination coefficients (r²) all exceeding 0.9989. The spiked recovery rates were within the range of 80.33%-108.63%, and both the intra-day and inter-day precisions were less than 8.89%. The detection limits of the methods were 0.005-0.010 μg/kg, and the limits of quantitation were 0.02 μg/kg, which were significantly below the maximum residue limits specified in GB 2763—2021 National food safety standard-Maximum residue limits of pesticides in food and EU Regulation No 396/2005, ensuring compliance within an academic context. Conclusion The covalent organic framework materials synthesize in this study demonstrate exceptional adsorption capacity for CPs via π-π interactions and hydrogen bonding. Furthermore, the develope MSPE-HPLC-MS/MS method enables rapid, highly sensitive, and precise detection of CPs in Vigna unguiculata, thereby offering an efficient and innovative approach for monitoring pesticide residues in agricultural products.

Objective To evaluate the effects of forchlorfenuron dipping and spraying on the quality of Actinidia chinensis in Sichuan Province after flowering and determine the optimal application method. Methods At 20 days after flowering, Hongyang and Jinyan Actinidia chinensis were treated with forchlorfenuron by dipping and spraying. At maturity, fruits were harvested, and their morphological structure, texture, external quality, amino acid content, and internal nutritional quality indicators were analyzed. Results Compared to spraying, forchlorfenuron dipping could significantly increase soluble sugar and dry matter content in Jinyan Actinidia chinensis but had no significant effect on fruit longitudinal and transverse diameters, fruit shape index, amino acid content as well as other parameters. Different from Jinyan Actinidia chinensis, forchlorfenuron dipping could increase Hongyang fruit longitudinal and transverse diameters, single fruit weight, and the content of alanine and histidine. It also reduced fruit firmness and titratable acid content while improving the ascorbic acid, solid-acid ratio, dry matter, soluble sugar, soluble solids and total polyphenol content, enhancing taste and quality. Conclusion According to the results of principal component analysis, forchlorfenuron dipping is more effective than spraying in optimizing fruit morphology, softening fruit, improving taste, and enhancing the quality of both Hongyang Actinidia chinensis. Therefore, dipping is recommended as the optimal forchlorfenuron application method for the cultivation of Hongyang Actinidia chinensis, yet dipping and spraying with forchlorfenuron are both suitable for Jinyan Actinidia chinensis. This study provides technical support for the scientific and standardized use of forchlorfenuron in Sichuan Actinidia chinensis production.

Objective To establish a method for the detection of furosine in milk by microwave hydrolysis-ultra performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS). Methods The optimal conditions for microwave hydrolysis were optimized by single factor experiments and response surface methodology. The hydrolysis solution obtained under the optimal hydrolysis conditions was filtered to a constant volume. The hydrolysate was diluted 10-fold with 6.0 g/L ammonium acetate solution and then analyzed. Gradient elution was performed with 0.1% formic acid aqueous solution and methanol solution as mobile phases, and the separation was carried out on a T3 liquid chromatography column (100 mm×2.1 mm, 1.8 μm). Under the positive ion mode of electrospray ion source (ESI⁺), multiple reaction monitoring (MRM) mode was selected for detection and external standard method was used for quantification. Results The optimal microwave hydrolysis conditions for furosine in milk were hydrolysis temperature of 160 ℃, hydrochloric acid concentration of 8.1 mol/L, and hydrolysis time of 52 min. The primary-to-secondary order of influencing factors was hydrochloric acid concentration>hydrolysis time>hydrolysis temperature. Furosine in milk showed a good linear relationship within the range of 0.005-0.500 µg/mL, with a correlation coefficient (r) of 0.9958. The limit of quantitation (LOQ) and limit of detection (LOD) were 0.20 µg/mL and 0.07 µg/mL, respectively. The average recoveries were 89.09%-97.33%, with relative standard deviations (RSDs) of 3.37%-7.02% (n=6). Conclusion This method is efficient and accurate. Compared with the traditional hydrolysis methods(12-24 hours), microwave hydrolysis shortens the hydrolysis time to 52 minutes, and there is no significant difference (P>0.05) in the detection results compared with the conventional hydrolysis methods in the industry standard NY/T 939—2016 Identification of reconstituted milk in pasteurized and UHT milk. It can provide technical reference for quality control and heat treatment process evaluation of dairy products.

Objective To establish an analytical method for the determination of enrofloxacin residues in complex mixed matrix of the “soil-vegetable” system by ultra performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS). Methods The sample was subjected to vortex ultrasonic extraction with acidified acetonitrile extract [containing 5% ethylene diamine tetraacetic acid (EDTA)-Mcllvaine buffer solution], settling with centrifugation, getting solvent conversion and being filtered by 0.22 μm nylon filter membrane. The mobile phase was composed of acetonitrile and 0.1% formic acid aqueous solution (containing 2 mmol/L ammonium acetate), and the mixture was subjected to Waters ACQUITY UPLC ® BEH C₁₈ chromatographic column (2.1 mm×100 mm, 1.7 μm) gradient elution separation, using mass spectrometry as a detector for qualitative and quantitative analysis of enrofloxacin. Results In the mass concentration range of 1-200 ng/mL, the standard curve showed a good linear relationship (correlation coefficient=0.9996), the limit of detection of the method was 0.11 μg/kg, the recovery rates ranged from 87.4% to 103.3%, and the relative standard deviations (RSDs) were 0.4% to 4.0% (n=6). Conclusion This method has fast analysis speed, high accuracy and good repeatability, and is suitable for the detection of enrofloxacin residues in complex mixed matrix of the “soil-vegetable” system. It also has the potential to indirectly reveal the risk of antibiotic resistance genes (ARGs) contamination in the system.

Objective To evaluate the toxicological safety of xylooligosaccharides. Methods According to the national food safety standards, the safety of xylooligosaccharides was evaluated through acute oral toxicity test in mice, micronucleus tests in mammalian bone marrow red blood cells, chromosomal aberration tests in spermatocytes, Bacterial reverse mutation (Ames) test, and 28 day oral toxicity test. Results The acute maximum tolerated dose (MTD) of xylooligosaccharides in male and female mice was greater than 10000 mg/(kg·bw), which was classified as practically non-toxic; the micronucleus test of mammalian bone marrow red blood cells, chromosome aberration test of spermatocytes, and Ames test were all negative; set up 3 dose groups: 0 (basic feed control), 4167, 8333 and 16667 mg/(kg·bw) (equivalent to 25 times, 50 times and 100 times the maximum recommended intake), orally administered once a day for 28 consecutive days. The high-dose group of animals showed a decrease in total weight gain related to the test sample, changes in biochemical indicators such as alanine aminotransferase, alkaline phosphatase, glucose and urea nitrogen, and a decrease in organ weight and visceral to body ratio in male rats. However, there were no corresponding changes observed in the medium and low-dose groups (equivalent to 50 times and 25 times the maximum recommended intake) and the Weixing group. Conclusion Xylooligosaccharides do not show acute toxicity or genetic toxicity; the no observed adverse effect level (NOAEL) of the sample for 28 days of oral toxicity in female and male rats is 8333 mg/(kg·bw).

Objective To study the optimization of convenient mixed grain rice process through response surface methodology. Methods Using purple rice, black rice, oatmeal rice and red rice as the main raw materials, the pregelatinization process was determined by the water absorption and pasting degree of the miscellaneous grains. To optimize the production process of convenient omnivorous rice through single-factor and response surface tests using sensory evaluation as an index. Results The result showed that the pregelatinization process of mixed grains was soaking at 23 ℃ for 120 min and steaming for 20 min; the suitable parameters of the process for the convenient mixed grain rice were 27% of mixed grain rice addition, 54 min of cooking time, and 1:1.30 of rice-water ratio. This time, it was possible to produce a convenient mixed grain rice with superior flavor, tissue state, texture and color. Conclusion In this study, a convenient and flavorful rice of convenient mixed grains was developed. This provides a certain theoretical basis for pre-cooking treatment in the processing of mixed grain rice and promotes the industrialization of mixed grain food.

Objective To use coleslaw at the retail-to-consumption level as a source of contamination with Staphylococcus aureus, assess the health risk posed to residents of Jilin Province and identify the key contributing factors. Methods Based on the monitoring data of Staphylococcus aureus in coleslaw in Jilin Province from 2011 to 2019, combined with the data of residents’ coleslaw consumption and temperature, a prediction model of Staphylococcus aureus growth was established. The results were analysed and Monte Carlo simulated using @Risk8.0 software, and a quantitative risk assessment of Staphylococcus aureus in commercially available coleslaw in Jilin Province was carried out in 4 parts: Hazard identification, exposure assessment, hazard characterization and risk analysis. Results The data statistics showed that the initial contamination rate of Staphylococcus aureus in coleslaw was 3%, and the average contamination was -2.37 log10CFU/g, with a 95% confidence interval of (-5.88, 1.27) log10CFU/g. The assessment results showed that the probability of triggering Staphylococcus aureus intoxication was 0.1%, and the number of cases of illness that could be caused by Staphylococcus aureus was 154500 cases per year. Conclusion The initial level of Staphylococcus aureus contamination in coleslaw is most important in causing the risk of Staphylococcus aureus infection, follow by storage temperature. Keeping the source ingredients, preparation environment clean and hygienic, and having good refrigerator use habits are important measures to reduce the risk of developing Staphylococcus aureus infections in coleslaw.

Objective To establish 2 kinds of methods for the determination of 17-pentatriacontene in honey by gas chromatography-flame ionization detection (GC-FID) and gas chromatography-mass spectrometry (GC-MS). Methods After dissolved in water, the sample was extracted with petroleum ether, purified on a florisil cartridge, separated by DB-5MS column (15 m×0.25 mm, 0.25 μm), and determined by GC-FID and GC-MS, then quantified by external standard method. Results The GC-FID and GC-MS were quantified using matrix-free standard curve and matrix-matched standard curve respectively, with limits of quantification of 1.0 mg/kg and 0.5 mg/kg, linear ranges of 1-100 mg/kg and 0.5-40.0 mg/kg, and recovery rates ranging from 88.9% to 94.5% and from 91.2% to 98.2%, respectively. The relative standard deviations were 4.0%-6.4% and 4.6%-7.3%, respectively. The results of the 2 kinds of methods were basically consistent, with a relative deviation of no more than 2.4%. The proposed methods were applied to 158 honey samples of Apis cerana honey and Apis mellifera honey, 17-pentatriacontene was only detected in Apis cerana honey, with a content range of 0.58-51.10 mg/kg. Conclusion The accuracy and precision of the GC-FID and GC-MS methods established in this study are both good, and the 2 kinds of methods can be applied to the determination of 17-pentatriacontene in honey. The results of real sample tested indicate that 17-pentatriacontene can be used as a characteristic marker for Apis cerana honey.