Objective To verify whether the laboratory can accurately detect fluoroquinolone residues in aquaculture products according to standard Methods. Methods In this article, according to the Methods of Determination of 17 Sulfonamides and 15 Quinolones Residues in Aquatic Products by Liquid Chromatography-Tandem Mass Spectrometry (Ministry of Agriculture Announcement No. 1077-1-2008) and Laboratory Quality Control Specifications for Food Physical and Chemical Testing (GB/T 27404-2008), the method validation of the determination of 5 fluoroquinolones residues in cultured aquatic products by Liquid Chromatography-Tandem Mass Spectrometry was carried out, including linearity range, method sensitivity, accuracy and precision. Results The results showed that the 5 target compounds had good linear relationships in the range of $0 \sim {100\mu}\mathrm{g}/\mathrm{{kg}}$ , with correlation coefficients above 0.99 . The method sensitivity (detection limit, quantification limit) met the method requirements, the average recovery rate was ${93.0}\%\sim {110}\%$ , and the relative standard deviation was $\leq {15}\%$ , all of which met the method requirements. Conclusion It indicates that the laboratory can correctly apply this method for detection work under the existing detection conditions.

Objective To analyze and identify a strain numbered sznj2009. Methods A strain of sznj2009 was isolated from aquatic products, and the colony morphology, biochemical characteristics and biological characteristics of the strain were analyzed and identified. Results The strain showed round, smooth, small colorless colonies on the Vibrio chromogenic plate; Round, flat yellow colonies with opaque centers but transparent edges on CC and mCPC plates; Round, milky white colony on 3% sodium chloride tryptone soybean agar plate. By 16s rDNA sequence analysis found that the strain and vibrio harveyi (ATCC33843) closer, high homology, the evolution of the similarity of 100%. Conclusion The strain sznj2009 isolated from aquatic products was Vibrio harveyi. In the traditional biochemical identification and detection of Vibrio vulnificus, through comparison, it is found that Vibrio harveyi is similar to Vibrio vulnificus in colony characteristics and biochemical characteristics, however, the two strains can be clearly distinguished in the plate and biochemical reaction of Vibrio vulnificus, which can improve the identification accuracy of Vibrio vulnificus and provide reference for the traditional isolation and identification of Vibrio harveyi.

ABSTRACT: In the setting of escalating international trade, distinct variances emerge in the prerequisites for the quality and safety benchmarks of modified starch across different countries and regions. Taking distarch phosphate as an example, this article compares and analyzes the similarities and differences in relevant standard technical indicators and testing Methods between China and major trading regions or countries such as JECFA, the European Union, the United States, Japan, and South Korea, providing technical support for the international trade of modified starch.

Ecological environment monitoring refers to the use of physical, chemical, biochemical, ecological and other technological means to monitor and test various elements in the ecological environment, the interrelationships between organisms and the environment, the structure and function of ecosystems. Ecological environment monitoring plays an important role in monitoring environmental pollution, protecting the ecological environment, ensuring public health, and promoting sustainable development. In order to achieve resource sharing and complementary advantages among ecological environment monitoring regions, and improve the accuracy and standardization of environmental monitoring data, this paper explored the Methods, technologies, and implementation paths of regional integration of information systems in the field of environmental monitoring from the perspective of ecological environment monitoring quality management. Based on practical cases, this paper elaborated on the implementation path and Methods, including how the contracting and construction units participate and cooperate, how to implement in stages, etc, provided a detailed introduction to the design concept, functions, and interrelationships of each module of the integrated system, and summarized the effectiveness and significance of regional integration in the inspection and testing industry which provides theoretical support for the reform and innovation in the field of ecological environment monitoring.

Objective The accuracy of the test results was evaluated by the interlaboratory comparison of the blind samples, and the test quality and test ability were improved. Methods According to the “National Standard for Food microbiology inspection of food safety” and other Methods for the 2012-2023 assessment of blind samples for testing. Results During the 2012-2023 Blind examination in Yizheng’s CDC Microbiology Laboratory, 3 strains of Enterocoliform Yersinia, 5 strains of Bacillus cereus, 4 strains of Klebsiella (E. sakazakii) and 2 strains of Enterobacter cloacae were detected, 3 strains of Enterobacter aerogenes, 3 strains of Streptococcus hemolyticus, 1 strain of Streptococcus $A,2$ strains of Streptococcus $B,3$ strains of salmonella,1 strain of salmonella enteritidis, 2 strains of Salmonella enterica, two strains of Liszt. Escherichia coli, Shigella, Citrobacter freundii, Pseudomonas aeruginosa, Vibrio alginolyticus, Vibrio vulnificus, Vibrio parahaemolyticus, Staphylococcus epidermidis. Conclusion From 2012 to 2023, all the results were correct, and the combination of manual and instrument can improve the detection capability and quality of the laboratory.

Objective To establish an analytical method for the rapid determination of mold and yeast in dried rice noodles based on matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS). Methods GB 4789.15-2016 "National Food Safety Standard Food Microbiological Inspection Mold and Yeast Enumeration" was used to detect and analyze the molds and yeasts of dried rice flour in the laboratory from 2021 to 2022, and 10 wild strains were obtained, and identified by matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS). Results According to statistics, the dried rice noodles sampled by the laboratory from 2021 to 2022 are contaminated by fungi. of which the total detection rate of mold and yeast is about 45.45%. Through MALDI-TOF MS identification, among the 10 wild strains, mold accounts for 80% and yeast accounts for 20%. Conclusion MALDI-TOF MS, as a rapid, sensitive, accurate and high-throughput microbial identification technology, has realized the rapid and specific identification of mold yeast in dried rice noodles, and can provide scientific basis for the detection of mold yeast in dried rice noodles.

Objective Due to the poor application effect of current technology in groundwater pollution source water quality monitoring, the recovery rate of pollutants is low, and the RSD is relatively high, aiming at the defects of linear method, the application of ion chromatography technology in groundwater pollution source water quality monitoring is proposed. Methods An automatic sampling device is used to collect water samples upstream of groundwater pollution sources and filter them. By diluting the standard solution of each pollutant, preparing the standard working solution, centrifuging the water sample with the centrifuge, testing the water sample with the ion chromatograph, identifying the pollutants according to the standard working curve and generating the corresponding ion chromatogram, calculating the mass concentration according to the ion content of the pollutant, so as to complete the water quality monitoring of groundwater pollution sources based on the ion chromatographic technology. Results The recovery rate of pollutants is above 90% and the RSD value is lower than 0.1, the application effect of this technology is relatively good. Conclusion The technique has good adaptability and reliability, can be used for water quality monitoring.

Objective To evaluate the uncertainty evaluation for the determination of imidacloprid in Caidian lotus root by ultra performance liquid chromatography-tandem quadrupole mass spectrometry. Methods According to GB/T 20769 - 2008 Determination of 450 pesticides and related chemicals residues in fruits and vegetables-Liquid chromatography-tandem mass spectrometry, the content of imidacloprid in Caidian lotus root was determined and the mathematical model was built. According to the provisions of JJF 1135-2005 Evaluation of measurement uncertainty in chemical analysis and JJF 10591-2012 Technical specification for evaluation and representation of measurement uncertainty, the uncertainty was quantified by scientific analysis, and the extended uncertainty of imidacloprid content in Caidian lotus root　was finally calculated. Results When the residue imidacloprid in Caidian　lotus root was ${0.322}\mathrm{{mg}}/\mathrm{{kg}}$ , the　relative standard synthetic uncertainty was 0.08689 and the expanded　uncertainty was ${0.0560}\mathrm{{mg}}/\mathrm{{kg}}$ . The　determination results were　 $\left({{0.322}\pm {0.0560}}\right)\mathrm{{mg}}/\mathrm{{kg}},P ={95}\%, k = 2$ . Conclusion The main sources of uncertainty in　the determination of imidacloprid in Caidian lotus root by ultra　performance liquid chromatography-tandem quadrupole mass spectrometry　are the preparation of standard solution, sample pretreatment and　measurement process of the measuring instrument.

Objective To evaluate the uncertainty evaluation for the determination of imidacloprid in Caidian lotus root by ultra performance liquid chromatography-tandem quadrupole mass spectrometry. Methods According to GB/T 20769 - 2008 Determination of 450 pesticides and related chemicals residues in fruits and vegetables-Liquid chromatography-tandem mass spectrometry, the content of imidacloprid in Caidian lotus root was determined and the mathematical model was built. According to the provisions of JJF 1135-2005 Evaluation of measurement uncertainty in chemical analysis and JJF 10591-2012 Technical specification for evaluation and representation of measurement uncertainty, the uncertainty was quantified by scientific analysis, and the extended uncertainty of imidacloprid content in Caidian lotus root　was finally calculated. Results When the residue imidacloprid in Caidian　lotus root was ${0.322}\mathrm{{mg}}/\mathrm{{kg}}$ , the　relative standard synthetic uncertainty was 0.08689 and the expanded　uncertainty was ${0.0560}\mathrm{{mg}}/\mathrm{{kg}}$ . The　determination results were　 $\left({{0.322}\pm {0.0560}}\right)\mathrm{{mg}}/\mathrm{{kg}},P ={95}\%, k = 2$ . Conclusion The main sources of uncertainty in　the determination of imidacloprid in Caidian lotus root by ultra　performance liquid chromatography-tandem quadrupole mass spectrometry　are the preparation of standard solution, sample pretreatment and　measurement process of the measuring instrument.

Objective This study aims to accurately quantify two key components in Baijiu (Chinese liquor) production and quality control: acetic acid and hexanoic acid. Methods A direct injection-gas chromatography (GC) technique was used for the rapid and precise simultaneous determination of acetic acid and hexanoic acid in Baijiu. Results Using this method, the detection limit for acetic acid reached 0.012 g/L and for hexanoic acid, 0.0050 g/L. All correlation coefficients exceeded 0.999. The relative standard deviations (RSD) were 0.32% for acetic acid and 0.33% for hexanoic acid, with spiked recovery rates of 96.15% for acetic acid and 96.69% for hexanoic acid, respectively. Conclusion The new detection method proposed in this study not only overcomes the limitations of traditional detection methods and gas chromatography in many aspects but also demonstrates high efficiency, sensitivity, and excellent selectivity. This method has significant practical implications for improving the production process of Baijiu, ensuring the consistency of product flavor, and safety.