Magnetic covalent organic framework as an absorbent coupled with a portable mass spectrometer for rapid detection of malachite green and its metabolite residues.

It is important to develop specific adsorbents for malachite green and other fish drug residues. Herein, a simple strategy for synthesizing a novel magnetic covalent organic frameworks (rFe3O4@Py-COF) has been studied, and the materials were used as a magnetic absorbent for solid phase extraction (MSPE) of malachite green (MG) and its metabolite as leucomalachite green (LMG) in fishes. In this study, the mild reduction program of formic acid replacing traditional sodium borohydride as a reducing agent has been adopted to increase the stability of the framework, which can maintain the original high crystallinity and surface area of the reduced COF. The secondary amine bond is expected to be used as the reaction center for further functionalization of COF pore wall. Subsequently, rFe3O4@Py-COF (rmCOF) obtained after reduction was used as MSPE materials to detect MG and LMG by a portable mass spectrometer. After optimizing the conditions, the linearity is good within the range of 1.25∼100 µg/kg (R2≥0.9954), the limits of detection (LODs) are 0.31∼0.44 µg/kg with satisfactory recovery (85.0 %∼106.0 %). These results indicate that the assay is suitable for monitoring MG and LMG in complex aquatic foods, providing protection for food safety.

Identification and quantitative analysis of genotoxic impurities in rifampicin: Development and validation of a targeted LC-MS/MS method for 1-amino-4-methylpiperazine.

Rifampicin, essential for long-term tuberculosis treatment, requires rigorous control of non-therapeutic impurities due to their potential adverse, including mutagenic effects. Reports on control strategies for genotoxic impurities in rifampicin have been limited. This study introduced an analytical method to identify potential genotoxic impurities from the synthesis of raw materials. The structure of the 25-deacetyl-23-acetyl-rifampicin genotoxic impurity was confirmed using nuclear magnetic resonance, high-resolution mass spectrometry (HRMS), and high-performance liquid chromatography (HPLC). An HPLC-HRMS method was established and validated for detecting another genotoxic impurity, 1-amino-4-methylpiperazine, adhering to the International Council on Harmonization guidelines, which include specificity, linearity, detection and quantification limits, accuracy, precision, and robustness. These developments improve the quality control strategy for genotoxic impurities in rifampicin, ensuring product safety.

A practical HPLC-MS method for the analysis of nitrosamine drug substance related impurities using an inexpensive single quadrupole mass spectrometer.

Nitrosamine drug substance related impurities (NDSRIs) are often analyzed using high performance liquid chromatography (HPLC) with mass spectrometry (MS) detection. Due to high sensitivity requirements, high resolution MS or MS/MS is commonly used. However, it is difficult to implement this type of method for routine analysis at a supply site. Herein, we report a systematic approach to develop and validate a practical, robust, and user-friendly method for the analysis of NDSRIs using an inexpensive single quadrupole MS instrument such as QDa. We used 7-nitroso-3-(trifluoromethyl)-5,6,7,8-tetrahydro- [1,2,4] triazolo [4,3-a] pyrazine (NTTP) as an example to demonstrate the method development process. By optimizing the HPLC and MS parameters, we were able to develop a simple HPLC-MS method that provides the desired specificity and sensitivity for the analysis of NTTP and can be easily implemented in an analytical lab. The limit of quantitation is 0.5 ng/mL, corresponding to 0.1 ppm with respect to 5 mg/mL sitagliptin. The method has been successfully validated per ICH guidelines.

Signal processing for miniature mass spectrometer based on LSTM-EEMD feature digging.

Miniature mass spectrometers exhibit immense application potential in on-site detection due to their small size and low cost. However, their detection accuracy is severely affected by factors such as sample pre-processing and environmental conditions. In this study, we propose a data processing method based on long short-term memory-ensemble empirical mode decomposition (LSTM-EEMD) to improve the quality of on-site detection data from miniature mass spectrometers. The EEMD method can clearly decompose the different physical feature components in the small-scale spectrometer signals, while the LSTM method can adaptively learn the internal feature relationships of the signals. Thus, by combining the two, the parameters for the EEMD signal reconstruction can be optimized in an adaptive manner, obtaining the optimized coefficients. Compared to the previous EEMD feature enhancement approach, the LSTM-EEMD method not only significantly improves the coefficient of determination (R2) and relative standard deviation (RSD) of the data, enhancing the linear range, but also achieves fully adaptive processing throughout the workflow, greatly boosting the efficiency. By leveraging a miniature mass spectrometer, data for N-acetyl-l-aspartic acid (NAA), 2-Hydroxyglutarate (2-HG), and γ-Aminobutyric acid (GABA) in actual blood samples have been obtained. The experimental results demonstrate that the LSTM-EEMD method can markedly enhance the accuracy and usability of the biological sample data in practical testing, providing new perspectives and possibilities for research and applications in the relevant domain.

Optimized analysis for related substances in spiramycin based on high performance liquid chromatography with hybrid particle column and characterization of its impurities by single heartcut two-dimensional liquid chromatography coupled with quadrupole time-of-flight mass spectrometer.

This article described the development and validation of a method for spiramycin related substances based on hybrid particle column. The chromatographic conditions were as follows: water - 0.2 mol/L dipotassium hydrogen phosphate (the pH value adjusted to 9.5 using a 1 mol/L KOH solution) - acetonitrile - methanol (10: 60: 28.5: 1.5, v/v/v/v) as mobile phase A, water - 0.2 mol/L dipotassium hydrogen phosphate (pH 9.5) - acetonitrile - methanol (10: 30: 57: 3, v/v/v/v) as mobile phase B and gradient elution was performed. Compared with previous analytical methods, this method has strong specificity, excellent sensitivity and stability, which could be used for the daily testing of related substances of spiramycin. Furthermore, impurities above 0.1 % were characterized using two-dimensional liquid chromatography coupled with quadrupole time-of-flight mass spectrometer (2D LC-QTOF-MS/MS) and there were 6 impurities reported for the first time.

Detection of PCBs and OCPs in the Irtysh River Water (GC-MS/MS) and ecological risk assessment.

This study optimized a gas chromatography-tandem triple quadrupole mass spectrometry (GC-MS/MS) method for the determination of 21 persistent organic pollutants (POPs) in Irtysh River water, including 14 organochlorines (OCPs) and 7 polychlorinated biphenyls (PCBs). Factors such as column temperature ramping, selection of qualitative and quantitative ion pairs and collision energy were considered to achieve perfect separation and accurate quantification of all 21 target compounds. The limits of detection (LOD) for PCBs and OCPs ranged from 0.21 to 1.18 ng/L. Applying this method to detect POPs in the Irtysh River revealed concentrations of OCPs ranging from ND to 20.2 ng/L and PCBs from ND to 0.411 ng/L. Source analysis indicated that POPs in the Irtysh River mainly originate from historical industrial and agricultural activities, particularly the deliberate use of pesticides. To ensure ecological safety and human health, expanding the range of target analytes and monitoring periods is necessary. This study provides:•Qualitative and quantitative analysis methods for 7 PCBs and 14 OCPs.•Recoveries achieved ranged between 74.6 to 109 % with RSD less than 15 %.•Analysis of sources, transport pathways, accumulation status, and ecological risks of PCBs and OCPs in the Irtysh River.

LC-MS metabolomics and lipidomics in cerebrospinal fluid from viral and bacterial CNS infections: a review.

There is compelling evidence that a dysregulated immune inflammatory response in neuroinfectious diseases results in modifications in metabolic processes and altered metabolites, directly or indirectly influencing lipid metabolism within the central nervous system (CNS). The challenges in differential diagnosis and the provision of effective treatment in many neuroinfectious diseases are, in part, due to limited understanding of the pathophysiology underlying the disease. Although there are numerous metabolomics studies, there remains a deficit in neurolipidomics research to provide a comprehensive understanding of the connection between altered metabolites and changes in lipid metabolism. The brain is an inherently high-lipid organ; hence, understanding neurolipidomics is the key to future breakthroughs. This review aims to provide an integrative summary of altered cerebrospinal fluid (CSF) metabolites associated with neurolipid metabolism in bacterial and viral CNS infections, with a particular focus on studies that used liquid chromatography-mass spectrometry (LC-MS). Lipid components (phospholipids) and metabolites (carnitine and tryptophan) appear to be the most significant indicators in both bacterial and viral infections. On the basis of our analysis of the literature, we recommend employing neurolipidomics in conjunction with existing neurometabolomics data as a prospective method to enhance our understanding of the cross link between dysregulated metabolites and lipid metabolism in neuroinfectious diseases.

A simple numerical simulation model can elucidate the key factors for designing a miniaturized ion trap mass spectrometer.

BACKGROUND: Miniature ion trap mass spectrometer enables mass-to-charge ratio analysis of ions via quadrupole field in a low vacuum environment. It plays an important role in on-site detection due to its portability and specificity. In order to gain a deeper understanding of the analysis mechanism of miniature ion trap mass spectrometers, a quadrupole MS ion trajectory numerical simulation model (QITNS) is established in this paper for ions trajectory calculation under the action of quadrupole field, exciting field and neutral gas molecule collision. Compared with the existing methods, the model in this paper is simpler and more direct, which effectively explored the effects of dipole excitation and quadrupole excitation on ion manipulation under high background pressure. RESULTS: The simulation results demonstrate that high RF amplitude, low auxiliary AC amplitude and quadrupole excitation can effectively improve the isolation resolution. Besides, it clarified the difference between the analysis mechanism of ion trap mass spectrometers under high background pressure (above 13.332 Pa) and absolute vacuum conditions. The relevant results are consistent with the conclusions of previous experiments and other theories, proving the applicability and accuracy of the proposed calculation model and solution method. SIGNIFICANCE: This research bears the guiding significance for further understanding the mechanism of quadrupole mass spectrometry as well as designing and developing miniature mass spectrometers.

[Establishment of collection methods and laboratory testing methods for active pharmaceutical ingredient in the workplace air].

Objective: To establish collection methods and laboratory testing methods for qualitative and quantitative analysis of 9 typical active pharmaceutical ingredient in the workplace air. Methods: In December 2021, a mixed solution of nine analytes was prepared and then dispersed in aerosol state to simulate sampling. Glass fiber filter membrane was selected as air collector and collected active pharmaceutical ingredient in the air at a rate of 2.0 L/min for 15 minutes. Then, the obtained filter membrane samples were eluted with 25%ACN/75%MeOH. Finally, the eluent was qualitatively and quantitatively analyzed with liquid chromatography-triple quadrupole mass spectrometer. Results: This method could effectively collect active pharmaceutical ingredient in the air, with an average sampling efficiency of more than 98.5%. The linear correlation coefficient r was greater than 0.9990. The lower limit of quantification for each analyte ranged from 0.6~500.0 ng/ml, and the average recovery rate ranged from 97.6%~102.5%. Conclusion: This method could simultaneously collect 9 active pharmaceutical ingredient in the workplace air, and could provide accurate qualitative and quantitative analysis in subsequent laboratory tests.

The marriage between stable isotope ecology and plant metabolomics - new perspectives for metabolic flux analysis and the interpretation of ecological archives.

Even though they share many thematical overlaps, plant metabolomics and stable isotope ecology have been rather separate fields mainly due to different mass spectrometry demands. New high-resolution bioanalytical mass spectrometers are now not only offering high-throughput metabolite identification but are also suitable for compound- and intramolecular position-specific isotope analysis in the natural isotope abundance range. In plant metabolomics, label-free metabolic pathway and metabolic flux analysis might become possible when applying this new technology. This is because changes in the commitment of substrates to particular metabolic pathways and the activation or deactivation of others alter enzyme-specific isotope effects. This leads to differences in intramolecular and compound-specific isotope compositions. In plant isotope ecology, position-specific isotope analysis in plant archives informed by metabolic pathway analysis could be used to reconstruct and separate environmental impacts on complex metabolic processes. A technology-driven linkage between the two disciplines could allow us to extract information on environment-metabolism interaction from plant archives such as tree rings but also within ecosystems. This would contribute to a holistic understanding of how plants react to environmental drivers, thus also providing helpful information on the trajectories of the vegetation under the conditions to come.

MassARRAY: a high-throughput solution for rapid detection of foodborne pathogens in real-world settings.

Introduction: Bacterial foodborne pathogens pose a substantial global public health concern, prompting government agencies and public health organizations to establish food safety guidelines and regulations aimed at mitigating the risk of foodborne illness. The advent of DNA-based amplification coupled with mass spectrometry, known as MassARRAY analysis, has proven to be a highly precise, sensitive, high-throughput, and cost-effective method for bacterial detection. This study aimed to develop, validate, and evaluate a MassARRAY-based assay for the detection and identification of significant enteropathogenic bacteria. Methods: The MassARRAY-based assay was developed for the detection of 10 crucial bacterial foodborne pathogens, including Campylobacter coli, Campylobacter jejuni, Clostridium perfringens, Escherichia coli, Enterococcus faecalis, Enterococcus faecium, Listeria monocytogenes, Salmonella spp., Shigella spp., and Staphylococcus aureus. The assay was optimized using the reference gDNA (n = 19), followed by validation using gDNA (n = 85) of reference and laboratory isolates. Additionally, the evaluation of the assay's reaction using a mixture of gDNA from all nine targeted species was performed. The limit of detection of the developed MassARRAY-based assay was determined using bacterial cells. Moreover, the validation method for field samples was evaluated by comparing it with standard microbiological testing methods routinely analyzed. Results: The developed MassARRAY-based assay demonstrated 100% concordance with known bacterial pure cultures. The assay's reaction using a mixture of gDNA from all nine targeted species revealed the MassARRAY's capability to detect all targeted species in a single assay with the lowest concentration of 1 ng/µL of gDNA. The limits of detection of the assay range from 357 ± 101 to 282,000 ± 79,196 cells. Moreover, the validation of the assay in field samples revealed a 100% correlation between the data obtained from the standard microbiological method and the MassARRAY-based assay. Discussion: These findings suggested that the developed MassARRAY-based assay exhibited the excellence in high-throughput detection of foodborne bacterial pathogens with high accuracy, reliability, and potential applicability within real-world field samples.

Study on Pharmacological Activities and Mechanisms of the Essential Oil of the Flowers of Hemerocallis citrina Baroni (EOFHCB) in the Treatment of Anxiety Disorders by GC-MS, Network Pharmacology, and Molecular Docking.

BACKGROUND: Hemerocallis citrina Baroni (Huanghuacai), a plant of the genus Hemerocallis in the family Asphodelaceae, is widely planted in China. Based on our survey results, the chemical compounds in the essential oil of the flowers of Hemerocallis citrina Baroni (EOFHCB) and relevant pharmacological activities have never been studied systematically. OBJECTIVE: To preliminarily decipher the pharmacological activities and mechanisms of EOFHCB in the treatment of anxiety disorders by GC-MS, Network Pharmacology, and Molecular docking. METHODS: EOFHCB compositions were identified using GC-MS, and their targets were predicted using Swiss Target Prediction databases. The targets of anxiety disorders were obtained by GeneCards, DisGeNET, and OMIM databases. The STRING database was used to construct the protein-protein interaction networks, and the DAVID database was used to carry out GO enrichment and KEGG pathway enrichment analysis. The EOFHCB-components-targetspathways- anxiety disorders network was constructed by Cytoscape software (Version 3.10.0). Finally, the result was verified by molecular docking. RESULTS: 28 chemical components were identified by GC-MS, including 3-furanmethanol (28.43%), 2-methyl-1-butanol (27.13%), nerolidol (10.62%), and so on, which correspond to 241 potential targets. Several 2440 biological processes, 187 cellular compositions, and 311 molecular functions were enriched by GO enrichment analysis and 174 pathways by KEGG enrichment analysis. The key targets are PTGS 2, SRC, DRD 2, ESR 1, MAOB, and SLC6A4. The most important pathway is the neuroactive ligand-receptor interaction. CONCLUSION: EOFHCB exerts its therapeutic effects on anxiety disorders through multicomponents, multi-targets, and multi-pathways, which provided new ideas and methods for the in-depth research of aromatic Chinese medicine in the treatment of anxiety disorders.

Gas chromatography mass spectrometer determination of dimethylamine impurity in N,N-dimethylformamide solvent by derivatization of N,N-dimethylbenzamide with benzoyl chloride agent.

This study describes the development of a reliable and linear analytical method for precisely determining dimethylamine impurity in N,N-dimethylformamide solvent utilizing a benzoyl chloride derivatization reagent and a gas chromatography mass spectrometer. Benzoyl chloride was used to derivatize dimethylamine. At normal temperature, benzoyl chloride combined with dimethylamine, producing N,N-dimethylbenzamide. This method separated N,N-dimethylbenzamide using Rtx-5 amine (30 m × 0.32 mm × 1.50 µm) as the stationary phase, helium as the carrier gas, argon as the collision gas, and methanol as the diluent. The column flow rate was 2 mL/min. The retention time of N,N-dimethylbenzamide was determined to be 8.5 min. Precision, linearity, and accuracy were tested using ICH Q2 (R2) and USP<1225> guidelines. The percentage coefficient of variation (CV) for N,N-dimethylbenzamide in the system suitability parameter was 1.1%. The correlation coefficient of N,N-dimethylbenzamide was found to be >0.99. In the method precision parameter, the % CV for N,N-dimethylbenzamide was found to be 1.9%, whereas the % CV for N,N-dimethylbenzamide was 1.2% in intermediate precision. The percentage recovery of N,N-dimethylbenzamide was determined to be between 80% and 98%.

HPLC-QQQ-MS/MS-based authentication and determination of free and bound sialic acids content in human, bovine, sheep, goat milk, and infant formula.

An accurate method for qualitative and quantitative analysis of lipid-bound (LB), protein-bound (PB), oligosaccharides-bound, and free sialic acids in milk was developed by using high-performance liquid chromatography -triple quadrupole-tandem mass spectrometer. The profile of free and bound sialic acids in milk (human, bovine, goat, and sheep) and infant formula (IF) was examined in the present study. Human milk contains only N-acetylneuraminic acid (Neu5Ac) and was mainly present in the form of oligosaccharide-bound. The content of total Neu5Ac (T-Neu5Ac), free and bound Neu5Ac in human milk decreased with the prolongation of lactation. The most intriguing finding was the increase in the proportion of PB and LB sialic acids. The sialic acids in bovine and sheep milk were mainly PB and oligosaccharides-bound Neu5Ac. T-Neu5Ac in goat milk (GM) was 67.44-89.72 µg/mL and was mainly PB Neu5Ac, but total N-glycolylneuraminic acid (T-Neu5Gc) content of GM can be as high as 100.01 µg/mL. The concentration of T-Neu5Gc in sheep and GM was significantly higher than that of bovine milk (BM). T-Neu5Gc content of GM -based IF was 264.86 µg/g, whereas T-Neu5Gc content of BM -based IF was less (2.26-17.01 µg/g). Additionally, our results found that there were also sialic acids in IF ingredients, which were mainly bound with protein and oligosaccharides, primarily derived from desalted whey powder and whey protein concentrate.

A Sample Preparation Procedure for Isobaric Labeling-Based Single-Cell Proteomics.

Mass spectrometry-based proteomics has traditionally been limited by the amount of input material for analysis. Single-cell proteomics has emerged as a challenging discipline due to the ultra-high sensitivity required. Isobaric labeling-based multiplex strategies with a carrier proteome offer an approach to overcome the sensitivity limitations. Following this as the basic strategy, we show here the general workflow for preparing cells for single-cell mass spectrometry-based proteomics. This protocol can also be applied to manually isolated cells when large cells, such as cardiomyocytes, are difficult to isolate properly with conventional fluorescence-activated cell sorting (FACS) sorter methods.

Rapid chemical characterization and pharmacological mechanism of Fining Granules in the treatment of chronic bronchitis based on UHPLC-Q-exactive orbitrap mass spectrometer and network pharmacology.

Background: Senecio cannabifolius Less. is a perennial herb belonging to the Compositae family that has been used in traditional medicine as an antitussive and expectorant for treating chronic bronchitis and acute respiratory infections. Traditionally, Feining Granules are prepared from water extracts of the raw plant material. However, the chemical composition and pharmacological mechanisms of Feining Granules have not been thoroughly investigated. Methods: A systematic strategy for the rapid detection and identification of the constituents of Feining Granules was developed using ultrahigh-performance liquid chromatography-quadrupole-exactive orbitrap mass spectrometry (MS) with parallel reaction monitoring. Results: Overall, 162 compounds, including flavonoids, alkaloids, organic acids, and others, were identified unambiguously and tentatively by comparing the retention times and MS fragmentation with reference standards and literature data. Ninety-nine of these were reported for the first time to the best of our knowledge. Network pharmacology suggests that Feining Granules can be used to treat chronic bronchitis as they contain active components associated with the ALB, VEGFA, and SRC target genes influenced by HIF-1, VEGF, and other signaling pathways. Conclusion: These results provide information that can help understand the effective substances of S. cannabifolius Less. and improve quality control.

Efficient acid hydrolysis for compound-specific δ15N analysis of amino acids for determining trophic positions.

Compound-specific isotope analysis of nitrogen in amino acids (CSIA-AA, δ15NAA) has gained increasing popularity for elucidating energy flow within food chains and determining the trophic positions of various organisms. However, there is a lack of research on the impact of hydrolysis conditions, such as HCl concentration and hydrolysis time, on δ15NAA analysis in biota samples. In this study, we investigated two HCl concentrations (6 M and 12 M) and four hydrolysis times (2 h, 6 h, 12 h, and 24 h) for hydrolyzing and derivatizing AAs in reference materials (Tuna) and biological samples of little egret (n = 4), night heron (n = 4), sharpbelly (n = 4) and Algae (n = 1) using the n-pivaloyl-iso-propyl (NPIP) ester approach. A Dowex cation exchange resin was used to purify amino acids before derivatization. We then determined δ15NAA values using gas chromatography-combustion-isotope ratio mass spectrometry (GC-C-IRMS). The results revealed no significant differences (p > 0.05) in δ15NAA values among samples treated with different HCl concentrations or hydrolysis times, particularly for δ15NGlx (range: 21.0-23.5‰) and δ15NPhe (range: 4.3-5.4‰) in Tuna (12 M). Trophic positions (TPs) calculated based on δ15NAA at 2 h (little egret: 2.9 ± 0.1, night heron: 2.8 ± 0.1, sharpbelly: 2.0 ± 0.1 and Algae: 1.3 ± 0.2) were consistent with those at 24 h (3.1 ± 0.1, 2.8 ± 0.1, 2.2 ± 0.1 and 1.1 ± 0.1, respectively), suggesting that a 2-h hydrolysis time and a 6 M HCl concentration are efficient pretreatment conditions for determining δ15NAA and estimating TP. Compared to the currently used hydrolysis conditions (24 h, 6 M), the proposed conditions (2 h, 6 M) accelerated the δ15NAA assay, making it faster, more convenient, and more efficient. Further research is needed to simplify the operational processes and reduce the time costs, enabling more efficient applications of CSIA-AA.

Stereoscopic imaging of volatile organic compounds distribution in the region and tracing emission sources of volatile organic compounds using a novel movable single-photon ionization time-of-flight mass spectrometer.

This paper presents a newly developed high-performance mobile single-photon ionization time-of-flight mass spectrometry (M-SPI-TOFMS) system for on-line analysis and stereoscopic monitoring of complex gas mixtures. The system is designed for stereoscopic imaging to map the distribution of volatile organic compounds (VOCs) and trace their emission sources in urban areas and industrial parks. It mainly consists of a SPI-TOFMS instrument, a customized commercial vehicle, a meteorological five-parameter monitor with GPS, a high-power generator, and an uninterruptible power supply. The SPI technique, using a 118 nm VUV lamp, can ionize compounds with an ionization potential below 10.78 eV. Mass spectra obtained using this technique show the profiles of various VOCs and some inorganic compounds. The VOCs composition information and mobile location data are simultaneously sent to the GIS software. In GIS software, this data is used for real-time stereoscopic imaging of VOC distribution and precise tracking of VOC movement. The system can achieve a spatial data resolution of 0.69 mm at 25 km/h due to the microsecond detection speed of the M-SPI-TOFMS instrument. The laboratory test provides a rapid overview characterization of benzene, toluene, and xylene. The M-SPI-TOFMS has limits of detection and mass resolution of 33.7 pptv and 1060, respectively. Several field applications were carried out using M-SPI-TOFMS at various locations to identify VOC sources near different factories. The M-SPI-TOFMS system has a navigation monitoring speed of 25 km/h with a time resolution of 1 s. The widespread use of this system will provide accurate data to support environmental management departments in formulating VOCs pollution control policies and improving control efficiency.

Evaluation of a miniature mass spectrometer based point-of-care-test method for direct analysis of amlodipine and benazepril in whole blood.

A miniature mass spectrometer (mMS) based point-of-care testing (POCT) method was evaluated for on-site detecting the hypertension drugs, amlodipine and benazepril. The instrument parameters, including voltage, ISO1, ISO2, and CID, were optimized, under which the target compounds could be well detected in MS2. When these two drugs were injected simultaneously, the mutual ionization inhibition and mutual reduction between amlodipine and benazepril were evaluated. This phenomenon was severe on the precursor ions but had a small impact on the product ions, thus making this POCT method suitable for analysis using product ions. Finally, the method was validated and applied. The blood samples from patients were tested one hour after oral administration of the drugs (20 mg), and the benazepril was quantitatively analyzed using a standard curve, with detected concentrations ranging from 190.6 to 210 µg L-1 and a relative standard deviation (RSD) of 8.6 %. In summary, amlodipine has low sensitivity and can only be detected at higher concentrations, while benazepril has high sensitivity, good linearity, and even meets semi-quantitative requirements. The research results of this study are of great clinical significance for monitoring blood drug concentrations during hypertension medication, predicting drug efficacy, and customizing individualized medication plans.