Journal of Chromatography A最新文献

{"title":"A rapid protocol for distinguishing the quality of Sanshengyin and identifying potential markers by the “three-in-one” fingerprint profiles with antioxidant activity","authors":"Xiaoding Zhang ,&nbsp;Lingjiao Wang ,&nbsp;Rui Zong ,&nbsp;Zhongyang Zhang ,&nbsp;Fangfang Cheng ,&nbsp;Chaohui Song ,&nbsp;Guoxiang Sun ,&nbsp;Haixia Gao","doi":"10.1016/j.chroma.2024.465553","DOIUrl":"10.1016/j.chroma.2024.465553","url":null,"abstract":"<div><div>It is imperative to establish a standardized model for the quality control of traditional prescriptions, exemplified by Sanshengyin (SSY). This study introduces a multi-component and multi-level \"three-in-one\" fingerprint quality evaluation system designed to predict the comprehensive quality of traditional Chinese medicine (TCM). Initially, a five-wavelength high-performance liquid chromatography (HPLC) fusion spectrum was developed to enhance the stability of SSY within the chromatographic system. Additionally, a quantification method was employed to streamline the calculation and visualization processes of ultraviolet (UV) and infrared (IR) spectral systems. Through this approach, chromatographic and spectral fingerprints were amalgamated into a holistic analytical strategy. The average linear quantitative fingerprint method (ALQFM) was employed to swiftly differentiate the grades of 17 sample batches. Additionally, six quality markers were identified for content determination. Correlation analysis between the total content of these quality markers and macroscopic quantitative similarity was conducted to assess the accuracy of ALQFM in evaluating the quality of TCM represented by SSY. Finally, the binary correlation analysis model was employed to investigate the correlation between antioxidant activity and fingerprint profiles, facilitating the prediction of potential bioactive compounds in SSY. This research offers a straightforward, cost-effective, and holistic approach for assessing the quality consistency of TCM. The method is recommended for adoption by medical institutions and enterprises to enhance the standardization of TCM quality control.</div></div>","PeriodicalId":347,"journal":{"name":"Journal of Chromatography A","volume":"1740 ","pages":"Article 465553"},"PeriodicalIF":3.8,"publicationDate":"2024-11-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142756692","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Modeling the extra column volume of a micro simulated moving bed chromatography system: Introducing the equivalent radial flow rate distribution","authors":"Juliane Diehm,&nbsp;Matthias Franzreb","doi":"10.1016/j.chroma.2024.465543","DOIUrl":"10.1016/j.chroma.2024.465543","url":null,"abstract":"<div><div>Recently, the focus in chromatography model development has expanded to include the modeling of extra column volume (ECV), particularly in small- and lab-scale systems where ECV can constitute a significant portion of the total volume. Typically, ECV is modeled with 1D approaches, for example with combinations of dispersed plug flow reactors (DPFRs) and continuously stirred tank reactors (CSTRs). However, radial inhomogeneities in the ECV concentration profile necessitate higher-dimensional models for more accurate predictions. Searching for a suitable modeling approach for a micro simulated moving bed chromatography (<span><math><mi>μ</mi></math></span>SMB) system, we investigated whether the 2D laminar flow model can be extended to account for additional dispersion effects, such as Dean vortices, through an equivalent radial flow rate distribution (eqFRD). For this purpose, we conducted 3D CFD simulations of the respective ECV and adapted the radial flow rate profile of a 2D simulation to match the residence time distribution observed in the CFD results. Applying the eqFRD model led to a significant improvement in prediction accuracy for isolated ECV segments, increasing from 90% to 97% compared to traditional ECV models. However, when these models were applied to the full <span><math><mi>μ</mi></math></span>SMB system, the choice of ECV model had minimal impact on overall results as long as retention time within the ECV was accurately predicted. This suggests that, in the studied system, the column has a greater influence on peak shape than the ECV, allowing simpler ECV models to suffice in certain contexts. Despite these advances, significant deviations between predicted and experimental results were observed, indicating that factors such as the transition between the column and ECV, as well as detector effects, should be considered in future research. The results underscore the importance of selecting an ECV model in the context of the entire system, balancing accuracy with computational efficiency.</div></div>","PeriodicalId":347,"journal":{"name":"Journal of Chromatography A","volume":"1740 ","pages":"Article 465543"},"PeriodicalIF":3.8,"publicationDate":"2024-11-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142756549","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Separation of phenylpropionic acids both by strong anion exchange stationary phase and strong cation exchange stationary phase in supercritical fluid chromatography, using the same additive","authors":"Dandan Ge ,&nbsp;Yanxiong Ke ,&nbsp;Zimo Yu ,&nbsp;Jiahao Lu ,&nbsp;Songbo Chen ,&nbsp;Qi Zhang ,&nbsp;Qing Fu ,&nbsp;Yu Jin ,&nbsp;Xinmiao Liang","doi":"10.1016/j.chroma.2024.465555","DOIUrl":"10.1016/j.chroma.2024.465555","url":null,"abstract":"<div><div>This study demonstrates the expanded application of ion-exchange stationary phases (including strong cation exchange, SCX and strong anion exchange, SAX) in supercritical fluid chromatography (SFC), and more importantly, provides a deeper understanding of the retention mechanisms of these two stationary phases when using the same acidic additive. Phenylpropionic acid compounds (belonging to phenolic acids) were selected as probes. On the SCX column, the π-π and polar interactions originating from the bonded benzenesulfonic acid groups were important foundations for prolonging the retention time of solutes, but they were also the main reason for solutes’ tailing profiles. It was found that adding 0.1 % phosphoric acid can generate sufficient strength of electrostatic repulsion to obtain satisfactory peak shapes. Here, phosphoric acid can be adsorbed on the surface of the stationary phase to accumulate more negative charges, and at the same time, the phosphate anion and the phenylpropionic acid in mobile phase might combine into the contact ion pair (CIP)- like through the polar interactions to form the apparently negatively charged solute. On the SAX column, phosphate anions generated by ionization of phosphoric acid, were considered as counterions to effectively mask the electrostatic attraction of quaternary ammonium groups, to significantly reduce the retention of phenylpropionic acids, but improve their resolution. Finally, utilizing two developed SFC methods, i.e., SCX with MeOH + 0.1 % phosphoric acid in CO₂, or SAX with MeOH + 0.3 % phosphoric acid in CO₂, the baseline separation of the extract of <em>Lonicerae Japonicae Flos</em> was achieved within 6 min and 10 min, respectively.</div></div>","PeriodicalId":347,"journal":{"name":"Journal of Chromatography A","volume":"1739 ","pages":"Article 465555"},"PeriodicalIF":3.8,"publicationDate":"2024-11-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142744225","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Nontarget analysis of natural flavor metabolites in tobacco extracts","authors":"Xiu-Juan Xu ,&nbsp;Jian-Wei Wang ,&nbsp;Min Wang ,&nbsp;Shan Liu ,&nbsp;Meng Ren ,&nbsp;Chun-Qiang Yang ,&nbsp;Ren-Qi Wang","doi":"10.1016/j.chroma.2024.465554","DOIUrl":"10.1016/j.chroma.2024.465554","url":null,"abstract":"<div><div>Large-scale production of tobacco generates significant amounts of waste, making the reuse and recycling of tobacco waste crucial for sustainability. However, the high diversity of tobacco metabolites requires a comprehensive analysis of tobacco waste extracts, so as to optimize extraction selectivity and recovery. In this study, we thoroughly analyzed the metabolic composition of 168 tobacco extracts using nontarget analysis. The extracts were derived from 56 tobacco wastes covering all four major tobacco types: flue-cured, dark air-cured, Burley, and Oriental tobaccos. From each sample, we obtained three types of extracts, such as concretes, absolutes, and supercritical fluid extraction (SFE) oils, through various extraction protocols. By matching deconvolved experimental MS/MS spectra with databases, 587 metabolites were putatively annotated, which were categorized into 24 groups, including alkaloids, indoles, and flavor compounds. The metabolic compositions of extracts from dark air-cured and Burley tobaccos were found to be similar, whereas flue-cured and Oriental tobaccos contained more diverse flavor components. Notably, concretes of various tobaccos prepared with 70 %-ethanol contained similar amounts of addictive alkaloids. However, the absolutes obtained by sequential extraction of these concretes with 95 %-ethanol effectively removed alkaloids while modestly maintaining the flavor compounds. Conversely, extraction protocols incorporating supercritical fluid extraction followed by 95 %-ethanol extraction resulted in the loss of most flavor compounds, likely due to the incompatibility between the solvents used in the two extraction steps. In conclusion, our study demonstrates that absolutes derived through secondary extraction with varying ethanol-water ratios holds significant potential for utilization.</div></div>","PeriodicalId":347,"journal":{"name":"Journal of Chromatography A","volume":"1740 ","pages":"Article 465554"},"PeriodicalIF":3.8,"publicationDate":"2024-11-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142756550","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Features of gas chromatographic analysis of thermally unstable compounds","authors":"Igor G. Zenkevich,&nbsp;Tatiana A. Kornilova","doi":"10.1016/j.chroma.2024.465508","DOIUrl":"10.1016/j.chroma.2024.465508","url":null,"abstract":"<div><div>Confirming the stability of analytes during gas chromatographic (GC) analysis is an important criterion, especially for previously uncharacterized compounds. However, the variations of absolute peak areas at different injector temperatures usually do not allow us to reveal the thermal instability of analytes during GC analysis. Such variations may be caused by peak area known discrimination typical for using capillary columns, especially at low split injection. The thermal instability can be revealed only when using relative peak areas.</div><div>The dependences of the relative peak areas of unstable analytes on the injector temperature (descending), as well as similar dependences for products of their decomposition (ascending), are characterized by the existence of two limits. Low-temperature limits correspond to the initial quantities of unstable analytes, and high-temperature limits, to their complete transformations. Such dependences can be approximated with an equation of logistic regression (synonymous: sigmoid or Boltzmann approximation).</div><div>The relationships and features of gas chromatographic analysis of thermally unstable compounds are considered with products of free-radical isopropylbenzene (cumene) chlorination and with solutions of ethyl diazoacetate in different solvents as examples. The major cumene chlorination product, (1-chloro-1-methylethyl)benzene, undergoes dehydrochlorination at injector temperatures above 200 °С to form a single product, α-methylstyrene. The analysis of the ethyl diazoacetate solutions is accompanied by the formation of ethyl alkoxyacetates, products of the insertion of intermediate ethoxycarbonylcarbene into O<img>H bonds of alcohols, if they are used as solvents. Comparing the temperatures of half-conversion of the initial ester, <em>T</em>(50 %), and half-formation of the products shows that they are equal to each other. This confirms both the process mechanism and the correctness of the data approximation.</div></div>","PeriodicalId":347,"journal":{"name":"Journal of Chromatography A","volume":"1740 ","pages":"Article 465508"},"PeriodicalIF":3.8,"publicationDate":"2024-11-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142756694","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Retention behavior of Hg2+, MeHg+, thimerosal and phenylmercuric acetate on a C18 RP-HPLC column","authors":"Minh Van Khanh Le,&nbsp;Negar Pourzadi,&nbsp;Jürgen Gailer","doi":"10.1016/j.chroma.2024.465546","DOIUrl":"10.1016/j.chroma.2024.465546","url":null,"abstract":"<div><div>Humans are exposed to potentially toxic mercuric mercury (Hg²⁺) and methylmercury (MeHg⁺) by the ingestion of food, to the bactericidal vaccine additive thimerosal (THI), and/or to the antifungal compound phenylmercuric acetate (PMA) which is used in some lens cleaning ophthalmic fluids. While numerous HPLC methods have been developed to separate Hg²⁺ and MeHg⁺ in environmental samples (e.g. food, surface waters), comparatively few have been reported for THI and PMA, in part owing to their increased hydrophobicity. We investigated the retention behavior of Hg²⁺, MeHg⁺, THI and PMA on a reversed-phase (RP) HPLC column using a flame atomic absorption spectrometer (FAAS) as a Hg-specific detector. Mobile phases comprised of 50 mM phosphate buffer (pH 7.4) with acetonitrile (ACN) concentrations of 30–50 % (v:v) produced single Hg-peaks, which eluted in the order THI, Hg²⁺, MeHg⁺ and PMA. With the 50 % ACN mobile phase, all mercurials eluted within 5 min. While the utilization of a FAAS precludes the analysis of environmental waters with the developed RP-HPLC-FAAS method, the latter is useful to probe the stability of THI and PMA in the presence of physiologically relevant concentrations of salt (100 mM in blood plasma) and l-cysteine (0.5 mM in hepatocyte cytosol), which is important as both mercurials have been recently shown to effectively inhibit the main protease of SARS-CoV-2, though the actual inhibitory Hg-species is unknown.</div></div>","PeriodicalId":347,"journal":{"name":"Journal of Chromatography A","volume":"1739 ","pages":"Article 465546"},"PeriodicalIF":3.8,"publicationDate":"2024-11-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142722488","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Construction of poly (styrene-divinylbenzene)@tris(4-aminophenyl)amine-p-phthalaldehyde-triethylenetetramine core-shell microspheres for the preparation of ion chromatography stationary phase","authors":"Junwei Liu,&nbsp;Yidan Zhang,&nbsp;Yuqi Yan,&nbsp;Haojie Li,&nbsp;Qichao Zhang,&nbsp;Guoqing Wang,&nbsp;Yu-an Sun","doi":"10.1016/j.chroma.2024.465549","DOIUrl":"10.1016/j.chroma.2024.465549","url":null,"abstract":"<div><div>Core-shell composite microspheres are increasingly favored for the development of stationary phases due to their ability to integrate the monodispersity of inner core with the functional versatility of outer shell. In this study, poly(styrene-divinylbenzene)@(tris(4-aminophenyl)amine-<em>p</em>-phthalaldehyde-triethylenetetramine) (PS-DVB@TAPA-PPA-TETA) core-shell composite microspheres were constructed via an amine-aldehyde condensation reaction. The resultant microspheres were subsequently quaternized using the residual amine groups of TETA in the shell to create an effective anion-exchange stationary phase. The composite microspheres were characterized by SEM, FTIR, N₂ adsorption-desorption experiment, et al. According to the results, the surface of PS-DVB microspheres was wholly covered by TAPA-PPA-TETA. The obtained PS-DVB@TAPA-PPA-TETA exhibited good reactivity, mechanical and chemical stability. The customized column exhibited good separation performance for seven conventional anions, five organic acids and three carbohydrates. The results demonstrate that PS-DVB@TAPA-PPA-TETA is a highly suitable material for the preparation of ion chromatographic stationary phase, exhibiting exceptional chemical stability and robust chromatographic performance in practical application. Finally, the customized column was successfully utilized for the determination of phosphate in waste acid sample.</div></div>","PeriodicalId":347,"journal":{"name":"Journal of Chromatography A","volume":"1739 ","pages":"Article 465549"},"PeriodicalIF":3.8,"publicationDate":"2024-11-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142722586","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A combination screening strategy based on UPLC-HRMS and UPLC-MRM for the comprehensive analysis of malonyl-substituted flavonoid glycosides in Astragalus","authors":"Yaxuan Guo ,&nbsp;Yuyao Li ,&nbsp;Yukun Wang ,&nbsp;Yuanpeng Hao ,&nbsp;Yaru Yan ,&nbsp;Xuemei Qin ,&nbsp;Zhenyu Li","doi":"10.1016/j.chroma.2024.465548","DOIUrl":"10.1016/j.chroma.2024.465548","url":null,"abstract":"<div><div>Recently, malonylated glycosides have received increasing attention in the study of medicinal plants due to their significant physiological functions. A few malonyl-substituted flavonoid glycosides (MFGs) have been reported in Astragalus, however, the number of MFGs was limited. This study established screening strategies based on ultra-high-performance liquid chromatography - high resolution mass spectrometry (UPLC-HRMS) and ultra-high-performance liquid chromatography - multiple reaction monitoring (UPLC-MRM) to screen and quantify MFGs in Astragalus. In the UPLC-HRMS strategy, the neutral loss values of 248.0526 Da and 85.9998 Da, along with the fragmentation patterns of flavonoid aglycones, were utilized as criteria for the selection of MFGs. In the UPLC-MRM strategy, the ion pair [M+H]⁺/[Aglycone+H]⁺ was designated as the primary characteristic ion pair for candidate MFGs. Additionally, the ion pair [M+H]⁺/[M-Mal+H]⁺ was selected as a secondary ion pair to facilitate validation. A total of 48 and 133 MFGs were screened from Astragalus using the UPLC-HRMS strategy and UPLC-MRM strategy, respectively. Thus, more MFGs were screened by the UPLC-MRM strategy, which demonstrates its advantage over the UPLC-HRMS strategy. The UPLC-MRM method was applied to the screening of MFGs in different parts of Astragalus samples, and further analytical assessments revealed a significant correlation between the structures of MFGs and the expression of malonyltransferase genes in Astragalus samples. In conclusion, we provide an efficient screening strategy for the analysis of MFGs in Astragalus, laying a foundation for the study of these compounds.</div></div>","PeriodicalId":347,"journal":{"name":"Journal of Chromatography A","volume":"1739 ","pages":"Article 465548"},"PeriodicalIF":3.8,"publicationDate":"2024-11-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142744226","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Improving the sustainability of biopharmaceutical downstream processing through buffer recycling","authors":"Madelène Isaksson,&nbsp;Niklas Andersson,&nbsp;Bernt Nilsson","doi":"10.1016/j.chroma.2024.465545","DOIUrl":"10.1016/j.chroma.2024.465545","url":null,"abstract":"<div><div>The production of biopharmaceuticals is a chemical- and water-intensive process. The consumption of water and chemicals is partly due to the need for many different buffers in large volumes during the downstream process, typically consisting of several chromatography steps. Given the global commitment to the goals for sustainable development and the anticipated growth of the biopharmaceutical market, the consumption of large buffer volumes is expected to become problematic. To address this, we propose the introduction of buffer recycling to reduce the consumption of water and chemicals. For solvent based pharmaceutical processes, solvent recycling through re-distillation is already established, but for water-based processes, this concept is still rather unexplored.</div><div>In this study, buffer recycling was implemented during the equilibration phase of Protein A chromatography for antibody purification. We have investigated the potential gains of buffer recycling and demonstrated buffer recycling in two technical implementations: buffer recycling in a batch-to-batch process and buffer recycling in a multi-column process. Buffer recycling consists of buffer recovery and buffer reuse. During recovery, buffer that has been used during equilibration is collected and pH adjusted, and during the reuse step, the recovered buffer is reintroduced into the process. By introducing buffer recycling, we could reduce the equilibration buffer consumption by almost 50 % in this phase, corresponding to more than 10 % of the total buffer use in the Protein A protocol, and have seen no changes in antibody yield or purity. Hence, through buffer recycling, we can improve the sustainability in biomanufacturing by using less water and chemicals.</div></div>","PeriodicalId":347,"journal":{"name":"Journal of Chromatography A","volume":"1740 ","pages":"Article 465545"},"PeriodicalIF":3.8,"publicationDate":"2024-11-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142756693","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A fast thermal desorption unit for micro thermal desorption tubes, Part II: Method development and validation for explosives and chemical warfare agent simulants","authors":"Miriam D. Chopra ,&nbsp;Benny Duong ,&nbsp;Florian A. Menger ,&nbsp;Thomas M. Klapötke ,&nbsp;Matthias Wüst ,&nbsp;Peter Boeker","doi":"10.1016/j.chroma.2024.465537","DOIUrl":"10.1016/j.chroma.2024.465537","url":null,"abstract":"<div><div>A thermal desorption FF-TG-GC/MS method with a cycle time of just 164<!--> <!-->s including cryofocusing, thermal desorption, analyte separation and system cool down was developed for the analysis of ten explosives and six chemical warfare agent (CWA) simulants. Sampling was carried out both in liquid and gaseous form using micro thermal desorption tubes (<span><math><mi>μ</mi></math></span>TD-tubes, 1.4<!--> <!-->mm I.D., 10<!--> <!-->mg Tenax TA). In addition to the desorption conditions, the effects of deactivated <span><math><mi>μ</mi></math></span>TD-tubes, the spatial temperature gradient along the separation column and additional cryofocusing to refocus the analytes were evaluated. Limits of detection between 0.17 and 9.18<!--> <!-->ng/<span><math><mi>μ</mi></math></span>L and R<span><math><msup><mrow></mrow><mrow><mn>2</mn></mrow></msup></math></span> values <span><math><mo>≥</mo></math></span> <!--> <!-->0.983 for calibration curves (with the exception of PETN) were obtained. Relative standard deviations of mainly <span><math><mo>&lt;</mo></math></span>15% were achieved for within day repeatability. The fluctuations in the peak areas were mostly below 20% with between-day repeatability measured across three days.</div></div>","PeriodicalId":347,"journal":{"name":"Journal of Chromatography A","volume":"1739 ","pages":"Article 465537"},"PeriodicalIF":3.8,"publicationDate":"2024-11-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142722588","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}