To study the element distribution characteristics in 4 kinds of poultry pre-made dishes,including chicken, duck, visceral and claw sold in Beijing in 2024, and evaluate the dietary exposure risk of harmful elements.

Inductively coupled plasma mass spectrometry was used to determine 14 kinds of elements in 46 poultry pre-made dishes sold in Beijing. Pollution index method, target hazard quotient/total target hazard quotient(THQ/TTHQ), hazard quotient (HQ), hazard index (HI) and carcinogenic risk index (CR) were used to evaluate the health risks of harmful elements.

All 14 kinds of elements were detected in poultry pre-made dishes, with median content of aluminum, manganese, boron, chromium, nickel and molybdenum exceeding 0.01 mg/kg. The detection rates of harmful elements were as follows: Arsenic (100%)>chromium (97.8%)>lead (41.3%) and mercury(41.3%)>cadmium (39.1%). The content of these elements were all below the standards of the GB 2762—2022 National food safety standard-Limits of pollutants in food. There were significant differences in the median values of 14 kinds of elements among 4 kinds of poultry pre-made dishes. Among the visceral pre-made dishes, the content of vanadium, manganese, cobalt, arsenic, molybdenum, cadmium and lead were the highest. Among the claw pre-made dishes, the content of mercury was the highest, followed by lead. Among the chicken pre-made dishes, the content of arsenic and lead were the lowest. The median chromium content in 4 kinds of poultry pre-made dishes showed little variation, but the average chromium content (0.10 mg/kg) in chicken pre-made dishes was approximately twice that of the other 3 kinds of poultry pre-made dishes, with Kung Pao chicken exhibiting a notably high chromium characteristic. The pollution index for lead, cadmium, arsenic, mercury and chromium were all less than 0.7,indicating that the sample was not contaminated with harmful elements. For the assessment of non-carcinogenic health risks, 2 sets of assessment methods from the United States Environmental Protection Agency and the World Health Organization/International Codex Alimentarius Commission were employed. The THQ/TTHQ and HQ/HI assessment values for cadmium, mercury and chromium were all less than 1, indicating that the risks were at an acceptable level. The results from both assessment methods were consistent, and both identify that Cd posed the highest risk in visceral pre-made dishes, while Hg posed the highest risk in claw pre-made dishes. The CR of Pb in 4 kinds of poultry pre-made dishes was less than 1×10^–6, indicating no carcinogenic risk. The CR of arsenic ranged from 1×10^–6–1×10^–4, indicating an acceptable carcinogenic risk.

The health risks posed by harmful elements in 4 kinds of poultry pre-made dishes sold in Beijing are at a safe level. Although the detection rate and content levels of multiple elements in claw pre-made dishes are relatively low, the mercury and lead contents in these dishes are at a higher level among the 4 kinds of poultry pre-made dishes, which should be recommended to strengthen monitoring.

To establish a method for rapid determination of derquantel residues in 4 kinds of sheep edible tissues by dispersive solid-phase extraction coupled with liquid chromatography-tandem mass spectrometry.

Veterinary drug residues in samples were extracted with acetonitrile, and the extracts were purified via dispersive solid-phase extraction. Gradient elution was performed on a C₁₈ chromatographic column using 5 mmol/L ammonium formate solution-acetonitrile as the mobile phase. Detection was carried out in positive electrospray ionization mode, and quantification was achieved by matrix-matched external standard method.

The results showed that there were good linearity in the range of 0.01–20.00 μg/L for the 4 kinds of matrix-matched calibration curves, and the correlation coefficients were above 0.999. The limit of detection and limit of quantitation were 0.03 μg/kg and 0.10 μg/kg, respectively. The average recoveries ranged from 89.9% to 99.8%, with relative standard deviations below 10%.

This method is rapid and sensitive, and can be used for the practical determination of derquantel residues in sheep edible tissues.

To evaluate the protective effects of ergothioneine against D-galactose (D-gal)-induced oxidative damage in rats and elucidate the underlying molecular mechanisms.

Oxidative damage in rats was induced by intraperitoneal injection of D-gal (200 mg/kg) once daily for 6 consecutive weeks. Male SD rats were randomly assigned to 5 groups: The control group, which received intraperitoneal saline injection, and the model group as well as the low-dose (EGT-L, 1.4 mg/kg), mid-dose (EGT-M, 2.8 mg/kg) and high-dose (EGT-H, 5.6 mg/kg)ergothioneine groups, which were administered intraperitoneal D-gal. Starting from week 3 and continuing through week 6, each treatment group received daily intragastric administration of ergothioneine, while the control and model groups were given an equal volume of saline, for a total duration of 4 weeks. The levels of oxidative stress markers,including malondialdehyde (MDA) as a marker of lipid peroxidation and protein carbonyls as markers of protein oxidation, antioxidants such as reduced glutathione (GSH), and antioxidant enzymes including catalase (CAT) and superoxide dismutase (SOD) were measured in the serum and liver of rats using colorimetric assays. A preliminary network pharmacology analysis was performed to investigate the potential mechanisms underlying the antioxidant effects of ergothioneine, and further validation was carried out using western blotting to assess the impact of ergothioneine on the hepatic protein expression levels of Acetyl-FOXO1, FOXO1 and SIRT1.

Compared with the model group, ergothioneine-treated groups decreased MDA and protein carbonyl levels in serum and liver,and increased SOD and CAT activities and GSH content. Western blotting indicated that ergothioneine administration reduced the ratio of Acetyl-FOXO1/FOXO1 and upregulated SIRT1 protein expression in liver tissue.

Ergothioneine exhibits significant protective effects against D-gal-induced oxidative damage in rats. The underlying mechanism may predominantly involve modulation of the FoxO signaling pathway.

To established a method for the simultaneous determination of 18 kinds of illegally added chemical components in uric-acid-lowering health food by ultra performance liquid chromatography.

The samples were extracted by methanol (with 0.1% formic acid) ultrasonic extraction, the separation was executed on an Phenomenex Luna ®Omega C₁₈ column (2.1 mm×100 mm, 1.6 μm), using methanol (A)-acetonitrile (B)-0.2% formic acid aqueous solution (C) as the mobile phase for gradient elution, and detected by diode array detector.

This method effectively distinguishes between salicylic acid and aspirin and the results showed that the 18 kinds of uric-acid-lowering components had good linearity in the linear range with the correlation coefficients greater than or equal to 0.9995; the limits of detection ranged from 2.0–112.8 mg/kg, the average recoveries ranged from 98.5%–110.6%, and the relative standard deviations ranged from 0.2%–4.4%. The method was applied to screen 35 batches of samples, 4 batches of unlabeled components were detected, 2 batch detected diclofenac, 1 batch detected piroxicam and 1 batch detected prednisone acetate.

The method is easy to operate, has good selectivity,sensitivity and accuracy, and can be used for the determi nation of illegally added drugs of uric-acid-lowering components in health food.

To meet the practical industrial demand for real-time, batch detection of freshness in white feather broiler meat, this study explores a multidimensional rapid method for assessing meat freshness and validates its validity.

This study focuses on the breast meat of white-feathered broilers, with freshness assessment as its central theme. Under refrigerated storage at 4 ℃, a gradient of storage durations from 0 to 144 hours was established.The pH and moisture content values obtained via rapid detection methods were validated in accordance with GB 5009.237—2016 National food safety standard-Determination of pH in foods and GB 5009.3—2016 National food safety standard-Determination of moisture in foods, respectively, to analyze their variation patterns as freshness deteriorates. Concurrently, hyperspectral imaging technology was employed to collect spectral data of the samples.Spectral preprocessing was conducted using Savitzky-Golay (S-G) smoothing combined with first-derivative transformation to extract characteristic wavelengths related to physicochemical indices. Subsequently, a freshness discriminant model for chicken breast meat was constructed based on the partial least squares regression (PLSR)algorithm.

The results of the rapid determination method showed no significant difference from those determined by GB 5009.237—2016 and GB 5009.3—2016 for pH and moisture content (P>0.05). Among them, the P values of pH and moisture content were 0.8141 and 0.2586 respectively. At the same time, the model constructed based on PLSR had good predictive performance for various physicochemical indicators, with the correlation coefficient (R²p)of the prediction set ranging from 0.74 to 0.87, and the predicted root mean square error (RMSEP) ranging from 0.12 to 1.80.

Spectral pre-processing can effectively reduce instrument noise and external interference and highlight characteristic absorption peaks. There is a significant difference in the characteristic wavelength spectral responses between fresh meat and spoiled meat. The constructed PLSR model can achieve accurate discrimination between fresh meat and spoiled meat. The multi-index collaborative detection system established in this study provides effective and reliable technical support for the monitoring of chicken breast meat quality and safety, and enriches the theoretical and practical research on non-destructive detection of chicken freshness.

To establish a method for the determination of nitrite and multiple phosphates including phosphate, pyrophosphate, triphosphate and trimetaphosphate in ham sausage by ion chromatography.

The samples were ultrasonically extracted, deproteinized with chloroform, purified by ion chromatography-reversed phase solid phase extraction column, and then detected by ion chromatography.

There was a good linear relationship in the range of 0.01–4.00 mg/L for nitrite, and 0.10–40.00 mg/L for phosphate, pyrophosphate,triphosphate and trimetaphosphate, and the correlation coefficients were all over 0.999. The limits of detection were 0.06–0.60 mg/kg and the limits of quantitation were 0.20–2.00 mg/kg. The recoveries were between 89.4%–103.5%,and the relative standard deviations were between 1.4%–6.1%.

This method is highly sensitive,accurate and reliable, with simple operation, making it suitable for the simultaneous determination of nitrite and various phosphates in ham sausage.

To establish a quantitative analysis method for determining illegally added uric acid-lowering substances in food by ultra performance liquid chromatography-tandem mass spectrometry.

The sample was extracted with methanol and 5% methanol solution as the extraction solvent, and extracted by ultrasound, and then separated on a C₁₈ column with a gradient elution of 0.1% form acid aqueous solution and methanol as the mobile phase. The detection was performed using multiple reaction monitoring (MRM) mode of mass spectrometry, and quantification was done by external standard method.

In the solvent curve such as allopurinol, colchicine, topiroxostat, lesinurad and tranilast all showed linear correlation coefficients of r>0.999 in the range of 20–400 ng/mL, while risperidone, fenofibrate, febuxostat, probenecid and benzbromarone showed linear correlation coefficients of r>0.999 in the range of 2–40 ng/mL. The recovery rates ranged from 81.62% to 109.61% within 3 levels in 5 kinds of matrices such as tablets (compressed candy tablets), liquid beverage, powdered beverage,pollen and effervescent tablet and the relative standard deviations (RSDs) were 1.0% to 8.6% (n=6).

This method has high accuracy, good precision, high reproducibility and good applicability between instruments, and can meet the needs of qualitative and analysis of allopurinol and other 10 kinds of uric acid-lowering compounds in food.

To establish an analytical method for the determination of zearalenone (ZEN) in Triticum aestivum L powder by molecularly imprinted solid-phase column purification-ultra performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS).

The ZEN from Triticum aestivum L powder samples were extracted with acetonitrile/water containing acetic acid, purified by a ZEN-specific molecularly imprinted solid-phase extraction column method, eluted with the mobile phase of 5 mmol/L ammonium acetate solution and acetonitrile, separated on the Luna®Omega Polar C₁₈ column (100 mm×2.1 mm, 3 μm) at a flow rate of 0.5 mL/min. The analysis was conducted using UPLC-MS/MS and then analyzed in negative ion mode of electrospray ionization source with multiple reaction monitoring mode for qualitative and quantitative analysis.

In the range of 1.0–50.0 μg/L, the peak area of ZEN was linearly correlated with the content, and the determinationn coefficient (r²) was 0.9997. Meanwhile, the average recoveries of ZEN in Triticum aestivum L powder were 80.2%–95.8% with the maximum relative standard deviations of 7.6% at the spiked concentration of 3.00, 6.00 and 30.00 μg/kg. The limit of detection was 3.0 μg/kg.

This study establishes an efficient detection method for ZEN in Triticum aestivum L powder using molecularly imprinted solid-phase extraction purification. This method effectively removes matrix interference and enriches ZEN in the sample, demonstrating high precision and accuracy. The research results provide reliable technical support and experimental data for establishing detection standards and quality control guidelines for ZEN in Triticum aestivum L powder.

To establish a method for the determination of 12 kinds of antiviral drugs (ATVs) in shellfish and dried shellfish products by ultra performance liquid chromatography-tandem mass spectrometry.

Samples were extracted with acetonitrile containing 1% formic acid, purified using FaVEx-NM50 multi-veterinary drug residue clean-up columns, concentrated under nitrogen in a water bath, and reconstituted with a redissolving solution to obtain the test solution. The analytes were separated on a ZORBAX Eclipse Plus C₁₈ column using gradient elution with a mobile phase consisting of acetonitrile‑methanol (80:20, V:V, containing 0.1% formic acid) and 5 mmol/L ammonium acetate (containing 0.1% formic acid). Detection was carried out by ultra performance liquid chromatography-tandem mass spectrometry in multiple reaction monitoring mode, and quantification was performed using the internal standard method.

The 12 kinds of target compounds showed good linearity over certain concentration ranges, and the limits of detection and recoveries met the requirements. The correlation coefficients (r) of the calibration curves ranged from 0.9931 to 0.9997, limits of detection were 0.07–1.50 μg/kg, and limits of quantitation were 0.14–3.00 μg/kg. At 3 spiked levels (n=6), the average recoveries in mussel matrix ranged from 66.7% to 106.2% with relative standard deviations of 1.0%–11.6%,while in dried scallop matrix the average recoveries ranged from 69.1% to 109.5% with relative standard deviations of 0.9%–10.3%. Meanwhile, 161 batches of shellfish and dried shellfish products were purchased and analyzed for the target compounds using this method. The results showed that amantadine was detected in 37 batches. A dietary exposure risk assessment of amantadine residues was conducted by combining the residue data with dietary consumption and population data. The assessment indicated that the current amantadine residues in shellfish posed a low risk to human health.

The method is sensitive, accurate, simple and rapid in sample pretreatment,making it suitable for the determination of ATVs residues in shellfish.

To establish an method for the determination of tamoxifen in solid drinks, liquid drinks,hard capsules, soft capsules and table candy by high performance liquid chromatography-tandem mass spectrometry.

The samples were extracted with 0.1% formic acid acetonitrile solution as ultrasonic extractant, and the analytical solution was purified by pass-through solid-phase extraction to detect tamoxifen in solid drinks, liquid drinks, hard capsules, soft capsules and tablet candy. Agilent Eclipse Plus RRHD C₁₈ column (100 mm×2.1 mm,1.8 μm) was used for separation, electrospray negative ion mode, tandem mass spectrometry for detection, and external standard method for quantification.

That concentration of tamoxien was good linear relationship within the range of 1.0–100.0 ng/mL, and the correlation coefficient was above 0.999; the limit of detection was 0.015 mg/kg; The limit of quantitation was 0.050 mg/kg.

The method has been verified by the method with high sensitivity, good stability and simple operation, which can meet the requirements of precision and sensitivity for the detection of tamoxifen in solid drinks, liquid drinks, hard capsules, soft capsules and tablet candy.