<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™ TRACE™ 1310 Gas Chromatograph

Modular GC with touch screen control, instant-connect injectors, helium-saving capability, and fast oven cycles—ideal for method development and routine analysis.

<h4><strong>Premium modular GC system with full local control for method development and routine analysis</strong></h4><p><strong>The TRACE 1310 GC combines the modular, tool-free architecture of the TRACE 1300 Series with a powerful built-in user interface for complete instrument control. Designed for analysts who demand flexibility, speed, and intuitive access to GC parameters, the system supports all injection and detection configurations and delivers exceptional performance for both routine QA/QC and advanced method development.</strong></p><p><img src="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/application::product.product/Thermo-Trace-1310-GC-System-1.jpg" alt="Thermo Scientific™ TRACE™ 1310 Gas Chromatograph" width="null" height="null"></p><h3><strong>Key Features and Benefits</strong></h3><h4>🖥️ <strong>Full Local Control</strong></h4><ul><li>Integrated <strong>touch screen interface</strong> for real-time method setup and control</li><li>Intuitive navigation for injector, detector, oven, and flow parameters</li><li>Ideal for <strong>method development</strong> and <strong>standalone operation</strong> without PC</li></ul><h4>⚙️ <strong>Modular Instant Connect Design</strong></h4><ul><li>Exchange injectors and detectors in under 2 minutes</li><li>Tool-free reconfiguration without downtime</li><li>Compatible with all TRACE 1300 modules and autosamplers</li></ul><h4>💨 <strong>Fast and Stable Thermal Performance</strong></h4><ul><li>Oven ramp rate up to <strong>125 °C/min</strong>, cool-down in under 4 minutes</li><li>Excellent retention time and area reproducibility</li><li>Cryogenic cooling available down to –100 °C</li></ul><h4>♻️ <strong>Helium Saver Ready</strong></h4><ul><li>Use helium, hydrogen, or nitrogen as carrier gases</li><li>Reduce helium consumption by over 90%</li><li>Maintain method integrity while switching gases</li></ul><h4>🧪 <strong>Broad Application Coverage</strong></h4><ul><li>Supports SSL, PTV, On-Column, Large Volume Injection, Backflush</li><li>Detector options: FID, TCD, ECD, NPD, FPD, MS interface</li><li>Compatible with manual or automated workflows (AI/AS 1310, TriPlus RSH)</li></ul><h3><strong>Software and Integration</strong></h3><ul><li>Fully controllable via <a target="_blank" rel="noopener noreferrer" href="https://gcms.labrulez.com/products/76"><strong>Chromeleon™</strong></a><strong>, </strong><a target="_blank" rel="noopener noreferrer" href="https://lcms.labrulez.com/products/1758"><strong>Xcalibur™</strong></a><strong>, or Chrom-Card™</strong></li><li>eWorkflows for simplified operation and data processing</li><li>Built-in QC, audit trail, and LIMS compatibility</li></ul><p><img src="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/application::product.product/Thermo-TriPlus-500-GC-Headspace-Autosampler-3.jpg" alt="Thermo Scientific™ TRACE™ 1310 Gas Chromatograph" width="null" height="null"></p>

Thermo Scientific TRACE™ 1600 Series Gas Chromatograph

The TRACE 1600 GC is designed for minimum interaction with the instrument, limiting the local operations to the essentials and enabling full instrument control through the chromatography data system.

<div><div id="product-description"><p><strong>Maximize the operational efficiency and profitability of your lab with the Thermo Scientific™ TRACE™ 1600 Series Gas Chromatograph and its unique modular concept for optimized instrumental usage. The TRACE 1600 GC is designed for minimum interaction with the instrument, limiting the local operations to the essentials and enabling full instrument control through the chromatography data system.</strong></p><figure class="image"><img style="aspect-ratio:992/1088;" src="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/Pragolab_Porovnani_vlastnosti_plynovych_chromatografu_Thermo_Scientific_TRACE_1600_vs_TRACE_1610_4f943d7033/Pragolab-Porovnani-vlastnosti-plynovych-chromatografu-Thermo-Scientific-TRACE-1600-vs-TRACE-1610.jpg" alt="Thermo Fisher Scientific: TRACE 1600 vs TRACE 1610" width="992" height="1088"></figure><h3><strong>The TRACE 1600 Series Gas Chromatograph offers:</strong></h3><h4><strong>Maximized instrument productive time</strong></h4><ul><li>Keep your GC system up and running even when deeper cleaning is required, thanks to the offline maintenance capabilities of the iConnect injector and detector modules</li><li>Optimize the use of GC instruments in the lab and avoid having idle systems with interchangeable iConnect injector and detector modules</li><li>Avoid unplanned downtime through alerts on consumables usage</li><li>Reduce run time and system contamination through integrated backflush capabilities</li><li>Extend unattended operations through a full portfolio of sampling automation products</li></ul><h4><strong>Monitor key aspects of your GC systems</strong></h4><ul><li>With Thermo Scientific™ SmartStatus™ instrument tracking within Chromeleon CDS, quickly see whether instruments are ready to run samples, if maintenance is required or if consumables should be replaced. The fully customizable software enables you to make data-driven decisions on when to perform maintenance and avoid unnecessary downtime.</li></ul><h4><strong>Simplified operations for quick adoption</strong></h4><ul><li>Facilitate operations through how-to videos directly available on the local touch-screen interface</li><li>Easily adapt the GC system configuration to your needs in minutes without special tools or training requirements with iConnect injector and detector modules, also available for online purchasing and one day delivery</li><li>Simplify troubleshooting operations through quick replacement of iConnect injector and detector modules, without the need for service calls</li><li>Make capillary column installation quick and safe through tool-free Thermo Scientific™ iConnect Column Lock connectors</li></ul><h4><strong>Lower cost of ownership</strong></h4><ul><li>Reduce operational costs with a GC system that allows the use of standard consumables</li><li>Save energy with low thermal mass and a quick start-up</li><li>Reduce helium carrier gas consumption while operating with a SSL injector</li></ul><h3><strong>Specifications:</strong></h3><ul><li><strong>Cool-Down Time:</strong> 450°C to 50°C in less than 4 minutes</li><li><strong>Heat Up Time:</strong> Max. of 125°C/min</li><li><strong>Temperature Range:</strong> Ambient +3°C to 450°C (cryogenic option for sub-ambient operation)</li><li><strong>Voltage:</strong> 230 V</li><li><strong>Certifications/Compliance:</strong> Conforms to safety standards according to Machinery Directive 2006/42/EC and Low Voltage Directive 2006/95/EC. Conforms to the regulations on Electromagnetic Compatibility (EMC) and Radio Frequency Interference (RFI) according to directive 2004/108/EC.</li><li><strong>Description:</strong> TRACE™ 1600 Gas Chromatograph</li><li><strong>Inlet Type:</strong> Up to 2: SSL, PTV, SSL-BKF, PTV-BKF, COC, GSV</li><li><strong>Detector Type:</strong> Up to 2: FID, TCD, ECD, NPD, FPD, PDD</li><li><strong>Dimensions (L x W x H):</strong> 45 × 44 × 67 cm (17.7 x 17.3 x 26.4 in) (H × W × D)</li></ul></div></div>

Thermo Scientific™ TRACE™ 1610 Series Gas Chromatograph

The TRACE 1610 GC is designed to enhance the workflow experience for both new and expert users through its advanced multi-functional touch screen with instrument health monitoring and how-to videos.

<p><strong>The TRACE 1610 GC is designed to enhance the workflow experience for both new and expert users through its advanced multi-functional touch screen with instrument health monitoring and how-to videos. The TRACE 1600 GC is designed for minimum interaction with the instrument, limiting the local operations to the essentials and enabling full instrument control through the chromatography data system.</strong></p><p><img src="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/Pragolab_Porovnani_vlastnosti_plynovych_chromatografu_Thermo_Scientific_TRACE_1600_vs_TRACE_1610_4f943d7033/Pragolab-Porovnani-vlastnosti-plynovych-chromatografu-Thermo-Scientific-TRACE-1600-vs-TRACE-1610.jpg" alt="Thermo Scientific™ TRACE™ 1610 Series Gas Chromatograph:  TRACE 1600 vs TRACE 1610." srcset="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/thumbnail_Pragolab_Porovnani_vlastnosti_plynovych_chromatografu_Thermo_Scientific_TRACE_1600_vs_TRACE_1610_4f943d7033/thumbnail_Pragolab-Porovnani-vlastnosti-plynovych-chromatografu-Thermo-Scientific-TRACE-1600-vs-TRACE-1610.jpg 142w," sizes="100vw" width="992" height="1088"></p><h3><strong>Maximized instrument productive time</strong></h3><ul><li><strong>Keep your GC system up and running</strong> even when deeper cleaning is required, thanks to the <strong>offline maintenance capabilities</strong> of the <strong>iConnect injector and detector modules</strong></li><li><strong>Optimize the use of GC instruments</strong> in the lab and avoid having idle systems with <strong>interchangeable iConnect injector and detector modules</strong></li><li><strong>Avoid unplanned downtime</strong> through <strong>alerts on consumables usage</strong></li><li><strong>Reduce run time and system contamination</strong> through <strong>integrated backflush capabilities</strong></li><li><strong>Extend unattended operations</strong> through a <strong>full portfolio of sampling automation products</strong></li></ul><p><img src="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/Pragolab_Moduly_injektoru_a_detektoru_i_Connect_2_ba43f76c80/Pragolab-Moduly-injektoru-a-detektoru-iConnect-2_l.webp" alt="Thermo Scientific™ TRACE™ 1610 Series Gas Chromatograph: Interchangeable injector and detector modules allow for flexible configuration." width="1202" height="417"></p><h3><strong>Monitor key aspects of your GC systems</strong></h3><p>With <strong>Thermo Scientific™ SmartStatus™ instrument tracking</strong> within <a target="_blank" rel="noopener noreferrer" href="https://lcms.labrulez.com/products/76"><strong>Chromeleon CDS</strong></a>, quickly see whether <strong>instruments are ready to run samples</strong>, if <strong>maintenance is required</strong> or if <strong>consumables should be replaced</strong>. The <strong>fully customizable software</strong> enables you to make <strong>data-driven decisions</strong> on when to perform maintenance and <strong>avoid unnecessary downtime</strong>.</p><h3><strong>Simplified operations for quick adoption</strong></h3><ul><li><strong>Facilitate operations</strong> through <strong>how-to videos</strong> directly available on the <strong>local touch-screen interface</strong></li><li><strong>Easily adapt the GC system configuration</strong> to your needs in minutes <strong>without special tools or training requirements</strong> with <strong>iConnect injector and detector modules</strong>, also available for <strong>online purchasing and one day delivery</strong></li><li><strong>Simplify troubleshooting operations</strong> through <strong>quick replacement</strong> of iConnect injector and detector modules, <strong>without the need for service calls</strong></li><li><strong>Make capillary column installation quick and safe</strong> through <strong>tool-free Thermo Scientific™ iConnect Column Lock connectors</strong></li></ul><p><img src="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/Thermo_Scientific_TRACE_1610_Series_Gas_Chromatograph_4e84dd71ff.jpg" alt="Thermo Scientific™ TRACE™ 1610 Series Gas Chromatograph:   Finger-tight connections with a simple click, allowing capillary column length adjustments to be made before installation." srcset="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/thumbnail_Thermo_Scientific_TRACE_1610_Series_Gas_Chromatograph_4e84dd71ff.jpg 245w," sizes="100vw" width="1529" height="413"></p><h3><strong>Lower cost of ownership</strong></h3><ul><li><strong>Reduce operational costs</strong> with a GC system that allows the use of <strong>standard consumables</strong></li><li><strong>Save energy</strong> with <strong>low thermal mass</strong> and a <strong>quick start-up</strong></li><li><strong>Reduce helium carrier gas consumption</strong> while operating with a <strong>SSL injector</strong></li></ul>

Thermo Scientific™ TRACE™ 1300 Series Gas Chromatograph

Modular GC system with instant-connect injectors and detectors for fast setup, low maintenance, and high-throughput routine analysis with helium-saving capability.

<h4><strong>Modular, fast, and robust GC system for modern analytical labs</strong></h4><p><strong>The TRACE 1300 Series GC platform offers a uniquely modular design that combines productivity, simplicity, and operational flexibility. With instant-connect user-exchangeable injectors and detectors, the system enables tool-free configuration changes in under 2 minutes. Designed for high-throughput QA/QC and routine labs, it reduces downtime and cost of ownership while delivering industry-leading performance.</strong></p><p><img src="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/application::product.product/Trace-1300-GC.jpg-650.jpg" alt="Thermo Scientific™ TRACE™ 1300 Series Gas Chromatograph" width="null" height="null"></p><h3><strong>Key Features and Benefits</strong></h3><h4>⚙️ <strong>Modular Design with Instant Connect Technology</strong></h4><ul><li>Plug-in injector and detector modules install in minutes without tools</li><li>No need for service engineers or downtime during reconfiguration</li><li>Dual-channel and multi-detector setups supported</li><li>Ideal for evolving lab needs and future upgrades</li></ul><h4>💨 <strong>Exceptional Speed and Thermal Performance</strong></h4><ul><li>Ultra-fast oven with heating rates up to <strong>125 °C/min</strong></li><li>Oven cooldown from 450 °C to 50 °C in under 4 minutes</li><li>Retention time RSD &lt; <strong>0.0008 min</strong>, peak area RSD &lt; <strong>0.5%</strong></li><li>IEC (Integrated Electronic Control) for precise pressure and flow control</li></ul><h4>♻️ <strong>Helium Saver and Alternative Gas Compatibility</strong></h4><ul><li><strong>Instant Connect Helium Saver Injector</strong> reduces helium use by 90%+</li><li>Supports nitrogen or hydrogen as alternative carrier gases</li><li>Extend helium cylinder life up to <strong>14 years</strong> without method changes</li></ul><h4>🔁 <strong>Injection Versatility</strong></h4><ul><li>Split/splitless (SSL), PTV, Gas Sampling Valve, and On-column injection</li><li>Large volume injections and backflush options available</li><li>Cryogenic cooling options down to <strong>–100 °C</strong></li></ul><h4>🔬 <strong>Flexible Detector Options</strong></h4><ul><li>Instant Connect detectors: <strong>FID, TCD, ECD, NPD, FPD</strong></li><li>Miniaturized cells with fast acquisition rates up to <strong>300 Hz</strong></li><li>Connects seamlessly with Thermo Scientific GC-MS systems or FT-IR</li><li>Optional methanizer for CO/CO₂ detection</li></ul><h4>🧠 <strong>Smart Software Integration</strong></h4><ul><li>Full control via <a target="_blank" rel="noopener noreferrer" href="https://gcms.labrulez.com/products/76"><strong>Chromeleon™</strong></a><strong>, </strong><a target="_blank" rel="noopener noreferrer" href="https://lcms.labrulez.com/products/1758"><strong>Xcalibur™</strong></a><strong>, Chrom-Card™</strong></li><li>eWorkflows and intelligent automation for efficient operation</li><li>Dynamic data processing, QA/QC checks, and LIMS integration</li></ul><h3><strong>Additional Benefits</strong></h3><ul><li><strong>TRACE 1300 model:</strong> budget-friendly, simple interface for routine use</li><li><strong>TRACE 1310 model: </strong>touch screen interface for method development</li><li>Small footprint, low energy consumption, and fast startup</li><li>GLP-compliant modules, multilingual UI, and remote operability</li></ul><p><img src="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/application::product.product/Thermo-TriPlustm-100-LS-Liquid-Autosampler-5.jpg" alt="Thermo Scientific™ TRACE™ 1300 Series Gas Chromatograph" width="null" height="null"></p>

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