最新刊期
卷 43 ， 期 9 ， 2024
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摘要：Carbon fiber reinforced polymer（CFRP） is extensively utilized in the aerospace industry due to its exceptional properties including high strength，high modulus，lightweight，and corrosion resistance. The microstructure of CFRP is susceptible to variations induced by manufacturing processes and service environments，which can subsequently alter its mechanical properties such as tensile and shear strengths，interfacial performance，and thermoelectric characteristics. To bolster the structural integrity and ensure the performance and service safety of CFRP，in-situ and non-destructive microstructural testing，damage identification，and monitoring are of significant importance. Raman spectroscopy，as a non-destructive testing technique with high resolution capabilities，can be employed for characterizing microstructural features such as carbon fiber orientation，crystallinity，and interfacial interactions，which enables the evaluation of the composition，defects，and deformations of the material. This article outlines the advantages of applying CFRP in the aerospace field，such as weight reduction for aircraft and electromagnetic wave absorption，and summarizes the principles and applications of Raman spectroscopy in structural characterization，physical property research，and investigation of high-temperature damage processes in CFRP. Additionally，it addresses considerations when using Raman spectroscopy for the analysis and detection of CFRP. The aim is to provide theoretical support and practical guidance for optimizing performance，ensuring quality assurance，and monitoring service behavior of CFRP in aerospace industry.关键词：carbon fiber reinforced polymer;Raman spectroscopy;aerospace field;structural characterization- 479
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发布时间：2024-11-04 - 摘要：This paper introduces the basic principles of X-ray fluorescence analysis（XRF） and the theoretical basis of qualitative analysis，semi-quantitative analysis and quantitative analysis. A brief introduction of the matrix effect，spectral overlap and mathematical correction methods. This paper summarizes the application of aluminum alloy，magnesium alloy，titanium alloy，steel，superalloy，ceramics，metal matrix composite，coating analysis，handheld fluorescence，semi-quantitative rapid analysis in aviation metal materials. The results of the detection and application in these kinds of materials are simply sorted out，and the key points and difficulties of XRF are refined and summarized. The development of XRF technology is also discussed.关键词：aviation;metal materials;matrix effect;qualitative analysis;quantitative analysis;alloy
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发布时间：2024-11-04 -
摘要：The experimental conditions of fast-flow glow discharge ion source to analyze the trace elements in superalloy were optimized in details. Based on comprehensively investigation on mass spectrometry interferences due to the most complex matrix elements in nickel superalloy，the analytical isotopes and appropriate mass spectrometry resolution for analyze the trace rare earth & precious metal elements were adopted. Relative sensitivity factors calibration scheme，which was calibrated in matched matrix by the homemade wrought superalloy reference material series of gradient content，has been established. Thus the relative error of analysis results was optimized from 4.0%-80% to 7.7%-20%. In addition，the reliable guarantee for metrological traceability of trace analysis has been achieved. The glow discharge mass spectrometry（GDMS） method for determining rare earth elements and precious metal elements in nickel base superalloy has been developed with detection limit in 0.001 0-0.015 μg/g，and quantitative limit in 0.003 0-0.045 μg/g. The established method was applied to analyze rare earth elements and precious metal elements in actual samples of wrought or cast superalloy，the measurement results are in good agreement with the reference values of wet analysis，which verifies the advantages fast treating solid samples by glow discharge，and the characteristics of high resolution mass spectrometry with low detection limit，wide linear range，and multiple elements analytical ability. It also shows great application prospects in the quality control of superalloy materials.关键词：glow discharge mass spectrometry;nickel base;superalloy;rare earth element;precious metal element;relative sensitivity factors- 324
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发布时间：2024-11-04 -
摘要：Metallic materials can experience early damage formation and even catastrophic failure when subjected to loading under high-temperature hydrogen environment. The corresponding mechanical properties are，however，not widely reported due to the difficulty of performing environmental mechanical testing. Here an in-situ material mechanical testing system is designed to address this issue. This system is capable of performing tensile tests under either pure hydrogen or hydrogen mixed environment at temperatures up to 600 ℃ and pressures up to 2 MPa. The facility features a hydrogen environment chamber equipped with vacuum，gas purging and heating systems. Deformation can be measured accurately by using a linear variable displacement transducer（LVDT） in combination with accurate sensors. The facility was utilized to assess the tensile performance of a GH4169 superalloy under various temperatures（25，200，400 and 600 ℃） in both pure gaseous hydrogen and pure gaseous Ar environment. The findings highlight a significant embrittlement effect of the hydrogen environment on the material，reflected by the reduced elongation and reduction of area in compassion to the corresponding values under Ar. Analysis is further conducted using scanning electron microscopy（SEM） to investigate the fracture modes and hydrogen-induced damage mechanisms of the alloy tested under 25 and 200 ℃. It is concluded that hydrogen-induced damage in GH4169 is more severe at 200 ℃ when compared with 25 ℃. This increased hydrogen sensitivity is primarily due to the accelerated diffusion of hydrogen atoms at high temperature，which leads to a faster hydrogen accumulation at grain boundaries and thereby a facile hydrogen-induced intergranular fracture.关键词：hydrogen damage;high-temperature;mechanical testing;superalloy- 401
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发布时间：2024-11-04 -
摘要：As fundamental materials of advanced materials and chemical metrological traceability，high purity metals play an important role. The impurity and purity values are important indicators of them. The total purity analysis，means deducting all elemental impurities including non-metals and gas elements，has become an authoritative method for determining the purity of high purity metals. With high purity gold certified reference material（GBW02793） as an example，this paper described in detail the research points of various methods in total purity analysis，including glow discharge mass spectrometry，high resolution inductively coupled plasma mass spectrometry，combustion infrared absorption and inert gas fusion infrared absorption methods. A systematic correction has been made to the relative sensitivity factor，which is an important factor causing measurement bias in glow discharge mass spectrometry method，reducing the measurement uncertainty from 200% to 30%. High mass fraction of metallic elemental impurities Na，Fe and Cu were measured by using glow discharge mass spectrometry and high resolution inductively coupled plasma mass spectrometry. Both results were agreed with each other. Trace gas elements H，C，N，and S were detected by combustion infrared absorption method and inert gas fusion infrared absorption method. And all of them were lower than the limits of quantitative，which were 0.35 mg/kg，0.51 mg/kg，0.45 mg/kg，and 0.85 mg/kg，respectively. Trace oxygen was measured by using inert gas fusion infrared absorption method and secondary ion mass spectrometry. Two measurement results were close. A reasonable evaluation was conducted on the mass fractions of inert gas elements and radioactive elements，and the uncertainty of gold purity was evaluated. Finally，the determination method of total purity of high purity gold was established. The mass fraction of gold in high purity gold certified reference material was 99.999 5% and the extended uncertainty was 0.000 2%.关键词：high purity metal;purity;gold;glow discharge mass spectrometry;certified reference material- 268
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发布时间：2024-11-04 -
摘要：Thermal decomposition process and pyrolysis mechanism of polyamide 6，66，56（PA6，66，56） were investigated by simultaneous thermal analyzer-fourier transform infrared spectroscopy-mass spectrometer（STA-FTIR-MS） and pyrolysis/gas chromatography-mass spectrometer（Py/GC/MS）. The activation energy（Ea） can be calculated by Arrhenius equation. The thermal degradation products of PA6，PA66，PA56 were further analyzed by pyrolysis experiments. The results showed that the thermal degradation processes of PA6，PA66，PA56 in argon were one step reaction and the thermal degradation activation energy was PA6＞PA66＞PA56，all greater than 185 kJ/mol，indicating that PA6，PA66 and PA56 all have good thermal stability，and PA6 and PA66 have better thermal stability. The breaking modes of the three are similar, mainly involving the breaking of the α - position chemical bond of the amide bond.关键词：polyamide;thermal degradation kinetics;pyrolysis mechanism- 331
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发布时间：2024-11-04 -
摘要：By dissolving the Ti65 samples with HCl，HF and HNO3 system，amounts of 8 alloy elements（Al，Sn，Zr，Mo，Si，Ta，Nb，W） and amounts of 8 impurity elements（Cr，Mn，Cu，Re，Ni，B，Y，Fe） were determined by inductively coupled plasma atomic emission spectroscopy（ICP-AES）. The influence of titanium matrix and coexisting elements on the measured elements and the influence of silicon standard solution matrix on the determination of Al elements were investigated. Matrix matching method was used to eliminate the influence of matrix effect and alloy element matching method was used to eliminate the spectral interference. The analysis parameters of the instrument were optimized，and the high generator power was 1.2 kW and the nebulizer gas pressure was 200 kPa. The working curve is established under the selected experimental conditions.The linear correlation coefficients of the calibration curve were not less than 0.998 7，and the limits of detection of method were between 0.000 03% and 0.010%. Test results of titanium CRMs and simulated Ti65 samples were consistent with the theoretical values. The relative standard deviations（RSDs） of the test results were not more than 8.6%，and the recoveries were in the range of 98.0%-104%.关键词：Ti65;high temperature titanium alloy;inductively coupled plasma atomic emission spectroscopy（ICP-AES）;chemical composition- 253
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发布时间：2024-11-04 -
摘要：In this paper，the relative sensitivity factor（RSF） of 14 key trace elements with three different particle size ranges of FGH96 superalloy powder were systematically analyzed by glow discharge mass spectrometry（GDMS），and the asymmetric charge transfer（ACT） theory was applied to the RSF coefficient correction problem of Mg element in nickel-based superalloys for the first time. The experimental results show that the RSF coefficients of 13 trace elements such as B，P，and S are basically not affected by the particle size of powder samples，and their RSF can be corrected by bulk standard materials. Through the investigation of samples with different Mg content gradients，a new calibration scheme was proposed for the RSF coefficient of Mg element. Considering the ACT influence of matrix element Ni on Mg element，two sets of RSF coefficients should be established according to the actual Mg content and particle size range for correction when the accuracy requirement is high. This paper gives the reference values of two sets of RSF coefficients. The corresponding RSF reference values for samples with Mg content of 3 μg/g and average particle size of 200 mesh and samples with Mg content of 30-300 μg/g and average particle size of -80～+120 mesh are 1.16 and 0.41，respectively.关键词：nickle based superalloy;trace elements;relative sensitivity factor;asymmetric charge transfer;glow discharge mass spectrometry;powder size range- 272
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发布时间：2024-11-04 -
摘要：In this study，vacuum induction melting（VIM） processing is used for the undirectly used revert of GH738 alloy，and electroslag remelting（ESR） processing is taken afterwards. Then the change of chemical composition during the whole process is analysed and the difference of carbides and nonmetallic inclusions in VIM ingot and ESR ingot is also investigated. The difference of dendrite character in VIM and ESR condition is studied as well.The main problem is the relatively higher N and O content，which needs to be strictly controlled in the VIM stage to avoid the impact on the properties of the finished products. After electroslag remelting，the dendrite growth has obvious orientation，and the size and quantity of carbide precipitates between dendrites is increased compared with the vacuum induction melting state，the inclusions distribution is relatively more dispersed and the size is also reduced at the same time. At last we come to a conclusion that to the undirectly usable revert，by adding the VIM processing and then can be used as the raw material of superalloy production.关键词：revert;inclusions;vacuum induction melting;electroslag remelting- 331
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发布时间：2024-11-04 -
摘要：The accurate analysis results of determined oxygen and nitrogen elements in nickel-based superalloys by glow discharge mass spectrometry were obtained by optimizing the glow discharge parameters，analyzing mass spectrum interference and correcting relative sensitivity factor（RSF） and comparing the results of ONH-Analyzer（LECO）. Above all，equipment was operated stably，the optimized test parameters were selected and the corrected RSF value was used to test the superalloy samples. The results of oxygen and nitrogen determined by GDMS and ONH-Analyzer were compared，the deviations of the results are less than 10% and less than 5.0% respectively，and the relative standard deviations of stability are less than 5.0%. The corrected RSF values and test results were stable and reliable.关键词：glow discharge mass spectrometry;superalloy;determination of oxygen and nitrogen elements;relative sensitivity factor correcting- 226
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发布时间：2024-11-04
Aerospace New Materials Testing Column
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摘要：A rapid and comprehensive method for analyzing and identifying the chemical components of Qizhiweitong Capsule was established using ultra high performance liquid chromatography-quadrupole time-of-flight mass spectrometry（UPLC-Q-TOF MS） technology. Agilent poroshell 120 SB-C18 chromatography column was used，with 0.1% formic acid water-acetonitrile as the mobile phase for gradient elution. Under positive and negative ion modes，97 components were identified from the 80% methanol extract of Qizhiweitong Capsule，including 41 flavonoids，19 alkaloids，12 organic phenolic acids，8 saponins，5 terpenes，10 phenylpropanoids，1 nucleoside and 1 quinone，by retention time，mass spectrometry first order quasi molecular ion peak，and second order mass spectrometry fragmentation，combined with reference materials and literature data. Among them，50 components were compared with reference materials. At the same time，a classification of the structural types of the identified components and the sources of medicinal materials were carried out，and various structural fragmentation patterns were explored. This study provides a basis for the quality control and clinical application of Qizhiweitong Capsule，as well as a reference for the identification of components with similar structural types.关键词：Qizhiweitong Capsule;chemical composition;structure identification;fragmentation pathways;UPLC-Q-TOF MS- 55
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Study on HPLC Fingerprint and Quantity Transfer Rule of Benchmark Sample of Qingjin Huatan Decoction
摘要：The HPLC fingerprint combined with a multi index component content determination method was established to study the quantity-quality tranmitting in Qingjin Huatan Decoction（QJHTD）. 15 batches of QJHTD substances benchmark samples were prepared，and HPLC fingerprint spectra of QJHTD substances benchmark samples were established，evaluated the similarity and determined common peaks. A method for determining the content of four indicator components（geniposide，mangiferin，baicalin，and glycyrrhetinic acid） in the QJHTD substances benchmark samples was established，and a study was conducted on the quantity-quality tranmitting between the crude herbs and substance benchmarks. The results showed that the similarity between the fingerprint spectra of 15 batches of QJHTD substances benchmark samples and the reference spectra was greater than 0.98. 26 common peaks were demarcated and the herbs were assigned to each common peak. Peaks of 10（geniposide），17，23，24 were exclusive to Zhizi（Gardeniae Fructus，GF），peaks of 11（mangiferin），12，13 were exclusive to Zhimu（Anemarrhenae Rhizoma，AR），peaks of 19（baicalin） was exclusive to Huangqin（Scutellariae Radix，SR），peaks of 25（glycyrrhetinic acid） was exclusive to Gancao（Glycyrrhiza Radix，GR）. In addition，peaks of 1-4，6，9 were the common peaks of SR，Jiegeng（Platycodonis Radix，PR），Sangbaipi（Mori Cortex，MC），Beimu（Fritillariae Thunbergii Bubus，FTB），AR，Gualouzi（Trichosanthis Semen，TS），Juhong（Citri Exocarpium Rubrum，CER），Fuling（Poria，P） and GR. Peaks of 5 was the common peaks of PR，FTB，AR，TS，CER，P and GR. Peaks of 7 was the common peaks of SR，PR，Maidong（Ophiopogonis Radix，OR），MC，FTB，TS，CER，P and GR. Peaks of 8 was the common peaks of SR，PR，OR，MC，FTB，AR，TS，CER，P and GR. Peaks of 14 and 20 were the common peaks of PR，OR，MC，FTB. Peaks of 15 was the common peaks of PR，OR，MC. Peaks of 16，21，22 were the common peaks of PR，OR，MC，FTB，TS，P and GR. Peaks of 18 was the common peaks of SR，GF，PR，OR，MC，FTB，TS，P and GR. Peaks of 26 was the common peaks of PR，MC. The index components of geniposide，mangiferin，baicalin and glycyrrhizic acid were 44.60-76.82 mg∙g-1，98.04-145.25 mg∙g-1，46.82-75.64 mg∙g-1 and 81.60-126.63 mg∙g-1，respectively. Transfer rate were 32.91%-62.42%，21.78%-35.93%，29.98%-57.12% and 27.51%~49.34%. The yield of 15 batches of QJHTD samples ranged from 16.98% to 25.19%，and the average yield of transfer was 67.19%. Combined with fingerprint，multi-component contents determination and paste yield，the transfer rule of QJHTD benchmark sample was studied to provide reference for the quality control of preparation of classical prescription.关键词：Qingjin Huatan Decoction;extract yield;fingerprint chromatogram;quantity-quality tranmitting;content determination;high performance liquid chromatography- 59
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发布时间：2024-11-04 -
摘要：In this paper，the fluorescent whitening agents in 144 types of A4 copy paper，along with their identification and aging patterns，were investigated using the ultra-high performance liquid chromatography method，laying a research foundation for further determination of the production time of the documents based on the aging patterns of the paper. A 40% aqueous acetonitrile solution was employed as the extractant，while a methanol-aqueous solution（5∶95，volume ratio） containing 25 mmol/L tetrabutylammonium bromide（TBA） and an acetonitrile-methanol mixed solution（2∶3，volume ratio） were utilized as the mobile phase with gradient elution. The flow rate was 1 mL/min，the column temperature was 35 ℃，the detection wavelength of the ultraviolet detector was 350 nm，and the injection volume was 10 μL. The results indicated that a good linear relationship was observed for the seven common fluorescent whitening agent standards in copy paper within the range of 0.5-200 μg/mL，with all r2 values greater than 0.999. The detection limits of the method ranged from 0.03 to 0.08 μg/mL，and the quantitation limits of the method were 0.11-0.28 μg/mL. The average recoveries at three spiked levels were 92.1%-108%，and the relative standard deviations（RSDs） were 1.6%-5.9%. Among the 144 types of A4 copy paper，a total of three fluorescent whitening agents，namely BBU，VBL and MST，were detected. Based on their composition and proportion，the paper samples could be classified into 8 major categories and 45 minor categories. Combined with the measured whiteness values，53 types could be distinguished. It was discovered during the experiment that for the same brand and model of paper，if the grammage differed，the dye ratio and content contained might not be the same. Copy papers numbered 89，29，and 28 were selected and underwent transmission aging in an ultraviolet instrument for 10 days，with measurements taken once every two days. The contents of fluorescent whitening agents and the whiteness values of the three copy papers decreased significantly，demonstrating the feasibility of using fluorescent whitening agents to test the production time of the documents. This method features simple pretreatment and stable and reliable data，providing a certain reference basis for the authenticity identification of documents.关键词：UHPLC;fluorescent whitening agent;forensic science;paper identification;paper aging- 104
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摘要：A new oxyphenisatin analogue was discovered from a pressed candy claiming to be a weight loss product during the inspecting and monitoring of illegal adulteration. According to the law of ion fragments in the high-resolution mass spectrum of oxyphenisatin analogues，the unknown compound was characterized by ultra high performance liquid chromatography equipped with quadrupole-orbitrap mass spectrometry（UPLC-Q-Orbitrap MS）. Combined with the 1H NMR spectrum，the unknown compound was finally identified as oxyphenisatin dihexylester，a derivative of oxyphenisatin known as a cathartic drug. Oxyphenisatin dihexylester was a homologous compound of oxyphenisatin diacetate and oxyphenisatin dipropinate. Ultra high performance liquid chromatography-triple quadrupole mass spectrometry（UPLC-QQQ MS） was applied to the quantification of oxyphenisatin diacetate，oxyphenisatin dipropionate and oxyphenisatin dihexylester. There were good linear relationships for the three analytes in the range of 0.5-50 ng/mL. The limit of detection and limit of quantification were 0.025 mg/kg and 0.050 mg/kg，respectively. Recoveries at three spiked levels in pressed candies and solid drinks were ranged from 82.6%-114%，with relative standard deviations（RSDs，n=6） of 1.3%-6.6%. The method has the superiorities in simple pretreatment，high sensitivity and good accuracy，which can be applied to the detection of illegal additive oxyphenisatin diacetate，oxyphenisatin dipropinate and oxyphenisatin dihexylester in foods.关键词：oxyphenisatin dihexylester;illegal addition;food;ultra high performance liquid chromatography;quadrupole-orbitrap mass spectrometry;triple quadrupole mass spectrometry- 86
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发布时间：2024-11-04 -
摘要：In this study，wines from four regions，Australia，France，Xinjiang，China and Georgia，were selected as the research objects. Ultra-high performance liquid chromatography-quadrupole-orbitrap mass spectrometry（UHPLC-Q-Orbitrap-MS） technology was utilized to analyze the metabolomics of the wines，and the traceability was conducted by combining multivariate statistical analysis. The classification models of wines from different regions were constructed by combining with principal components analysis（PCA） and partial least squares-discriminant analysis（PLS-DA），resulting in accurate discrimination of actual wine samples. Based on fold changes（FC） greater than 2.0 or less than 0.5，significance difference（p） less than 0.05 and variable importance for projection（VIP） greater than 1.5，a total of 9 characteristic markers were screened. The KEGG metabolic pathway analysis revealed that the quality differences in wines from different regions arise from the influence of the flavone and flavonol biosynthesis on flavonoid substances. This study demonstrated that the untargeted metabolomics combined with chemometrics method based on UHPLC-Q-Orbitrap-MS is feasible to identify wine origin，which provides technical support and theoretical basis for wine origin traceability and quality evaluation.关键词：ultra-high performance liquid chromatography-quadrupole-orbitrap mass spectrometry;wine;origin traceability;metabolomics;chemometrics- 53
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发布时间：2024-11-04 -
摘要：Nickel is a toxic metal element that causes sensitization and is classified as a human carcinogen. Improper handling of nickel can make it a major source of water and soil pollution. The recovery of nickel ions from wastewater containing nickel is considered to be one of the effective ways to reduce pollution and solve the shortage of nickel resources. However，the problem of efficient and selective separation of nickel from complex environments has not been fully solved. In this paper，polyethylene glycol（PEG） and sodium sulfate were used to construct a two-phase aqueous system（ATPS） to selectively extract and separate nickel from wastewater. The types and concentration of nickel extractant，pH value of salt solution，temperature and co-existing metal ions were further optimized. The results showed that：At 35 ℃，the sodium alginate（SA） concentration is 0.1 g/L，more than 80% of nickel ions are efficiently and accurately separated from pH 2.0 salt solutions. The interference of multiple co-existing ions is avoided. Therefore，this work provides theoretical guidance for the treatment and reuse of nickel ions in wastewater，and the research content of hydrogel ligand-two-phase aqueous extraction system in green production technology was enriched.关键词：aqueous two-phase system;extraction;nickel ion;ICP-MS;industrial wastewater- 59
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发布时间：2024-11-04 -
摘要：To explore the differences of volatile compounds in different degrees of mildewed tobacco and achieve rapid discrimination，headspace-gas chromatography-ion mobility spectrometry（HS-GC-IMS） was employed to analyze the volatile compounds in different mildewed tobacco from Nanxiong，Shaoguan，Guangdong，and a classification model was constructed based on distinctive volatile components which was screened by the chemometric pattern recognition and relative odor activity value（ROAV） analysis. The results revealed discernible patterns of volatile compounds among tobacco with varying mold severity by the HS-GC-IMS differential maps，volatile compound fingerprints，and similarity correlation heatmaps. A total of 50 volatile compounds were qualitatively identified in different leaf samples，including 13 alcohols，6 aldehydes，8 ketones，13 esters，1 acid，1 terpene，and 8 other compounds. Principal component analysis（PCA），hierarchical clustering（HCA），and partial least squares discriminant analysis（PLS-DA） effectively differentiated tobacco samples with different mold severity. 20 distinct volatile compounds were screened out based on variable importance projection（VIP） values greater than 1. Furthermore，17 differential volatile compounds were chosed，using ROAV analysis，to construct a support vector machine（SVM） classification model，achieving a 100% classification rate. The method effectively discriminated tobacco with varying mold severity，providing technical and data support for moldew identification and prediction.关键词：tobacco;mildew;headspace-gas chromatography-ion mobility spectrometry;volatile compounds;chemometric pattern recognition;relative odor activity value- 33
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发布时间：2024-11-04 -
摘要：To improve the extraction efficiency of volatile organic compounds（VOCs） in blood，this study employed an artificially synthesized simulated blood standard addition solution as the working solution. Partial factorial experiments，single-factor alternating experiments，and response surface methodology were adopted to optimize the conditions for headspace solid-phase microextraction（HS-SPME）. An analytical method combining HS-SPME with gas chromatography-mass spectrometry（GC-MS） was established for the determination of common VOCs in blood. The final optimized extraction method in this study involved the following steps：2.0 mL of blood sample was taken，and 65 μm polydimethylsiloxane/divinylbenzene（PDMS/DVB） extraction fiber was used. Extraction was conducted at 57 ℃ for 45 minutes，with stirring speed set at 1 000 r/min. Desorption was performed at 280 ℃ for 5 minutes，and the sodium chloride content was set at 0. Internal standard method was used for quantification. The results of methodological validation showed that 15 VOCs exhibited good linearity within the mass concentration ranges of 0.4-4，4-40，and 40-400 ng/mL（r2 > 0.99）. The limits of detection（LODs） of this method ranged from 0.03 to 0.1 ng/mL，and the limits of quantification（LOQs） ranged from 0.1 to 0.3 ng/mL. The average recoveries of 15 VOCs at the mass concentration levels of 2.0，20，and 200 ng/mL ranged from 71.1% to 122%，and the relative standard deviations（n=6） ranged from 7.5% to 16%. This method was used to determine fresh human blood samples and standard addition samples with the same VOCs concentrations to assess matrix effects. The results showed that the p-values of the Shapiro-Wilk test，two-tailed F-test，and two-tailed T-test of the two sets of sample components were all greater than 0.05. The VOCs distributions in both sets of samples conformed to normal distribution，and there were no significant differences in variance and mean values，indicating no significant difference in matrix effects between simulated blood and real blood. The HS-SPME/GC-MS method established in this study possesses wide linear range，low detection limit and lower limit of quantification，simple pretreatment，and low detection threshold. It is suitable for the detection of multiple VOCs in blood and can provide a basis for subsequent analysis.关键词：response surface methodology;headspace solid-phase microextractio;gas chromatography-mass spectrometry;volatile organic compounds;blood- 96
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Detection of Volatile Organic Compounds in Nail Polish Products Based on Solid-phase Microextraction
摘要：Nail polish is a cosmetic commonly used by modern women to beautify their nails. Traditional oil-based nail polish has been widely reported to be harmful to human health. Although new water-based and UV gel nail polish take “non-toxic and harmless” as the slogan，their pungent odors is contrary to this. This study employed headspace solid-phase microextraction combined with gas chromatography-mass spectrometry to investigate the volatile organic compounds（VOCs） released from seven types of nail polish. We analyzed the release rates of VOCs before and after application，as well as their release characteristics post-application. Results showed that 78 VOCs were detected in untreated nail polish，21 of which are listed in the “Hazardous Chemicals Directory”. Significant differences were found in the types and contents of VOCs among different types of nail polish. The main VOCs include solvents，photoinitiators，plasticizers and antioxidants. During the nail application process，drying or curing operations cause most VOCs to volatilize significantly，with loss rates reaching up to 99%. After the nail application，VOCs continued to be released，with the half-lives of VOCs release from oil-based，water-based and UV gel nail polish being 0.41，0.46，and 0.29 days，respectively. This study provides essential data support for assessing the potential health risks associated with the nail application.关键词：nail polish;headspace solid-phase microextraction;gas chromatography-mass spectrometry;volatile organic compounds;release feature- 85
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发布时间：2024-11-04 -
摘要：A method for the determination of 21 mycotoxins in coffee by ultra-high performance liquid chromatography-tandem mass spectrometry（UPLC-MS/MS） was developed. Coffee samples were extracted with acetonitrile-water-formic acid solution （80∶19∶1，volume ratio），cleaned up by 0.05 g magnesium oxide and Captiva EMR-Lipid solid phase extraction column. Methanol and 1 mmol/L ammonium formate solution（containing 0.1% formic acid） were used as mobile phases with gradient elution. The sample solution was separated by Agilent ZORBAX Eclipse Plus C18 column（2.1 mm×100 mm，1.8 μm）. The detection was performed under multiple reaction monitoring（MRM） of electrospray ionization in positive and negative ion modes. The matrix matching curve external and internal standard（fumonisin） method were used for quantification. The results showed that 21 mycotoxins had good linear relationships within their respective mass concentration ranges（r2 > 0.998）. The limits of detection（LODs） were 0.001-2.000 μg/kg，and the limits of quantification（LOQs） were 0.003-6.000 μg/kg. Average recoveries at three spiked levels were 78.2%-106% with relative standard deviations（RSDs） of 0.93%-9.5%. A total of 13 samples of coffee product were detected using the established method and the results showed that beauvercin and enniatins were detected and the maximum content was 17.1 μg/kg. The method is quick，easy，accurate and sensitive，which is suitable for the simultaneous determination of 21 mycotoxins in coffee product.关键词：ultra-high performance liquid chromatography-tandem mass spectrometry（UPLC-MS/MS）;solid phase extraction;mycotoxin;coffee- 75
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发布时间：2024-11-04 -
摘要：An analytical method was developed for the rapid determination of three quinolone antibiotics in urine and fish tissues by electromembrane extraction（EME） coupled with high performance liquid chromatography（HPLC）. The urine was diluted，and the fish meat was minced and extracted with pH 5.0 phosphate buffer，followed by EME. The receiving solvent for drug extraction was determined to be 10 mmol/L hydrochloric acid at pH 2.0，extraction voltage of 35-70 V，extraction time of 20 min，and HPLC detection. Results showed that the three quinolone antibiotics in urine and fish meat showed good linearity in their respective mass concentration ranges with correlation coefficients（r2） greater than 0.99. The limits of detection and limits of quantification of the drugs ranged from 2.0 to 5.2 ng/mL and from 6.8 to 17.6 ng/mL in urine and from 12 to 36 ng/g and from 42 to 121 ng/g in fish，respectively. The recoveries of quinolone antibiotics in urine and fish matrix spiked at three different concentration levels were 67.7%-127% with the relative standard deviations（RSDs，n=6） of 4.2%-10%. The pretreatment method is simple，with low dosage of organic reagents，good purification effect and reproducibility，and can meet the requirements for the determination of the three quinolone antibiotics in urine and fish.关键词：quinolone;electromembrane extraction;high performance liquid chromatography;urine;fish;antibiotics- 99
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发布时间：2024-11-04 -
摘要：This study introduces a solid phase microextraction/gas chromatography/combustion-isotope ratio mass spectrometry（SPME/GC/C-IRMS） technology for analyzing the carbon isotopes of seven benzene series compounds in water. The pretreatment conditions for headspace solid phase microextraction（HS-SPME） were optimized. The results demonstrated that the extraction efficiency reached its maximum at an extraction temperature of 30 ℃ and an extraction time of 60 minutes. Variations in extraction temperature（30-60 ℃） and extraction time（15-60 min） did not cause carbon isotope fractionation during HS-SPME. Under the optimized extraction conditions，both HS-SPME and D-SPME methods were employed to measure the δ13C values of the seven benzene series compounds. The standard deviations ranged from 0.08‰-0.45‰ and 0.05‰-0.39‰，and the test error varied from -0.16‰-0.33‰ and -0.41‰-0.46‰，respectively. No obvious carbon isotope fractionation occurred during the extraction process in both SPME methods，and the sensitivity of the HS-SPME method is 1-2 orders of magnitude higher than the D-SPME method. Utilizing the moving average algorithm，the detection limits for benzene，m-/p-xylene，and isopropylbenzene were determined to be 1 μg/L，while for toluene，ethylbenzene，o-xylene and styrene，the detection limits were 2 μg/L. This method was applied to analyze groundwater from an abandoned pesticide factory in Jiangsu，yielding δ13C values for the seven benzene series compounds with good repeatability （standard deviation：0.01%-0.43‰）. This method can be applied to detect the carbon isotope for trace benzene series compounds in water，because of the simple pretreatment procedure，high sensitivity and good accuracy.关键词：benzene series compounds;solid phase microextraction;gas chromatography/combustion-isotope ratio mass spectrometry;compound specific carbon isotope analysis;water- 52
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发布时间：2024-11-04
Scientific Papers
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