Objective To study the determination of total phosphorus in carbon compound lithium iron phosphate by direct carbon removal gravimetric method. Methods After the sample was decomposed by perchloric acid and the carbon in the sample was removed at the same time, the yellow quinoline phosphomolybdate was precipitated by the reaction of orthophosphoric acid with the precipitant quinomolymonone in the acidic medium. The phosphorus content could be obtained by filtration, washing, drying and weighing. Results The carbon removal by perchloric acid was complete and clear, and the steps of filter and carbon removal were reduced. The precision and accuracy tests of the method were carried out by optimizing the conditions. The relative standard deviation (RSD) of the method was less than 0.2%, and the recovery rate of standard addition was 98.4% ~ 101.1%. The biggest advantage of this method is that carbon is directly removed in the digestion process, eliminating the influence of carbon encapsulation on phosphorus determination, no need to filter carbon removal, shorten the operation process, short analysis time, high content of phosphorus is determined by classical gravimetric method, which has high precision and accuracy, and can provide rapid and accurate results for production. Conclusion This method is suitable for the rapid and accurate determination of total phosphorus in carbon complex lithium iron phosphate.

Objective By means of High Performance Liquid Chromatography (HPLC), the extraction method and content determination method of $\alpha$ -cyperone were explored to achieve the purpose of accuracy, reliability, convenience and easy operation. Methods High performance liquid chromatography was used. The chromatography was performed on Agilent Eclipse Plus $\left({{150}\times {4.6}\mathrm{\;{mm}},5\mathrm{\;{\mu m}}}\right)$ silica gel column with mobile phase consisted of methanol-water (70:30) and UV-VIS spectrometer. The flow rate was ${1.0}\mathrm{{mL}}/\mathrm{{min}}$ . The detection wavelength was ${240}\mathrm{\;{nm}}$ . The column temperature was ${35}^{\circ }\mathrm{C}$ . Results The results showed a good linear relationship in the linear range of ${0.02314}- {0.46287}\mathrm{{mg}}/\mathrm{{mL}}$ with ${\mathrm{R}}^{2}= 1$ , the average recovery rate of ${99.84}\%$ and relative standard deviation (RSD)=0.09%. Conclusion The method has the advantages of simple operation, high sensitivity, good repeatability, accuracy and reliability, and can be used to determine the content of $\alpha$ -cyperone in order to control the quality of cyperone effectively.

Driven by the development of nanotechnology, silver nanomaterials are widely used in the field of sensing due to their catalytic performance, conductivity, and optical properties. The silver nano triangular sensing array has become a research hotspot in the field of biochemical substance detection, supported by its performance in multi-component simultaneous detection and high sensitivity. Based on this, this article summarizes the synthesis methods, characteristics, and research progress of sensing arrays of silver nano triangles, and focuses on the practical applications of colorimetric sensing arrays, surface enhanced Raman scattering, and other technologies in biochemical substance detection, providing useful references for research and practice in related fields.

Objective To establish a rapid method for the determination of neutral degreaser concentration by quantitative acid addition and nonlinear fitting, and to solve the problem of titration method and weighing method lack of accuracy and detection efficiency. Methods Prepare the working curve solutions of different concentrations by using the degreaser original solution, and measure the $\mathrm{{pH}}$ value after adding a quantitative amount of acid.The relationship function between the $\mathrm{{pH}}$ value and the concentration of degreaser is obtained by non-linear fitting, and then the concentration in the production sites degreasing solution is calculated by the function.Explore the amount of acid added, curve fitting method, and fitting order, and determine the optimal experimental conditions. Results The method was applied to the rapid determination of neutral degreaser concentration, with a relative standard deviation (RSD) of 0.85% to 1.17% and a recovery rate between 98.52% to 103.34%. Conclusion The new method proposed in this study is accurate, reliable, simple and rapid.And overcomes the shortcomings of traditional titration and gravimetric methods, it can effectively guide the application of neutral degreaser and improve the surface quality of metal materials.

Objective To establish a method for the determination of six phthalates [diisobutyl phthalate (DIBP), di-n-butyl phthalate (DBP), di(2-butoxy)ethyl phthalate (DBEP), dicyclohexyl phthalate (DCHP), di(2-ethyl)hexyl phthalate (DEHP) and diisononyl phthalate (DINP)] in semi-solid food by gas chromatography-mass spectrometry (GC-MS/MS). Methods The optimization of chromatography and mass spectrometry conditions, the comparison of pretreatment extraction methods, and the selection of purification columns were carried out. The samples were extracted with an organic solvent, and the supernatant was purified by a solid phase extraction column made of ethylenediamine-N-propylsilane/silica gel (PSA/Silica) composite packing glass, and separated by a capillary column TG-5MS (${{30}\mathrm{\;m}}\times {0.25}\mathrm{\;{mm}}\times {0.25}\mathrm{\;{\mu m}}$). The optimal conditions were selected by mass spectrometry full scan (SCAN) mode, and then by feature selective ion monitoring scan mode (SIM) detection, the retention time and qualitative ion fragment abundance ratio were qualitatively analyzed, and the external standard method was used for quantitative analysis. Results The separation was completed within 26.5 min. Linear range: DINP had a good linear relationship in the concentration range of${0.2}\sim {5.0}\mathrm{{\mu g}}/\mathrm{{mL}}$, with$\mathrm{r}> {0.9995}$, and the other five species had a good linear relationship in the range of ${0.02}\sim {0.50\mu}\mathrm{g}/\mathrm{{mL}}$, with$>\mathrm{r}{0.9995}$。The limit of quantification was${9.0}\mathrm{{mg}}/\mathrm{{kg}}$, DINP was ${0.3}\mathrm{{mg}}/\mathrm{{kg}}$, and the others were ${0.5}\mathrm{{mg}}/\mathrm{{kg}}$, and the three-level standard solution was added to the two dipping materials and bottom materials, respectively: DINP was 20,40 and ${60}\mathrm{{mg}}/\mathrm{{kg}}$, and the others were 4,6 and 8 $\mathrm{{mg}}/\mathrm{{kg}}$, and the recovery rates were 89.1%~101%. The RSD % was less than 3.8%. Conclusion This method has simple pretreatment, good selectivity, sensitivity and accuracy, and can be widely used for the determination of plasticizers in semisolid composite seasonings.

This study aims to explore the specific application of non-destructive testing technology in quality control of pouring molds, in order to improve the accuracy and reliability of mold manufacturing. Mainly using ultrasonic testing technology to detect mold materials, in order to accurately identify defect locations and evaluate material stress distribution. At the same time, infrared thermal imaging technology is used to monitor the temperature distribution and processing parameters of the mold surface, in order to evaluate the surface quality. The research results indicate that non-destructive testing technology has significant advantages in quality control of pouring molds and can effectively improve the level of quality control. I hope that through the research in this article, we can effectively improve the technological level of the mold manufacturing industry and promote its development.

To explore the limitations of the low air pressure test methods for electronic and electrical products, and to propose ways to optimize and improve the test methods. To analyze the influence of low air pressure environment on the performance, reliability and life of electronic products, and to summarize the important role of low air pressure test in the reliability assessment of electronic products. From the four aspects of test equipment, test conditions, test point arrangement and data processing methods, suggestions are made to improve the low air pressure test methods. For the test equipment, it is proposed to adopt new vacuum pumps, high vacuum chamber materials, optimize the sealing structure, and introduce precise temperature control algorithms; for the test conditions, it is proposed to reasonably select the air pressure value and rate of change according to the product environment, match the temperature conditions, and take into account the test efficiency and failure incentives; for the test point layout, it is proposed to focus on the key devices and weak structures, and adopt suitable wiring materials and direction design; for the data processing method, it is proposed to improve the low air pressure test method. For the data processing method, it is suggested to introduce new methods such as machine learning and signal processing to explore the failure law and performance trend, and focus on the visualization of the analysis results. Strengthening the research on low air pressure test methods is of great significance to enhance the reliability of electronic products and promote their application in rail transportation, aerospace and other fields, which requires the joint efforts of industry, academia and research institutes.

Objective To improve temperature check technology for resistance to thermal shock of ceramic cookware products and to enhance the work efficiency. Methods By using different temperature testing tools of infrared thermometer and compact spot finder infrared camera to test resistance to thermal shock of samples, and the experimental steps and results were compared and analyzed. Results For infrared thermometer, manual handheld operation is required to detect the bottom temperature of a sample, which has low safety and poor detection repeatability; For the compact spot finder infrared camera, it can be connected to a computer for automation to detect temperature of sample, which can achieve the temperature visualization, easy to operate, more safety and reliable. Conclusion The experimental data shows that the compact spot finder infrared camera provides safe and reliable technical support for the detection of resistance to thermal shock of ceramic cookware. This experiment provides technical guidance for improving the quality of ceramic cookware products.

With the rapid development of information technology, laboratory information management has become a key means to improve research efficiency and quality. This article delves into the application and significant benefits of laboratory information management in data processing, resource utilization, team collaboration, and research innovation. By implementing electronic data management, online resource scheduling, cross regional collaboration platforms, and advanced data analysis, information management not only improves research efficiency, but also promotes the improvement of research quality and innovation capabilities. The further development of information technology will make laboratory management more efficient, secure, and collaborative, providing strong support for scientific research.

With the acceleration of globalization and the advancement of technology, testing laboratories are playing an increasingly important role in ensuring product quality and compliance with international standards. Compliance management is key to ensuring the safe, effective, and lawful operation of laboratories and is crucial for enhancing work efficiency and ensuring the quality of services. This paper provides a comprehensive assessment of compliance management and analyzes its key elements, aiming to assist testing laboratories in enhancing their compliance and strengthening their market competitiveness.