<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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Phenomenex Zebron ZB-XLB GC Columns

Zebron ZB-XLB is an unique, low polarity si-arylene column

<p><strong>Extra Low Bleed</strong></p><ul><li>Unique, low polarity si-arylene column</li><li>Engineered specifically for use with bleed sensitive detectors such as MS</li><li>Provides alternate selectivity to standard 5-type phases</li><li>Often used for confirmation of pesticides, PCBs, or other environmental samples</li><li>Good tool for sample screening to identify unknown contaminants</li></ul><h5><strong>Recommended Use</strong></h5><ul><li>Herbicides / Insecticides, PCBs, Pesticides , Unknown Samples</li></ul><p><img src="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/Phenomenex_Zebron_ZB_XLB_24bf657d8c.jpg" alt="Phenomenex: Zebron ZB-XLB" srcset="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/thumbnail_Phenomenex_Zebron_ZB_XLB_24bf657d8c.jpg 145w," sizes="100vw" width="688" height="741"></p><p><strong>Upgrade to Zebron from these similar* phases:</strong></p><h5><strong>Agilent®</strong></h5><ul><li>DB®-XLB</li><li>VF-XMS</li></ul><h5><strong>Restek®</strong></h5><ul><li>Rxi®-XLB</li><li>Rtx®-XLB</li></ul><p><strong>Supelco®</strong></p><ul><li>MDN-12</li></ul><p><strong>*not exact equivalent, selectivity may differ</strong></p>

Phenomenex Zebron ZB-FFAP GC Columns

Zebron ZB-FFAP - Popular choice for food industry method development

<p><strong>Improved Resolution for Free Fatty Acids</strong></p><ul><li>Popular choice for food industry method development</li><li>High polarity column with excellent thermal and chemical stability</li><li>Improve peak shape for underivatized acids, organic acids, free fatty acids, and alcohols</li><li>Bonded, solvent rinsable nitroterephthalic acid modified polyethylene glycolphase</li></ul><p><img src="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/Phenomenex_Zebron_ZB_WAX_85cadc4b26.webp" alt="Phenomenex: Zebron ZB-FFAP" srcset="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/thumbnail_Phenomenex_Zebron_ZB_WAX_85cadc4b26.webp 245w," sizes="100vw" width="500" height="150"></p><h5><strong>Recommended Applications</strong></h5><ul><li>Acrylates, Alcohols, Aldehydes, Free Fatty Acids, Ketones, Organic Acids, Phenols, Volatile Free Acids</li></ul><p><img src="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/Phenomenex_Zebron_ZB_FFAP_131d038bab.jpg" alt="Phenomenex: Zebron ZB-FFAP." srcset="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/thumbnail_Phenomenex_Zebron_ZB_FFAP_131d038bab.jpg 164w," sizes="100vw" width="670" height="636"></p><p><strong>Upgrade to Zebron from any nitroterephthalic acid modified polyethylene glycol phase:</strong></p><h5><strong>Agilent®</strong></h5><ul><li>DB®-FFAP</li><li>HP-FFAP</li><li>CP-Wax 58 FFAP CB</li><li>CP-FFAP CB</li></ul><h5><strong>Restek®</strong></h5><ul><li>Stabilwax®-DA</li></ul><h5><strong>SGE®</strong></h5><ul><li>BP21</li></ul><h5><strong>Supelco®</strong></h5><ul><li>Nukol</li><li>SPB®-1000</li></ul><h5><strong>OV®</strong></h5><ul><li>OV-351</li></ul>

Phenomenex Strata X-AW Solid Phase Extraction (SPE)

Strata-X-AW mixed-mode SPE sorbent enables strong retention of acids (pKa ≤5) with 100% organic wash, ensuring maximum removal of interferences for clean, reliable extractions.

<p><strong>Weak Anion Mixed-Mode Solid Phase Extraction (SPE)</strong></p><p>A weak anion-exchange functionalized polymeric sorbent that allows for complete retention of acidic compounds with a <strong>pKa less than 5</strong>, making <strong>100% organic wash conditions possible</strong>. A 100% organic wash ensures that the maximum amount of interferences are removed from the target compound.</p><p><img src="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/Phenomenex_Strata_X_AW_SPE_cd5908db4d.jpg" alt="Phenomenex: Strata-X-AW SPE" srcset="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/thumbnail_Phenomenex_Strata_X_AW_SPE_cd5908db4d.jpg 245w," sizes="100vw" width="500" height="268"></p><ul><li><strong>Recommended Use: </strong>Extraction of acidic compounds, particularly strong acids</li></ul><h4><strong>Starting Method</strong></h4><h5><strong>For Acids with pKa ≤ 5</strong></h5><ul><li><strong>Column: </strong>1 mL Methanol</li><li><strong>Equilibrate: </strong>1 mL Water, pH 6-7</li><li><strong>Load: </strong>Diluted Sample pH 6-7</li><li><strong>Wash 1: </strong>1 mL 25 mM Ammonium Acetate Buffered, pH 6-7</li><li><strong>Wash 2: </strong>1 mL Methanol</li><li><strong>Elute Any Acid: </strong>2x 500 µL 5 % NH<sub>4</sub>OH in Methanol</li><li><strong>Elute Weak Acids: </strong>2x 500 µL 5 % Formic Acid in Methanol</li></ul><p><img src="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/Phenomenex_Strata_X_single_tube_435d45d0ad.jpg" alt="Phenomenex: Strata X single tube" srcset="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/thumbnail_Phenomenex_Strata_X_single_tube_435d45d0ad.jpg 156w," sizes="100vw" width="1080" height="1080"></p><p><i>Based on 30 mg/1 mL sorbent mass. The above is a convenient starting point for SPE method development, further optimization may be required to tailor the method for your specific extraction needs.</i></p><h4><strong>Available Formats</strong></h4><ul><li><strong>96-Well-Plate</strong></li></ul><p><img src="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/Phenomenex_Strata_X_96_well_plate_9a66005814.jpg" alt="Phenomenex: Strata X 96-well plate" srcset="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/thumbnail_Phenomenex_Strata_X_96_well_plate_9a66005814.jpg 156w," sizes="100vw" width="1080" height="1080"></p><ul><li><strong>1, 3, and 6mL Tubes</strong></li></ul><p><img src="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/Phenomenex_Strata_X_tubes_1_9b04cab6c1.jpg" alt="Phenomenex: Strata X 1, 3, and 6mL Tubes" srcset="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/thumbnail_Phenomenex_Strata_X_tubes_1_9b04cab6c1.jpg 156w," sizes="100vw" width="1080" height="1080"></p><ul><li><strong>Giga Tubes (12-150mL Tubes)</strong></li></ul><p><img src="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/Phenomenex_Strata_X_tubes_2_a8cd1706ec.jpg" alt="Phenomenex: Strata X Giga Tubes (12-150mL Tubes)" srcset="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/thumbnail_Phenomenex_Strata_X_tubes_2_a8cd1706ec.jpg 156w," sizes="100vw" width="1080" height="1080"></p>

Phenomenex Strata X-A Solid Phase Extraction (SPE)

Strata-X-A strong anion-exchange SPE retains weak acids (pKa >2) with 100% organic wash, maximizing interference removal. Available in tubes, plates, and giga formats.

<p><strong>Strong Anion Mixed-Mode Solid Phase Extraction (SPE)</strong></p><p>A strong anion-exchange functionalized polymeric sorbent that allows for complete retention of weakly acidic compounds with a <strong>pKa greater than 2</strong>, making <strong>100% organic wash conditions possible</strong>. A 100% organic wash ensures that the maximum amount of interferences are removed from the target compound.</p><p><img src="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/Phenomenex_Strata_X_A_SPE_e107f0b6bf.jpg" alt="Phenomenex: Strata-X-A SPE" srcset="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/thumbnail_Phenomenex_Strata_X_A_SPE_e107f0b6bf.jpg 245w," sizes="100vw" width="500" height="268"></p><ul><li><strong>Recommended Use: </strong>Extraction of weakly acidic compounds</li></ul><h4><strong>Starting Method</strong></h4><h5><strong>For Acids with pKa &gt; 2</strong></h5><ul><li><strong>Column: </strong>1 mL Methanol</li><li><strong>Equilibrate: </strong>1 mL Water, pH 6-7</li><li><strong>Load: </strong>Diluted Sample pH 6-7</li><li><strong>Wash 1: </strong>1 mL 25 mM Ammonium Acetate Buffered, pH 6-7</li><li><strong>Wash 2: </strong>1 mL Methanol (collect this fraction to analyze Neutral/Bases)</li><li><strong>Elute Acid: </strong>2x 500 µL 5 % Formic Acid in Methanol</li></ul><p><img src="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/Phenomenex_Strata_X_single_tube_435d45d0ad.jpg" alt="Phenomenex: Strata X single tube" srcset="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/thumbnail_Phenomenex_Strata_X_single_tube_435d45d0ad.jpg 156w," sizes="100vw" width="1080" height="1080"></p><p><i>Based on 30 mg/1 mL sorbent mass. The above is a convenient starting point for SPE method development, further optimization may be required to tailor the method for your specific extraction needs.</i></p><h4><strong>Available Formats</strong></h4><ul><li><strong>96-Well-Plate</strong></li></ul><p><img src="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/Phenomenex_Strata_X_96_well_plate_9a66005814.jpg" alt="Phenomenex: Strata X 96-well plate" srcset="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/thumbnail_Phenomenex_Strata_X_96_well_plate_9a66005814.jpg 156w," sizes="100vw" width="1080" height="1080"></p><ul><li><strong>1, 3, and 6mL Tubes</strong></li></ul><p><img src="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/Phenomenex_Strata_X_tubes_1_9b04cab6c1.jpg" alt="Phenomenex: Strata X 1, 3, and 6mL Tubes" srcset="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/thumbnail_Phenomenex_Strata_X_tubes_1_9b04cab6c1.jpg 156w," sizes="100vw" width="1080" height="1080"></p><ul><li><strong>Giga Tubes (12-150mL Tubes)</strong></li></ul><p><img src="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/Phenomenex_Strata_X_tubes_2_a8cd1706ec.jpg" alt="Phenomenex: Strata X Giga Tubes (12-150mL Tubes)" srcset="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/thumbnail_Phenomenex_Strata_X_tubes_2_a8cd1706ec.jpg 156w," sizes="100vw" width="1080" height="1080"></p>

Phenomenex Strata X-C Solid Phase Extraction (SPE)

Strata-X-C strong cation-exchange SPE retains basic compounds (pKa ≤10.5) with 100% organic wash for maximum cleanup. Offered in tubes, plates, and giga formats.

<p><strong>Strong Cation Mixed-Mode Solid Phase Extraction (SPE)</strong></p><p>A strong cation-exchange functionalized polymeric sorbent that allows for complete retention of basic compounds with a <strong>pKa less than 10.5,</strong> making <strong>100% organic wash conditions possible</strong>. A 100% organic wash ensures that the maximum amount of interferences are removed from the target compound.</p><p><img src="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/Phenomenex_Strata_X_C_SPE_4927d7340d.jpg" alt="Phenomenex: Strata-X-C SPE" srcset="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/thumbnail_Phenomenex_Strata_X_C_SPE_4927d7340d.jpg 245w," sizes="100vw" width="500" height="268"></p><ul><li><strong>Recommended Use: </strong>Extraction of weakly basic compounds</li></ul><h4><strong>Starting Method</strong></h4><h5><strong>For Bases with pKa ≤ 10.5</strong></h5><ul><li><strong>Column: </strong>1 mL Methanol</li><li><strong>Equilibrate: </strong>1 mL Acidified Water</li><li><strong>Load: </strong>Diluted Acidified Sample</li><li><strong>Wash 1: </strong>1 mL 0.1 N HCI in Water (collect this fraction to analyze Polar Neutrals)</li><li><strong>Wash 2: </strong>1 mL 0.1 N HCI in Methanol (collect this fraction to analyze Neutrals/Acids)</li><li><strong>Elute Bases: </strong>2x 500 µL 5 % NH4OH in Methanol</li></ul><p><img src="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/Phenomenex_Strata_X_single_tube_435d45d0ad.jpg" alt="Phenomenex: Strata X single tube" srcset="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/thumbnail_Phenomenex_Strata_X_single_tube_435d45d0ad.jpg 156w," sizes="100vw" width="1080" height="1080"></p><p><i>Based on 30 mg/1 mL sorbent mass. The above is a convenient starting point for SPE method development, further optimization may be required to tailor the method for your specific extraction needs.</i></p><h4><strong>Available Formats</strong></h4><ul><li><strong>96-Well-Plate</strong></li></ul><p><img src="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/Phenomenex_Strata_X_96_well_plate_9a66005814.jpg" alt="Phenomenex: Strata X 96-well plate" srcset="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/thumbnail_Phenomenex_Strata_X_96_well_plate_9a66005814.jpg 156w," sizes="100vw" width="1080" height="1080"></p><ul><li><strong>1, 3, and 6mL Tubes</strong></li></ul><p><img src="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/Phenomenex_Strata_X_tubes_1_9b04cab6c1.jpg" alt="Phenomenex: Strata X 1, 3, and 6mL Tubes" srcset="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/thumbnail_Phenomenex_Strata_X_tubes_1_9b04cab6c1.jpg 156w," sizes="100vw" width="1080" height="1080"></p><ul><li><strong>Giga Tubes (12-150mL Tubes)</strong></li></ul><p><img src="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/Phenomenex_Strata_X_tubes_2_a8cd1706ec.jpg" alt="Phenomenex: Strata X Giga Tubes (12-150mL Tubes)" srcset="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/thumbnail_Phenomenex_Strata_X_tubes_2_a8cd1706ec.jpg 156w," sizes="100vw" width="1080" height="1080"></p>

Phenomenex Strata X-CW Solid Phase Extraction (SPE)

Strata-X-CW weak cation-exchange SPE retains strong bases (pKa >8) with 100% organic wash for maximum cleanup. Available in tubes, 96-well plates, and giga formats.

<p><strong>Weak Cation Mixed-Mode Solid Phase Extraction (SPE)</strong></p><p>A weak cation-exchange functionalized polymeric sorbent that allows for complete retention of basic compounds with a <strong>pKa greater than 8</strong>, making <strong>100% organic wash conditions possible</strong>. A 100% organic wash ensures that the maximum amount of interferences are removed from the target compound.</p><p><img src="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/Phenomenex_Strata_X_CW_SPE_b16a0e0baf.jpg" alt="Phenomenex: Strata-X-CW SPE" srcset="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/thumbnail_Phenomenex_Strata_X_CW_SPE_b16a0e0baf.jpg 245w," sizes="100vw" width="500" height="268"></p><ul><li><strong>Recommended Use: </strong>Extraction of basic compounds, particularly strong bases</li></ul><h4><strong>Starting Method</strong></h4><h5><strong>For Bases with pKa &gt; 8</strong></h5><ul><li><strong>Column: </strong>1 mL Methanol</li><li><strong>Equilibrate: </strong>1 mL Water, pH 6-7</li><li><strong>Load: </strong>Diluted Sample, pH 6-7</li><li><strong>Wash 1: </strong>1 mL Water, pH 6-7</li><li><strong>Wash 2: </strong>1 mL Methanol (collect this fraction to analyze Neutrals/Acids)</li><li><strong>Elute Any Bases: </strong>2x 500 µL 5 % Formic Acid in Methanol</li><li><strong>Elute Weak Bases: </strong>2x 500 µL 5 % NH4OH in Methanol</li></ul><p><img src="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/Phenomenex_Strata_X_single_tube_435d45d0ad.jpg" alt="Phenomenex: Strata X single tube" srcset="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/thumbnail_Phenomenex_Strata_X_single_tube_435d45d0ad.jpg 156w," sizes="100vw" width="1080" height="1080"></p><p><i>Based on 30 mg/1 mL sorbent mass. The above is a convenient starting point for SPE method development, further optimization may be required to tailor the method for your specific extraction needs.</i></p><h4><strong>Available Formats</strong></h4><ul><li><strong>96-Well-Plate</strong></li></ul><p><img src="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/Phenomenex_Strata_X_96_well_plate_9a66005814.jpg" alt="Phenomenex: Strata X 96-well plate" srcset="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/thumbnail_Phenomenex_Strata_X_96_well_plate_9a66005814.jpg 156w," sizes="100vw" width="1080" height="1080"></p><ul><li><strong>1, 3, and 6mL Tubes</strong></li></ul><p><img src="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/Phenomenex_Strata_X_tubes_1_9b04cab6c1.jpg" alt="Phenomenex: Strata X 1, 3, and 6mL Tubes" srcset="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/thumbnail_Phenomenex_Strata_X_tubes_1_9b04cab6c1.jpg 156w," sizes="100vw" width="1080" height="1080"></p><ul><li><strong>Giga Tubes (12-150mL Tubes)</strong></li></ul><p><img src="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/Phenomenex_Strata_X_tubes_2_a8cd1706ec.jpg" alt="Phenomenex: Strata X Giga Tubes (12-150mL Tubes)" srcset="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/thumbnail_Phenomenex_Strata_X_tubes_2_a8cd1706ec.jpg 156w," sizes="100vw" width="1080" height="1080"></p>

Phenomenex Strata X Solid Phase Extraction (SPE)

Strata-X reversed phase SPE retains neutrals, acids, and bases via π-π, hydrogen bonding, and hydrophobic interactions. Robust cleanup under high organic wash.

<p><strong>Reversed Phase Solid Phase Extraction (SPE)</strong></p><p>A reversed phase functionalized polymeric sorbent that gives strong retention of neutral, acidic, or basic compounds under aggressive, high organic wash conditions. This sorbent relies on <strong>3 mechanisms of retention</strong>: <strong>pi-pi bonding</strong>, <strong>hydrogen bonding</strong> (dipole-dipole interactions), and <strong>hydrophobic interaction</strong>.</p><p><img src="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/Phenomenex_Strata_X_d8f4451e42.jpg" alt="Phenomenex: Strata-X" srcset="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/thumbnail_Phenomenex_Strata_X_d8f4451e42.jpg 245w," sizes="100vw" width="433" height="247"></p><ul><li><strong>Recommended Use: </strong>Extraction of neutrals and aromatics</li></ul><h4><strong>Starting Method</strong></h4><h5><strong>For Neutral Compounds</strong></h5><ul><li><strong>Column: </strong>1 mL Methanol</li><li><strong>Equilibrate: </strong>1 mL Water</li><li><strong>Load: </strong>Diluted Sample</li><li><strong>Wash: </strong>1 mL 5-60 % Methanol</li><li><strong>Elute:</strong> 2x 500 µL 2 % Formic Acid in Methanol/Acetonitrile</li></ul><p><img src="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/Phenomenex_Strata_X_single_tube_435d45d0ad.jpg" alt="Phenomenex: Strata X single tube" srcset="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/thumbnail_Phenomenex_Strata_X_single_tube_435d45d0ad.jpg 156w," sizes="100vw" width="1080" height="1080"></p><p><i>Based on 30 mg/1 mL sorbent mass. The above is a convenient starting point for SPE method development, further optimization may be required to tailor the method for your specific extraction needs.</i></p><h4><strong>Available Formats</strong></h4><ul><li><strong>96-Well-Plate</strong></li></ul><p><img src="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/Phenomenex_Strata_X_96_well_plate_9a66005814.jpg" alt="Phenomenex: Strata X 96-well plate" srcset="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/thumbnail_Phenomenex_Strata_X_96_well_plate_9a66005814.jpg 156w," sizes="100vw" width="1080" height="1080"></p><ul><li><strong>1, 3, and 6mL Tubes</strong></li></ul><p><img src="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/Phenomenex_Strata_X_tubes_1_9b04cab6c1.jpg" alt="Phenomenex: Strata X 1, 3, and 6mL Tubes" srcset="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/thumbnail_Phenomenex_Strata_X_tubes_1_9b04cab6c1.jpg 156w," sizes="100vw" width="1080" height="1080"></p><ul><li><strong>Giga Tubes (12-150mL Tubes)</strong></li></ul><p><img src="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/Phenomenex_Strata_X_tubes_2_a8cd1706ec.jpg" alt="Phenomenex: Strata X Giga Tubes (12-150mL Tubes)" srcset="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/thumbnail_Phenomenex_Strata_X_tubes_2_a8cd1706ec.jpg 156w," sizes="100vw" width="1080" height="1080"></p>

Phenomenex Zebron ZB-1XT SimDist GC Columns

Zebron ZB-1XT SimDist columns deliver outstanding reproducibility and up to 70% higher efficiency thanks to Glass Infusion™ technology—ensuring sharper peaks, accurate high-temperature SimDist, and long column lifetime.

<h4><strong>Consistent, Reliable Results for Simulated Distillation</strong></h4><ul><li>Glass Infusion™ technology for higher efficiency and greater column-to-column reproducibility</li><li>Individual QC testing for every column</li><li>Up to 70 % higher efficiency than other columns</li><li>Increased accuracy for high temperature simulated distillation</li></ul><p>Want a flexible fused-silica alternative for SimDist testing? See <a target="_blank" rel="noopener noreferrer" href="https://gcms.labrulez.com/products/1563"><strong>ZB-1HT-Inferno</strong></a></p><h5><strong>Recommended Use</strong></h5><ul><li>ASTM Methods (D2887, D2887X, D3710, D6352, D7169), Crude Oil, Gasoline Fractions, Petroleum Distillates, Petroleum Fractions, Simulated Distillation, Vacuum Distillates</li></ul><h5><strong>Upgrade to Zebron from any 100 % dimethylpolysiloxane phase:</strong></h5><p><strong>Agilent®&nbsp;&nbsp;</strong>&nbsp;&nbsp;</p><ul><li>DB®-1</li><li>DB-HT SimDis</li><li>DB-PS1</li><li>DB-PS2887</li><li>CP-SimDist</li><li>CP-SimDist UltiMetal</li></ul><p><strong>Restek®</strong></p><ul><li>Rtx®-1</li><li>Rxi®-1HT</li><li>MXT®-1HT SimDist</li></ul><p><strong>SGE®</strong></p><ul><li>BP1</li><li>BPX1-SimD</li></ul><h3><strong>Sharper Peak Shape and Better Efficiency through Uniform Glass Infusion™ Coating Technology</strong></h3><ul><li><strong>Sharper Peaks and Higher Efficiency:</strong><ul><li>Glass Infusion Technology Provides &nbsp; &nbsp;&nbsp;</li><li>Uniform Coating and Minimizes</li><li>Unwanted Activity.</li></ul></li><li><strong>Consistency and Reliability:</strong><ul><li>Zebron Columns are INDIVIDUALLY</li><li>Tested for Better Reproducibility and</li><li>Overall Performance.</li></ul></li><li><strong>Higher Efficiency:</strong><ul><li>Up to 70 % Higher Column Efficiency.</li></ul></li><li><strong>Long Lifetime and Better Results:</strong><ul><li>Improved Resolution of C50/C52 &nbsp; &nbsp;&nbsp;</li><li>Hour after Hour.</li></ul></li><li><strong>Guaranteed:</strong><ul><li>100 % Risk-Free</li></ul></li></ul><p><img src="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/Phenomenex_Zebron_ZB_1_XT_Sim_Dist_GC_Columns_dd3e7f0c32.jpg" alt="Phenomenex: Zebron ZB-1XT SimDist GC Columns" srcset="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/thumbnail_Phenomenex_Zebron_ZB_1_XT_Sim_Dist_GC_Columns_dd3e7f0c32.jpg 146w," sizes="100vw" width="677" height="722"></p><h3><strong>Improved Recovery and Peak Shape</strong></h3><h4><strong>The Benefits of Glass Infusion™ Technology</strong></h4><p>The Zebron ZB-1XT SimDist metal columns employ a new proprietary bonding called Glass Infusion Technology. The Glass Infusion technology starts by depositing a very uniform layer of glass that completely covers the internal metal surfaces of the column. The result is a uniform coating throughout the column.</p><h5><strong>Glass Enclosed</strong></h5><ul><li>Uniform Glass Infusion ensures adequate covering of exposed metal to promote better recovery and peak shape.</li><li>Each Zebron ZB-1XT is individually tested to confirm and ensure excellent reproducibility.</li><li>The uniform glass coating provides a consistent foundation for stationary phase bonding, thus promoting better over-all efficiency and resolution.</li></ul><p><img src="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/Phenomenex_Glass_Enclosed_b434ad6540.jpg" alt="Phenomenex: Glass Enclosed" srcset="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/thumbnail_Phenomenex_Glass_Enclosed_b434ad6540.jpg 245w," sizes="100vw" width="709" height="232"></p><h5><strong>Exposed Metal</strong></h5><ul><li>Non-glass infused with exposed metal can cause tailing peaks and sample adsorption.</li><li>Some manufacturers batch test their columns, leading to poor column-to-column reproducibility.</li><li>These exposed surfaces result in abnormal bonding of the stationary phase which affects chromatographic performance, decreases efficiencies, and inconsistent performance between columns.</li></ul><p><img src="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/Phenomenex_Exposed_Metal_00e4466d96.jpg" alt="Phenomenex: Exposed Metal" srcset="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/thumbnail_Phenomenex_Exposed_Metal_00e4466d96.jpg 245w," sizes="100vw" width="706" height="237"></p>

Phenomenex Zebron Z-Guard GC Columns

Phenomenex Zebron Z-Guard GC columns protect analytical columns, improve peak shape and sensitivity, and extend column lifetime. Individually QC tested.

<h4><strong>Protect and Extend Column Lifetime</strong></h4><ul><li>Individually QC tested to ensure the highest level of quality</li><li>Extend column lifetime by preventing stationary phase damage</li><li>Improve separation and peak shapes (especially early elutors)</li><li>Improve sensitivity and accuracy of quantitative results</li><li>Available as individual guard columns or as complete kits with connectors</li></ul><p>To ensure that all Z-Guards are the highest possible quality, we individually test each one! The columns are attached to a reference <a target="_blank" rel="noopener noreferrer" href="https://gcms.labrulez.com/products/1577"><strong>Zebron ZB-5 column</strong></a> and are tested using our specially designed QC mix. We carefully monitor activity, bleed, and stability. This way, we are able to say with confidence that Z-Guards will provide the low activity and high quality your methods require.</p><h5><strong>Recommended Use</strong></h5><p>Extends column lifetime by preventing stationary phase damage and improves separation, peak shapes (especially early elutors), sensitivity, and accuracy of quantitative results</p><h4><strong>Zebron Z-Guard Phase Information</strong></h4><p>Z-Guard columns are universal GC guard columns, designed for use with virtually any GC capillary column, from virtually any manufacturer.</p><ul><li>Extend column lifetime by preventing stationary phase damage</li><li>Improve separation, peak shapes (especially early elutors), sensitivity, and accuracy of quantitative results</li><li>Alternative to Agilent, Restek, Supelco, and many more</li></ul><h5><strong>Easy Use Z-Guard Column Kits</strong></h5><p>Try Z-Guard columns individually or get the convenient, complete kit. Each kit includes:</p><ul><li>5 or 10 meters of deactivated fused-silica tubing</li><li>5 universal connectors</li><li>0.5 mL of high-temperature polyimide resin</li></ul><h5><strong>Guard Column Usage</strong></h5><p><img src="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/Phenomenex_Zebron_Z_Guard_GC_Columns_Guard_column_usage_675cd327b8.jpg" alt="Phenomenex: Zebron Z-Guard GC Columns: Guard column usage" srcset="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/thumbnail_Phenomenex_Zebron_Z_Guard_GC_Columns_Guard_column_usage_675cd327b8.jpg 245w," sizes="100vw" width="1039" height="359"></p><h5><strong>Tips: Using Z-Guard Columns</strong></h5><p>When using a guard at high temperatures, make sure that the press-fit connection is secure.</p><p><img src="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/Phenomenex_Zebron_Z_Guard_GC_Columns_Using_Z_guard_columns_6842e6a4bd.jpg" alt="Phenomenex: Zebron Z-Guard GC Columns: Using Z-guard columns" srcset="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/thumbnail_Phenomenex_Zebron_Z_Guard_GC_Columns_Using_Z_guard_columns_6842e6a4bd.jpg 245w," sizes="100vw" width="414" height="164"></p><p>The most important aspect of a good seal is a good column cut.</p><ul><li>The column end should be square and smooth (like a straw). Any irregularities will cause leaks.</li><li>Columns are long - repeat cutting until a good cut is achieved.</li><li>Lightly scoring the column usually creates a cleaner opening.</li></ul>

Phenomenex Phenex LC/GC Approved Syringe Filters

Phenex syringe filters deliver fast, reliable sample filtration with excellent flow rates and broad chemical compatibility. Designed to protect columns, reduce downtime, and ensure particulate-free samples for LC, GC, and MS analysis.

<p><strong>Phenex syringe filters are designed for efficient and rapid filtration of almost any solution prior to analysis, and are optimized for superior flow rates and high-throughput. Proper syringe filter membrane and size selection is the key to choosing the best product to maintain the integrity of your sample components as well as to protect your system from particulate contamination. Phenex offers a wide variety of membranes ideal for any application.</strong></p><h5><strong>Try our Phenex Syringe Filters for:</strong></h5><ul><li>High quality filtration product</li><li>Increased column lifetime</li><li>Less system downtime</li><li>Low protein absorption</li></ul><h4><strong>Phenex Offers:</strong></h4><ul><li>Broad chemical compatibility</li><li>Minimized extractables</li><li>Excellent flow rate</li><li>High total throughput</li><li>Certified quality</li><li>100 % integrity tested</li><li>Low hold-up volume</li><li>Low protein adsorption</li><li>Bi-directional use</li></ul><h3><strong>Maximum Quality</strong></h3><p><img src="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/Phenomenex_Phenex_LC_GC_Approved_Syringe_Filters_2_44145fa074.jpg" alt="Phenomenex: Phenex LC-GC Approved Syringe Filters: Maximum Quality" srcset="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/thumbnail_Phenomenex_Phenex_LC_GC_Approved_Syringe_Filters_2_44145fa074.jpg 218w," sizes="100vw" width="1156" height="828"></p><h5><strong>A: Identification</strong></h5><ul><li>Syringe filter membrane type and pore size are clearly marked on each syringe filter</li></ul><h5><strong>B: Luer Lock Inlet Tip</strong></h5><ul><li>Secures connections to prevent “blow off”</li></ul><h5><strong>C: Sample Distribution Rings</strong></h5><ul><li>Creates even sample distribution for high sample flow rates</li></ul><h5><strong>D: Medical Grade Polymer Housing</strong></h5><p>Offers the most inert syringe filter and helps eliminate unwanted secondary interactions with the filter housing</p><h5><strong>E: Ultrasonically Welded</strong></h5><ul><li>Ensures robust housing - filter integrity</li></ul><h4><strong>Guaranteed Reliability and Consistency</strong></h4><p>Quality filtration products from Phenomenex offer a convenient way to clean up your samples - for improved analytical results with a simple method. Phenex syringe filters are designed for efficient and rapid filtration of almost any solution prior to analysis, and are optimized for superior flow rates and high-throughput. Phenex offers a wide variety of membranes ideal for any application.</p><ul><li>High quality filtration product</li><li>Increased column lifetime</li><li>Less system downtime</li></ul><p>The housing attaches to any standard luer lock syringe, so the sample can easily be pushed through the membrane with minimal pressure. The result is a particulate-free eluent that is ready for use with LC, GC, or other analytical techniques. One of the most popular sample preparation methods is filtration using a sample preparation solution. It has the ability to remove particulates before injection onto the column and the ability to use it in parallel with another sample preparation technique. It requires no method development.</p><ul><li><strong>A:</strong> Particulates Trapped</li><li><strong>B:</strong> Particulate-free Sample</li></ul><p><img src="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/Phenomenex_Phenex_LC_GC_Approved_Syringe_Filters_631acccb54.jpg" alt="Phenomenex: Phenex LC/GC Approved Syringe Filters: Guaranteed Reliability and Consistency" srcset="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/thumbnail_Phenomenex_Phenex_LC_GC_Approved_Syringe_Filters_631acccb54.jpg 42w," sizes="100vw" width="143" height="523"></p><h3><strong>Recommendation Based on Your Industry</strong></h3><h5><strong>Environmental</strong></h5><p>Water, wastewater, soil and sludge, and pollution control samples are especially challenging. No matter the sample type, Phenex offers filtration products to meet your demanding requirements.</p><ul><li><strong>Recommended Filter: </strong>GF/NY</li><li><strong>First Alternative:</strong> RC</li></ul><h5><strong>Pharmaceutical / Biotech</strong></h5><p>At every stage of the drug discovery process target compounds must be isolated, purified, and prepared prior to testing. Sample complexity in DMPK work can be even more challenging. Difficult samples such as serum, urine, and other physiological fluids are easily filtered and clarified using Phenex syringe filters.</p><ul><li><strong>Recommended Filter: </strong>PES</li><li><strong>First Alternative: </strong>RC</li></ul><h5><strong>Clinical / Toxicology</strong></h5><p>Removal of particulate matter to sub-micron levels is critical before any clinical sample is injected into an LC, GC or mass spectrometer. At every stage in toxicology, samples should be filtered, preferably with a rapid and simple sample preparation method to reduce downtime in the fast paced environment. Phenex is designed for higher flow rates and throughputs than those of competing products.</p><ul><li><strong>Recommended Filter: </strong>RC</li><li><strong>First Alternative: </strong>PES</li></ul><h5><strong>Food and Beverage</strong></h5><p>Food safety is more important than ever and lower detection limits are making analysis even more challenging. Accurate and reliable testing is critical and Phenex filters are routinely used in preparation for analysis of pesticides, herbicides, fungicides, flavors, and fragrances. For samples with large amounts of particulate and/or large fibrous matter, use a glass fiber prefilter.</p><ul><li><strong>Recommended Filter: </strong>GF/NY</li><li><strong>First Alternative: </strong>RC</li></ul><h3><strong>How to Use Phenex Syringe Filters</strong></h3><h4><strong>Easy to assemble and even easier to get consistent and particulate-free samples</strong></h4><h5><strong>Step 1: Load</strong></h5><ul><li>Fill a syringe barrel with the liquid sample. Allow a small amount of air (approximately 10 % of the sample volume) to enter the syringe. The air is used as a purge to minimize fluid retention when expelling the sample from the syringe (Step 3 below).</li></ul><p><img src="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/Phenomenex_Phenex_LC_GC_Approved_Syringe_Filters_Step_1_f8246ba832.jpg" alt="Phenomenex: Phenex LC/GC Approved Syringe Filters - Step 1: Load" srcset="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/thumbnail_Phenomenex_Phenex_LC_GC_Approved_Syringe_Filters_Step_1_f8246ba832.jpg 155w," sizes="100vw" width="423" height="427"></p><h5><strong>Step 2: Assemble</strong></h5><ul><li>Twist the luer lock end of the filter securely onto the syringe.</li><li><strong>Caution: </strong>Do not use syringes without a matching luer lock, otherwise the pressure applied may cause the filter to come off unexpectedly.</li></ul><p><img src="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/Phenomenex_Phenex_LC_GC_Approved_Syringe_Filters_Step_2_2833584d34.jpg" alt="Phenomenex: Phenex LC/GC Approved Syringe Filters: Step 2: Assemble" srcset="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/thumbnail_Phenomenex_Phenex_LC_GC_Approved_Syringe_Filters_Step_2_2833584d34.jpg 158w," sizes="100vw" width="349" height="344"></p><h5><strong>Step 3: Filter</strong></h5><ul><li>Apply gentle pressure to the syringe plunger.</li><li><strong>Caution: </strong>Small syringes can generate excessive pressures.) Push the liquid sample, as well as the remaining air, through the syringe filter to maximize sample recovery.</li></ul><p><img src="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/Phenomenex_Phenex_LC_GC_Approved_Syringe_Filters_Step_3_d8c5f61231.jpg" alt="Phenomenex: Phenex LC/GC Approved Syringe Filters - Step 3: Filter" srcset="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/thumbnail_Phenomenex_Phenex_LC_GC_Approved_Syringe_Filters_Step_3_d8c5f61231.jpg 177w," sizes="100vw" width="375" height="331"></p>

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