Objective The article studies the determination of ${\mathrm{{COD}}}_{\mathrm{{Mn}}}$ and ${\mathrm{{COD}}}_{\mathrm{{Cr}}}$ inwater using microwave digestion spectrophotometry. Methods Explore thisdetection method from multiple perspectives such as detection limit,precision, accuracy, linear range, analysis speed, and testing cost, andcompare it with traditional national standard methods. Results Theexperimental results show that the detection results of this method aresimilar to those of the national standard method, with a high recoveryrate of sample spiking, a lower detection limit, and a lower relativestandard deviation. Conclusion It can be seen that the method is easy and fast to operate, with good detection accuracy, high precision, wide detection range, and reduces time and material costs, reducing secondary pollution. It is suitable for the detection of different types of water bodies such as surface water, groundwater, and sewage.

The treatment and detection of nickel-containing electroplating wastewater is an important topic in the field of environmental protection. This paper analyzes the generation and composition of nickel-containing wastewater in the electroplating process, and discusses the impact of nickel-containing wastewater on the environment and human health. In order to improve the detection accuracy and efficiency, this paper optimizes the existing detection methods, including the improvement of pre-treatment technology, the optimization of detection equipment and methods, and the application of automated and intelligent detection systems. The experimental study verified the effectiveness of the optimized detection method in improving sensitivity, shortening detection time, and reducing detection costs, providing technical support for the effective management and treatment of electroplating wastewater.

As the core component of the current power system of automobiles, the durability of key components has a decisive impact on the overall performance and safety of the vehicle. The purpose of this article is to explore an efficient method for evaluating the durability of core components of automotive engines, in order to improve the reliability of components and the safety of the entire vehicle. The article examines the current development trend of durability assessment technology and analyzes the limitations of existing technologies. Propose a comprehensive evaluation method that integrates experimental verification and numerical simulation, which can effectively evaluate the durability of components in different working environments. Through experimental verification and data analysis, the accuracy and efficiency of the proposed method were verified, and future research directions and improvement suggestions were predicted and anticipated.

As an important energy resource, the quality of coal directly affects combustion efficiency, environmental emissions, and product quality. Traditional detection methods rely on manual sampling and laboratory testing, which have issues such as uneven sampling, cumbersome operations, and long cycles, making it difficult to meet real-time and accurate requirements. This paper proposes optimization solutions including multimodal information fusion, standardization and automation, and intelligent monitoring systems. These technologies significantly improve the accuracy and efficiency of coal quality detection and have been validated in both laboratory and industrial applications, demonstrating their great potential in real-time monitoring and management of coal quality. The optimized methods not only more accurately reflect the actual ash and sulfur content in coal products but also provide strong technical support for the development of the coal industry, achieving intelligent and efficient coal quality monitoring.

With the continuous development of coal mining, the safe operation of coal mine mechanical and electrical equipment is very important. This paper discusses the application of ultrasonic detection technology in the safety detection of coal mine mechanical and electrical equipment, expounds the principle and characteristics of ultrasonic detection technology, and analyzes its specific application methods in the detection of various faults and defects of coal mine mechanical and electrical equipment, including the detection of mechanical parts and electrical equipment. By discussing the measures of improving the application effect of ultrasonic detection technology, the effectiveness of ultrasonic detection technology in the safety detection of coal mine electromechanical equipment is shown for its reference.

Phosphorus is one of the important nutrient elements in the soil, which has an important influence on crop growth. The availability and availability of phosphorus elements vary in their morphology. Accurate and rapid analysis of phosphorus morphology in soil is crucial for rational fertilization and increasing crop yield. This paper discusses the rapid analysis method of phosphorus elements in soil morphology, introduces the determination of phosphorus including instrument working conditions setting, working curve and ICP method. The application of ICP method as a simple and easy detection method in phosphorus analysis was discussed, through the actual detection method to verify the accuracy and reliability of different detection methods. Finally, the comprehensive application of various methods can quickly and accurately analyze the morphology of phosphorus in soil.

Objective To establish a high-performance liquidchromatography method for the detection of dibenzothiazole disulfide(MBTS) in soil. Methods Extract using acetonitrile ultrasound for 30minutes, filter through an organic membrane filter, and purify through aC18 column. Use an HPLC analyzer with set flow rate of ${0.7}\mathrm{\;{mL}}/\mathrm{{min}}$ andcolumn temperature of ${40}^{\circ }\mathrm{C}$ , and the soilsample is separated for qualitative analysis and quantitative analysisusing external standard method at a detection wavelength of ${275}\mathrm{\;{nm}}$ . Results Byoptimizing the pre-treatment and chromatographic conditions for MBTSdetection, acetonitrile was used as the extraction solvent, C18 columnserves as the purification column. An appropriate gradient elutionprogram has a good effect on reducing matrix effects in soil andanalyzing target compounds. Through methodological validation, it wasfound that, the relative standard deviation of MBTS spiked precisionranges from 0.070% to 0.201%. The relative standard deviation of MBTSspiking accuracy ranges from 0.071% to 0.646%, and the spiking recoveryrate ranges from 91.0% to 97.1%, the detection limit of MBTS method is0.003 mg/kg, and the lower limit of determination is ${0.013}\mathrm{{mg}}/\mathrm{{kg}}$ . Conclusion This method has the advantages of simple operation, lowdetection limit, short testing time, low interference, high precisionand accuracy, and can provide technical support for the MBTS insoil.

Water is a necessary substance for all living things on the earth, so it is very important to monitor pollutants in the water environment. At present, many analytical methods have been proposed for the detection of water pollutants. Portable sensor detector is of special importance because of its simple operation, low cost and portability. This paper first introduces the application of portable rapid detection technology, and further reviews the research progress of rapid detection technology for biological and non-biological pollutants in water bodies. Finally, the current research progress is summarized, which provides a reference for the further development of rapid detection technology.

In order to further explore the application value of enterprise environmental monitoring laboratories and enhance the feasibility of using laboratory data for self monitoring work, this article analyzes the development status, quality status, and influencing factors of enterprise environmental monitoring laboratories in Dongguan City one by one. At the same time, combined with field research data, real cases are analyzed, and specific reference opinions and suggestions are proposed to promote the continuous improvement of the value of enterprise environmental monitoring laboratories.

Laser surface acoustic wave technology is an emerging non-destructive testing method that exhibits unique advantages in surface damage assessment during material processing. This article focuses on the application of this technology in the quantitative characterization of surface cracks, roughness, and thermal damage. High sensitivity and strong quantification ability for damage detection have been achieved through laser excitation of surface waves and analysis of their propagation characteristics. Optimizing the incentive reception scheme and signal processing algorithm can further improve detection performance. Experimental studies have shown that there is a deterministic correlation between the time-frequency domain characteristic parameters of surface waves and the damage dimension, laying the foundation for engineering applications.

Objective To study the application of cell morphology inblood smear and automatic blood cell analyzer detection in blood routineexamination. Methods A analys was was conducted on 180 patients withsuspected Macrocellular anemia at Yishui County People’s Hospital fromFebruary 2020 to February 2023. The positive detection rates of diseasewere statwastically analyzed for individual and combined tests, and thepositive detection rates of toxic particles/vacuolar degeneration,nucleated red blood cells, and atypical lymphocytes were alsostatwastically analyzed for individual and combined tests, statwasticalanalyswas of diagnostic efficacy for individual and joint testing. Results The positive detection rates of monocytes, neutrophils,lymphocytes, basophils, and eosinophils detected by the combination ofblood smear cell morphology and fully automated blood cell analyzer werehigher than those detected alone $\left({P<{0.05}}\right)$ . The positive detection rates of toxicparticle/vacuolar degeneration, nucleated red blood cells, and atypicallymphocytes detected by the combination of blood smear cell morphologyand fully automated blood cell analyzer were higher than those detectedalone $\left({P <{0.05}}\right)$ .The sensitivity, specificity, accuracy, and negative predictive value ofthe combined detection of blood smear cell morphology and fullyautomated blood cell analyzer were higher than those of individualdetection $\left({P<{0.05}}\right)$ . Conclusion The value of combined detectionof blood smear cell morphology and fully automated blood cell analyzerin blood routine examination is higher, so is worthy of promotion.

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.

Objective Determination of silicon dioxide in fluorite byalkali fusion-molybdenum blue spectrophotometry. Methods The method ismelted with potassium hydroxide, extracted with water and acidified withsulfuric acid, then, in a weak acidic solution, silicic acid andammonium molybdate form soluble yellow silicomolybdic heteropoly acids,to improve acidity, reduce silicomolybdate yellow to silicomolybdateblue by reducing agent, the absorbance was measured at ${700}\mathrm{\;{nm}}$ and the silicondioxide content was measured. A large number of fluoride interference,the addition of aluminum salt to eliminate. Results Determination ofsilicon dioxide in fluorite by alkali fusion-molybdenum bluespectrophotometry, the silicon dioxide has good calibration curvelinearity, the linear regression equation is $\mathrm{Y}= {0.34733}\mathrm{p}+{0.00228}$ , the correlation coefficient was 0.999; the precisionof the method is less than 1.5%, the accuracy was measured with thenational reference materials, and the relative standard deviation (RSD)was less than 2%. Conclusion It was found that the precision andaccuracy of this method for the determination of silicon dioxide influorite samples were satisfactory and met the requirements of relevantstandards.

With the development of social economy and the improvement of living standards, drinking water quality and safety issues have attracted much attention. Therefore, it is necessary for relevant department staff to pay more attention and reasonably apply gas chromatography technology to detect drinking water quality, so as to reduce the adverse effects of drinking water pollution as much as possible. In this case, this article studies and analyzes the application effect of gas chromatography technology in drinking water quality testing, in order to provide valuable reference opinions for relevant staff, protect people's health, and promote the harmonious and stable development of society.

Objective To explore the effectiveness of gas chromatography-mass spectrometry in detecting volatile organic compounds in soil. Methods Gas chromatography-mass spectrometry was used to detect 24 groups of soil samples from a certain factory. Results There are certain differences in the types and concentrations of VOCs in soil from different regions. The soil of this factory contains volatile organic compounds such as benzene series, chlorinated hydrocarbons, and esters, which meet the monitoring requirements for VOCs in soil. Conclusion Experimental results have shown that gas chromatography-mass spectrometry can accurately detect the types, components, and contents of volatile organic compounds in soil, with high accuracy in the detection results. It is worth promoting and applying.

Objective To establish an inductively coupled plasma massspectrometry (ICP-MS) method for the determination of $\mathrm{{Pb}},\mathrm{{As}},\mathrm{{Hg}},\mathrm{{Cd}},\mathrm{{Hg}}$ in astragali radix, crataegi fructus, lycii fructus, lonicerae japonicaeflos and glycyrrhizae radix et rhizome. Methods After microwavedigestion of forty-five batches of samples, the contents of five heavymetals in commom TCM decoction pieces were determinationed by ICP-MS.The RF power is 1550 W. Kinetic Energy Discrimination mode is used. Thecollisional gas was Helium.The carrier gas was Argon with ${0.8}\mathrm{\;L}/\mathrm{{min}}$ , theplasma gas flow rate was ${14.0}\mathrm{\;L}/\mathrm{{min}}$ . Results Five heavy metal elements showed a good linear relationships $\left({r >{0.999}}\right)$ , whoserecoveries were 84.6%~115.3%, the detection limit was ${0.0001}\sim {0.0140}\mathrm{{mg}}/\mathrm{{kg}}$ .Among the 45 batches of samples, there were individual samples oflonicerae japonicae flos that exceeded the limit. Conclusion This methodis simple, efficient, stable and reliable, which can be used for thequality study of a variety of heavy metals, and provides more basis forits quality control and scientific supervision.

This paper aims to discuss the key points of quality control of on-site testing in mine safety inspection laboratory, including the quality and skills of analysts, the management and maintenance of instruments and equipment, the specification of sample management, and the condition control of environmental facilities. Through the implementation of a strict quality control system and the application of highly automated inspection technology, the accuracy and trust of inspection data can be significantly improved. Formulate specific requirements and implementation strategies for laboratory personnel training, instrument maintenance system, sample management process and environmental condition control, so as to comprehensively improve the quality of on-site testing work.

In education and teaching, university laboratories have a dual function of carrying teaching and research, and providing social services. The safety management of university laboratories has also attracted people's attention. Therefore, this article conducts research and analysis on the "6S Management" and "dual prevention mechanism" in the safety management of university laboratories. By focusing on the management of 6S and introducing the "dual prevention mechanism" approach, it can better achieve on-site operations, graded management and control, and safety hazard investigation in university laboratories, thereby avoiding physical injuries to students caused by the use of physical, chemical and other experimental equipment in university laboratory teaching. Based on the research of "6S" and dual prevention mechanism in laboratory safety management, the goal of comprehensively improving laboratory safety management level can be achieved through measures such as optimizing laboratory equipment and establishing effective emergency prevention plans, laying a solid foundation for ensuring the safe operation of university laboratories and protecting personnel and equipment safety.

High school physics laboratory is an important place for science education, but it is also a concentrated point of potential risks. With the increasing complexity of experimental content and the continuous update of experimental instruments, laboratory safety management and risk prevention are particularly important. In recent years, with the emphasis on safety education, how to effectively prevent and deal with experimental accidents has become the focus of attention of school administrators. Based on this, this study systematically combs the current status of laboratory safety management, analyzes existing problems, and puts forward feasible improvement measures, aiming at providing theoretical support and practical guidance for building a safe and standardized experimental teaching environment.

The article conducted a study on the optimization of standardized processes, focusing on the problems in the maintenance and repair of laboratory testing equipment, as well as the shortcomings in the current process. An analysis was conducted on the types, functions, current problems, and challenges faced by laboratory testing equipment. And the necessity of developing standardized maintenance and upkeep processes was proposed, including principles, methods, and design points for optimizing the process. A standardized plan for maintaining laboratory testing equipment, including process construction, time nodes and frequency settings, as well as quality control and acceptance standards, was provided. Through this study, the operational efficiency and stability of laboratory testing equipment can be improved, ensuring the normal operation of various laboratory tasks.

With the rapid development of medical education, medical laboratory plays a crucial role in cultivating medical talents and scientific research innovation. However, due to the complexity and specificity of laboratory management, traditional management methods are no longer able to meet the needs of modern laboratory management. This article aims to explore the application of standardized management measures in the management of medical school laboratories. Through in-depth analysis of the current situation of medical school laboratory management, a series of standardized management measures are proposed to improve the efficiency of laboratory management, ensure the safe and stable operation of laboratories, and provide strong guarantees for medical education and scientific research innovation.

Colleges and universities incorporate the evaluation system into the laboratory safety management, which is very important for carrying out the laboratory safety management works effectively. It is not only meets the objective requirements of the state, but also is contribute to guide teachers and students to establish correct safety awareness and create great laboratory safety culture atmosphere. Based on the college safety requirements of the Ministry of Education, we could create an open, fair and equitable evaluation contents and selection process on the laboratory safety, and set up awards and rewards foe excellent laboratories. In this way to arouse the enthusiasm of teachers and students for the laboratory safety works, and gradually form laboratory safety culture.

Objective to analyze the impact of the application ofLaboratory Information Management System (LIMS) in laboratory testquality management on the existence of test return pass rate. Methods328 specimens were selected from the specimens tested in our laboratoryfrom January 2022 to December 2023, and were divided into routine team(January 2022-December 2022, routine quality management of tests) andsurvey team (January 2023-December 2023, quality management of testscompleted by LIMS system) according to the time, with 164 specimens ineach team. Comparison of specimen test reporting, adverse events andlaboratory staff satisfaction among the two teams. Results Comparing thetest reporting of specimens in the two teams, the critical value returnrate (95.73%), the timely rate of critical value reporting (96.95%), andthe qualified rate of test return (97.56%) were higher in the surveyteam $\left({{\chi }^{2}={6.821},{4.525},{5.878}, P <{0.05}}\right)$ ; and in thecomparison of the incidence rate of adverse events among the teams, thesurvey team (3.05%) was lower $\left({{\chi}^{2}= {4.525}}\right.$ , $P<{0.05}$ ); compared with before the implementation of LIMSsystem, the scores of laboratory staff efficiency $\lbrack \left({{9.12}\pm {0.55}}\right)$ points], management effectiveness [(9.16±0.57) points], and risk control[(9.27±0.54) points] were higher after the implementation $\left({t ={2.369},{2.270},{2.291}, P<{0.05}}\right)$ . Conclusion Laboratory test qualitymanagement under LIMS can improve test return pass rate, critical valuereturn rate and critical value return timely rate, reduce the risk ofadverse events, and improve the satisfaction of laboratory staffmanagement, with significant practical value.

This study aims to respond to the call of the Dali Bai Autonomous Prefecture Ecological Environment Bureau to intensify monitoring of the Erhai Lake area and its main rivers, and conduct long-term and continuous monitoring of the chemical oxygen demand (COD) and dissolved oxygen (DO) in the river channel entering Erhai Lake in Dali Manjiang. By deeply analyzing nearly 170 sets of monitoring data and drawing a relationship diagram between COD and DO, we have a deep understanding of the relationship between these two water quality indicators in the river channel entering Erhai Lake in Dali Manjiang. This study not only provides strong data support for further monitoring and control of the river channel entering Erhai Lake, but also provides a scientific basis for promoting the protection of Erhai Lake. By revealing the relationship between COD and DO, it is possible to more accurately assess the water quality of the river channel entering Erhai Lake, so as to more effectively formulate and implement environmental protection measures and contribute to the sustainable and healthy development of the ecological environment of Erhai Lake.

As an inevitable product in coal mine production, dust has a wide range of sources. These dust not only have complex physical and chemical properties, but their concentration and distribution characteristics are also affected by various factors. This article aims to comprehensively and systematically study the characteristics and hazards of coal mine underground dust through fixed-point sampling and detection analysis methods. By selecting and arranging sampling points, preparing and calibrating sampling instruments, and performing specific operations during the sampling process, the accuracy of data is ensured. At the same time, based on the detection results, the concentration, particle size distribution, chemical composition, and explosiveness of dust are revealed, in order to provide effective basis for the development of targeted dust prevention measures.

Objective To evaluate and analyze the value of halophilicbacteria culture in the detection of Vibrio parahaemolyticus in seafoodin Dalian area. Methods 46 samples of Marine products were collectedfrom Dalian from July 2023 to October 2023, and halophilic bacteria werecultured and isolated. The salt-tolerance test was carried out toidentify and analyze the virulence of Vibrio parahaemolyticus, and thecharacteristics and detection of Vibrio parahaemolyticus in Marineproducts were analyzed. Results A total of 45 halophilic and salttolerant strains were screened, with a yield of 44.44% at 20% salinity,55.56% at 15% salinity, and 11.11% at 50°C cultivation environment. Theisolated strains continued to grow at a concentration of ${25}\%\mathrm{{NaCl}}$ , and the bestgrowth was observed at a concentration of ${10}\%\mathrm{{NaCl}}$ . Seventeenmoderately halophilic bacteria were detected, with a total of 28 salttolerant strains. Conclusion The detection rate of Vibrioparahaemolyticus in Marine products in Dalian area can be improved byusing halophilic bacteria culture detection. The results of virulenceidentification show that Vibrio parahaemolyticus has strong virulenceand potential risk of food poisoning.

Objective To analyze the quality control results of detecting influenza virus nucleic acid by fluorescence real-time quantitative PCR. Methods From May 2021 to November 2022, 120 samples of influenza virus infection were studied. The RNA of influenza virus in these samples was extracted by nucleic acid and detected by PCR real-time fluorescence quantitative technique to evaluate its effect. Results 44 cases of influenza B virus, 40 cases of influenza A 1 virus and 36 cases of influenza A 3 virus were detected by this technique. All the test results meet the quality control standards of molecular biology operation, and the qualified rate reaches 100.0%. Conclusion Real-time nucleic acid PCR technology is widely used in clinical influenza virus detection. PCR real-time fluorescence quantitative detection method is accurate and rapid in the detection of influenza virus nucleic acid, which is suitable as the first choice to deal with public health emergencies.

Objective Exploring the influence of crystal form of ceftriaxone sodium on the quality of ceftriaxone sodium for injection products. Methods Analyze the relationship and reasons between crystal form and product quality by comparing the changes in polymer content of different crystal form products after long-term and accelerated testing. Results There are differences in the quality stability of different crystal forms of ceftriaxone sodium products. Conclusion Production enterprises should pay attention to the production process and choose the optimal crystal form to improve product quality

Objective To evaluate the analytical performance of serumamyloid A protein and C-reactive protein detection reagents based onmicrofluidic technology, so as to determine whether they can meetclinical requirements. Methods The precision, accuracy, linear range,interference test and other technical indicators of the detectionreagent were determined according to the CLSI EP scheme. Results Theintra-batch coefficients of variation of high and low concentrationsamples were 0.54% and 1.79%, and the inter-batch coefficients ofvariation were 0% and 1.20%, respectively, for the serum amyloid Adetection reagent; the intra-batch coefficients of variation of high andlow concentration samples were 0.30% and 2.28%, and the inter-batchcoefficients of variation were 0.17% and 0%, respectively, for theC-reactive protein detection reagent; the experimental results of themethodological comparison of the two methods were $\mathrm{Y}=$ -0.0609+0.9871X, ${\mathrm{R}}^{2}= {0.9975}$ and $\mathrm{Y}= {0.3354}+{0.9857}\mathrm{X},{\mathrm{R}}^{2}= {0.9990}$ , respectively,and the allowable errors were greater than the upper limit of theexpected bias confidence interval, and the biases were acceptable; thelinear range of the serum amyloid A detection reagent was $3 \sim {100.0}\mathrm{{mg}}/\mathrm{L}$ ,and the linear range of the C-reactive protein detection reagent was $3\sim {150.0}\mathrm{{mg}}/\mathrm{L}$ . Conclusion The analytical performance of serum amyloid A and C-reactive protein detection reagents based on microfluidic technology can meet the needs of clinical laboratories.

The purpose is to study the vertical linear uncertainty of ultrasonic flaw detectors. Firstly, introduce the specific instrument models and technical parameters, analyze the basis and methods for evaluating the vertical linear uncertainty of ultrasonic flaw detectors, and conduct uncertainty evaluation through modeling. Finally, issue a vertical linear uncertainty report and propose the key points for calibrating the ultrasonic flaw detector calibration device. Intended to provide reference for ultrasonic detection personnel, master the exploration skills of vertical linear uncertainty of ultrasonic flaw detectors, truly optimize the quality and performance of ultrasonic flaw detectors, and truly play its functional role.

With the improvement of people's living standards, food safety issues have become the focus of attention. Food microorganisms as an important indicator of food hygiene, which has an important role in ensuring food safety. To a large extent, determine the accuracy of the test results. This article conducts research and discussion of process control from the entire link of the medium procurement, acceptance, storage, preparation, use, and abandonment of the medium, which explains the measures to improve the quality of the medium. It is expected to provide some references for the effective development of food microorganisms.

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.

Grain and oil safety is related to the foundation of the safety of the entire food chain, and the testing of grain and oil institutions provides important technical support for government supervision. Quality control lies at the core of institutional testing, which not only ensures the accuracy and reliability of testing data, but also provides basic guarantee for establishing a scientific and sound testing system in testing institutions. This paper summarizes the main methods, monitoring links, and analyzes existing problems and challenges of quality control in grain and oil testing institutions. It proposes four suggestions for improving the further effectiveness of quality controlto provide reference for peers.

Objective Compare the performance differences of threeprotein content determination kits (Lowry method of Aimei, BCA method ofKangwei, and BCA method of Thermo Fisher) in detecting micro $\left({0 \sim {20\mu}\mathrm{g}/\mathrm{{mL}}}\right)$ protein. Select the mostaccurate and reliable reagent kit for the detection of trace proteinsamples. Methods Use these three test kits to detect micro proteincontent, compare their accuracy, sensitivity, linearity andrepeatability, and evaluate their equivalence. Results The recoveryrates of the three test kits for detecting trace amounts $\left({{1.25}\sim {20\mu}\mathrm{g}/\mathrm{{mL}}}\right)$ of protein were all withinthe range of 75%~120%, demonstrating qualified accuracy; Thermo FisherBCA meets the acceptable precision range (RSD $\leq 6\%$ ) in the range of ${2.5\mu }\mathrm{g}/\mathrm{{mL}}$ to ${20\mu }\mathrm{g}/\mathrm{{mL}}$ ,while Aimei Lowry and Kangwei BCA meet the acceptable precision range(RSD $\leq 6\%$ ) in the range of ${5\mu }\mathrm{g}/\mathrm{{mL}}$ to ${20\mu }\mathrm{g}/\mathrm{{mL}}$ ,demonstrating good repeatability; the correlation coefficient ${\mathrm{R}}^{2}$ of the standard curvesof the three test kits $\left({0\sim {20}\mathrm{{\mu g}}/\mathrm{{mL}}}\right)$ are all higherthan 0.980 . The linearity of Aimei Lowry is slightly poor, with ${\mathrm{R}}^{2}$ of 0.981 . The linearityof Kangwei BCA is qualified, with ${\mathrm{R}}^{2}$ of 0.991 . The linearityof Thermo Fisher BCA is the best, with ${\mathrm{R}}^{2}$ of 0.993; The abovemethodological validation results indicate that the minimumquantification limits for the sensitivity of the three test kits are ${5\mu }\mathrm{g}/\mathrm{{mL}}$ forthe Aimei Lowry method, ${5\mu}\mathrm{g}/\mathrm{{mL}}$ for the Kangwei BCA method, and ${2.5\mu }\mathrm{g}/\mathrm{{mL}}$ for theThermo Fisher BCA method, respectively; Paired curves of values detectedby three reagent kits for the same series of BSA concentrations andtheir correlation coefficients were all higher than 0.990 . ConclusionThrough experiments, we found that each reagent kit exhibited differentperformance in different concentrations of BSA samples, among which theThermo Fisher BCA method performed the best in terms of accuracy andrepeatability, and there was a certain correlation between these threemethods.

Objective To investigate and analyze the microbial contamination in the production and processing of pre-packaged sauced meat products in Sichuan Province. Methods The total number of bacterial colonies, coliform, Staphylococcus aureus, Listeria monocytogenes, Salmonella and Bacillus cereus were detected in 52 samples from a pre-packaged spiced meat factory in Sichuan province by national standard method. Results The results showed that the meat products were contaminated by Escherichia coli, Staphylococcus aureus, Bacillus cereus and Listeria monocytogenes during the curing process. The detection rate of microorganisms gradually decreased with the process of processing, and high temperature sterilization had a significant effect on reducing the microbial pollution of the final product; By tracing analysis, it was found that the environment and equipment in the raw and cooked area were contaminated by Listeria monocytogenes of the same serotype. Conclusion The factory has a big problem of staff hygiene, raw food area and cooked food area cross-contamination, it is recommended that enterprises strictly control the production environment and personnel hygiene, regular cleaning and disinfection, reduce the pollution of processing environment and equipment, workshop operators and food cross-contamination and raw and cooked food cross-contamination, in order to reduce the risk of product microbial contamination.

The high and low temperature test chamber can provide thecorresponding high and low temperature environment for instruments andmaterials, and its temperature field performance and measurementuncertainty are important indicators that affect the measurement resultsof the temperature test chamber. Through the uncertainty evaluation andinfluence analysis of temperature deviation calibration results, themeasurement performance of high and low temperature test chamber, errorsources and methods to reduce the influence of error are furtherunderstood. According to the calibration method specified in GB/T10592-2023 Technical Conditions for High and Low Temperature TestChamber, select the temperature sensor that meets the measurementrequirements and calibrate the temperature deviation of the high and lowtemperature test chamber. The calibration confirms that the temperaturefield performance of the high and low temperature test chamber meets thetolerance requirement of temperature deviation $\pm {2}^{\circ }\mathrm{C}$ , and themeasurement uncertainty meets the technical index requirement of $1/3$ maximum allowable error. Thetemperature field performance of the high-low test chamber is good, andthe short-branch A-class platinum thermal resistance selected by themeasurement standard meets the calibration requirements and has goodstability.

Objective This article mainly introduces three methods for measuring pitting depth: metallographic method, micrometer method and microscopy method, and discusses their differences in different pitting conditions and their influence on the measurement results. Methods Pitting pits on the surface of carbon steel and stainless steel were respectively measured by using these three measuring methods. and the measured results were analyzed and discussed. Results By comparing the measurement results, we can see that the metallographic method is more accurate, but it is destructive. The micrometer method is only suitable for wide and shallow pitting pits. The microscope method is not only suitable for wide and shallow pitting pits, but also for the small pit bottom. Conclusion (1) For wide and shallow pitting pits, metallographic method, micrometer method and microscopic method are applicable and the results are consistent; (2) For the small pitting pit at the bottom, metallography and microscopy are more suitable and the results are consistent; (3) When the corrosion depth is measured by metallographic, microscope and micrometer methods, the thickness reduction caused by uniform corrosion should be taken into account and the results should be corrected, especially in the case of more obvious uniform corrosion.

Objective To establish a spectrophotometric evaluationmethod for determining sulfur dioxide uncertainty in formaldehydeabsorption fluid. Methods According to JJF 1059-2012, Evaluation andrepresentation of measurement Uncertainty, establish a mathematicalmodel to calculate each uncertainty component and synthetic uncertainty. Results The uncertainty introduced by repeated measurement is 0.27%; thestandard curve preparation is 0.40%; the standard curve drawing andfitting is 0.20%; the instrument measurement is 0.35%; the syntheticrelative standard uncertainty is 0.63%, and the extended uncertainty is ${0.008}\mathrm{{mg}}/\mathrm{L}$ . Conclusion This method is suitable for measuring the uncertaintyassessment of sulfur dioxide in formaldehyde absorption fluid.

Objective To understand the sanitary condition of secondarywater supply in jinan railway area and provide scientific basis forrailway departments to improve secondary water supply. Methods Accordingto ( Standard test method for drinking water $\}$ , we sampled and tested the waterquality. On the basis of $《$ Hygienic specification for facilities of secondary water supply》, weanalyzed the data about engineering acceptance and daily detection waterquality. Results Daily detection of secondary water supply qualifiedrate was ${82.69}\%$ , higher thanengineering acceptance of secondary water supply qualified rate ${65.77}\%\left({P <{0.05}}\right)$ .Acoording to the daily detection qualified rate analysis of secondarywater supply, the qualified rate of water supply from living area,passenger station, well of the train track and train water tank wasdecreased successively. The difference of the qualification rate amongthe sampling locations is statistically significant $\left({P <{0.05}}\right)$ ; Thequalified rate in each month is all above ${74}\%$ . The qualified rate in March,April, June and September is below 80%.Soil microbial indicators anddisinfectant indicators qualified rate trend consistent with allindicators qualified rate trend. The qualified rate of ex-factory waterwas ${90.54}\%$ , which was higherthan ${81.19}\%$ of peripheral water $\left({P <{0.05}}\right)$ . Theunqualified soil microbial indicators and disinfectant indicators arethe main factors causing the unqualified secondary water supply. Conclusion The qualified rate of secondary water supply in jinan railwayarea is higher than other water supply types, but there are hiddendangers in the health situation. The supervision of secondary watersupply should have further strengthen.

Objective To investigate the distribution of hepatitis Bvirus (HBV) genotypes and drug resistance mutation sites in Kaifengarea. Methods A total of 200 hepatitis B surface antigen (HBsAg)positive patients were selected from Kaifeng area from January 2018 toDecember 2020. The genotype of the patients was detected by genesequencing technology, and the test results were statistically analyzed.Nucleoside analogues (NAs) resistance gene loci in serum HBV-DNA of 200untreated patients were analyzed. Results Among 200 HBsAg positivepatients in Kaifeng area, 179 cases were genotype C, accounting for ${97.8}\%,4$ cases were genotype B,accounting for ${2.2}\%$ , and no B+Cor other types were detected. Among the 200 patients, 26 were detectedNAs gene drug resistance mutation sites, and the detection rate of drugresistance mutation sites in patients with gene $\mathrm{C}$ was higher than that inpatients with gene B. Conclusion Hepatitis B surface antigen positivepatients in Kaifeng area of HBV genotype mainly $\mathrm{C}$ type, B type is less, no othergenotype was detected. The detection rate of NAs resistance sites ingenotype C was higher than that in genotype B. A total of 9 differentcombinations of NAs drug-resistant mutation sites were detected, mainlyunit point mutation.

Based Perchlorate is a new type of pollutant in drinkingwater, which is harmful to human health. The newly promulgated“Standards for Drinking Water Quality”(GB 5749-2022) has been listed asan expanded indicator. The uncertainty of determination of perchloratein drinking water by ion chromatography was evaluated, and the factorsaffecting the accuracy of the result were determined. On the StandardTest Method for Drinking Water Part 5: Inorganic Nonmetallic Indicators(GB/T 5750.5-2023), the perchlorate in drinking water was measured byion chromatography, and the uncertainty introduced in each step wasanalyzed and calculated. And evaluate its expanded uncertainty. Theperchlorate concentration in drinking water was ${0.101}\mathrm{{mg}}/\mathrm{L}$ and theextended uncertainty was ${0.005}\mathrm{{mg}}/\mathrm{L}\left({k =2}\right)$ . The measurement uncertainty is mainly introducedfrom six aspects, namely, the standard material itself, the preparationof standard working fluids, the preparation of series of standardworking fluids, the determination of sample repeatability, the recoveryrate and the main equipment. The most important factor affecting thetotal uncertainty is the uncertainty introduced in the preparationprocess of standard series working fluids.