Latest ArticlesObjective To evaluate the risk of pesticide residues in cucurbit vegetables in Guizhou Qiandongnan Prefecture. Methods LC-MS and GC-MS was used for determination of residues of the level of 50 pesticide residues in cucurbit vegetable samples collected randomly from Guizhou Qiandongnan Prefecture. Results It showed that Pesticide residues were detected in 15 samples of 100 cucurbit vegetables, 8 pesticides were detected, 20 times in total, The average value of food safety index in cucurbit vegetables related to pesticide residues did not exceed the national maximum residue limit in Guizhou Qiandongnan Prefecture. Conclusion Our findings suggest that the potential hazard level of pesticide residues in cucurbit vegetables in Guizhou Qiandongnan Prefecture is acceotable.
Objective To evaluate the risk of pesticide residues in cucurbit vegetables in Guizhou Qiandongnan Prefecture. Methods LC-MS and GC-MS was used for determination of residues of the level of 50 pesticide residues in cucurbit vegetable samples collected randomly from Guizhou Qiandongnan Prefecture. Results It showed that Pesticide residues were detected in 15 samples of 100 cucurbit vegetables, 8 pesticides were detected, 20 times in total, The average value of food safety index in cucurbit vegetables related to pesticide residues did not exceed the national maximum residue limit in Guizhou Qiandongnan Prefecture. Conclusion Our findings suggest that the potential hazard level of pesticide residues in cucurbit vegetables in Guizhou Qiandongnan Prefecture is acceotable.
Objective In the present paper, the influences of matrix effect (ME) to the quantification of imidacloprid, thiamethoxam and clothianidin in ginger and banana were evaluated, and especially, the influencing factors and compensating means of matrix effect in LC-MS/MS analysis were proposed. Methods In this research, the matrix effects of three neonicotinoid insecticides in ginger and banana were evaluated by LC-MS/MS analysis after QuEChERS pretreatment. Both matrix-matched calibration curves and solvent calibration curves were established for the assessment of matrix effect. Results The linear regression coefficients of the matrix-matched calibration curves were all above 0.999 and the precision of the measured sample results was better than that of the solvent standard. The recoveries and relative standard deviations of all compounds at matrix-matched calibration curves were 86.7%~103.0% and 2.1%~8.3%, respectively. Conclusion Matrix effects can compromise the precision and accuracy of the analysis results. These results also indicated that matrix effects were mainly affected by matrix concentration, the types and samples of matrices and the overall chemical structure of the pesticide. The linear regression coefficients and precision as well as accuracy were more satisfactory for all the pesticides when matrix-matched standard was used, which reflected an excellent compensating means of matrix effect. This can improve the accuracy of quantitative results, which is feasible in routine testing, and is of great significance for ensuring the quality and safety of ginger and banana products.
Objective In the present paper, the influences of matrix effect (ME) to the quantification of imidacloprid, thiamethoxam and clothianidin in ginger and banana were evaluated, and especially, the influencing factors and compensating means of matrix effect in LC-MS/MS analysis were proposed. Methods In this research, the matrix effects of three neonicotinoid insecticides in ginger and banana were evaluated by LC-MS/MS analysis after QuEChERS pretreatment. Both matrix-matched calibration curves and solvent calibration curves were established for the assessment of matrix effect. Results The linear regression coefficients of the matrix-matched calibration curves were all above 0.999 and the precision of the measured sample results was better than that of the solvent standard. The recoveries and relative standard deviations of all compounds at matrix-matched calibration curves were 86.7%~103.0% and 2.1%~8.3%, respectively. Conclusion Matrix effects can compromise the precision and accuracy of the analysis results. These results also indicated that matrix effects were mainly affected by matrix concentration, the types and samples of matrices and the overall chemical structure of the pesticide. The linear regression coefficients and precision as well as accuracy were more satisfactory for all the pesticides when matrix-matched standard was used, which reflected an excellent compensating means of matrix effect. This can improve the accuracy of quantitative results, which is feasible in routine testing, and is of great significance for ensuring the quality and safety of ginger and banana products.
Objective To separate and identify the miscellaneous bacteria in sterilized lactic acid bacteria beverages provided by an enterprise. Methods The miscellaneous bacteria of lactic acid bacteria beverages were isolated and purified using a variety of medias. The isolated strains were identified at the genus and species levels by analysis of ${16}\mathrm{\;S}$ rRNA sequence and matrix-assisted laser desorption/ionization time of flight mass spectrometry. Results A total of 16 strains were isolated, Among them, 5 strains of Acetobacter, 2 strains of Gluconobacter japonicus, 1 strain of Gluconacetobacter liquefaciens, 1 strain of Kocuria palustris, 1 strain of Streptomyces hydrogenans, 1 strain of Staphylocaccus saprophyticus, 1 strain of Bacillus sp, 1 strain of Novosphingobium aromaticivorans, 1 strain of Brevundimonas vesicularis, 2 strains of Yeast, most of which (n=8, 50%)were identified as Acetobacteraceae. Conclusion Acetobacter, Bacillus, Staphylococcus, Brevundimonas vesicularis, mold, Yeast and other microorganisms were isolated from the bactericidal lactobacillus beverage, most of which belongs to Acetobacteraceae.
Objective Based on gas chromatography-mass spectrometry (GC-MS) technology and partial least squares analysis (PLS-DA) metabolomics methods, observe the changes in serum metabolites of mice after administration of traditional Chinese medicine Yuanbaocao, and provide a preliminary explanation for the analgesic mechanism. Methods Establish two analgesic models, the hot plate method and the acetic acid writhing method, and use GC/MS to detect and analyze etabolites in mouse serum. After collecting data, PLS-DA method is used to detect and classify endogenous small molecule metabolites in the samples. Results The hot plate analgesic experiment showed that there were extremely significant differences $\left({P<{0.01}}\right)$ in the licking time between the aspirin group, the high and medium dose groups of Yuanbaocao mice, and the model group at 30 and 60 minutes. As the administration time prolonged, Yuanbaocao showed different inhibitory effects on pain symptoms, which was inferred to be related to the high or low blood drug concentration. Compared with the blank group, the number of body twists in the Yuanbaocao group mice decreased significantly $\left({P <{0.01}}\right)$ , indicating that Yuanbaocao has a certain degree of analgesic effect. There are significant differences in the metabolic characteristics of mouse serum, and further screening of metabolic pathways that have a significant impact on data classification identified that taurine, glutathione, arginine and proline, ascorbic acid 5 metabolic pathways are related to pain metabolism. Conclusion The Yuanbaocao group can reverse abnormal changes to a certain extent and has analgesic effects.
Objective To evaluate the precision and accuracy level of four Dimai DM79x blood cell analyzers in the most suitable working state of our department's daily indoor quality control by comparing the indoor quality control data, so as to improve the accuracy and consistency of test results. Methods In February 2023 (28 days), the indoor quality control data of four laboratory instruments using original low, medium and high fixed value quality control products and daily testing of a random outpatient fresh patient sample were collected. The items included: White blood cells (WBC), red blood cells (RBC), hemoglobin (HGB), hematocrit (HCT), platelets (PLT), mean red blood cell volume (MCV), mean red blood cell hemoglobin volume (MCH), mean red blood cell hemoglobin concentration (MCHC) calculated mean (X), standard deviation (S) and coefficient of variation (CV), Coefficient of variation index (CVI) and standard deviation index (SDI) were used as precision and accuracy evaluation indexes respectively. Result The statistical analysis showed that the blood cell analysis of the DM79x instrument included 8 parameters, including WBC, RBC, HGB, PLT, HCT, MCV, MCH and MCHC. The coefficient of variation index of CVI of each instrument was different, and the indoor quality control result of SDI was <2.0. The measured values of CVI and SDI of fresh sample comparison data are all within the required range. Conclusion Four Dimai DM79x automatic blood cell analyzers in our department have good precision and high accuracy by comparing the indoor quality control data between laboratories. The performance of the instrument can meet the work needs of clinical laboratories. Moreover, the accuracy and consistency of the results in different instruments can be ensured by comparing the fresh samples of patients.
Objective To evaluate the precision and accuracy level of four Dimai DM79x blood cell analyzers in the most suitable working state of our department's daily indoor quality control by comparing the indoor quality control data, so as to improve the accuracy and consistency of test results. Methods In February 2023 (28 days), the indoor quality control data of four laboratory instruments using original low, medium and high fixed value quality control products and daily testing of a random outpatient fresh patient sample were collected. The items included: White blood cells (WBC), red blood cells (RBC), hemoglobin (HGB), hematocrit (HCT), platelets (PLT), mean red blood cell volume (MCV), mean red blood cell hemoglobin volume (MCH), mean red blood cell hemoglobin concentration (MCHC) calculated mean (X), standard deviation (S) and coefficient of variation (CV), Coefficient of variation index (CVI) and standard deviation index (SDI) were used as precision and accuracy evaluation indexes respectively. Result The statistical analysis showed that the blood cell analysis of the DM79x instrument included 8 parameters, including WBC, RBC, HGB, PLT, HCT, MCV, MCH and MCHC. The coefficient of variation index of CVI of each instrument was different, and the indoor quality control result of SDI was <2.0. The measured values of CVI and SDI of fresh sample comparison data are all within the required range. Conclusion Four Dimai DM79x automatic blood cell analyzers in our department have good precision and high accuracy by comparing the indoor quality control data between laboratories. The performance of the instrument can meet the work needs of clinical laboratories. Moreover, the accuracy and consistency of the results in different instruments can be ensured by comparing the fresh samples of patients.
This study will start with the current problems in the safety and management of multi campus university laboratories, and explore new methods and approaches for intelligent management and security system design of laboratories based on the perspective of the Internet of Things. We will use Internet information technology to build a resource sharing, fully open and efficient experimental teaching platform, build a laboratory management system based on the big data era, monitor the whole process before, during and after the experiment through the collection and analysis of data generated by the use and operation of various instruments and equipment, find problems in the experiment in time, carry out targeted guidance, effectively warn laboratory hazards, improve laboratory safety management efficiency, push laboratory management to a higher level, and achieve the win-win effect of talent training, scientific innovation, and safety management.
Objective Therefore, the purpose of this study is to verify and optimize the microbial contamination control strategies during the production of sterile injections to ensure product safety and improve production quality. Methods A randomized trial design was conducted between January 2022 and December 2023, a traditional control strategy between January 2022 and December 2022, and a post-optimized strategy between January 2023 and December 2023. By comparing the microbial pollution under different strategies, combining with the production environment monitoring, process process analysis and operator behavior code assessment, the effectiveness of the control strategy is comprehensively evaluated, and the strategy is optimized. Results The study found that the optimized strategy greatly reduced the risk of microbial contamination and improved production efficiency and product quality. Conclusion The validation and optimized microbial contamination control strategy has significant results in the production of sterile injection, which provides a strong guarantee to ensure the sterility and safety of the injection products. In the future, the production process will be continuously monitored, and the control strategy will be dynamically adjusted according to the actual situation to meet the changing production environment and regulatory requirements.