Journal of chromatography open最新文献

{"title":"Application of high-performance liquid chromatography with electrochemical detection for the analysis of N-(1,3-dimethylbutyl)-N’-phenyl-p-phenylenediamine quinone in ambient particulates","authors":"Natsumi Okawa ,&nbsp;Akira Ito ,&nbsp;Vonika Ka-Man Au ,&nbsp;Nozomu Tsuchiya ,&nbsp;Takayuki Kameda","doi":"10.1016/j.jcoa.2025.100232","DOIUrl":"10.1016/j.jcoa.2025.100232","url":null,"abstract":"<div><div>A simple and sensitive high-performance liquid chromatography (HPLC) method with electrochemical detection (ECD) was developed for measuring <em>N</em>-(1,3-dimethylbutyl)-<em>N’</em>-phenyl-<em>p</em>-phenylenediamine quinone (6-PPDQ) in environmental samples. The system used C30 columns for sample separation and a dual-mode electrochemical detector with a reduction cell, followed by an oxidation/detection cell connected in series. Under the optimal reduction voltage (–600 mV vs. Au) and optimal oxidation voltage (+600 mV vs. Ag/AgCl), the assay demonstrated high accuracy (96 %–107 %) when applied to airborne particulate sample extracts spiked with known amounts of 6-PPDQ. The detection limit was 3 fmol per injection (signal-to-noise ratio = 3), with a calibration range of 0.1–100 pmol, exhibiting excellent linearity (<em>R²</em> &gt; 0.9995). Using this newly developed HPLC-ECD analytical method with simple sample preparation, daily variations in 6-PPDQ concentrations in airborne particles collected in Kyoto, Japan, ranging from 21 to 165 fmol m^–3 (<em>n</em> = 20), were successfully measured, highlighting the high potential of this HPLC-ECD method for routine trace analysis in environmental samples.</div></div>","PeriodicalId":93576,"journal":{"name":"Journal of chromatography open","volume":"7 ","pages":"Article 100232"},"PeriodicalIF":0.0,"publicationDate":"2025-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144242861","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Development, optimisation, and pre-validation of a gas chromatography—Ion mobility spectrometry method with preliminary twofold enrichment for the sensitive detection of NNitrosamines in drinking water","authors":"Jana Hinz ,&nbsp;Kaliyani Wickneswaran ,&nbsp;Ursula Telgheder ,&nbsp;Michaela Wirtz","doi":"10.1016/j.jcoa.2025.100220","DOIUrl":"10.1016/j.jcoa.2025.100220","url":null,"abstract":"<div><div>N<img>Nitrosamines have long been identified as a relevant contaminant in potable water due to their identification as probable human carcinogens. Thus, highly sensitive detection of these pollutants in the ultra-trace range is imperative to comply with strict regulatory specifications. To this end, many institutions rely on mass spectrometry-based analysis methods, which have the disadvantage of being cost- and resource intensive. This study aims to develop, optimise, and evaluate a gas chromatography-drift tube-ion mobility spectrometry (GC-IMS) based method with a twofold enrichment strategy consisting of solid phase extraction (SPE) followed by in-tube extraction (ITEX) of the eluate for nine different nitrosamines in drinking water in order to offer a sensitive alternative to the current state of the art. Optimisation of ITEX parameters was successfully performed using a simplex self-directing design approach, so that a calibration range between 5 and 50 ng/L could be achieved. The suitability of a linear regression model was demonstrated via analysis of variance (ANOVA) criteria. The analysis of different spiked drinking water samples allowed for the determination of the method’s accuracy (27.3 – 114.5 % across different nitrosamine analytes and matrices, with most above 70 % recovery) and detection limits (1.12 – 12.48 ng/L across different nitrosamine analytes and matrices), which fall within the range of required limit values. Tested drinking waters show innate nitrosamine concentrations well below detection limits and can thus be deemed free from contaminants.</div></div>","PeriodicalId":93576,"journal":{"name":"Journal of chromatography open","volume":"7 ","pages":"Article 100220"},"PeriodicalIF":0.0,"publicationDate":"2025-04-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143874825","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Biochar-based contaminant removal: A tutorial on analytical quality assurance and best practices in batch sorption","authors":"Tellulah A. Fernando ,&nbsp;Dinushi N. Fernando ,&nbsp;Sameera R. Gunatilake ,&nbsp;Chanaka Navarathna ,&nbsp;Xuefeng Zhang","doi":"10.1016/j.jcoa.2025.100219","DOIUrl":"10.1016/j.jcoa.2025.100219","url":null,"abstract":"<div><div>Biochar, a biomass-derived, ubiquitous, porous, carbonaceous material that is rich in surface functional groups, is a research frontier in water remediation due to its sustainability and efficacy. The accuracy and the reliability of laboratory scale biochar-based batch sorption experiments are essential for a successful transition to pilot scale applications. The accuracy in preparation of solutions, proper storage conditions, and selection of the most appropriate instrumental method and its corresponding sensitivity, selectivity, detection limits and repeatability should be assessed to ensure analytical quality assurance (QA) during the quantification of analytes. A comprehensive batch sorption study involves optimizing sorption parameters and conducting kinetic studies, isotherm fitting, regeneration studies, competitive sorption experiments, and evaluating remediation in a real water matrix. Moreover, sorption parameters such as the pH, and contact time, should be optimized through iterative adjustments utilizing standard procedures to avoid erroneous assessments. Biochar-based sorption studies are conducted by scientists from various disciplines; thus, there is a propensity to overlook the above-mentioned factors which can impact the credibility of results. This tutorial aims to bridge this gap by expounding analytical QA and best practices in batch sorption experiments, ensuring accuracy to obtain reliable results and conclusions.</div></div>","PeriodicalId":93576,"journal":{"name":"Journal of chromatography open","volume":"7 ","pages":"Article 100219"},"PeriodicalIF":0.0,"publicationDate":"2025-04-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143869435","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A high-performance liquid chromatography method for detecting acylation impurities in acetate triptorelin microspheres for injection","authors":"Yan-nan Zan ,&nbsp;Yu Chen ,&nbsp;Fei Xie ,&nbsp;Shao-hua Shang ,&nbsp;Ning Chen ,&nbsp;Yi-mei Ding","doi":"10.1016/j.jcoa.2025.100218","DOIUrl":"10.1016/j.jcoa.2025.100218","url":null,"abstract":"<div><div>An efficient high-performance liquid chromatography (HPLC) method was established to detect acylated impurities in triptorelin acetate microspheres for injection. Additionally, HPLC coupled with quadrupole time-of-flight tandem mass spectrometry (HPLC-QTOF-MS) was employed to identify the types of acylated impurities. In HPLC, the separation of triptorelin and its acylated impurities was achieved on a Welch Ultimate XB-C18 column (250 mm × 4 mm, 5 μm). The mobile phase consisted of a 20 mmol·L^-1 aqueous solution of ammonium acetate (pH 6.9) and acetonitrile, delivered in a gradient elution mode with a flow rate of 0.5 mL min^-1. The detection wavelength was set at 210 nm. For the HPLC-QTOF-MS method, the aforementioned HPLC conditions were utilized, and the mass spectrometer employed an electrospray ionization (ESI) ion source in positive ion mode. The scanning range spanned from 100 to 2000 <em>m/z</em>. The carrier gas was N₂, with an atomization gas flow rate of 3 L·min^-1. The interface voltage was maintained at 4.5 kV, the desolvation temperature at 250 °C, and the drying gas flow rate at 15 L·min^-1. Additionally, the heating block temperature was set at 400 °C, and the interface temperature at 350 °C.</div></div><div><h3>Results</h3><div>Using this method, 14 types of acylated impurities in triptorelin were identified, further confirming that the acylation site of triptorelin is the serine alcohol hydroxyl group.</div></div><div><h3>Conclusion</h3><div>Both the HPLC and HPLC-QTOF-MS methods can be effectively utilized for routine quality control analysis of triptorelin acetate microspheres for injection.</div></div>","PeriodicalId":93576,"journal":{"name":"Journal of chromatography open","volume":"7 ","pages":"Article 100218"},"PeriodicalIF":0.0,"publicationDate":"2025-04-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143855763","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Green analytical protocol for the liquid chromatographic determination of ketoprofen in human urine after microextraction using Carbowax 20 M – modified cellulose membrane","authors":"Christina Patakidou ,&nbsp;Marianna Ntorkou ,&nbsp;Abuzar Kabir ,&nbsp;Constantinos K. Zacharis","doi":"10.1016/j.jcoa.2025.100217","DOIUrl":"10.1016/j.jcoa.2025.100217","url":null,"abstract":"<div><div>A Carbowax 20 M – modified cellulose membrane was utilized for the fabric sorptive phase extraction of ketoprofen from human urine samples followed by liquid chromatographic analysis. Among the various sorbents examined, the sol-gel Carbowax 20M-modified fabric phase sorptive extraction membrane was found to be the most effective for the drug extraction. Due to their engineered affinity, these membranes exhibit high permeability, enabling the extraction of biological samples without prior pretreatment. Experimental parameters were systematically studied and optimized using a face-centered central composite design and one-factor-at-a-time approaches. The analytical method was validated for linearity (25 – 2000 ng/mL), selectivity, limit of detection (LOD) (8 ng/mL), limit of quantitation (25 ng/mL), precision (&lt;10.2 % in all cases), and accuracy (relative recovery: 82.9–101.6 %). The membranes maintained their performance for at least 30 extractions, with a maximum allowable deviation of 10 % from the initial performance. The green character and the applicability of the method were evaluated through ComplexMoGAPI, BAGI, AGREE and AGREEprep tools. The final method was successfully applied to detect ketoprofen in authentic human urine samples after oral administration of a ketoprofen-containing tablet (25 mg/tab).</div></div>","PeriodicalId":93576,"journal":{"name":"Journal of chromatography open","volume":"7 ","pages":"Article 100217"},"PeriodicalIF":0.0,"publicationDate":"2025-04-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143799394","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A high-performance liquid chromatography with fluorescence detection for measurement of hydrogen sulfide in rat plasma","authors":"Wumei Shi,&nbsp;Rui Zhang,&nbsp;Xiaoyan Wu,&nbsp;Qingfeng Yu,&nbsp;Ying Xiao","doi":"10.1016/j.jcoa.2025.100216","DOIUrl":"10.1016/j.jcoa.2025.100216","url":null,"abstract":"<div><div>Hydrogen sulfide (H₂S), previously known as a toxic gas with a rotten egg odor, is now the third largest gasotransmitters after carbon monoxide (CO) and nitric oxide (NO). Precisely determining the levels of H₂S in organisms is crucial for elucidating the biological functions of H₂S and treating H₂S-related diseases. This study presents a novel and sensitive high-performance liquid chromatographic method coupled with fluorescence detection (HPLC-FL) for measuring the concentration of H₂S in plasma using (maleimide) ethyl 4-(pyren-1-yl) butanoate (MEPB) as a derivatization reagent. In particular, we employed the standard addition method to exclude potential interference from complex endogenous substances in plasma. This HPLC-FL approach was validated in accordance with ICH and FDA guidelines, confirming its specificity, linearity, accuracy, precision and stability. Compared with classical UV-Vis method, this HPLC-FL method provides higher sensitivity and specificity for more accurate detection of H₂S in plasma, attributable to the distinct sample pretreatment and derivatization conditions. HPLC-FL method was further utilized in assessing the release kinetics of H₂S from 5-(4-hydroxyphenyl)-3H-1,2-dithiole-3thione (ADT-OH) in rat plasma. To our knowledge, this is the first application of MEPB for the determination of H₂S in plasma.</div></div>","PeriodicalId":93576,"journal":{"name":"Journal of chromatography open","volume":"7 ","pages":"Article 100216"},"PeriodicalIF":0.0,"publicationDate":"2025-03-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143704183","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Advancing clinical liquid chromatography-mass spectrometry analysis: Rational design and optimization of derivatization techniques for enhanced sensitivity and throughput","authors":"Hua-Ming Xiao ,&nbsp;Azamat Temerdashev ,&nbsp;Na An ,&nbsp;Quan-Fei Zhu ,&nbsp;Yu-Qi Feng","doi":"10.1016/j.jcoa.2025.100215","DOIUrl":"10.1016/j.jcoa.2025.100215","url":null,"abstract":"<div><div>Clinical laboratories are engaged in early disease diagnosis, health status monitoring, and clinical outcome prediction through the analysis of small-molecule analytes, thereby facilitating precise clinical decision-making. In comparison with immunoassays, liquid chromatography-tandem mass spectrometry (LC-MS/MS) methods provide enhanced detection coverage, sensitivity, and specificity, and also improve comparability between laboratories. Their utilization has markedly increased across various clinical conditions. However, certain small-molecule analytes in clinical laboratory studies exhibit limited stability during sample storage or pretreatment and demonstrate poor detection sensitivity and specificity in LC-MS/MS analysis due to complex matrices and other factors, such as lack of an easily ionizable group. Chemical derivatization has emerged as a straightforward and efficient tool to facilitate the LC-MS/MS analysis of certain analytes since the introduction of butylation of amino acids for neonatal screening. This review focuses on discussing chemical derivatization-based LC-MS/MS methods for small-molecule analyte screening in traditional clinical laboratories. Nearly 20 years of publications on this topic indicate that chemical derivatization improves chemical stability or storage lifetime, detection sensitivity and specificity, as well as screening coverage for diseases or other clinical applications such as clinical diagnosis and new drug evaluation for disease therapy. The discussion emphasizes the application of chemical derivatization in LC-MS/MS-based clinical studies concerning detection-oriented parameters (coverage, sensitivity, throughput), separation-oriented aspects (specificity), along with metabolite stability and structural integrity, suggesting it has the potential to be established as one of the standard tools for determination of small-molecule analytes in clinical laboratories.</div></div>","PeriodicalId":93576,"journal":{"name":"Journal of chromatography open","volume":"7 ","pages":"Article 100215"},"PeriodicalIF":0.0,"publicationDate":"2025-03-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143696803","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Assessment of machine learning and group contribution solvation parameter model descriptors for model retention in reversed-phase liquid chromatography and gas chromatography","authors":"Sanka N. Atapattu ,&nbsp;Azamat Temerdashev","doi":"10.1016/j.jcoa.2025.100213","DOIUrl":"10.1016/j.jcoa.2025.100213","url":null,"abstract":"<div><div>Abraham's solvation parameter model is a valuable tool for modelling reversed-phase liquid chromatography and gas chromatography systems. Except for the solute descriptor McGowan's characteristic volume, V, the remaining solute descriptors E, S, A, B, and L of the solvation parameter model are experimentally determined. Estimation approaches, machine learning, and group contribution methods are two alternatives to experimental approaches to estimating solute descriptors. In this work we evaluated the applicability of solvation parameter model solute descriptors estimated using machine learning and group contribution methods. Overall solute descriptors estimated using the machine learning approach fit better than solute descriptors estimated using the group contribution method for both reversed-phase liquid chromatography and gas chromatography systems studied in this work. For the studied methanol-water binary solvent system on a Luna C18(2) stationary phase model, coefficient of determination ranged from 0.982 to 0.953 when using machine learning estimated descriptors, whereas with group contribution estimated descriptors, models ranged between 0.923 and 0.943. For the studied gas chromatography models, coefficient of determination ranged from 0.995 to 0.987 when using machine learning estimated descriptors, whereas with group contribution estimated descriptors ranged between 0.941 and 0.977. However, both machine learning and group contribution descriptors did not fit in models as well as experimentally determined reference WSU descriptors.</div></div>","PeriodicalId":93576,"journal":{"name":"Journal of chromatography open","volume":"7 ","pages":"Article 100213"},"PeriodicalIF":0.0,"publicationDate":"2025-03-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143631823","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Separation, identification, and quantification of dicyclohexylformyl oxyphenisatin, an illegal additive, from a fruit and vegetable plum","authors":"Wanqin Wu ,&nbsp;Songsong Zhu ,&nbsp;Jintao Xia ,&nbsp;Feng Jiang ,&nbsp;Xiaolong Fan ,&nbsp;Li Zhang","doi":"10.1016/j.jcoa.2025.100214","DOIUrl":"10.1016/j.jcoa.2025.100214","url":null,"abstract":"<div><h3>Purpose</h3><div>This study is to develop an effective method for separating, identifying, and quantifying suspected illegal additives from fruit and vegetable plums.</div></div><div><h3>Methods</h3><div>Ultra performance liquid chromatography coupled with quadrupole-time-of-flight mass spectrometry (UPLC-Q-TOF/MS) was employed to perform non-targeted screening of illegal additives from more than 10 batches of fruit and vegetable plums. A diesterified oxyphenisatin analog never detected before in foodstuffs was identified from a batch of fruit and vegetable plum. This analog was separated and purified by column chromatography, and its molecular structure was analyzed and identified using one dimension and two dimension-nuclear magnetic resonance spectra (1D and 2D NMR). After obtaining the synthesized reference standard, an UPLC-PDA detection method for the quantitative analysis of this analog in real samples was established.</div></div><div><h3>Results</h3><div>The results showed that the characteristic fragment ions with mass/charge ratio (<em>m/z</em>) of 224.07 and 196.07 appeared in the MS² spectrum, indicating that the analog had the skeleton of oxyphenisatin. Combining the fitted molecular formula of suspected compound, its degree of unsaturation, and the fragment ions with mass/charge ratios of 428.18, 334.14, 83.08 in the secondary mass spectrum, we speculated that the anhydride of esterified oxyphenisatin might be cyclohexanecarboxylic anhydride, which was in good consistent with NMR spectroscopic analysis. Based on these findings, the analog was eventually named dicyclohexylformyl oxyphenisatin. UPLC-PDA test results showed that the content of this analog in a batch of fruit and vegetable plum was 614.0 mg/kg.</div></div><div><h3>Conclusion</h3><div>As far as we know, dicyclohexylformyl oxyphenisatin is not a food additive. Structurally, it is the product from dicyclohexylformylation of oxyphenisatin. The illegal addition of this analog to food will cause unknown harm to uninformed consumers and requires the attention of relevant departments.</div></div>","PeriodicalId":93576,"journal":{"name":"Journal of chromatography open","volume":"7 ","pages":"Article 100214"},"PeriodicalIF":0.0,"publicationDate":"2025-03-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143629260","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Simultaneous determination of ceftazidime and avibactam in patients by isocratic ion-pair liquid chromatography with photometric detection","authors":"Constantin Lier ,&nbsp;Frieder Kees ,&nbsp;Andrea Witowski ,&nbsp;Tim Rahmel ,&nbsp;Steffen Pockes ,&nbsp;Christoph Dorn","doi":"10.1016/j.jcoa.2025.100212","DOIUrl":"10.1016/j.jcoa.2025.100212","url":null,"abstract":"<div><div>A simple and fast HPLC-UV method is described for the simultaneous determination of total or free ceftazidime and avibactam in serum, which is suitable for therapeutic drug monitoring (TDM) or pharmacokinetic studies in man. Sufficient retention of the very polar avibactam was obtained by addition of tetrabutylammonium hydrogen sulfate (TBA) as ion pairing agent, thus allowing the determination of both drugs in serum by isocratic elution. Total concentrations were determined after protein precipitation with acetonitrile, free concentrations after ultrafiltration. Separation was performed using an XBridge BEH C18 column with a mobile phase consisting of 20 mM sodium phosphate buffer/acetonitrile 90:10 (v/v), pH 6.5, containing 5 mM TBA. The lower limit of quantification was 1 mg/L for ceftazidime and 0.5 mg/L for avibactam, respectively. The imprecision of the determination of total drug was &lt;3 %, the accuracy between 99.0 % and 104 %. Determination of free drug in quality control samples resulted in unbound fractions of 97.9 ± 2.0 % for ceftazidime and 99.4 ± 3.2 % for avibactam.</div></div>","PeriodicalId":93576,"journal":{"name":"Journal of chromatography open","volume":"7 ","pages":"Article 100212"},"PeriodicalIF":0.0,"publicationDate":"2025-03-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143620352","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}