最新刊期
卷 44 ， 期 7 ， 2025
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摘要：Immobilized metal affinity chromatography medium is widely used in the downstream processing of proteins due to their high purity and low preparation cost. The metal affinity chromatography medium which was based on the macroporous polyacrylate microspheres，was prepared by redox reaction using glycidyl methacrylate-iminodiacetic acid（GMA-IDA） functional monomer as ligand. Firstly，the GMA-IDA functional monomer is prepared by the reaction of the epoxy group of GMA with the imino of IDA. Secondly，the double bonds in the functional monomer are grafted to prepare macroporous polymer microspheres by redox reaction. Finally，the FastSep-GMA-IDA-Ni affinity chromatography medium was prepared by chelating Ni2+ in 0.1 mol/L nickel solution. The influence of various factors on protein binding capacity of graft polymerization was investigated，including functional monomer concentration，initiator concentration，reaction system pH，reaction temperature，reaction time，etc. The optimum preparation conditions of Fastsep-GMA-IDA-Ni affinity chromatography were determined. Using bovine hemoglobin as the model protein，the static binding capacity of FastSep-GMA-IDA-Ni affinity medium was 47.97 mg/mL，which was about 25.75% higher than that of commercial Ni affinity chromatography medium. FastSep-IDA-Ni affinity chromatography medium was prepared by coupling method with a static binding capacity of 12.518 mg/mL，which was much lower than that of FastSep-GMA-IDA-Ni affinity chromatography medium prepared by grafting method. Moreover，the mass transfer rate k2 value of FastSep-GMA-IDA-Ni is 0.001 18 mL/mg/min，and the mass transfer rate k2 value of commercial medium is 0.000 74 mL/mg/min，indicating that FastSep-GMA-IDA-Ni has better protein mass transfer efficiency than commercial medium. The relationship between nickel content and protein static binding capacity in Fastsep-GMA-IDA-Ni affinity chromatography was observed. The nickel content of chelate increased with the increase of ion-exchange capacity. The highest nickel content was 104.06 μmol/mL. The prepared FastSep-GMA-IDA-Ni was used to separate and purify the hemagglutinin（HA-His） protein expressed by CHO cells. The results showed that the medium has good separation performance.关键词：metal affinity chromatography medium;grafting method;polymer microspheres;protein binding capacity;separation and purification25|47|0更新时间：2025-07-10 -
摘要：Calibration free concentration analysis based on surface plasmon resonance can be used to determine the active protein concentration without reference to any standard，using only the known protein diffusion coefficient under diffusion-limited conditions. In this study，calibration free concentration analysis in a capture mode was proposed for the detection of CYFRA21-1 protein activity concentration. The results showed that the value of calibration free concentration analysis in a capture mode（CCFCA） was 0.67 mg/mL and the daytime precision was 4.6%，while the value of calibration free concentration analysis（CFCA） was 0.7 mg/mL and the daytime precision was 6.5%. In addition，the antibody coupling level has always been a key factor limiting the use of CFCA. If the chip storage method or activation method is improper，the level of the coupled antibody indicated by the chip will not meet the requirements of the CFCA method to overcome the mass transfer restriction （QCratio>0.2 required by CFCA fitting methodology），resulting in the unreliable detection results. Since the capture method can more appropriately pose the antibody space with the assistance of Protein G，the detection results of CCFCA method are still accurate and stable at low coupling level. Therefore，compared with the classical CFCA method，the detection results in a capture mode are reliable，a single chip can be used for the detection of multiple antibody-analyte through regeneration，and it is still sensitive at low coupling density，which can be a better choice for the detection of active protein concentration in the future.关键词：calibration free concentration analysis;CYFRA21-1;active protein concentration;capture method18|25|0更新时间：2025-07-10 -
摘要：In this study，a qualitative model and a rapid prediction model for the content of indicator components of Bupleuri radix from different origins were established based on Fourier transform-near infrared spectroscopy（FT-NIR） technology and chemometrics method. The optimal spectral preprocessing methods were firstly screened by combining multiple scattering corrections（MSC），standard normal variation（SNV），first-order derivative（1stD），second-order derivative（2ndD），etc. Partial least squares-discriminant analysis（PLS-DA），support vector machine（SVM），random forest（RF） and K-nearest neighbor（KNN） chemometrics method were used to analyze the contents of different origin Bupleuri radix. The optimal partial least squares（PLS） quantitative model was constructed based on interval combinatorial optimization（ICO） to screen the optimal spectral bands for quantifying the content of the indicator components of Bupleuri radix. The spectral preprocessing method of MSC has the best discriminatory accuracy of 97.5%，which can be used for the construction of the origin discriminatory model. The prediction of quasi-samples from the training set of KNN，RF and SVM algorithms can reach 100% accuracy. The accuracy of the KNN，RF and SVM algorithms can reach 100%. The relative analytical errors（RPD） of the prediction of PLS models based on ICO are all greater than 2，and the prediction coefficients of determination（R2p） are all greater than 0.90，with excellent prediction performance. It indicates that the FT-NIR technique combined with chemometrics method can be used for the differentiation of Bupleuri radix from different origins and the rapid prediction of the content of index components，and the method is simple and fast，with accurate and reliable results，which can be used as a reference for the rapid evaluation of the quality of Bupleuri radix.关键词：Bupleuri Radix;near infrared spectroscopy;saikosaponin a;saikosaponin d;chemometrics method;origin24|36|0更新时间：2025-07-10 -
摘要：A fast screening method for pesticide residues in tobacco was established based on the supercritical fluid chromatography-high-resolution mass spectrometry（SFC-HRMS） system. The SFC conditions，such as the type of analysis column，modifier composition，and flow rate of the compensation pump，were carefully optimized. As for the HRMS acquisition，the data-independent acquisition（DIA） mode was adopted to acquire the accurate mass and the abundance ratio of pesticide residue's precursor ion，isotope ion and product ion. The new method's screening capability and limit of quantitation（LOQ） were investigated using blank matrix samples spiked with 60 pesticide standards. When the recovery of pesticide residues was between 70%-120%，the LOQs of 53 pesticide residues were as low as 10 μg/kg，and one pesticide residue was 25 μg/kg，which indicated that the reported method could fulfill the determination requirements for the maximum residue limits in tobacco of China National Tobacco Corporation. Compared with reversed phase chromatography-high-resolution mass spectrometry（RPLC-HRMS），these two methods showed similar quantitative determination capability，and the separation performance of SFC for some pesticide residues was better than that of RPLC，which means the new SFC-HRMS method can be used to rapidly screen and confirm pesticide residues in tobacco and tobacco products.关键词：tobacco;pesticides residue;supercritical fluid chromatography（SFC）;high-resolution mass spectrometry（HRMS）;data-independent acquisition（DIA）27|42|0更新时间：2025-07-10 -
摘要：The mechanical properties of rocks，such as strength and deformation，vary significantly，and different methods are employed for the development of underground resources and disaster prevention related to various rock types. Therefore，accurately identifying and classifying different rocks is crucial for addressing practical issues in geotechnical engineering. This study conducted spectral acquisition on white sandstone，marble，mudstone，and salt rock，employing three classification methods：support vector machine，back propagation（BP） neural network，and classification and regression decision Tree. The models were quantitatively compared based on accuracy，recall，and Kappa coefficient to assess their effectiveness，aiming to achieve the optimal spectral model for rock classification. The results showed that the decision tree model had the lowest classification accuracy at only 93.1%，in contrast，the rock classification model utilizing sparse filtering combined with the BP neural network yielded the best results，with a classification accuracy of 97.1% and a Kappa coefficient of 0.958. This research provides a significant theoretical foundation and practical value for quickly identifying rock types through spectral measurement methods，thereby enhancing disaster prevention strategies for different rock types in actual engineering applications.关键词：rock classification;mid-infrared spectrum;machine learning;support vector machine;BP neural network22|6|0更新时间：2025-07-10 -
摘要：A method for the simultaneous determination of 51 veterinary drugs in animal-derived foods was establised by SinCHERS-TC/ultra-high performance liquid chromatography-tandem mass spectrometry（SinCHERS-TC/UPLC-MS/MS）. Weigh 2 g of the samples and extract it with a mixed solution of acidified acetonitrile and Mcllvaine-Na2EDTA buffer. The extract was filtered through a purification tube with the help of squeezing apparatus. The filtrate was diluted with water with a ratio of 1∶1 and then tested by ultra-high performance liquid chromatography-tandem mass spectrometry. Matrix-matched external standard method was used for quantification. The results showed that the linear relationships of the 51 drugs were good in the range of 0.5-10.0 µg/L，and the correlation coefficients（r2） were not less than 0.999 0. The detection limits（LODs） of 51 drugs were between 4 µg/kg and 10 µg/kg，and the quantification limits（LOQs） were between 8 µg/kg and 20 µg/kg. With beef as the substrate，the average recoveries were between 82.8% and 109% at spiked levels of LOQ，2LOQ and 10LOQ，and the relative standard deviations（RSDs，n=6） were between 0.30% and 8.0%. This method is simple in pretreatment，convenient and efficient in operation，and is characterized by high sensitivity and good accuracy. It is suitable for batch screening and detection of 51 drug residues in chicken，pork，beef，mutton and fish.关键词：SinCHERS-TC;ultra-high performance liquid chromatography-tandem mass spectrometry;animal-derived foods;drug residues24|14|0更新时间：2025-07-10 -
摘要：The study integrated the fingerprinting technique，multi-indicator determination of the content of each component，at the same time，chemical pattern recognition analysis to systematically explore the characteristics of different batches of Pingtiao granules and to provide a scientific basis for their quality assessment. The analytes were separated on an ACQUITY UPLC BEH Shield RP C18 column（150 mm×2.1 mm，1.7 μm） by gradient elution，with 0.1% aqueous phosphoric acid-acetonitrile as the mobile phase. A total of seven characteristic components were identified，and the contents of six active components，including gastrodin，paeoniflorin，Parishin A，Parishin E，pinoresinol diglucoside and quercetin were determined. Additionally，the 17 batches of Pingtiao granules were classified by cluster analysis（HCA） and principal component analysis （PCA），and then subjected to orthogonal least partial squares-discriminant analysis（OPLS-DA），in order to screen out the different components among the batches of the samples. The UPLC fingerprints of Pingtiao granules and the determination of the contents of 6 index components were established. 15 common peaks were identified and 7 components were designated，and the similarity of the 17 batches was greater than 0.9. The results of HCA and PCA showed that the components of the 17 batches were clustered into 3 categories，and the OPLS-DA analysis screened out 3 markers that caused the differences between batches. The determination of multi-component content showed that the differences in chemical content between batches were small. The established UPLC fingerprints and the method for determining the content of the six index components ensure their accuracy and reliability. When combined with the chemical pattern recognition technique，this method can be effectively applied to the quality monitoring and evaluation of Pingtiao granules.关键词：Pingtiao granules;UPLC;fingerprint;content determination;chemometrics;quality evaluation25|41|0更新时间：2025-07-10 -
摘要：Nitric oxide （NO） is one of three major signaling molecules，which involved in a great amount of physiological and pathological processes in biological systems. In addition，more and more evidences indicate that NO levels are closely related to several human health. Therefore，it is vital to develop a convenient and reliable method for NO detection in biological systems. In this paper，a new coumarin-Cu（Ⅱ） complex-based fluorescent probe YCY-Cu2+ was successfully developed. In the presence of Cu2+，coumarin-based ligand YCY can specifically perform 1∶1 coordination with Cu2+ to generate probe YCY-Cu2+. The strong green fluorescence of ligand YCY was quenched due to the paramagnetism of Cu2+. When NO was recognized by fluorescent probe YCY-Cu2+，the paramagnetic Cu2+ was reduced to the diamagnetic Cu+ and released from the complex，and the strong fluorescent emitting N-nitroso compound （YCY-NO） are generated to achieve the specific recognition of NO. The structure of the fluorescent probe YCY-Cu2+ and the recognition mechanism toward NO were confirmed by Job's analysis，high-resolution mass spectrometry （HRMS） and spectral titration analysis. The probe YCY-Cu2+ has the advantages of high selectivity and sensitivity （LOD=97.3 nmol/L），wide range of pH applications （3.5-11.5） and low cytotoxicity. Most importantly，the probe has been successfully applied to the fluorescence imaging of NO in living cells and animals.关键词：fluorescent probe;coumarin;copper（Ⅱ）-complex;nitric oxide;fluorescence imaging34|42|0更新时间：2025-07-10 -
摘要：Nanoclusters possess unique atomic configurations，electronic structures，and novel optical，electrical，and catalytic properties，which make them widely applicable in fields such as catalysis，luminescent materials，detection devices，biology，and pharmaceuticals. Mass spectrometric characterization of nanoclusters can obtain precise mass number information of the nanoclusters，providing important information for the establishment of structural theoretical models. This paper introduced the characterization of the process products and final products during oil-phase preparation of gold nanoclusters using triple quadrupole mass spectrometry and laser desorption/ionization mass spectrometry. Firstly，the ions at each reaction stage were characterized by triple quadrupole mass spectrometry，and the parent ions and their fragment ions obtained by neutral loss mode were assigned. Secondly，the final products of the nanoclusters were characterized using laser desorption ionization mass spectrometry，and the effects of laser energy and matrix on the ionized products were investigated. The results showed that when 2-［3-（4-tert-butylphenyl）-2-methyl-2-propenyl］ malononitrile was used as the auxiliary matrix，the signal intensity of the large number of clusters was significantly improved. A series of ions of gold nanoclusters were observed in the mass range of 2 500 to 5 300，with mass numbers of 2 817.7，3 014.7，3 211.7，3 441.8，3 637.8，3 866.7，4 063.8，4 260.7，4 489.7，4 688.8，4 883.8，5 112.9 and 5 309.9，respectively. These adjacent ions differed by one Au atom or AuS structural unit. Additionally，the peak of the gold cluster with the highest mass number was observed at positions 6 945 and 8 549，corresponding to Au21（C12H25S）14 and Au25（C12H25S）18，respectively. The research results of this paper have important guiding significance and reference value for the synthesis of nanoclusters and the establishment of cluster structure models.关键词：laser desorption time-of-flight mass spectrometry;triple quadrupole mass spectrometry;gold nanoclusters;synthesis;characterization21|25|0更新时间：2025-07-10 -
摘要：Porous metal-organic framework materials（UiO-66-NH2） were prepared using hydrothermal and composite materials of UiO-66-NH2/multi-walled carbon nanotubes（MWCNTs） were formed using ultrasonic mechanical mixing method. An electrochemical sensor was constructed using the drop-coating method. The composition and morphological structure of the materials were analyzed using X-ray diffraction，field emission scanning electron microscopy，field emission transmission electron microscope and Fourier-transform infrared spectroscopy. The electrochemical performance of the modified electrode was investigated using cyclic voltammetry with potassium ferricyanide as the electron probe，and the electrochemical response of the electrode to morphine was examined using pulse voltammetry. The detection conditions，such as the mass ratio of the modified materials，enrichment time，and pH were optimized. The constructed sensor exhibited a high electrochemical response to morphine，with a linear detection range of 10-100 μmol/L and a minimum detection limit（S/N=3）of 9.922 μmol/L. The sensor demonstrated good stability，repeatability（RSD=4.1%），and anti-interference ability（RSD<5.0%）. The standard addition method was used to detect morphine in sweat and urine samples with recoveries of 92.1%-98.4% and RSD（n=3） below 5.0%.关键词：Illicit drugs;morphine;electrochemistry;sensors;metal-organic frameworks16|49|0更新时间：2025-07-10 -
摘要：The 1，6-disubstituted pyrene-based conjugated microporous polymers（1，6-disubstituted pyrene-based CMPs，TTPDP and TDTPAP） were synthesized by Friedel-Crafts arylation reactions with the 1，6-disubstituted pyrene derivatives（TPDP and DTPAP） and 2，4，6-trichloride-1，3，5-triazine（TCT） at 140 ℃ for 48 h. After washing，extracted with Soxhlet's apparatus，and vacuum drying，TTPDP and TDTPAP gave 84.85% and 82.17% yield，respectively. The structures of the 1，6-disubstituted pyrene-based CMPs were characterized with FT-IR，solid state 13C NMR，and solid-state UV-visible spectroscopy and confirmed to be the target products. The morphology of the 1，6-disubstituted pyrene-based CMPs was analyzed by powder X-ray diffraction（PXRD） and scanning electron microscope（SEM）.The 1，6-disubstituted pyrene-based CMPs showed an amorphous network structures which have massive structures. TTPDP and TDTPAP are insoluble in any solvent and have excellent thermal stability with the high decomposition temperatures of 563 and 573 ℃，respectively. The pore properties of 1，6-disubstituted pyrene-based CMPs were investigated by nitrogen adsorption-desorption measurements of at 77.3 K. TTPDP and TDTPAP fit the type Ⅰ and Ⅱ gas adsorption isotherms and some hysteresis，respectively. The micropore diameters of TTPDP and TDTPAP are around 1.88 and 1.22 nm，respectively，and the BET surface areas are 187.5 and 695.2 m2·g-1，V0.1/Vtot values are higher than 0.40，respectively，indicating the predominance of micropores in the networks. The fluorescent sensing properties of TTPDP and TDTPAP for the nitroaromatic compounds（NACs） were studied. TTPDP and TDTPAP have good fluorescence properties either in the solid state or dispersed in the solvent. The TTPDP and TDTPAP are easily dispersed in N，N-dimethylformamide（DMF） and 1，4-dioxane（DOX） and can emit bright cyan fluorescence under UV light at 365 nm，which is basically consistent with the colors in the CIE diagrams. Both TTPDP and TDTPAP can detect picric acid（PA） and o-nitrophenol（o-NP） in real time，showing high sensitivity and selectivity. The quenching coefficient（KSV） of TTPDP to PA and TDTPAP to o-NP are 1.59×104 and 7.80×103 L·mol-1，with the limit of detection（LODs） of 2.82×10-12 and 1.92×10-10 mol·L-1，respectively. The mechanisms of TTPDP and TDTPAP fluorescence sensing PA and o-NP were explored by theoretical calculations using the program Gaussian 09 D.01 at the B3LYP/6-31G level and contrasting the UV-visible spectra of the analytes and the fluorescence spectra of the 1，6-disubstituted pyrene-based CMPs. TTPDP fluorescence sensing PA is the result of the combined action of electron transfer and energy transfer processes，whereas TDTPAP fluorescence detecting to o-NP is only the electron transfer process.1，6-Disubstituted pyrene-based CMPs have potential applications for the detection of NACs in environmental pollutants.关键词：conjugated microporous polymers;1，6-disubstituted pyrene;fluorescence sensing;picric acid;o-nitrophenol24|22|0更新时间：2025-07-10 -
摘要：Magnetic solid-phase extraction coupled with gas chromatography was developed for the sensitive determination of 8 kinds of polychlorinated biphenyls（PCBs） by using magnetic porous carbon@β-cyclodextrin/epichlorohydrin copolymer（MPC@β-CDEP） composites as magnetic solid-phase extraction agent. Effects of the amount of adsorbent，extraction time，type of desorption solvent，and desorption time on the extraction performance of MPC@β-CDEP were investigated. Under the optimized conditions，the 8 kinds of PCBs showed a good linearity in the concentration range of 1-500 μg/L. The correlation coefficients（r2） were greater than 0.995. The limits of detection and quantification were 0.022-0.030 µg/kg and 0.072-0.10 μg/kg，respectively. The method was applied to determine PCBs in grass carp and channa argus samples. The recoveries were 86.1%-106% and relative standard deviations（RSDs） were less than 8.0%. The developed method has the advantages of simple pretreatment，short extraction time，wide linear range，high sensitivity，good accuracy and precision，and can be applied to the efficient and rapid detection of multiple PCBs in real samples.关键词：polychlorinated biphenyls;magnetic solid-phase extraction;gas chromatography;β-cyclodextrin;porous carbon;fish37|21|0更新时间：2025-07-10 -
摘要：A method for the determination of 90 pesticides and their metabolites residues in coconut meat juice was established by liquid chromatography-tandem mass spectrometry（LC-MS/MS）. The coconut meat juice samples were extracted with 1% formic acid acetonitrile，purified by dispersive solid phase extraction columns containing N-propylethylenediamine（PSA），lipid and protein adsorbent （LPAS），Florisil and aminated-multi-walled carbon nanotubes（NH2-MWCNTs） purification materials，analyzed by multi-reaction monitoring （MRM） mode，and quantified by external standard method of matrix-matched standard curve. The results showed that the 90 pesticides and their metabolites showed good linearity in the range of 0.002-0.2 mg/L with the correlation coefficients（r2） more than 0.99，and the limit of quantification（LOQ） was 0.01 mg/kg. Average recoveries at three spiked levels were 60.6%-118% with relative standard deviations（RSDs） of 0.60%-12% （n=6）. This method has good purification effect and simple operation. It is suitable for the determination of various pesticide residues in coconut meat juice.关键词：coconut meat juice;pesticide residue;QuEChERS;LC-MS/MS27|3|0更新时间：2025-07-10 -
摘要：Surface enhanced Raman spectroscopy（SERS） is an analysis technique that improves Raman signals through rough metal nanoparticles，with the advantages of high sensitivity，strong specificity and simple operation. Therefore，this paper proposed a method to rapidly detect the residue of asomate in apple juice using concave Au nano-arrows（AuCNAs） as SERS substrate. The Au nanorods（AuNRs） were prepared based on seed-mediated growth strategy，and then used for the synthesis of AuCNAs. After that，the synthesized AuCNAs were analyzed to show good stability，homogeneity and repeatability. Meanwhile，the AuCNAs achieved high enhancement factor（1.10×106）. Compared to other nanospheres and nanorods，AuCNAs had significantly better SERS enhancement properties. The locations of SERS peaks can be attributed to the vibrations of chemical bonds through molecular simulation. The intensity at the Raman peak of 1 382 cm-1 was used to establish a correction curve with the residual concentrations of asomate in apple juices，and the limit of detection（LOD） of asomate was 8.93 nmol/L. The recovery experiments showed that the average recoveries of asomate in apple juice was 96.2%-109% with relative standard deviations ranging of 4.2%-8.8%. The results indicated that AuCNAs can be used as SERS enhanced substrates to detect asomate in apple juice.关键词：asomate;surface enhanced Raman spectroscopy;AuCNAs;pesticide residue;apple juice38|22|0更新时间：2025-07-10 -
摘要：Silicone wristbands，as an emerging，non-invasive passive sampling device，can effectively monitor the exposure of compounds entering the human body via inhalation and dermal contact routes. A method was developed for analyzing 17 bisphenols（BPs） in silicone wristbands by utilizing ultra performance liquid chromatography-tandem mass spectrometry（UPLC-MS/MS）. Wristband samples were extracted with acetonitrile solution through ultrasonic extraction，followed by purification using an HLB solid-phase extraction column. The purification involved washing with 40% methanol-water solution and elution with methanol solution. The eluent was then evaporated to near dryness under nitrogen，reconstituted with 50% methanol-water solution and analyzed. Quantification was performed using an isotope internal standard method，with good linearity observed for the 17 target compounds in the range of 0.001 μg/L to 100 μg/L，and correlation coefficients（r²） greater than 0.99. The method detection limits ranged from 0.001 μg/kg to 0.042 μg/kg，and the quantification limits ranged from 0.003 μg/kg to 0.141 μg/kg. The spiked recoveries for 17 BPs in the wristbands were between 71.7% and 124%，with intra-day and inter-day relative standard deviations of 6.5% to 20% and 2.3% to 16%，respectively. Applying this method to analyze 11 worn wristbands，twelve target compounds were detected，with contents ranging from 0.005 μg/kg to 2.552 μg/kg. Bisphenol A（BPA），bisphenol S（BPS），benzylparaben（PHBB），and 4，4'-thiobisphenol（TDP） were detected in all 11 wristbands，showing a 100% detection rate. This method demonstrates high sensitivity and can be used to detect 17 BPs adsorbed in silicone wristbands.关键词：bisphenols;silicone wristbands;ultra performance liquid chromatography-tandem mass spectrometry;passive sampler29|24|0更新时间：2025-07-10 -
摘要：A visual analysis method for in situ rapid screening of small molecular nutrients such as anthocyanins，anthocyanins and organic acids in blueberry was established by atmospheric pressure in situ desorption electrospray ionization-high resolution mass spectrometry imaging（DESI-MSI）. By comparing the main instrumental analysis conditions such as spray solvent type，flow rate and spatial resolution，the optimal mass spectrometry imaging parameters were determined. In the positive ion mode，when methanol∶water（95∶5，by volume） with 0.2% formic acid and 0.2 μg/mL leucine enkephalin was used as the spray solvent，the highest ion peak signal intensity of the six anthocyanin standard samples at the concentration of 100 μg/L was the highest. Blueberries can be directly scanned and analyzed after frozen sections. Combined with the mass spectrometry information in the PubChem，a total of 4 anthocyanins，12 anthocyanins and 4 organic acids were identified，with a mass accuracy of ≤ 5×10-6. The in-situ mass spectrometry imaging map intuitively showed the spatial distribution differences of small molecular nutrients in blueberry from different producing areas. The method was simple，rapid，accurate and reproducible，which provided effective technical support for the in-situ spatial distribution and metabolomics study of small molecular nutrients in blueberry.关键词：desorption electrospray ionization-high resolution mass spectrometry imaging;blueberry;anthocyanins;in-situ;screening analysis;small molecule nutrients75|85|0更新时间：2025-07-10
Scientific Papers
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摘要：A method was established based on gas chromatography-tandem mass spectrometry（GC-MS/MS） to analyze the residual condensing agents N，N'-diisopropylcarbodiimide（DIC） and N，N'-dicyclohexylcarbodiimide（DCC），and catalyst N，N'-dimethylaminopyridine（DMAP） in semaglutide active pharmaceutical ingredient（API）. After extraction with acetonitrile，sample were separated on an Agilent CP-Volamine column（30 m × 0.32 mm），detected in electron impact ionization source（EI） with multiple reaction monitoring（MRM） mode and quantified by the external standard calibration. Target compounds exhibited excellent linearities in the concentration ranges of 10-500 ng/mL，with correlation coefficients（r2） of 0.998 8-0.999 9. The limits of detection were 0.1-0.5 μg/g，while the limits of quantitation were all 1.0 μg/g. The average recoveries（n=9） of target compounds were 97.6%-99.2%，while relative standard deviations（RSDs） for precision，repeatability，stability，and robustness were all below 6.0%，indicating good method reliability. Thirteen batches of semaglutide API were detected，and a positive sample was found with DMAP content of 1.3 μg/g. The method established in this study offers the advantages of convenience and high accuracy，providing reliable technical support for quality control of semaglutide API.关键词：gas chromatography-tandem mass spectrometry（GC-MS/MS）;Semaglutide;active pharmaceutical ingredient（API）;impurity;carbodiimides;N，N'-Diisopropylcarbodiimide（DIC）;N，N'-dicyclohexylcarbodiimide（DCC）;N，N'-dimethylaminopyridine（DMAP）27|26|0更新时间：2025-07-10 -
摘要：A method based on ultra-high performance liquid chromatography-tandem mass spectrometry（UPLC-MS/MS） was established for the simultaneous determination of catecholamines（CAs） and their three metabolites in blood. This method requires only 100 µL of blood sample，which is purified using an ultrafiltration centrifuge tube and extracted by solid-phase extraction. Separation is achieved using an HSS PFP column，with acetonitrile-0.1% formic acid aqueous solution as the mobile phase for gradient elution. The samples were scanned by electrospray positive ion multiple reaction monitoring（MRM） mode and quantified by internal standard method. The results showed that the linearities of CAs and their metabolites were good in the concentration range of 0.5-50 ng/mL（r² > 0.99）. The limits of detection and quantification were 0.2 ng/mL and 0.5 ng/mL，respectively. The recoveries of six target analytes at spiked levels of 1，10 and 50 ng/mL ranged from 68.9%-101%，with matrix effects ranging from 86.2%-102%，and the relative standard deviations（RSDs） from 2.3%-10%. The established method can provide effective technical means for clinical diagnosis and the detection and identification of epinephrine poisoning cases.关键词：forensic toxicological analysis;UPLC-MS/MS;blood;catecholamines28|29|0更新时间：2025-07-10 -
摘要：Gold nanoparticles（AuNPs） were deposited on the surface of a glassy carbon electrode（GCE） via cyclic voltammetry to fabricate a GCE-AuNPs modified electrode in this paper. With norfloxacin（NOFX） as the template molecule，pyrrole（Py） and o-phenylenediamine（OPD） as bi-functional monomers，NOFX molecular-imprinted membranes were prepared on the GCE-AuNPs through electropolymerization，and an electrochemical sensor for NOFX（MIP/GCE-AuNPs） was constructed. The sensor was characterized by scanning electron microscopy（SEM），X-ray diffraction（XRD） and a series of electrochemical methods. Using Fe（CN）64-/Fe（CN）63- as an electrochemical probe，the relevant performance of the sensor was investigated. The results showed that the current value（∆I） of the sensor had a good linear relationship with the NOFX concentration in the range of 0.01-5.0 μmol/L and 5.0-60 μmol/L，respectively. The detection limit（LOD） was 3.3 nmol/L，and the sensor had strong selectivity. The sensor was applied to the detection of actual samples. The recoveries were 94.0%-111%，with the relative standard deviations of 2.4%-3.1%.关键词：Au nanoparticles;molecular imprinting;electrochemical sensor;norfloxacin42|32|0更新时间：2025-07-10 -
摘要：A novel fluorescent probe L was synthesized by condensation reaction of naphthofuranoylhydrazide and 8-hydroxyquinoline-2-carbaldehyde. The structures were characterized by high resolution mass spectrometry（HR-MS），hydrogen NMR（1H NMR） and carbon NMR（13C NMR），the blue fluorescence of probe L was significantly quenched in the presents of Ag+ in HEPES buffer solution.Based on this，the probe L can identify Ag+ with high sensitivity. The response mechanism of probe L towards Ag+ was investigated by HR-MS. The detection limit of Ag+ by L was 5.62×10-8 mol/L. Because of its high sensitivity，fast response（80 s） and good biocompatibility，the probe L has been successfully applied to the detection of Ag+ in actual water samples by fluorescence standard curve method and atomic absorption spectrometry，the data showed that the two methods had essentially identical results.The probe L was also used to the confocal imaging of Ag+ in HeLa cells.关键词：naphthofuran;8-hydroxyquinoline-2-carbaldehyde;fluorescent probe;Ag+;response mechanism;water samples;bioimaging21|15|0更新时间：2025-07-10 -
摘要：A highly sensitive determination method capable of rapidly analyzing 11 common odorants in drinking water was successfully established using liquid-liquid extraction and gas chromatography-quadrupole electrostatic field orbitrap mass spectrometry（GC-Orbitrap-MS）. Four different scanning modes，GC gradient elution and other mass parameters were thoroughly investigated. Under the optimal conditions，the standard curves of all target substances showed good linearity with correlation coefficients（r²） greater than 0.99. The method detection limits were between 0.1 and 2.0 ng·L-1，and the quantitation limits were between 0.4 and 6.7 ng·L-1. Recoveries of the target odorants at three spiking levels in tap water samples ranged from 76.1% to 120%，with relative standard deviations（n=6） of 4.1%-18%. The established method was applied to analyze 17 source water samples and 44 terminal water samples collected from Beijing.Results showed that all target odorants were detected except for 2-methoxy-3，5-dimethylpyrazine and 2，4，6-trichloroanisole. This method is accurate and sensitive and may provide technical support for drinking water monitoring and relevant incidents responding.关键词：drinking water;odorants;gas chromatography;high-resolution mass spectrometry;liquid-liquid extraction41|26|0更新时间：2025-07-10 -
摘要：Khat is a common source plant for drugs，and cathinone，norpseudoephedrine，and norephedrine are its primary psychoactive components. The extraction conditions were optimized through the detection conditions such as chromatographic heating procedure and mass spectrometry acquisition mode，and the extraction conditions such as the concentration of hydrochloric acid aqueous solution，the amount of sodium hydroxide aqueous solution added，and whether it was concentrated or not. By using the technology of solvent extraction/GC-MS，a detection method of three alkaloids（norephedrine，norepseudoephedrine and cathinone） in dried Khat has been established. Sample was extracted with 0.05 mol/L hydrochloric acid aqueous，purified by aqueous sodium hydroxide solution，extracted with 6 mL of acetonitrile，and then concentrated by nitrogen blowing to 0.5 mL for the qualitative analysis of the cathinone，norephedrine and norepseudoephedrine components in the dried Khat，or 2 mL for the quantitative analysis of the norepseudoephedrine components in the dried Khat. The qualitative analysis was performed on a DB-5MS capillary column（30 m×0.25 mm×0.25 μm） with He as the carrier gas and an electron bombardment ion source（EI） in the full scan（SCAN） mode，and the quantitative analysis was performed in selected ion scan（SIM） mode. The results showed that the qualitative analysis method：the detection limits of the three alkaloids ranged from 13.39 mg/L to 23.43 mg/L，and norephedrine and norepseudoephedrine achieved effective resolution with a separation degree of 0.752. The quantitative analysis method：the limit of quantification（LOQ） for cathinone was 22.3 mg/L，and the recoveries of cathinone spiked at levels of 100 mg/kg，200 mg/kg were 109% and 111% ，the precision of the experimental instrument was 1.6%，the precision of the intra-day method was 1.7%，and the precision of the inter-day method was 2.8%. The method is quantitatively accurate and reproducible，which can meet the requirements of physicochemical test and identification of dry Kha.关键词：solvent extraction;gas chromatography-mass spectrometry;cathinone;Khat;alkaloids29|7|0更新时间：2025-07-10 -
摘要：As a class of porous materials，covalent organic polymers have the potential to be used as electrochemical sensors because of their large specific surface area，multiple active sites and strong designability. However，due to its poor electrical conductivity，its application as an electrocatalyst is limited. An effective strategy is to introduce a conductive phase. A novel covalent organic polymer Br-COPs was synthesized under solvothermal conditions. The structures were characterized by X-ray diffraction（XRD） and scanning electron microscopy（SEM）. XRD patterns showed that the prepared Br-COP had an amorphous structure. Scanning electron microscopy analysis showed that Br-COPs was a disc porous polymer. Br-COP was combined with multi-walled carbon nanotubes to modify the glass carbon electrode（GCE），which was used for the detection of dopamine. The experimental results showed that the synergistic effect of Br-COPs combined with multi-walled carbon nanotubes greatly improved the electrocatalytic dopamine performance of the modified electrode. Under the optimal conditions，the designed sensor responded quickly to dopamine，with a linear concentration range of 0.9-6.25 μmol/L and 12.5-400 μmol/L and a detection limit of 0.071 μmol/L. The sensor was successfully used to detect dopamine in real samples.关键词：Covalent organic polymer;multi-walled carbon nanotubes;dopamine;electrochemical sensor16|3|0更新时间：2025-07-10 -
摘要：In order to develop an electrochemical aptamer sensor for the sensitive detection of chloramphenicol（CAP），the label-free sulfhydryl-modified CAP-specific aptamer（Apt） was immobilized on the surface of the gold electrode through Au-S bonding. The sensitivity，specificity，and reproducibility of the sensor were investigated by electrochemical impedance spectroscopy（EIS），and the spiking tests were carried out using milk as the substrates. The results showed that the EIS response of the electrochemical aptamer sensor to CAP showed a good linear relationship in the range of 1-100 ng/mL，and the limit of detection（LOD） was 0.95 ng/mL. At the same time，the responses of the sensor to florfenicol（FFC），sulfadiazine（SDZ），and gentamicin（GEN） were significantly lower than that to CAP，indicating that the sensor had high selectivity. Furthermore，the EIS response of the sensor to CAP was still 90.06% of the initial signal after 14 days. With a relative standard deviation（RSD） of 3.7% for five electrodes prepared under the same conditions，the sensor exhibited good reproducibility and stability. The spiked recoveries in milk were 95.8%-111%，with RSD not more than 5.6%. It indicated that the established sensor could be used for the sensitive detection of CAP，which provided technical support and theoretical basis for the rapid and sensitive detection of CAP residues in animal-derived foods.关键词：aptamer;chloramphenicol;electrochemical aptamer sensor;electrochemical impedance spectroscopy;milk28|30|0更新时间：2025-07-10 -
摘要：A reduction in the level of phosphate in water bodies will result in the eutrophication of these ecosystems，which represents a significant threat to the ecological environment. Moreover，the existing phosphate detection technology is costly，time-consuming，and unable to meet the requirements for rapid detection and other pertinent criteria. A smartphone digital colorimetry （SDC） method based on phosphomolybdenum blue colorimetry was developed for the rapid determination of phosphate content in water bodies. The impact of diverse smartphone models，RGB values，shooting magnification，light source type and light intensity on the outcomes of SDC was examined in the experiments. The findings illustrated a favourable linear correlation between the red value（R-value） of phosphate and the HUAWEI P50e mobile phone within the concentration range of 0-800 μg·L-1，with the r2 value of 0.997 6. The variables included the red-channel value as the assay value，3× filming magnification，a white light source，and a high light intensity condition. The limit of detection of the method was 1.63 μg·L-1 and the limit of quantitation was 4.89 μg·L-1. Under the optimized conditions，two different concentrations of phosphate solutions，with the 100 μg·L-1 and 400 μg·L-1，were measured 10 times in parallel and the relative standard deviations（RSDs） were calculated to be 0.35% and 0.31%，respectively. Morever，the 400 μg·L-1 phosphate were further examined with intraday/interday RSDs（n=5） of 0.38% and 0.42%，respectively. The SDC method was employed for the determination of phosphate in four distinct real water bodies（tap water，rainwater，Siya River water and Baiyun Lake water），with spiked recoveries ranging from 96.1% to 101%. This indicates that the method is both feasible and accurate，providing a novel approach for the rapid determination of phosphate in aquatic environments in the field.关键词：digital colorimetric method;smartphone;rapid detection;phosphomolybdenum blue photometry;phosphate48|57|0更新时间：2025-07-10 -
摘要：The aquaculture industry faces frequent disease outbreaks due to issues such as high stocking density and environmental deterioration. Pathogenic bacteria have a rapid infection rate and high mortality rate. Once an outbreak occurs，it can cause serious economic harm to the aquaculture sector. Edwardsiella tarda is a highly harmful pathogenic bacterium in aquaculture. Rapid and efficient field detection methods can effectively prevent and control disease outbreaks. Rolling circle amplification（RCA） with lateral flow strip（LFS） technology，using latex microspheres as labels was combined to establish a novel RCA-LFS method for detecting E. tarda. This method has three steps in total. First，a conservative sequence of the unique gene of gyrb of this bacterium was used to designed the padlock probe and corresponding primer pair，and the Taq DNA ligase was used to circularize the single-stranded padlock probe. Then exonuclease Ⅰ was used to digest the uncircled single-stranded nucleic acid，and the circled padlock probe was rolling circle amplified by Bst DNA polymerase and primers. Finally the LFS was directly inserted into the amplification product solution for visual result reading just need to wait 15 min. The optimized RCA conditions was determined to be as follows：locking probe concentration，500 pmol/L；amplification temperature，61 ℃；and amplification time，50 min. The positive results showed a striking blue band on LFS detection line while a red band on quality control line. The negative results showed nothing on LFS detection line while a red band on quality control line. The RCA-LFS assay was specific，displaying no cross-reactivity with other common pathogenic bacteria. The detection limit for E. tarda genomic DNA was 50 ng/mL. Compared to the polymerase chain reaction（PCR） amplification，the reaction condition of RCA was stable. A large number of nucleic acid amplification could be completed without thermal circulation meter. Therefore，RCA was a kind of field detection method more suitable than PCR. Compared with common colloidal gold markers，latex microspheres were stable and colorful，and it was possible to achieve simultaneous detection of multiple bacteria through color changes alone. In addition，the established RCA-LFS simplified the operational steps by eliminating the need to detect probe hybridization；instead，it directly used LFS for detection after rolling circle amplification. The RCA-LFS method was used to detect samples of infected Anguilla japonica with E. tarda. We could get E. tarda positive result from sample DNA in liver，intestine，muscle，kidney and gill. The results were consistent with those obtained from conventional gel electrophoresis. This method was simpler，faster，and easier for result interpretation. RCA-LFS significantly promoted field detection of pathogenic bacteria.关键词：rolling circle amplification;Edwardsiella tarda;padlock probe;latex microspheres;lateral flow strip23|20|0更新时间：2025-07-10 -
摘要：A method for determination of glyceryl glucoside in cosmetics was established in this paper. The sample is extracted with 10% methanol water by ultrasonic extraction and vortex shaking，and the supernatant was filtered through a filter membrane before being tested on the instrument. The system used was a Hamilton RCX-30 anion exchange column，a pulse amperometric detector，a gold working electrode，a flow rate of 1 mL/min，ion chromatography measurement，and external standard quantification. The extraction solvent，extraction time，matrix effect were analyzed and studied. The results showed that glyceryl glucoside had good linearity within the concentration range of 0.1-5.0 mg/L，with recoveries of 96.0%-108% and relative standard deviations of 1.2%-5.0%，and correlation coefficient of 0.999 7. The detection limit is 0.2 mg/kg. The method is simple，efficient，and has good repeatability and stability，making it suitable for the accurate determination of glyceryl glucoside in cosmetics.关键词：pulse amperage;ion chromatography;glyceryl glucoside;cosmetics36|28|0更新时间：2025-07-10 -
摘要：The ability to integrate theory with practice and the systematic scientific thought are essential for undergraduate students. In order to improve this ability and promote the students from textbooks to practical application scenarios，this comprehensive experiment course that introduce the whole processes in the national/occupational standards of nucleic acid detection was designed，which included the sampling and extraction of nucleic acid， polymerase chian reaction （PCR） and loop-mediated isothermal amplification （LAMP） of the target nucleic acid，signal detection by real-time quantification PCR and polyacrylamide gel electrophoresis. The students can systematically and thoroughly acquire the knowledge of nucleic acid amplification in the current situation of their clinical applications. Meanwhile，the mini lecture about cutting-edge nucleic acid amplification researches was conducted during the waiting time，which can integrate the scientific research with clinical testing. In addition，the ideological and political education is brought in to trigger the idea of hard working by the introduction of scientists in nucleic acid detection. In conclusion，this course can consolidate the knowledge and stimulate the initiative of learning，which can lay a solid foundation for the future learning，research and employment.关键词：Clinical testing;nucleic acid amplification;COVID-19 detection;experiment course design29|52|0更新时间：2025-07-10
Experimental Techniques and Methods
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摘要：Chirality is a phenomenon that widely exists in nature. Chiral separation is significant in biochemical fields such as pharmacology，catalysis，and pesticide chemistry. Chiral porous organic materials are emerging materials with unique structures and functions that demonstrate huge potential applications in the field of chiral separation. These materials mainly include chiral metal-organic frameworks（CMOFs），chiral covalent organic frameworks（CCOFs），chiral porous organic cages（CPOCs），and so on. Due to their characteristics such as high porosity，large specific surface area，and flexibly adjustable pore structures，they have shown extensive application values in fields like gas adsorption，molecular separation，and chiral catalysis. Firstly，this article introduces the classifications of some typical chiral porous organic materials，as well as synthesis methods such as direct synthesis，post-modification synthesis，chiral induction，and self-assembly. It mainly summarizes the latest applications of chiral porous organic materials as chiral separation media in the chromatographic field in recent years，including gas chromatography（GC），high-performance liquid chromatography（HPLC），capillary electrochromatography（CEC），and membrane separation. Finally，it briefly outlines the difficulties and challenges existing in chiral separation when chiral porous organic materials are used as media and their future development trends.关键词：chirality;porous organic materials;synthesis methods;chromatographic separation;membrane separation29|41|0更新时间：2025-07-10 -
摘要：Methamphetamine（METH），as one of the most widely abused illegal drugs globally，poses severe risks to human health and significant threats to public safety and social stability due to its high addictive potential. Therefore，the detection of methamphetamine in various samples is of great significance for maintaining social stability and ensuring people's life and health. Gold nanomaterials are nanoscale materials composed of gold elements，with sizes ranging of 1-100 nm. Due to their unique physical，chemical，optical，and biological properties，gold nanomaterials hold significant potential for applications in areas such as sensor designing，catalytic chemistry，and biomedicine. Illegal drug molecule sensors based on gold nanomaterials have become a research focus in nanotechnology due to their excellent chemical and optical properties. This paper provides a comprehensive review of the development of various sensor or detecting techniques based on gold nanomaterials for methamphetamine detection. The application progress of methods such as colorimetry，fluorescence spectroscopy，electrochemical techniques，and surface-enhanced Raman spectroscopy（SERS） based on gold nanomaterials for methamphetamine detection were demonstrated. Additionally，the principles and performance of these different detection methods are discussed in detail. Finally，the prospect for research future，development directions，and application potential of gold nanomaterials in the detection of illegal drugs are explained.关键词：gold nanomaterials;nanosensor;methamphetamine（METH）;illegal drug detection20|45|0更新时间：2025-07-10
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