Objective: To achieve rapid on-site detection of benzoic acid and sorbic acid, two common preservatives in cosmetics, and improve detection efficiency and on-site detection capabilities. Methods: A portable Raman spectrometer which used silver nanoparticles as the enhancement substrate for surface enhanced Raman spectroscopy (SERS) was used to detect benzoic acid and potassium sorbate in cosmetics. Results: Benzoic acid and sorbic acid had characteristic Raman peaks at ${1157}{\mathrm{\;{cm}}}^{-1}$ and ${871}{\mathrm{\;{cm}}}^{-1}$,respectively. Further research showed that the concentrations of benzoic acid and sorbic acid were linearly correlated with the intensity of their characteristic Raman peaks, making quantitative detection possible. This was confirmed by traditional liquid chromatography, and the quantitative results were consistent. Conclusion: This SERS method has the advantages of simplicity, speed, and efficiency, and is expected to achieve rapid on-site detection of preservatives.

Objective: To achieve rapid on-site detection of benzoic acid and sorbic acid, two common preservatives in cosmetics, and improve detection efficiency and on-site detection capabilities. Methods: A portable Raman spectrometer which used silver nanoparticles as the enhancement substrate for surface enhanced Raman spectroscopy (SERS) was used to detect benzoic acid and potassium sorbate in cosmetics. Results: Benzoic acid and sorbic acid had characteristic Raman peaks at ${1157}{\mathrm{\;{cm}}}^{-1}$ and ${871}{\mathrm{\;{cm}}}^{-1}$,respectively. Further research showed that the concentrations of benzoic acid and sorbic acid were linearly correlated with the intensity of their characteristic Raman peaks, making quantitative detection possible. This was confirmed by traditional liquid chromatography, and the quantitative results were consistent. Conclusion: This SERS method has the advantages of simplicity, speed, and efficiency, and is expected to achieve rapid on-site detection of preservatives.

Objective To develop an ultra high performance liquid chromatography tandem mass spectrometry (UPLC-MS/MS) to identification of the feeding status of turtle and turtle shell components in different batches of Gejie Dingchuan Pills. Methods This study used the identification method of characteristic peptides of Animal medicine for reference, Enzymatic hydrolysis of different batches of Ge jie Ding chuan Pill samples using trypsin, and Identification by using the ultra high performance liquid chromatography tandem mass spectrometry (UPLC-MS/MS). The characteristic ion pairs of Testudinis Carapax et Plastrum and Trionycis Carapax were as detection ion pairs. The positive electrospray ionization and multiple reaction monitoring were adopted. Result: 51 batches of Gejie Ding chuan Pills form 8 companies have all detected turtle shell components, but no other turtle source components have been detected. Conclusion This method is raliable for identification of Testudinis Carapax et Plastrum and Trionycis Carapax form Ge jie Ding chuan Pill.

Objective To develop an ultra high performance liquid chromatography tandem mass spectrometry (UPLC-MS/MS) to identification of the feeding status of turtle and turtle shell components in different batches of Gejie Dingchuan Pills. Methods This study used the identification method of characteristic peptides of Animal medicine for reference, Enzymatic hydrolysis of different batches of Ge jie Ding chuan Pill samples using trypsin, and Identification by using the ultra high performance liquid chromatography tandem mass spectrometry (UPLC-MS/MS). The characteristic ion pairs of Testudinis Carapax et Plastrum and Trionycis Carapax were as detection ion pairs. The positive electrospray ionization and multiple reaction monitoring were adopted. Result: 51 batches of Gejie Ding chuan Pills form 8 companies have all detected turtle shell components, but no other turtle source components have been detected. Conclusion This method is raliable for identification of Testudinis Carapax et Plastrum and Trionycis Carapax form Ge jie Ding chuan Pill.

Objective Analyze and evaluate the measurement uncertainty of phenylethanolamine A residue in beef using liquid chromatography tandem mass spectrometry. Methods By analyzing the detection process and mathematical model, the main sources of uncertainty in the residual amount of phenylethanolamine A are determined: uncertainty caused by detection equipment, uncertainty caused by standard and sample weighing, uncertainty caused by laboratory temperature, uncertainty caused by transfer and constant volume, uncertainty caused by sample pretreatment, and uncertainty caused by experimental repeatability. Results The measurement uncertainty of each component was calculated and the relative standard uncertainty $\left({{u}_{\mathrm{{rel}}}={0.11}}\right)$ was synthesized for the detection of phenylethanolamine A residue in beef by liquid chromatography-tandem mass spectrometry. The expanded uncertainty of the determination results was $\mathrm{U}\left( X\right)={0.11}\mathrm{{g}}/\mathrm{{kg}}$ . The detection result of measuring phenylethanolamine A in beef by liquid chromatography tandem mass spectrometry was: $X=\left({{0.51}\pm {0.11}}\right)\mathrm{{\mu g}}/\mathrm{{kg}}, k =2$ . Conclusion The detection equipment had the greatest impact on the measurement uncertainty of phenylethanolamine A residue, followed by sample pre-treatment, experimental repeatability, and transfer and constant volume. In daily testing, attention should be paid to the condition of the instruments and equipment, timely verification and calibration should be carried out, the experimental process, transfer and constant volume operation should be standardized, so that to minimize the impact of the above factors on measurement uncertainty as much as possible.

Objective Analyze and evaluate the measurement uncertainty of phenylethanolamine A residue in beef using liquid chromatography tandem mass spectrometry. Methods By analyzing the detection process and mathematical model, the main sources of uncertainty in the residual amount of phenylethanolamine A are determined: uncertainty caused by detection equipment, uncertainty caused by standard and sample weighing, uncertainty caused by laboratory temperature, uncertainty caused by transfer and constant volume, uncertainty caused by sample pretreatment, and uncertainty caused by experimental repeatability. Results The measurement uncertainty of each component was calculated and the relative standard uncertainty $\left({{u}_{\mathrm{{rel}}}={0.11}}\right)$ was synthesized for the detection of phenylethanolamine A residue in beef by liquid chromatography-tandem mass spectrometry. The expanded uncertainty of the determination results was $\mathrm{U}\left( X\right)={0.11}\mathrm{{gg}}/\mathrm{{kg}}$ . The detection result of measuring phenylethanolamine A in beef by liquid chromatography tandem mass spectrometry was: $X=\left({{0.51}\pm {0.11}}\right)\mathrm{{\mu g}}/\mathrm{{kg}}, k =2$ . Conclusion The detection equipment had the greatest impact on the measurement uncertainty of phenylethanolamine A residue, followed by sample pre-treatment, experimental repeatability, and transfer and constant volume. In daily testing, attention should be paid to the condition of the instruments and equipment, timely verification and calibration should be carried out, the experimental process, transfer and constant volume operation should be standardized, so that to minimize the impact of the above factors on measurement uncertainty as much as possible.

Objective A method for simultaneous determination of MBAA, DBAA, DCAA, TCAA and ${\mathrm{{ClO}}}_{2}{}^{- }$ in drinking water was established by ion chromatography. Methods The water samples were determined by ${0.22\mu}\mathrm{m}$ qeuosystem filter membrane with a volume of ${500\mu }\mathrm{L}$ . The samples were rinsed with $\mathrm{{KOH}}$ solution gradient and separated by IonPac AS19 anion column. The column temperature was set at ${30}^{\circ }\mathrm{C}$ , and the current of the inhibitor was ${75}\mathrm{\;{mA}}$ . Results The results showed that the linearity ranges of ${\mathrm{{ClO}}}_{2}{}^{- }$ , MBAA, DBAA, DCAA and TCAA were found in the range of ${10}\sim {1000\mu}\mathrm{g}/\mathrm{L},\mathrm{r}> {0.9990}$ , with detection limits $\left({3\mathrm{\;S}/\mathrm{N}}\right)$ of ${0.32},{0.76},{1.30},{0.69},{1.58\mu}\mathrm{g}/\mathrm{L}$ . The standard recoveries were ${80}\%\sim {110}\%$ and RSD (n=6) of the determined values were all less than 5.0%. Conclusion The method was simple, sensitive, can meet the detection requirements of four kinds of Haloaeetic Acids and Chlorite in drinking water. The method can be used for the determination of kour kinds of haloaeetic acids and chlorite in drinking water.

Objective A method for simultaneous determination of MBAA, DBAA, DCAA, TCAA and ${\mathrm{{ClO}}}_{2}{}^{- }$ in drinking water was established by ion chromatography. Methods The water samples were determined by ${0.22\mu}\mathrm{m}$ qeuosystem filter membrane with a volume of ${500\mu }\mathrm{L}$ . The samples were rinsed with $\mathrm{{KOH}}$ solution gradient and separated by IonPac AS19 anion column. The column temperature was set at ${30}^{\circ }\mathrm{C}$ , and the current of the inhibitor was ${75}\mathrm{\;{mA}}$ . Results The results showed that the linearity ranges of ${\mathrm{{ClO}}}_{2}{}^{- }$ , MBAA, DBAA, DCAA and TCAA were found in the range of ${10}\sim {1000\mu}\mathrm{g}/\mathrm{L},\mathrm{r}> {0.9990}$ , with detection limits $\left({3\mathrm{\;S}/\mathrm{N}}\right)$ of ${0.32},{0.76},{1.30},{0.69},{1.58\mu}\mathrm{g}/\mathrm{L}$ . The standard recoveries were ${80}\%\sim {110}\%$ and RSD (n=6) of the determined values were all less than 5.0%. Conclusion The method was simple, sensitive, can meet the detection requirements of four kinds of Haloaeetic Acids and Chlorite in drinking water. The method can be used for the determination of kour kinds of haloaeetic acids and chlorite in drinking water.

Objective A method based on performance liquid chromatography-tandem mass spectrometry (LC-MS/MS) has been developed for the determination of salbutamol in aquatic products and their products. Methods The analyte was enzymatic hydrolyzed in ${\mathrm{{NH}}}_{4}\mathrm{{AC}}$ solution overnight at ${37}^{\circ }\mathrm{C}$ , and extracted by ethyl acetate-isopropanol $\left({1 :1,\mathrm{v}/\mathrm{v}}\right)$ . The extract was cleaned up by QuEChERS method. Quantification was achieved by HPLC-MS/MS with multiple reaction monitoring (MRM) using internal standard method. Results The limit of quantification of salbutamol was ${0.5\mu }\mathrm{g}/\mathrm{{kg}}$ . The average recoveries at three spiked levels of 0.5,1.0 and ${5.0\mu }\mathrm{g}/\mathrm{{kg}}$ ranged from 87.8% to 110.7% with the relative standard deviations of ${2.7}\%\sim {9.6}\%\left({\mathrm{n}=6}\right)$ . Conclusion The method has the advantages of simple pretreatment steps and its sensitivity, precision, and recoveries all meet the requirements of residue detection regulations, accurately solving the problem of lack of relevant technical support for monitoring salbutamol residues in aquatic products and their products.

Objective: This study aims to explore a method for determining the concentration of free amino acids in cell culture media based on ultra performance liquid chromatography (UPLC). Methods Researchers used UPLC technology combined with optimized sample processing Methods to efficiently and accurately determine free amino acids in cell culture medium. Results The research results indicate that the UPLC method can quickly and reliably determine the concentration of free amino acids in cell culture medium, providing an effective means for monitoring and optimizing cell culture in the biopharmaceutical industry. Conclusion Accurate determination of amino acid concentration not only helps to better understand the dynamic changes of key nutrients in cell culture media, but also provides important data support for process optimization in the production process.