<p><strong>Scientists at IOCB Prague are uncovering new details of gene transcription. They have identified a previously unknown molecular mechanism by which the transcription of genetic information from deoxyribonucleic acid (DNA) into ribonucleic acid (RNA) can be initiated. The researchers focused on a specific class of molecules known as alarmones, which are found in cells across a wide range of organisms and whose levels often increase under conditions of cellular stress. The results were published in the prestigious scientific journal </strong><i><strong>Nature Chemical Biology</strong></i><strong>.</strong></p><p><img src="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/UOCHB_Vyzkum_z_UOCHB_odhaluje_dosud_nepoznany_zpusob_prepisu_geneticke_informace_bc2bfffa6c.jpg" alt="IOCB Prague/Tomáš Belloň: Research from IOCB Prague reveals a previously unknown mechanism of genetic transcription: Dr. Hana Cahová, head of the Chemical Biology of Nucleic Acids research group." srcset="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/thumbnail_UOCHB_Vyzkum_z_UOCHB_odhaluje_dosud_nepoznany_zpusob_prepisu_geneticke_informace_bc2bfffa6c.jpg 234w," sizes="100vw" width="2000" height="1335"></p><div><p>Molecules of ribonucleic acid can carry a variety of chemical modifications at one end, known as caps. In eukaryotic organisms, including human cells, the best-known cap plays an important role in RNA stability and in regulating its subsequent fate. In recent years, however, it has become clear that alternative, non-canonical RNA caps also exist, although their formation and the mechanisms by which they are attached to RNA remain only partially understood. These include alarmone caps, formed by dinucleoside polyphosphate molecules, that protect cellular RNA at moments when the cell is under threat.</p><p>In their study,<strong> </strong><a target="_blank" rel="noopener noreferrer" href="https://cahova.group.uochb.cz/en"><strong>Dr. Hana Cahová</strong></a> and colleagues examined bacterial RNA polymerase and investigated how this enzyme can initiate transcription using dinucleoside polyphosphates (NpNs) instead of the standard RNA building blocks. For the first time, the scientists described, at the atomic level, how RNA bearing an alarmone cap can be generated directly at the initiation of gene transcription. They also observed that NpNs bind through a different type of base pairing than is typically observed.</p><p>The work was significantly shaped by <strong>Valentina Serianni from Hana Cahová’s team</strong>, who demonstrated the ability of dinucleoside polyphosphates to initiate gene transcription, and by <strong>Jana Škerlová</strong>, who focused on the structural analysis of RNA polymerase. Using cryogenic electron microscopy data, she showed how dinucleoside polyphosphate molecules bind within the active site of RNA polymerase – that is, the core of the enzyme where genetic information is transcribed. Together, their findings help to elucidate the processes that accompany the transcription of genetic information from DNA to RNA.</p><p>Hana Cahová adds: <i>“We’re describing something that truly occurs in cells and that we’re now able to observe directly at the level of individual molecules. This allows us to answer fundamental questions about cellular processes, such as how cells adapt to stress. RNA plays a central role in this, as it carries the cascade of information underlying any cellular response – for example, to threatening conditions caused by nutrient deprivation or temperature shock.”</i></p><p><img src="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/UOCHB_Vyzkum_z_UOCHB_odhaluje_dosud_nepoznany_zpusob_prepisu_geneticke_informace_2_0fe88ff9e9.jpg" alt="IOCB Prague/Tomáš Belloň: Research from IOCB Prague reveals a previously unknown mechanism of genetic transcription: Dr. Tomáš Kouba, head of the Cryogenic Electron Microscopy core facility." srcset="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/thumbnail_UOCHB_Vyzkum_z_UOCHB_odhaluje_dosud_nepoznany_zpusob_prepisu_geneticke_informace_2_0fe88ff9e9.jpg 234w," sizes="100vw" width="2000" height="1335"></p><div><p>Cryogenic electron microscopy (cryo-EM) was central to the project. This part of the work was led by<strong> Dr. Tomáš Kouba</strong>, one of the authors of the study. <i>“Cryogenic electron microscopy allows us to freeze biological molecules in a state very close to their natural form and then determine their three-dimensional structure. This makes it possible to look directly into the active centers of enzymes and observe their function down to the atomic level,”</i> he explains.</p><p>Last year, IOCB Prague opened a new <a target="_blank" rel="noopener noreferrer" href="https://cryoem.group.uochb.cz/en"><strong>cryo-EM center</strong></a><strong> </strong>that is unique within the Czech research environment. State-of-the-art cryogenic electron microscopes are housed in a specially designed building and enable the study of biological processes with exceptional structural precision.</p><p><img src="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/UOCHB_Vyzkum_z_UOCHB_odhaluje_dosud_nepoznany_zpusob_prepisu_geneticke_informace_3_4d881e7a58.jpg" alt="IOCB Prague: Research from IOCB Prague reveals a previously unknown mechanism of genetic transcription: This work shows how NpnNs initiate bacterial transcription. Cryo-EM reveals how nucleobases pair with the template: one in canonical and one in reverse Watson–Crick mode, providing a structural basis for their function as non-canonical RNA caps." srcset="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/thumbnail_UOCHB_Vyzkum_z_UOCHB_odhaluje_dosud_nepoznany_zpusob_prepisu_geneticke_informace_3_4d881e7a58.jpg 245w," sizes="100vw" width="2000" height="1077"></p><blockquote><h4><strong>The Original article</strong></h4><h4><a target="_blank" rel="noopener noreferrer" href="https://www.nature.com/articles/s41589-025-02134-5"><strong>Molecular insight into 5′ RNA capping with Np<sub>n</sub>Ns by bacterial RNA polymerase</strong></a></h4><p>Valentina M. Serianni, Jana Škerlová, Anna Knopp Dubánková, Anton Škríba, Hana Šváchová, Tereza Vučková, Anatolij Filimoněnko, Milan Fábry, Pavlína Řezáčová, Tomáš Kouba &amp; Hana Cahova&nbsp;</p><p>Nat. Chem. Biol. 21 (2026)</p><p><a target="_blank" rel="noopener noreferrer" href="https://doi.org/10.1038/s41589-025-02134-5">https://doi.org/10.1038/s41589-025-02134-5</a></p><h6>licensed under <a target="_blank" rel="noopener noreferrer" href="https://creativecommons.org/licenses/by/4.0/"><strong>CC-BY 4.0</strong></a></h6></blockquote><h4><strong>Abstract</strong></h4><p>RNA capped with dinucleoside polyphosphates has been discovered in bacteria and eukaryotes only recently. The likely mechanism of this specific capping involves direct incorporation of dinucleoside polyphosphates by RNA polymerase as noncanonical initiating nucleotides. However, how these compounds bind into the active site of RNA polymerase during transcription initiation is unknown. Here, we explored transcription initiation in vitro, using a series of DNA templates in combination with dinucleoside polyphosphates and model RNA polymerase from <i>Thermus</i> <i>thermophilus</i>. We observed that the transcription start site can vary on the basis of the compatibility of the specific template and dinucleoside polyphosphate. Cryo-electron microscopy structures of transcription initiation complexes with dinucleoside polyphosphates revealed that both nucleobase moieties can pair with the DNA template. The first encoded nucleotide pairs in a canonical Watson–Crick manner, whereas the second nucleobase pairs noncanonically in a reverse Watson–Crick manner. Our work provides a structural explanation of how dinucleoside polyphosphates initiate RNA transcription.</p></div></div>

Research from IOCB Prague reveals a previously unknown mechanism of genetic transcription

<p><strong>In the week of February 9, the following webinars await you in the field of gas / solid phase and especially Raman, FTIR, GC and GC/MS.</strong></p><blockquote><h4><a target="_blank" rel="noopener noreferrer" href="https://gcms.labrulez.com/webinars"><strong>👉 DETAILS AND REGISTRATION IN THE WEBINARS SECTION</strong></a></h4><p><strong>👉 Search and filter in the largest global database</strong> with over <strong>5 000 GC, LC, MS and spectroscopy webinars</strong>.</p></blockquote><div><div><div><div><div><div><h5><strong>1. Thermo Fisher Scientific: Process Raman – A Reliable and Versatile Tool for Downstream Process Monitoring and Control for mAb Production</strong></h5><ul><li>Tu, 10.2.2026 16:00 CET</li><li><a target="_blank" rel="noopener noreferrer" href="https://gcms.labrulez.com/webinar/5808">Registration</a></li></ul><p>The presentation highlights how process Raman spectroscopy offers several advantages over traditional in-line UV-Vis analysis for process monitoring and metabolite production control in mAb manufacturing.</p><h5><strong>2. Wasson-ECE Instrumentation: The Data Driven Plant – How AI Transforms Chemical Manufacturing</strong></h5><ul><li>Tu, 10.2.2026 21:30 CET</li><li><a target="_blank" rel="noopener noreferrer" href="https://gcms.labrulez.com/webinar/5744">Registration</a></li></ul><p>Explore how artificial intelligence is applied to improve process efficiency, monitoring, and decision-making in modern chemical manufacturing.</p><h5><strong>3. New Food Magazine: The Science of Next-Gen Ingredients – Fermentation, Formulation and Function</strong></h5><ul><li>We, 11.2.2026 16:00 CET</li><li><a target="_blank" rel="noopener noreferrer" href="https://gcms.labrulez.com/webinar/5720">Registration</a></li></ul><p>Discover how fermentation-driven innovation is transforming functional food ingredients, with analytical insights to optimize flavour, functionality, and product stability.</p></div></div></div></div></div></div>

Webinars LabRulezGCMS Week 07/2026

<p><strong>This study presents an analytical strategy combining QuEChERS extraction with low-temperature partitioning (LTP) for the determination of multiclass pesticide residues in cocoa beans by GC–MS. Extraction conditions were optimized using a fractional factorial design, resulting in a simple and efficient workflow suitable for complex cocoa matrices.</strong></p><p>The validated method showed satisfactory limits of detection and quantification, recoveries within 70–120%, and good overall performance. Application to cocoa samples from Brazil detected permethrin in several samples, demonstrating that the QuEChERS–LTP approach is an effective and reliable cleanup strategy for routine pesticide residue analysis in cocoa.</p><blockquote><h4><strong>The original article</strong></h4><h4><a target="_blank" rel="noopener noreferrer" href="https://pubs.acs.org/doi/10.1021/acsomega.5c10360"><strong>QuEChERS Combined with Low-Temperature Partitioning and GC–MS as an Analytical Strategy for the Determination of Multiclass Pesticide Residues in Cocoa Beans</strong></a></h4><p>Priscilla M. de Freitas Machado, Madson M. Nascimento, Paulo R. R. Mesquita, Manuela B. Nascimento, Lilian Lefol N. Guarieiro, Gisele O. da Rocha, Jailson B. de Andrade, Raildo M. de Jesus*</p><p>ACS Omega 2025, 10, 51, 63464–63473</p><p><a target="_blank" rel="noopener noreferrer" href="https://doi.org/10.1021/acsomega.5c10360">https://doi.org/10.1021/acsomega.5c10360</a></p><h6>licensed under <a target="_blank" rel="noopener noreferrer" href="https://creativecommons.org/licenses/by/4.0/"><strong>CC-BY 4.0</strong></a></h6></blockquote><p><strong>Selected sections from the article follow. Formats and hyperlinks were adapted from the original.</strong></p><p>Cocoa is best known as the primary raw material for chocolate but is also processed into products such as cocoa butter, biscuits, cocoa honey, and cocoa powder. Cocoa powder is derived from roasted, pressed, and milled nibs, containing on average 20% (w/w) lipids on a dry basis and less than 9% moisture. <a href="javascript:void(0);">(3,4)</a></p><p>According to the Brazilian Health Regulatory Agency (ANVISA), pesticides such as atrazine, bifenthrin, cyproconazole, metalaxyl, tebuconazole, trifloxystrobin, and permethrin are approved for use in Brazil. <a href="javascript:void(0);">(13)</a> However, among these, only metalaxyl, trifloxystrobin, and tebuconazole are authorized by the European Union. <a href="javascript:void(0);">(14)</a> Thus, investigating these contaminants in cocoa samples is of utmost importance, as Brazil is one of the largest cocoa exporters, supplying cocoa commodities to South America, the United States, and the European Union. <a href="javascript:void(0);">(2)</a> Furthermore, Organochlorine pesticides, in particular, belong to the class of persistent organic pollutants (POPs). Although banned in many countries, they continue to be used in some developing nations because of their chemical stability, resistance to degradation, volatility, and high lipophilicity, which promote bioaccumulation and neurotoxicity. <a href="javascript:void(0);">(15)</a> Epidemiological evidence also associates their exposure with Parkinson’s disease, certain cancers, diabetes, and endometriosis. <a href="javascript:void(0);">(16)</a></p><p>Residues of pesticides in cocoa have been reported in various studies. <a href="javascript:void(0);">(17)</a> Analyzing pesticide residues in cocoa presents analytical challenges due to the matrix’s complexity, comprising high lipid content, fatty acids and esters, sugars, polyphenols, and caffeine. These components can interfere with extraction efficiency and contaminate analytical instrumentation. <a href="javascript:void(0);">(18)</a> Therefore, efficient sample preparation methods incorporating effective cleanup steps are essential for accurate residue determination.</p><p>Several techniques have been employed for multiresidue pesticide analysis in cocoa. For instance, Idowu et al. <a href="javascript:void(0);">(19)</a> quantified 14 organochlorines using Soxhlet extraction and silica/Na<sub>2</sub>SO<sub>4</sub> cleanup, with GC ECD detection. Okoffo et al. <a href="javascript:void(0);">(20)</a> determined 13 organophosphates and 9 pyrethroids employing SPE cartridges (Envi-carb/LC-NH<sub>2</sub> and Bond Elute C18), acetonitrile extraction, and GC PFPD or GC ECD quantification. Yusiasih et al. <a href="javascript:void(0);">(21)</a> applied dispersive SPE with PSA, Florisil, and MgSO<sub>4</sub> for pyrethroids, followed by GC ECD and GC–MS.</p><p>Therefore, this study aimed to evaluate the effectiveness of a QuEChERS–LTP analytical procedure for the determination of multiclass pesticide residues in cocoa beans. The factors that affect the QuEChERS–LTP procedure efficiency were optimized. After validation, the procedure was employed to investigate the occurrence of 15 multiclass pesticides in cocoa samples.</p><h4><strong>Experimental Section</strong></h4><h5><strong>Instrumental Apparatus</strong></h5><p>Pesticide separation and identification were performed on a Shimadzu <a target="_blank" rel="noopener noreferrer" href="https://gcms.labrulez.com/library?mainauthorItems=1&amp;search=GC-MS-QP2010SE"><strong>GC-MS-QP2010SE</strong></a> system (Kyoto, Japan) equipped with an <a target="_blank" rel="noopener noreferrer" href="https://gcms.labrulez.com/library?mainauthorItems=1&amp;search=AOC-20i"><strong>AOC-20i autosampler</strong></a>. Separation was achieved using an <a target="_blank" rel="noopener noreferrer" href="https://gcms.labrulez.com/library?mainauthorItems=10&amp;search=DB-5MS"><strong>Agilent DB-5MS capillary column</strong></a> (30 m × 0.25 mm × 0.25 μm) with a stationary phase of 5% phenyl/95% dimethylpolysiloxane. The instrumental conditions were based on Nascimento et al. <a href="javascript:void(0);">(49)</a> and they are summarized in <a target="_blank" rel="noopener noreferrer" href="https://pubs.acs.org/doi/10.1021/acsomega.5c10360#tbl4">Table 4</a>.</p><p>For quantification, the base peak was used, while two additional ions were monitored for confirmation (<a target="_blank" rel="noopener noreferrer" href="https://pubs.acs.org/doi/suppl/10.1021/acsomega.5c10360/suppl_file/ao5c10360_si_001.pdf">Table S2</a>) in accordance with SANTE guidelines. <a href="javascript:void(0);">(50)</a> A GC–MS/SIM chromatogram illustrating the separation of all target pesticides is presented in <a target="_blank" rel="noopener noreferrer" href="https://pubs.acs.org/doi/10.1021/acsomega.5c10360#fig5">Figure 5</a>.</p><p><img src="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/ACS_Omega_2025_10_51_63464_63473_Figure_5_Extracted_ion_chromatogram_EIC_in_SIM_mode_of_the_target_pesticides_f2461c14f4.jpg" alt="ACS Omega 2025, 10, 51, 63464–63473: Figure 5. Extracted ion chromatogram (EIC) in SIM mode of the target pesticides obtained from the injection of a mixed standard solution at 100 μg L–1. Analytes are listed in order of elution: [1] Molinate (6.18 min); [2] α-HCH (8.15 min); [3] atrazine-d5 (8.69 min); [4] atrazine (8.75 min); [5] diazinon (9.31 min); [6] disulfoton (9.67 min); [7] dimethachlor (10.60 min); [8] metalaxyl (11.25 min); [9] p,p′-DDE (15.82 min); [10] cyproconazole I (16.50 min); [11] cyproconazole II (16.56 min); [12] p,p′-DDD (17.29 min); [13] ethion (17.34 min); [14] trifloxystrobin (18.43 min); [15] tebuconazole (19.13 min); [16] bifenthrin (20.47 min); [17] permethrin I (23.92 min); [18] permethrin II (24.18 min)." srcset="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/thumbnail_ACS_Omega_2025_10_51_63464_63473_Figure_5_Extracted_ion_chromatogram_EIC_in_SIM_mode_of_the_target_pesticides_f2461c14f4.jpg 245w," sizes="100vw" width="2080" height="835"></p><h5><strong>Application of the Proposed Procedure to Real Samples</strong></h5><p>In a 50 mL Falcon tube, 2.0 g of sample was weighed using an analytical balance (AUX320, Shimadzu, Kyoto, Japan). A total of 2.0 g of salt (NaCl and Na<sub>2</sub>SO<sub>4</sub> in a 1:1 w/w ratio) was added, followed by an aliquot of the atrazine-<i>d</i><sub>5</sub> solution (surrogate standard) to yield a final concentration of 250 μg kg<sup>–1</sup>. A mixture of acetonitrile (8.0 mL) and ultrapure water (2.0 mL) was then added. The system was vortexed (K40-10208, Kasvi, São Paulo, Brazil) for 3.0 min at 2500 rpm and centrifuged (MPW-351R, MPW Med. Instruments, Warsaw, Poland) for 10.0 min at 15 °C and 10,000 rpm. After phase separation, approximately 6.0 mL of the supernatant was transferred to a Falcon tube containing 150.0 mg of PSA sorbent. The mixture was vortexed again for 3.0 min at 2500 rpm and centrifuged for an additional 10.0 min under the same conditions. The tubes were then placed in the freezer for 24 h. Once the aqueous phase had frozen, the organic extract containing the analytes was collected, filtered through a Cytiva Whatman MiniUniprep G2 vial with a 0.20 μm membrane filter (Marlborough, Massachusetts, USA), and injected into the GC–MS system (<a target="_blank" rel="noopener noreferrer" href="https://pubs.acs.org/doi/10.1021/acsomega.5c10360#fig6">Figure 6</a>).</p><p><img src="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/ACS_Omega_2025_10_51_63464_63473_Figure_6_Schematic_representation_of_the_extraction_procedure_using_the_Qu_E_Ch_ERS_LTP_procedure_for_pesticide_extraction_in_cocoa_powder_samples_ed58549bcf.jpg" alt="ACS Omega 2025, 10, 51, 63464–63473: Figure 6. Schematic representation of the extraction procedure using the QuEChERS–LTP procedure for pesticide extraction in cocoa powder samples." srcset="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/thumbnail_ACS_Omega_2025_10_51_63464_63473_Figure_6_Schematic_representation_of_the_extraction_procedure_using_the_Qu_E_Ch_ERS_LTP_procedure_for_pesticide_extraction_in_cocoa_powder_samples_ed58549bcf.jpg 223w," sizes="100vw" width="1458" height="1022"></p><h4><strong>Results and Discussion</strong></h4><h5><strong>Evaluation of the Effect of Low and Ultralow Temperatures on the Analytical Response</strong></h5><p>Studies reporting the use of LTP generally employ a conventional freezer, which typically reaches −18 ± 2 °C as the minimum temperature. In this equipment, effective phase separation can require 8 to 24 h. <a href="javascript:void(0);">(35−37)</a> In contrast, ultralow temperature freezers (ultrafreezers) can reach −80 °C, leading to a substantial reduction in partitioning time. In this study, tests performed with the conventional freezer achieved satisfactory partitioning after 24 h, whereas in the ultrafreezer, complete partitioning was observed in only 20 min.</p><p>Considering the analytical response in terms of peak area (<a target="_blank" rel="noopener noreferrer" href="https://pubs.acs.org/doi/10.1021/acsomega.5c10360#fig3">Figure 3</a>), higher signals were obtained when LTP was performed in a conventional freezer rather than an ultrafreezer. This behavior can be attributed to the partitioning mechanism. <a href="javascript:void(0);">(32)</a> Partitioning depends on cooling and the subsequent freezing of the aqueous phase. In the conventional freezer, the slower freezing rate provides sufficient time for the system to approach thermodynamic equilibrium, favoring analyte diffusion between phases. Under these conditions, analyte molecules have more time to migrate and distribute optimally before complete solidification. In contrast, the rapid freezing in the ultrafreezer may trap analytes in a nonideal distribution, reducing the efficiency of the partitioning process <a href="javascript:void(0);">(32)</a> (<a target="_blank" rel="noopener noreferrer" href="https://pubs.acs.org/doi/10.1021/acsomega.5c10360#fig3">Figure 3</a>). According to these observations, the conventional freezer was selected for subsequent experiments.</p><p><img src="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/ACS_Omega_2025_10_51_63464_63473_Figure_3_Comparison_of_chromatographic_peak_areas_of_pesticides_after_partitioning_in_the_conventional_freezer_versus_the_ultrafreezer_9598bcfec3.jpg" alt="ACS Omega 2025, 10, 51, 63464–63473: Figure 3. Comparison of chromatographic peak areas of pesticides after partitioning in the conventional freezer versus the ultrafreezer." srcset="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/thumbnail_ACS_Omega_2025_10_51_63464_63473_Figure_3_Comparison_of_chromatographic_peak_areas_of_pesticides_after_partitioning_in_the_conventional_freezer_versus_the_ultrafreezer_9598bcfec3.jpg 175w," sizes="100vw" width="996" height="891"></p><h5><strong>Application to Real Samples</strong></h5><p>Fifteen samples were analyzed in triplicate, comprising two from the State of Pará and 12 from the State of Bahia, located in the North and Northeast regions of Brazil, respectively. Among the 15 pesticides investigated, only permethrin isomers were quantified in four samples (<a target="_blank" rel="noopener noreferrer" href="https://pubs.acs.org/doi/10.1021/acsomega.5c10360#tbl3">Table 3</a>). The herbicide molinate was also detected in three samples; however, its concentration was below LOQ. Permethrin isomers concentrations ranged from 17.1 ± 0.3 to 49.6 ± 1.8 μg kg<sup>–1</sup>. These values are below the MRL established by European Union regulation, which is 100 μg kg<sup>–1</sup>. <a href="javascript:void(0);">(42)</a> Although permethrin is not permitted in the European Union, <a href="javascript:void(0);">(42)</a> it remains authorized for use as insecticide in Brazil, particularly in crops such as cotton, rice, coffee, citrus, cabbage, beans, tobacco, maize, soybean, tomato, wheat, and grape. <a href="javascript:void(0);">(13)</a> However, no MRL values have been established for cocoa beans under Brazilian legislation. <a href="javascript:void(0);">(13)</a> <a target="_blank" rel="noopener noreferrer" href="https://pubs.acs.org/doi/10.1021/acsomega.5c10360#tbl3">Table 3</a> shows the concentration of detected compounds in the cocoa samples.</p><p><img src="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/ACS_Omega_2025_10_51_63464_63473_Table_3_Mean_Concentrations_mg_kg_1_Standard_Deviation_of_Target_Pesticides_Detected_in_This_Study_2427955699.jpg" alt="ACS Omega 2025, 10, 51, 63464–63473: Table 3. Mean Concentrations (μg kg–1 ± Standard Deviation) of Target Pesticides Detected in This Study" srcset="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/thumbnail_ACS_Omega_2025_10_51_63464_63473_Table_3_Mean_Concentrations_mg_kg_1_Standard_Deviation_of_Target_Pesticides_Detected_in_This_Study_2427955699.jpg 196w," sizes="100vw" width="1070" height="851"></p><p>To assess method performance for pesticides not detected in the cocoa samples, one of the analyzed samples was fortified with a mixed standard solution at concentrations of 50, 250, and 500 μg kg<sup>–1</sup>. The fortified analytes were subsequently detected in the chromatograms presented in <a target="_blank" rel="noopener noreferrer" href="https://pubs.acs.org/doi/suppl/10.1021/acsomega.5c10360/suppl_file/ao5c10360_si_001.pdf">Figures S2–S4</a>, indicating good response of the proposed method.</p><h4><strong>Conclusions</strong></h4><p>The QuEChERS–LTP procedure was successfully developed for the determination of 16 multiclass pesticide residues in cocoa beans. For the first time, ultralow temperature (−80 °C) was applied to accelerate the low-temperature partitioning process during pesticide extraction from cocoa beans. Nevertheless, conventional freezing at −12 °C proved to be more effective for the extraction of the target analytes.</p><p>Evaluation of the matrix effect demonstrated that matrix-matched analytical curves, constructed in an analyte-free cocoa bean extract, were more effective in compensating for matrix interferences than the use of analyte protectants.</p><p>The pyrethroid permethrin was quantified in four cocoa samples. However, the concentrations did not exceed the MRL established by European Union legislation.</p><p>Overall, the QuEChERS–LTP procedure proved to be a promising approach for pesticide residue determination, as it requires smaller volumes of solvents and reagents, involves fewer cleanup and extraction steps, and shows strong potential for application to other complex matrices.</p>

QuEChERS Combined with Low-Temperature Partitioning and GC–MS as an Analytical Strategy for the Determination of Multiclass Pesticide Residues in Cocoa Beans

Article

Webinars

Food

Scientific article

Science and research

Video

The Institute of Organic Chemistry and Biochemistry of the Czech Academy of Sciences (IOCB Prague) is a leading scientific institution in the Czech Republic, recognized internationally. Its primary mission is basic research in the fields of chemical biology and medicinal chemistry, organic and material oriented chemistry, chemistry of natural compounds, biochemistry and molecular biology, physical chemistry, theoretical chemistry, and analytical chemistry. 

Institute of Organic Chemistry and Biochemistry of the Czech Academy of Sciences

Everything from the world of analytical chemistry in one place. We connect people in solving their problems. At Labrulez you will find all the necessary information easily, quickly and clearly. Stop searching and start finding.

LabRulez

Thermo Scientific TriPlus™ RSH SMART Autosampler

Extend automation, performance, and versatility for GC and GC/MS applications, while ensuring easier and safer operations through SMART consumables ID recognition and usage tracking.

<div><div id="product-description"><p><strong>Expand automated sampling capabilities beyond liquid, headspace, and solid phase microextraction (SPME) injections. The advanced, built-in robotics of the Thermo Scientific™ TriPlus™ RSH SMART Autosampler deliver exceptional precision, sample handling flexibility, and reliable unattended operation. Enabling SMART consumables tracking, it offers easier, safer and traceable operations. Accurate and repeatable sample preparation and injection are essential to achieving the highest quality GC/GC-MS results. Enhance data quality and laboratory efficiency by automating your entire sample handling workflow.</strong></p></div><div><p>The TriPlus RSH SMART Autosampler brings together technological innovations that further expand automation, performance and versatility for GC and GC-MS applications, while ensuring easier and safer operations through SMART consumables ID recognition and usage tracking. Automated high-precision sample handling eliminates the manual labor and downtime typically required for tasks as standard/sample dilutions, internal standard addition and derivatization.</p><h3><strong>SMART Consumables</strong></h3><p>Validated SMART consumables are equipped with unique SMART chip storing parameters, ranges and usage history; enabling full traceability of sample preparation down to the syringe.</p><h3><strong>Automatic Syringe Changeout</strong></h3><p>Automatic Tool Change (ATC) capability automates the use of different syringes for sample preparation steps or different injection techniques within the sequence.</p><h3><strong>Vial Bottom Sensing Expands Application Range</strong></h3><p>Precise detection of vial bottoms enables the autosampler to accurately withdraw from sample amounts as little as 5 μL, enhancing data quality of sample-limited applications.</p><h3><strong>Flexible liquid sample handling</strong></h3><p>Optimized liquid injection modes and customizable syringe filling techniques, support a wide range of sample types and full GC inlet compatibility.</p><h3><strong>Automated headspace injection for volatile analysis</strong></h3><p>High temperature gas-tight syringe allows direct headspace injection into the GC inlet for increased injection volume flexibility. Sample vial capacity of up to 300x 10 mL/20 mL vials and sample incubation overlapping, facilitate long unattended operation.</p><h3><strong>Automated, solvent-free SPME</strong></h3><p>Precise control of all steps—fiber preconditioning, adsorption and desorption, as well as fiber washes—delivers maximum performance for SPME applications. Boost productivity with the optimized SPME Arrow design. It offers optimized fiber geometry to achieve 10x superior sensitivity compared to classical SPME, 2x faster extraction time and superior robustness.</p><h3><strong>Automated Sample Preparation</strong></h3><p>The Triplus RSH SMART Autosampler combines highly versatile sample injection capability with automated sample preparation procedures, eliminating typical GC-MS workflow bottlenecks. Daily operations ranging from sample/standard dilution to more complex derivatization protocols, can be fully automated and easily programmed with the Sampling Workflow Editor Software.</p><h3><strong>Extend productivity with the optional 1D barcode reader</strong></h3><p>The optional 1D barcode reader eliminates the need to log and track sample information manually; enabling you to streamline internal operations, save time, increase efficiency, and reduce errors.</p><h3><strong>Specifications</strong></h3><ul><li><strong>Type: </strong>TriPlus RSH SMART Standard Liquid, Regular Rail</li><li><strong>Sample Capacity:</strong> 4608 Well Plates, 840 x 0.5 mL or 0.7 mL Vials, 648 x 2 mL Sample Vials, 240 x 10 mL or 20 mL Vials</li><li><strong>Injection Mode: </strong>8 Fully Customizable Method-Specific Injection Mode Presets</li><li><strong>Injection Speed:</strong> Selectable from 0.1 μL/s to 2000 μL/s</li><li><strong>Injection Volume: </strong>0.1 to 10,000 μL</li><li><strong>Description: </strong>TriPlus RSH SMART configured for liquid injection on regular X-axis length. Only for manual tool change. Complete with liquid syringe tool, 2 x 10 μL SMART syringes, standard washing station and a single tray holder with 3 trays for 2 mL vials. Expandible to other sampling techniques (Headspace, SPME, SPME Arrow, ITEX-DHS) and with sample preparation tools.</li><li><strong>Tool Exchange:</strong> Only for manual tool exchange. No tool park station.</li><li><strong>For Use With (Equipment):</strong> Compatible with Smart syringes/fibers only.</li></ul></div></div>

Thermo Scientific™ TriPlus™ RSH Autosampler

Robotic GC autosampler with multimode injection, tool exchange, and full sample prep automation. Enables 24/7 workflows for food, environmental, and forensic labs.

<h4><strong>Flexible, high-capacity autosampler for GC and GC-MS with advanced sample prep automation</strong></h4><p><strong>The TriPlus RSH Autosampler is a versatile robotic sampling platform designed to maximize automation, precision, and productivity in gas chromatography workflows. Fully compatible with Thermo Scientific™ GC and GC-MS systems, it supports liquid, headspace (HS), and SPME/SPME Arrow injections, with optional modules for µSPE, ITEX-DHS, and automated sample preparation. The unique Automatic Tool Change (ATC) system allows the autosampler to switch between up to six syringes in a single sequence, enabling unattended workflows for complex multistep protocols.</strong></p><h3><strong>Key Features and Benefits</strong></h3><h4>🧪 <strong>Multimode Injection and Sample Handling</strong></h4><ul><li>Supports liquid, headspace, SPME, SPME Arrow, and ITEX-DHS techniques</li><li>Switch between injection modes in a single sequence using ATC</li><li>Bottom vial sensing enables precise injections from as little as <strong>5 μL</strong> of sample</li></ul><h4>🔁 <strong>Automated Sample Preparation</strong></h4><ul><li>Perform dilution, standard addition, derivatization, and internal standard workflows</li><li>Tools: Vortexer, Incubator, Heatex-Stirrer, Dilutor, µSPE module</li><li>Visual drag-and-drop <strong>Sampling Workflow Editor</strong> for custom prep protocols</li></ul><h4>📦 <strong>High Throughput and Capacity</strong></h4><ul><li>Unattended operation with up to <strong>972 × 2 mL vials</strong> or <strong>840 × 0.7 mL vials</strong></li><li>Extended X-arm option for larger trays and accessory support</li><li>Dual-GC configurations with Clone Mode or DoublePro setups</li></ul><h4>⚙️ <strong>Precision and Flexibility</strong></h4><ul><li>Automated Tool Change (ATC): Up to <strong>6 tools</strong> in one sequence</li><li>Injection volume range: <strong>0.1 μL to 10 mL</strong></li><li>Compatible with all major GC injector types (SSL, PTV, OC, PKD, PPKD)</li></ul><h4>🧠 <strong>Smart Software and Control</strong></h4><ul><li>Fully integrated with <a target="_blank" rel="noopener noreferrer" href="https://gcms.labrulez.com/products/76"><strong>Chromeleon™</strong></a>,<a target="_blank" rel="noopener noreferrer" href="https://lcms.labrulez.com/products/1758"><strong> Xcalibur™</strong></a>, and <strong>Chrom-Card™ CDS</strong></li><li>Local controller or virtual terminal control interface</li><li>Barcode readers for full sample tracking</li></ul><p><img src="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/application::product.product/Thermo-TriPlus-RSH-Autosampler-1.jpg" alt="Thermo Scientific™ TriPlus™ RSH Autosampler" width="null" height="null"></p><h3><strong>Applications</strong></h3><ul><li><strong>Food safety</strong>: Trace analytes, contaminants, derivatization (e.g. FAMEs, dioxins)</li><li><strong>Environmental</strong>: VOCs, SVOCs, POPs, air toxics</li><li><strong>Forensics &amp; clinical</strong>: Biological matrices, explosive residues, drugs</li><li><strong>Chemical industry</strong>: Routine QC, trace impurities, residual solvents</li><li><strong>High-throughput labs</strong>: 24/7 unattended workflows with complex prep steps</li></ul><p><img src="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/application::product.product/QExactive-GCMSMS-Orbitrap-with-Autosampler-sideangle-1856x1391.jpg-650.jpg" alt="Thermo Scientific™ TriPlus™ RSH Autosampler" width="null" height="null"></p>

Thermo Scientific Dionex AutoTrace 280 Solid-Phase Extraction Instrument

Extract analytes of interest from large volume aqueous samples easily and efficiently with the Thermo Scientific™ Dionex™ AutoTrace™ 280 Solid-Phase Extraction (SPE) Instrument.

<p><strong>Extract analytes of interest from large volume aqueous samples easily and efficiently with the Thermo Scientific™ Dionex™ AutoTrace™ 280 Solid-Phase Extraction (SPE) Instrument.&nbsp;</strong></p><p>The AutoTrace 280 automates all four steps of SPE (conditioning, loading, rinsing, and eluting), reducing solvent consumption and improving recovery and reproducibility. Boost productivity and reduce cost of analysis by simultaneously processing up to six samples in 2-3 hours with only 15 minutes of operator involvement. The AutoTrace 280 meets requirements in US EPA methods including the 500 and 600 series.</p><h5><strong>Improved reliability and recovery</strong></h5><ul><li>Automated SPE minimizes operator intervention</li><li>Positive pressure loading and elution of samples and solvents provide constant flow for improved analytical precision</li></ul><h5><strong>Flexibility in operation</strong></h5><ul><li>Loads sample volumes from 20 mL to 4 L</li><li>Compatible with 1, 3, and 6 mL cartridges and with 47 mm SPE disks</li><li>Automatically conditions, rinses, and elutes SPE cartridges with a choice of five solvents</li><li>Offers a choice of six different collection vial racks</li></ul><h5><strong>Improved laboratory safety</strong></h5><ul><li>Minimal sample handling reduces operator exposure to hazardous chemicals</li><li>No hood required</li></ul><h5><strong>Enhanced laboratory productivity and reduced costs</strong></h5><ul><li>Unattended operation</li><li>Batch processing of up to 6 samples</li><li>Reduced solvent usage</li><li>Segregates aqueous and solvent waste using separate waste lines for efficient, cost-effective waste handling</li></ul><h5><strong>Supports a range of matrices and applications</strong></h5><ul><li>Ability to process samples containing suspended solids</li><li>Meets requirements for solid-phase extraction for U.S. EPA methods including 500 and 600 series</li></ul><h5><strong>Recommended use</strong></h5><ul><li>Analyze prepared samples with Thermo Scientific LC or GC systems for a fully integrated workflow</li></ul><h4><strong>Specifications</strong></h4><ul><li><strong>Instrument Type:</strong> Automated Solid Phase Extraction (SPE) System</li><li><strong>Application:</strong> For use with 47 mm SPE disks</li><li><strong>Model Description:</strong> AutoTrace 280 SPE System</li></ul><h5><strong>Performance &amp; Operating Details</strong></h5><ul><li><strong>Disk Compatibility:</strong> Designed for 47 mm SPE disks</li><li><strong>Pressure Range:</strong><ul><li>Output: 0 to 30 psi (0 to 1.4 bar)</li><li>Input: Up to 100 psi (6.9 bar) maximum</li></ul></li><li><strong>Voltage:</strong> 100–240 V ±10%</li><li><strong>Frequency:</strong> 47–63 Hz</li></ul><h5><strong>Physical Specifications</strong></h5><ul><li><strong>Dimensions (D × W × H):</strong> 57 × 63.5 × 69 cm</li><li><strong>Unit Size:</strong> Each</li></ul>

Thermo Scientific EXTREVA ASE Accelerated Solvent Extractor

Achieve true walkaway sample-to-vial sample preparation with the Thermo Scientific™ EXTREVA™ ASE™ Accelerated Solvent Extractor. 

<p><strong>Achieve true walkaway sample-to-vial sample preparation with the Thermo Scientific™ EXTREVA™ ASE™ Accelerated Solvent Extractor. Without any intervention, perform sample extraction, in-cell cleanup and evaporation—all in one seamless operation—reducing manual labor from hours to minutes and enabling you to focus on other lab priorities while using up to 50% less solvent than other sample preparation techniques.</strong></p><p><strong>Accelerate your journey from sample to vial</strong></p><h5><strong>The EXTREVA ASE Accelerated Solvent Extractor offers:</strong></h5><ul><li><strong>All-in-one sample preparation.</strong> The EXTREVA ASE system automatically extracts and concentrates samples, eliminating the need to manually move sample extracts to another device for solvent evaporation.</li><li><strong>A walk-away solution. </strong>The system minimizes hands-on sample preparation tasks, enabling staff to accomplish other tasks.</li><li><strong>Parallel extraction. </strong>One EXTREVA ASE system can perform four parallel sample extractions, substantially increasing throughput.</li><li><strong>Gas-assisted extraction. </strong>The dynamic gas-assisted extraction mode reduces solvent consumption to between 5 and 100 milliliters per sample in most cases.</li><li><strong>Automation. </strong>Full automation improves recoveries and reproducibility while reducing training needs. Unlike humans, automated systems are ideal for performing the same tedious task repeatedly, and they don’t make mistakes.</li><li><strong>Method flexibility and optimization</strong>. Up to six different solvents can be used, including wash solvents for cleaning between methods. Precise flow control optimizes methods.</li><li><strong>Barcode-reading.</strong> The system tracks sample information and preparation parameters using a 2-D bar code reader to facilitate tracking and integrity. Data is recorded on the instrument or Thermo Scientific™ <a target="_blank" rel="noopener noreferrer" href="https://lcms.labrulez.com/products/76"><strong>Chromeleon™ Chromatography Data System (CDS) software</strong></a>.</li></ul><h4><strong>Specifications</strong></h4><ul><li><strong>Instrument Type:</strong> Automated Sample Preparation System</li><li><strong>Application:</strong> Simultaneous sample extraction and concentration</li><li><strong>Model Description:</strong> EXTREVA ASE Extraction and Evaporation System</li></ul><h5><strong>Performance &amp; Capabilities</strong></h5><ul><li><strong>Extraction Temperature Range:</strong> 40–200 °C</li><li><strong>Evaporation Temperature Range:</strong> 40–100 °C</li><li><strong>Compatible Solvents:</strong> Wide range of organic and aqueous solvents</li><li><strong>Pressure Capability:</strong> Up to 200 psi</li><li><strong>Power Consumption:</strong> 2000 W</li><li><strong>Frequency:</strong> 50/60 Hz</li></ul><h5><strong>Sample &amp; Solvent Handling</strong></h5><ul><li><strong>Extraction Cells (stainless steel):</strong> 1, 5, 10, 22, 34, 66, 100 mL</li><li><strong>Extraction Cell Tray:</strong> 16-position with 1 rinse</li><li><strong>Collection Vials:</strong><ul><li>60 mL and 100 mL evaporation vials</li><li>250 mL evaporation bottles</li><li>Direct concentrate to 2 mL sample vials with rinse capability</li></ul></li><li><strong>Collection Vial Tray:</strong> 16-position tray insert for 60 mL vials and 250 mL bottles; includes 4 rinse positions</li></ul><h5><strong>Utilities &amp; Requirements</strong></h5><ul><li><strong>Pneumatic Requirements:</strong><ul><li>Air: 130–140 psi</li><li>Nitrogen: 350–450 psi</li></ul></li></ul><h5><strong>Physical Specifications</strong></h5><ul><li><strong>Dimensions (D × W × H):</strong> 65.2 × 100 × 88.6 cm (25.6 × 39.4 × 34.8 in.)</li><li><strong>Weight:</strong> 160 kg (353 lb)</li><li><strong>Unit Size:</strong> Each</li></ul>

Thermo Scientific™ Dionex™ ASE™ 350 Accelerated Solvent Extractor

Save time, reduce solvent consumption, and boost productivity with Thermo Scientific™ Dionex™ ASE™ 350 Accelerated Solvent Extractor.

<div><p><strong>Automate extraction, filtration and clean up of compounds from solid and semisolid samples in minutes using the automated Thermo Scientific™ Dionex™ ASE™ 350 Accelerated Solvent Extractor. This system accommodates sample sizes of 1-100g, allows unattended extraction of up to 24 samples and uses 50 to 90% less solvent compared to other methods.&nbsp;</strong></p><p>The chemically inert pathway supports acid and alkaline sample matrices and solvents. Flexible, easy-to-operate and cost-effective, the Dionex ASE 350 is ideally suited for high-throughput laboratories and for a wide variety of applications.</p><div><h4><strong>Rapid and efficient extractions</strong></h4><ul><li>Elevated temperature (up to 200°C) and pressure (1500psi) reduce extraction times and solvent consumption</li><li>Fast pump (70mL/min.) enables fast extractions (typically 12-20 minutes)</li><li>Specialized oven design ensures precise temperature control for excellent reproducibility</li><li>Integrated solvent controller allows mixing and delivery of up to three solvents</li><li>The <strong>Thermo Scientific™ SmartRun™ System</strong> ensures cell size and collection vessel size are matched for an optimal extraction</li></ul><h4><strong>Enhanced flexibility to support multiple applications</strong></h4><ul><li>System accommodates <strong>1, 5, 10, 22, 34, 66 </strong>and <strong>100mL cell sizes</strong></li><li>pH-hardened pathway with <strong>Thermo Scientific™ Dionium™ components and cell</strong> enables compatibility with acid or alkaline pretreated matrices</li></ul><h4><strong>Dramatically reduced solvent consumption</strong></h4><ul><li>Requires less than 50mL solvent for a 20g sample</li><li>Includes solvent saver mode for further solvent savings</li></ul><h4><strong>Enhanced laboratory productivity</strong></h4><ul><li>System holds up to 24 samples for unattended operation</li><li>Flow-through technology allows in-line filtration and in-cell cleanup</li></ul><p><img src="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/Thermo_Scientific_Dionex_ASE_350_system_2_9426ff3f9a/Thermo-Scientific-Dionex-ASE-350-system_2.jpg" alt="Thermo Scientific™ Dionex™ ASE™ 350 Accelerated Solvent Extractor" srcset="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/thumbnail_Thermo_Scientific_Dionex_ASE_350_system_2_9426ff3f9a/thumbnail_Thermo-Scientific-Dionex-ASE-350-system_2.jpg 114w," sizes="100vw" width="579" height="792"></p><h3><strong>🛠️ Specifications</strong></h3><ul><li><strong>Collection Vial Tray</strong>: 26-position tray insert for 60 mL vials; 19-position tray insert for 250 mL bottles</li><li><strong>Depth (English)</strong>: 27.3 in.</li><li><strong>Depth (Metric)</strong>: 69.3 cm</li><li><strong>Description</strong>: Extractor Only</li><li><strong>Extraction Fluids</strong>: Compatible with a wide range of organic and aqueous solvents</li><li><strong>Fluid Sensors</strong>: IR</li><li><strong>Frequency</strong>: 50/60 Hz</li><li><strong>Height (English)</strong>: 24.3 in.</li><li><strong>Height (Metric)</strong>: 61.7 cm</li><li><strong>Pneumatic Requirements</strong>: Air at 400–827 kPa (60–120 psi); N2 (at 1034 ×–1340 kPa (150–200 psi))</li><li><strong>Power Consumption</strong>: 500 Max VA</li><li><strong>Pressure</strong>: 10 MPa (1500 psi)</li><li><strong>Pump Flow</strong>: 70 mL/min</li><li><strong>Temperature Control</strong>: Up to 200 °C</li><li><strong>Weight (English)</strong>: 140 lb.</li><li><strong>Weight (Metric)</strong>: 65 kg</li><li><strong>Width (English)</strong>: 26.5 in.</li><li><strong>Width (Metric)</strong>: 67.3 cm</li><li><strong>Collection Vials</strong>: 60, 250 mL</li><li><strong>Dimensions (D x W x H)</strong>: 69.3 x 67.3 x 61.7 cm</li><li><strong>Extraction Cell Tray</strong>: 24 Cell, 2 Rinse</li><li><strong>Extraction Cells</strong>: 1, 5, 10, 22, 34, 66, 100 mL</li><li><strong>For Use With (Equipment)</strong>: Dionex ASE 350</li><li><strong>Type</strong>: Dionex ASE 350 System</li><li><strong>Unit Size</strong>: Each</li></ul></div></div>

Products from category Sample preparation automation - page 1

Related content

QuEChERS Combined with Low-Temperature Partitioning and GC–MS as an Analytical Strategy for the Determination of Multiclass Pesticide Residues in Cocoa Beans

Webinars LabRulezGCMS Week 07/2026

Research from IOCB Prague reveals a previously unknown mechanism of genetic transcription