Water resources are an important foundation for Chinese national economy and social development, and water quality and environmental monitoring are of great significance for ensuring water resource security and water environment protection. Microbial detection technology, as a fast, accurate, and sensitive water quality monitoring method, has been widely applied in the field of water quality monitoring in China. In order to improve the effectiveness of microbial detection and enhance the monitoring of water quality and environment in China, this article will adopt literature review and practical research methods to analyze the commonly used microbial detection technologies and compare their advantages and disadvantages, aiming to provide scientific basis for water quality and environmental protection in China.

Objective Clarify and optimize the detection methods for 9antioxidants in oil samples. Methods After dissolving the oil sample in $3\mathrm{\;{mL}}$ of n-hexanesolution saturated with acetonitrile, repeat the extraction 5 times with $3\mathrm{\;{mL}}$ of n-hexanesaturated acetonitrile containing AP, and merge the 5 extractionsolutions. Purify with a C18 solid-phase extraction column, collect andconcentrate all extraction and eluent together to ${0.2}\mathrm{\;{mL}}$ , and finally make upto $2\mathrm{\;{mL}}$ withacetonitrile. Results 9 antioxidants linear relationship is good withinthe range of 1.0 to ${60.0}\mathrm{{\mug}}/\mathrm{{mL}}$ , and the correlation coefficients are allgreater than 0.99 ; the recovery rate ranges from 91.2% to 108.8%, witha relative standard deviation (RSD) of 0.6% to 10.0%; the detectionlimit is within the range of ${0.2}\sim {2.0}\mathrm{{mg}}/\mathrm{{kg}}$ ,and the quantitative limit is within the range of ${0.6}\sim {6.0}\mathrm{{mg}}/\mathrm{{kg}}$ . Conclusion This method optimizes the extraction frequency, purification method, and elution volume, and significantly improves the recovery rates of 9 antioxidants. The extraction frequency has a significant impact on the recovery rate of BHT and DG.

The convergence of laboratory testing standardization and automation technologies has had a profound impact on scientific research and industrial applications. Standardization provides a framework for consistency and comparability, while automated systems improve experimental efficiency and reliability of results. This article will explore the importance of standardization of laboratory testing and its integration with automation technology, as well as the importance of compliance with standards for automated systems.

Objective Study why nicotinamide is transformed tonicotinic acid occurred when detect vitamin ${\mathrm{B}}_{3}$ in milk powdercontaining lactic acid bacteria by GB 5009.89-2016 high performanceliquid chromatography method, and its mechanism was discussed. MethodsThe samples were pretreated according to standard procedures, and theeffects of the placement time of the sample extraction solution, theplacement time of the sample solution before acid hydrolysis and the $\mathrm{{pH}}$ value of acidhydrolysis were investigated by single factor test. Results Thetransformation of nicotinamide to nicotinic acid occurred in theplacement step after the sample was dissolved and before acidhydrolysis, but after adjusting the pH value to 1.7 specified in thestandard for acid hydrolysis, the transformation was completelyinhibited. Conclusion If you want to detect the content of nicotinicacid or nicotinamide separately in samples containing lactic acidbacteria, you need to adjust the $\mathrm{{pH}}$ value to 1.7 when thesample is dissolved to inhibit the transformation of nicotinamide tonicotinic acid.

By examining the fundamental concepts, classifications of metrological testing, and its roles in ensuring product quality, constructing a foundation for supervisory technology, and facilitating legal enforcement, this paper elucidates how metrological testing technology fosters standardized corporate production, enhances product quality control, and sustains market order. Integrating contemporary technological trends, notably advancements in intelligent inspection technologies, it prospects the future trajectory of metrological testing within the strategy of building a strong quality nation, while proposing strategies to enhance the emphasis on technology, cultivate professional talent, and refine management mechanisms. The research herein underscores the pivotal role of metrological testing technology as a pillar of the quality assurance system, thereby promoting industrial upgrading and securing high-quality economic development.

With the increasing demand of laboratory teaching and scientific research in colleges and universities, higher requirements are put forward for laboratory safety education, which is also an important content to ensure the safety of teachers and students, great importance must be attached to it. In view of this, colleges and universities should pay attention to laboratory culture, actively establish a safety education system, do a good job of top-level design, establish a sound evaluation mechanism, and gradually optimize educational methods and methods, and then build an integrated safety culture and education system.

This article aims to study the influence of electromagnetic interference on the testing of electric energy meters and corresponding protective measures. By combining experimental and theoretical analysis, this study focuses on the impact of electromagnetic interference on the accuracy of electric energy meter testing, including measurement errors, data instability, and equipment damage. Based on these factors, this article proposes protective measures against electromagnetic interference, including the application of physical shielding technology, reasonable design of filters, and strict attention to the testing of electric energy meters. The results indicate that electromagnetic interference can lead to increased errors in electric energy meter testing, which can cause malfunctions and even incorrect operations. To minimize the impact of electromagnetic interference, this article proposes a series of effective protective measures, including reasonable wiring, installation of filters, and use of shielded cables. These measures have achieved good results in practical applications and significantly improved the accuracy and stability of electric energy meter testing.

The re evaluation of qualification recognition capability is a capability confirmation work that inspection and testing institutions need to carry out every six years. The new version of the "Criteria for Qualification Recognition and Review of Inspection and Testing Institutions" has been officially implemented since December 1, 2023. This article mainly elaborates on how to efficiently pass the qualification recognition re evaluation work of inspection and testing institutions under the requirements of the new criteria. Taking a certain inspection and testing institution in Beijing as an example, this article briefly introduces the entire process of re evaluation, including organization preparation, online reporting, on-site audit, later rectification, and evidence collection. It provides a detailed analysis of the entire process of re evaluation and points out the precautions to be taken when preparing application materials for re evaluation. This provides a reference for the qualification recognition re evaluation application and related work of inspection and testing institutions.

Objective To explore the pathogenic factors causing outbreaks of bacterial foodborne diseases. Methods Collecting anal swabs, food retention samples, and food processing tool application samples from patients affected by this epidemic, refer to "Microbiological Testing of Food Hygiene" (GB/T 4789.4-2016、GB/T 4789.5-2012、GB/T 4789.6-2016, GB/T 4789.7-2013, GB/T 4789.10-2016) and "National Clinical Testing Operating Procedures" (Fourth Edition). Results Aeromonas sobria was detected in food samples from little yellow croaker and anal swabs from two patients. Aeromonas hydrophila was detected in a kitchen appliance application and one patient's anal swab. Conclusion This was a rare outbreak of foodborne disease caused by mixed Aeromonas, In the diagnosis and treatment of intestinal infectious diarrhea, in addition to considering common intestinal pathogenic bacteria, rare pathogenic bacteria such as Aeromonas should not be ignored to avoid clinical diagnosis and treatment difficulties.

Objective Analyze and summarize the factors and precautions that affect the use of N, N-diethylphenylenediamine spectrophotometry for the determination of sulfides in water through experimental analysis. Methods N,N-diethyl-p-phenylenediamine spectrophotometry was used for the determination of sulfide in water. The accuracy and precision of the method were verified by the standard samples with known sulfide content, and all aspects of the experiment were analyzed. Result The N,N-diethyl-p-phenylenediamine spectrophotometry method for the determination of sulfides in water meets the analytical requirements in terms of linearity, precision, and accuracy, making it suitable for the detection of sulfides in clean water. Conclusion When doing the experiment, attention should be paid to sampling, preparation and absorption of standard solutions, and preparation of colorimetric solutions etc. in order to achieve satisfactory results.