<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

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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. 

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Thermo Scientific™ Q Exactive™ GC Orbitrap GC-MS/MS System

High-resolution GC-MS system combining Orbitrap accuracy with full-scan sensitivity and MS/MS power for confident quantitation and compound identification in complex matrices.

<h4><strong>Next-generation high-resolution GC-MS for confident quantitation and unknown identification</strong></h4><p>The <strong>Q Exactive GC Orbitrap GC-MS/MS system</strong> is the first commercial benchtop system to combine <strong>gas chromatography with Orbitrap™ high-resolution accurate-mass (HRAM) detection</strong>. It offers unrivaled resolving power, sub-ppm mass accuracy, and the quantitation power of triple quadrupole systems — all in untargeted full-scan mode.</p><p>Designed for <strong>food safety, metabolomics, environmental, clinical, and pharmaceutical labs</strong>, this hybrid quadrupole-Orbitrap system brings unmatched performance for both discovery and targeted workflows, with robust EI/CI ionization, smart deconvolution, and intuitive software.</p><h3><strong>Key Benefits</strong></h3><h4>🎯 <strong>High-resolution power for confident detection</strong></h4><ul><li>Up to <strong>100,000 resolution (FWHM)</strong> at m/z 272</li><li><strong>Sub-1 ppm mass accuracy</strong> (internal) in routine full-scan MS</li><li>Accurate detection even in <strong>part-per-trillion</strong> range</li><li>Resolves coeluting peaks in complex matrices with ease</li></ul><h4>💡 <strong>Unmatched qualitative and quantitative versatility</strong></h4><ul><li>EI, PCI, NCI ionization with <strong>ExtractaBrite™ source</strong> (removable under vacuum)</li><li><strong>Full-scan sensitivity equal to SRM</strong> mode of triple quadrupoles</li><li>PRM and MS/MS with <strong>HCD collision cell</strong></li><li><strong>Variable electron voltage (VeV)</strong> for softer EI and improved identification</li></ul><h4>🧠 <strong>Advanced tools for unknown identification</strong></h4><ul><li><strong>Deconvolution software</strong> with HRAM fragment interpretation</li><li>Compatibility with NIST/Wiley libraries and <strong>HRAM spectral libraries</strong></li><li>Supports <a target="_blank" rel="noopener noreferrer" href="https://gcms.labrulez.com/products/77"><strong>TraceFinder™</strong></a>, <a target="_blank" rel="noopener noreferrer" href="https://gcms.labrulez.com/products/1759"><strong>Compound Discoverer™</strong></a>, and<a target="_blank" rel="noopener noreferrer" href="https://lcms.labrulez.com/products/1757"> <strong>Mass Frontier™</strong></a></li></ul><h3><strong>System Capabilities</strong></h3><ul><li><strong>Mass range</strong>: 30–3000 m/z</li><li><strong>Mass accuracy</strong>: &lt;1 ppm RMS (internal), &lt;3 ppm RMS (external)</li><li><strong>Quantitative dynamic range</strong>: &gt;10⁶</li><li><strong>In-spectrum dynamic range</strong>: &gt;5000:1</li><li><strong>Scan speed</strong>: up to 18 Hz @ 12,500 resolution</li><li><strong>Simultaneous detection</strong> of up to 10 precursors per scan</li></ul><h3><strong>Operation &amp; Workflow</strong></h3><ul><li><strong>Full MS</strong>, <strong>SIM</strong>, <strong>Timed SIM</strong>, <strong>PRM</strong>, polarity switching, DDA</li><li><strong>Automatic gain control (AGC)</strong> ensures optimal ion population in Orbitrap</li><li>Easy maintenance with <strong>vent-free source and column exchange</strong></li><li>Seamless <a target="_blank" rel="noopener noreferrer" href="https://lcms.labrulez.com/products/1758"><strong>Xcalibur™</strong></a> and <a target="_blank" rel="noopener noreferrer" href="https://gcms.labrulez.com/products/77"><strong>TraceFinder™</strong></a> control with automated tuning/calibration</li></ul><h3><strong>Sample Introduction &amp; Automation</strong></h3><ul><li>Compatible with <strong>TRACE™ 1310 GC</strong> with Instant Connect injectors</li><li>Autosamplers: <strong>TriPlus RSH</strong> for full automation and microsample workflows</li><li>Direct probes (DEP/DIP) for solid/liquid samples — no venting required</li></ul><h3><strong>Applications</strong></h3><ul><li>Food safety &amp; authenticity (pesticides, packaging migration)</li><li>Metabolomics, environmental &amp; clinical toxicology</li><li>Extractables &amp; leachables, forensics, pharmaceuticals</li><li>Untargeted and targeted multi-analyte screening</li></ul><p><img src="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/application::product.product/QExactive-GCMSMS-Orbitrap-with-Autosampler-Front-1858x1391.jpg-650.jpg" alt="Thermo Scientific™ Q Exactive™ GC Orbitrap GC-MS/MS System" width="null" height="null"></p>

Thermo Scientific™ Exactive™ GC Orbitrap™ GC-MS System

High-resolution Orbitrap GC-MS system for confident quantitation and unknown screening. Delivers sub-ppb sensitivity, <1 ppm accuracy, and routine full-scan workflows.

<h4><strong>Bringing high-resolution Orbitrap technology into routine GC-MS workflows</strong></h4><p><strong>The Exactive GC Orbitrap system offers the unmatched mass accuracy, resolving power, and sensitivity of Orbitrap technology in a platform optimized for routine applications. This high-performance GC-MS system enables both targeted and non-targeted full-scan workflows with confident quantitation and trace-level detection, even in complex matrices. Designed for maximum robustness and usability, it streamlines operations across food safety, environmental, industrial, forensic, and anti-doping laboratories.</strong></p><h3><strong>Key Features and Benefits</strong></h3><h4>💡 <strong>Unmatched HRAM Performance</strong></h4><ul><li>Resolving power up to <strong>60,000 FWHM at m/z 200</strong></li><li>Mass accuracy: <strong>&lt;1 ppm</strong> (internal), <strong>&lt;3 ppm</strong> (external)</li><li>Quantitative dynamic range: <strong>&gt;10⁶</strong>, with excellent linearity and precision</li><li>Routine IDLs in the <strong>sub-ppb to ppt range</strong></li></ul><h4>🧪 <strong>Full-Scan Sensitivity and Selectivity</strong></h4><ul><li>Combines triple-quad-like quantitation with full-scan Orbitrap capability</li><li>Sub-ppb sensitivity for 100+ pesticides in food matrices</li><li>High selectivity and confidence in trace-level compound identification</li><li>Spectral deconvolution with accurate-mass fragment filtering</li></ul><h4>⚙️ <strong>Proven Orbitrap Design</strong></h4><ul><li>Curved linear trap (C-Trap) and bent flatapole ion optics</li><li>ExtractaBrite™ ion source (EI/PCI/NCI) – removable under vacuum</li><li>Vent-free column exchange using patented source plug</li><li>Optional direct sample probes (DIP, DEP) for solid or thermolabile analytes</li></ul><h4>🧠 <strong>Streamlined Software and Data Processing</strong></h4><ul><li>Controlled by <a target="_blank" rel="noopener noreferrer" href="https://gcms.labrulez.com/products/77"><strong>TraceFinder™</strong></a> and <a target="_blank" rel="noopener noreferrer" href="https://lcms.labrulez.com/products/1758"><strong>Xcalibur™</strong></a> platforms</li><li>Full-scan acquisition with automated data mining</li><li>Integrated spectral libraries (NIST, Thermo Food/Environmental)</li><li>Spectral fidelity and mass accuracy retained across wide concentration range</li></ul><h4>🔁 <strong>Optimized GC Integration</strong></h4><ul><li>Built on the <strong>TRACE™ 1310 GC platform</strong></li><li>Supports all injection/detection configurations (SSL, PTV, backflush, etc.)</li><li>Paired with <strong>TriPlus™ RSH autosampler</strong> for advanced robotic sample handling</li><li>Excellent retention time stability and fast oven cycling</li></ul><h3><strong>Ideal For Applications In:</strong></h3><ul><li><strong>Food safety and authenticity</strong> (pesticide screening, additives)</li><li><strong>Environmental analysis</strong> (contaminants, pollutants, air toxics)</li><li><strong>Forensics and toxicology</strong> (unknowns, drugs, metabolites)</li><li><strong>Industrial QC</strong> (extractables, volatiles, impurity profiling)</li><li><strong>Non-targeted screening</strong> with full-scan HRAM and retrospective analysis</li></ul><p><img src="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/application::product.product/exactive-gc-orbitrap-gc-ms-front-2000x2000.jpg-650.jpg" alt="Thermo Scientific™ Exactive™ GC Orbitrap™ GC-MS System" width="null" height="null"></p>

Thermo Scientific Orbitrap™ Exploris™ GC Mass Spectrometer

Transform your data quality to deliver the right answer first time, every time with the Thermo Scientific™ Orbitrap™ Exploris™ GC Mass Spectrometer.

<div><div id="product-description"><strong>Simplify operations and deliver consistently accurate results in analytical testing using the Thermo Scientific™ Orbitrap™ Exploris™ GC Mass Spectrometer. This GC-MS system offers a unique depth of analysis and unparalleled accuracy and precision to improve everyday quantitation, screening and sample profiling. It provides the flexibility to keep pace with ever-changing regulations and explore new analytical opportunities through increased scope and method consolidation. Simple instrument set up and intelligent informatics enable users of all abilities to easily access data-rich information.</strong></div><div><h4><strong>Deliver accurate quantitative results and spend less time reviewing data in high throughput analytical testing</strong></h4><ul><li>Offers the power and flexibility of full-scan high-resolution accurate mass data to quantitative, screening and discovery workflows</li><li>Accelerates data reviewing with multi-point compound identification, including spectral matching, isotope pattern match, retention indices and multiple confirmation ions</li></ul><h4><strong>Be one step ahead of changing demands</strong></h4><ul><li>Provides the flexibility to keep pace with ever-changing regulations and enables you to explore new business opportunities through increased scope and method consolidation</li><li>Offers the option to configure the system with either 30,000 or 60,000 mass resolving power and the ability to add MS/MS capability today or in the future</li></ul><h4><strong>Focus on results, not instrument setup</strong></h4><ul><li>Simple instrument set up and intelligent informatics enable users of all abilities to easily access data-rich information</li><li>Next-generation software, including built-in method templates, provides easy-to-use and flexible options that are fully accessible to all members of the analytical team</li></ul><p><img src="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/Thermo_Fisher_Scientific_Thermo_Scientific_Orbitrap_Exploris_GC_Mass_Spectrometer_337a570de7.jpg" alt="Thermo Fisher Scientific: Thermo Scientific Orbitrap™ Exploris™ GC Mass Spectrometer" srcset="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/thumbnail_Thermo_Fisher_Scientific_Thermo_Scientific_Orbitrap_Exploris_GC_Mass_Spectrometer_337a570de7.jpg 245w," sizes="100vw" width="1032" height="617"></p><h4><strong>Benefits that boost productivity</strong></h4><h5><strong>Increase scope</strong></h5><p>Gain the flexibility to quickly add new compounds without compound optimization and decide post acquisition which analytes to measure.</p><h5><strong>Fast system setup</strong></h5><p>Walk up, tune, and calibrate in under five minutes with full confidence that the system is operating at maximum performance for all users.</p><h5><strong>Efficient review and reporting</strong></h5><p>Use multiple points of identification to quickly confirm or reject detections, increasing peace of mind. Spectral matching, isotope patterns, retention indices, and elemental compositions provide high confidence in results.</p><h5><strong>Accurate quantitation</strong></h5><p>Six orders of linear dynamic range covers the concentrations encountered in even the most complex sample matrices.</p><h5><strong>Method consolidation</strong></h5><p>Combine acquisition methods onto a single system, reducing the need for multiple systems and streamlining data processing.</p><h5><strong>Retrospective analysis</strong></h5><p>Interrogate previously acquired high-resolution accurate-mass (HRAM) data in multiple ways to answer additional analytical questions without additional sample injections.</p><h4><strong>Power GC-MS with Thermo Scientific software solutions</strong></h4><ul><li><strong>Chromeleon CDS:</strong> Enterprise-ready, regulatory-compliant quantitation</li><li><strong>TraceFinder software:</strong> High-throughput screening and quantitation</li><li><strong>Compound Discoverer software:</strong> Small-molecule unknown identification</li></ul><h3><strong>Specifications</strong></h3><ul><li><strong>Dynamic Range:</strong> &gt;5000 within a single Orbitrap mass analyzer spectrum</li><li><strong>Mass Range: </strong>30 to 3000 m/z</li><li><strong>Mass Accuracy: </strong>External calibration achieves &lt;3 ppm RMS drift over 24 hours, Internal lock mass calibration achieves &lt;1 ppm RMS drift over 24 hours</li><li><strong>Resolution: </strong>Up to 60,000 at m/z 200</li><li><strong>Scan Rates: </strong>Up to 40 Hz at resolution setting 7,500 at m/z 200</li><li><strong>Description:</strong> Orbitrap Exploris GC Mass Spectrometer, no MS/MS</li></ul></div></div>

Thermo Scientific™ Orbitrap™ Exploris™ GC 240 Mass Spectrometer

Take research capability to a new, unprecedented level of performance with the Thermo Scientific™ Orbitrap Exploris™ GC 240 mass spectrometer and accelerate your scientific discovery. 

<p><strong>Simplify the most complex analytical challenges and achieve excellent data quality with the Thermo Scientific™ Orbitrap™ Exploris™ GC 240 mass spectrometer.&nbsp;</strong></p><p>By delivering <strong>uncompromising qualitative and quantitative information</strong>, this <strong>high-resolution accurate-mass GC-MS system</strong> addresses the evolving requirements of research laboratories for <strong>compound identification and quantitation</strong>. From <strong>discovery profiling</strong>, <strong>metabolomics</strong> and <strong>applied quantification</strong>, scientists gain <strong>unparalleled access to information-rich data and results</strong>.</p><p><strong>Experience breakthrough performance in high resolution GC-MS analysis</strong> to gain the <strong>deepest insights</strong> into your sample.</p><p><img src="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/Thermo_Orbitrap_Exploris_GC_240_Mass_Spectrometer_1_99d830b929/Thermo-Orbitrap-Exploris-GC-240-Mass-Spectrometer-1.jpg" alt="Thermo Scientific™ Orbitrap™ Exploris™ GC 240 Mass Spectrometer" srcset="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/thumbnail_Thermo_Orbitrap_Exploris_GC_240_Mass_Spectrometer_1_99d830b929/thumbnail_Thermo-Orbitrap-Exploris-GC-240-Mass-Spectrometer-1.jpg 156w," sizes="100vw" width="650" height="650"></p><h5><strong>The Orbitrap Exploris GC 240 mass spectrometer:</strong></h5><ul><li><strong>Enables you to get the right answer first time</strong></li><li><strong>Offers the flexibility to adapt to ever-changing needs</strong> with its <strong>superior mass accuracy, dynamic range and robustness</strong></li><li><strong>Includes intelligent instrument setup and an intuitive user experience</strong> to make it fully accessible for users of all skill levels</li><li><strong>Offers unprecedented 240,000 resolution (at m/z 200)</strong> to deliver <strong>sub-1-ppm mass accuracy</strong> and <strong>sensitivity down to part-per-trillion concentrations</strong></li><li><strong>Maintains system sensitivity at all mass resolution levels</strong>, so there is <strong>no need to compromise between resolution and sensitivity</strong></li><li><strong>Features repeatable performance injection after injection</strong> to enable discoveries to be made across <strong>high sample studies</strong></li></ul><p><img src="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/Thermo_Orbitrap_Exploris_GC_240_Mass_Spectrometer_2_8a411289bf/Thermo-Orbitrap-Exploris-GC-240-Mass-Spectrometer-2.jpg" alt="Thermo Scientific™ Orbitrap™ Exploris™ GC 240 Mass Spectrometer" srcset="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/thumbnail_Thermo_Orbitrap_Exploris_GC_240_Mass_Spectrometer_2_8a411289bf/thumbnail_Thermo-Orbitrap-Exploris-GC-240-Mass-Spectrometer-2.jpg 156w," sizes="100vw" width="650" height="650"></p><h3><strong>Thermo Scientific™ Orbitrap™ Exploris™ GC 240 Mass Spectrometer Specifications</strong></h3><ul><li><strong>Description:</strong> Orbitrap Exploris GC 240 Mass Spectrometer</li><li><strong>Dynamic Range:</strong> &gt;5000 within a single Orbitrap mass analyzer spectrum</li><li><strong>Mass Accuracy:</strong> External calibration achieves &lt;3 ppm RMS drift over 24 hours, Internal lock mass calibration achieves &lt;1 ppm RMS drift over 24 hours.</li><li><strong>Scan Rates:</strong> Up to 40 Hz at resolution setting 7,500 at m/z 200</li><li><strong>Mass Range:</strong> 30 to 3000 m/z</li><li><strong>Resolution:</strong> Up to 240,000 at m/z 200</li><li><strong>Unit Size:</strong> Each</li></ul>

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