EU Regulation 396/2005: Pesticide Residue Testing and the Critical Role of QuEChERS Evaporation in Food Safety

<div><div><p><strong>Researchers led by </strong><a target="_blank" rel="noopener noreferrer" href="https://kudova.group.uochb.cz/en"><strong>Eva Kudová</strong></a><strong> from IOCB Prague and Jitka Viktorová from UCT Prague have identified new androstane-based steroid derivatives that can significantly improve the effectiveness of existing antibiotics against multidrug-resistant </strong><i><strong>Staphylococcus aureus</strong></i><strong>.</strong></p></div></div><div><p>The team screened dozens of natural steroidal hormones and synthetic derivatives to see whether they could block bacterial efflux pumps – mechanisms that bacteria use to eject antibiotics and survive treatment. Two compounds emerged as particularly promising: they inhibited efflux pumps and lowered the effective doses of antibiotics such as ciprofloxacin and erythromycin.</p><p>Further analysis showed that one of the compounds also suppressed genes linked to bacterial virulence. Another key finding is that the most active molecules are non-toxic to human immune cells and showed no detectable endocrine activity, suggesting a favorable safety profile.</p><p>These findings support the idea that rationally designed steroid-based molecules could act as antibiotic adjuvants, helping existing drugs overcome bacterial resistance.</p><p><img src="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/IOCB_Prague_Steroidal_hormones_and_neurosteroids_novel_therapeutic_strategies_in_bacterial_infections_8e5d2a7b48.jpg" alt="IOCB Prague: Steroidal hormones and neurosteroids – novel therapeutic strategies in bacterial infections" srcset="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/thumbnail_IOCB_Prague_Steroidal_hormones_and_neurosteroids_novel_therapeutic_strategies_in_bacterial_infections_8e5d2a7b48.jpg 222w," sizes="100vw" width="1258" height="886"></p><blockquote><h4><strong>Original Article</strong></h4><h4><a target="_blank" rel="noopener noreferrer" href="https://www.sciencedirect.com/science/article/pii/S0223523426001613?via%3Dihub"><strong>Steroidal hormones and neurosteroids - novel therapeutic strategies in bacterial infections: Design, synthesis, and biological evaluation</strong></a></h4><p>Daniela Brdová, Bára Křížkovská, Jan Špaček, Zdeněk Míchal, Eva Jablonská, Ondřej Strnad, Hana Chodounská, Eszter Szánti-Pintér, Marina Morozovová, Václav Hanžl, Jan Tkadlec, Martijn Riool, Jan Lipov, Jitka Viktorová, Eva Kudová&nbsp;</p><p><i><strong>Eur. J. Med. Chem., 2026, 308, 118716</strong></i></p><p><a target="_blank" rel="noopener noreferrer" href="https://doi.org/10.1016/j.ejmech.2026.118716">https://doi.org/10.1016/j.ejmech.2026.118716</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>The global rise of antibiotic resistance necessitates novel therapeutic strategies for infectious diseases. Inhibition of bacterial efflux pumps, which contribute to multidrug resistance, represents a promising approach to restore or even increase the efficacy of existing antibiotics. Using fluorescence-based ethidium bromide accumulation, broth microdilution, and checkerboard assays, we evaluated 26 endogenous steroidal hormones and neurosteroids, along with 30 synthetic derivatives, for their ability to enhance antibiotic susceptibility in multidrug-resistant <i>Staphylococcus aureus</i>. Structure-activity relationship analysis identified compounds <strong>13</strong> and <strong>16</strong> as lead candidates, exhibiting strong efflux pump inhibition and marked reductions in the minimum inhibitory concentrations of ciprofloxacin and erythromycin. Both compounds showed additive effects in checkerboard assays. Modifications at C-3 (polar substitution) and C-17 (3α,5β-stereochemistry and nonpolar substitution) were essential for potent efflux inhibition and sensitization, although these modifications were not additive when combined. Transcriptome analysis further revealed that compound <strong>13</strong> significantly downregulated <i>S. aureus</i> virulence-associated genes when administered alone or in combination with antibiotics. Cytotoxicity assessment in human peripheral blood mononuclear cells and receptor transactivation assays for estrogen, androgen, and progesterone receptors indicated that the most active derivatives were non-toxic and lacked detectable endocrine activity, suggesting a favorable safety profile. Overall, these findings support the concept that rationally designed andostane-based steroidal scaffolds can function as competitive bacterial efflux pump inhibitors and serve as potential antibiotic adjuvants to mitigate efflux-mediated resistance.</p><h4><strong>Instrumentation</strong></h4><h5><strong>Structural characterization</strong></h5><ul><li><strong>AVANCE III 400 MHz NMR spectrometer</strong> (Bruker)</li><li><a target="_blank" rel="noopener noreferrer" href="https://lcms.labrulez.com/library?mainauthorItems=3&amp;search=LTQ+Orbitrap+XL"><strong>LTQ Orbitrap XL HRMS</strong></a> (Thermo Fisher Scientific, ESI)</li></ul></div>

Steroidal hormones and neurosteroids – novel therapeutic strategies in bacterial infections

<p><strong>Metformin is currently the first-line oral drug of choice for the treatment of type 2 diabetes. It reduces glucose production in the liver, improves tissue sensitivity to insulin, and does not cause weight gain or hypoglycemia, which sets it apart from some other antidiabetic drugs. Moreover, its long-term beneficial effects on the risk of cardiovascular complications and mortality in people with type 2 diabetes have been well established. Researchers from the Institute of Physiology CAS (IPHYS) have identified a new group of blood metabolites that could help physicians objectively monitor whether patients with type 2 diabetes are taking their metformin as prescribed.</strong></p><h4><strong>New biomarkers for metformin use</strong></h4><p>A team led by Tomáš Čajka from the Laboratory of Translational Metabolism at IPHYS analyzed plasma samples from <strong>637 patients with type 2 diabetes treated with metformin</strong> and <strong>143 non-diabetic controls</strong> using advanced metabolomics and lipidomics. Among 614 detected metabolites, they identified five from the group of <strong>N-lactoyl-amino acids </strong>(e.g. N‑lactoyl-phenylalanine), which had previously been seen as unknown signals due to missing reference spectra in databases. The levels of these metabolites in the blood closely reflected the plasma concentrations of metformin. In patients with the highest metformin exposure, the concentrations of these metabolites were up to 7.2 times higher than in controls.</p><h4><strong>A sensitive “fingerprint” of the drug’s effect</strong></h4><p>N-Lactoyl-amino acids are formed in cells by combining lactate and amino acids, thus reflecting the metformin-induced changes in cellular energy metabolism. “<i>Importantly, even though they occur in plasma only at nanomolar concentrations, they reliably distinguish patients who take metformin regularly from those who take it irregularly or not at all</i>,” emphasizes T. Čajka.</p><h4><strong>Metabolomics in practice and international collaboration</strong></h4><p>The study also provides a detailed description of broader metabolic changes in type 2 diabetes, including increases in lactate, organic acids, and branched-chain amino acids, as well as extensive remodelling of the lipid profile. In addition to T. Čajka’s team, collaborators from the Institute for <strong>Clinical and Experimental Medicine in Prague</strong> and the <strong>West Coast Metabolomics Center</strong> (University of California, Davis) also participated in the study.</p><p>The results demonstrate that advanced metabolomics approaches developed at IPHYS within the <strong>CarDia project</strong> can find highly practical applications both in clinical studies and in personalized monitoring of treatment in patients with diabetes.</p><blockquote><h4><strong>The original article</strong></h4><h4><a target="_blank" rel="noopener noreferrer" href="https://ascpt.onlinelibrary.wiley.com/doi/10.1002/cpt.70205"><strong>Untargeted Metabolomics Identifies N-Lactoyl-Amino Acids as Dose-Responsive Plasma Biomarkers of Metformin Adherence in Type 2 Diabetes</strong></a></h4><p>Tomas Cajka, Jiri Hricko, Lucie Rudl Kulhava, Michaela Paucova, Michaela Novakova, Veronika Hola, Stanislava Rakusanova, Oliver Fiehn, Vojtech Skop, Ivana Lankova, Iva Miskova, Terezie Pelikanova, Martin Haluzik</p><p>Clin Pharmacol Ther, 119: 1057-1069</p><p><a target="_blank" rel="noopener noreferrer" href="https://doi.org/10.1002/cpt.70205">https://doi.org/10.1002/cpt.70205</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>Metformin is the most widely prescribed antidiabetic drug, yet adherence remains difficult to objectively assess. Using untargeted metabolomics and lipidomics, we analyzed plasma from 637 patients with type 2 diabetes (T2D) with confirmed metformin use and 143 nondiabetic controls, annotating 614 metabolites. Patients were stratified by plasma metformin into sub-therapeutic, therapeutic, and supra-therapeutic groups, and associations were evaluated by multiple linear regression and composite metabolite ranking. Five previously unannotated features were structurally identified as N-lactoyl-amino acids, whose levels correlated strongly with plasma metformin (ρ = 0.42–0.55, P &lt; 0.0001) and increased up to 7.2-fold in the supra-therapeutic group (&gt; 2000 ng/mL). While N-lactoyl-amino acids were consistently detected in the nanomolar range, they still displayed robust and dose-dependent associations with metformin. Broader metabolic changes in T2D included elevated lactate, organic acids, and branched-chain amino acids, together with reduced urea cycle metabolites. Lipidomics showed increases in saturated triacylglycerols and diacylglycerols and decreases in cholesteryl esters, sphingomyelins, and phospholipids. These findings establish N-lactoyl-amino acids as robust, dose-responsive plasma biomarkers of metformin exposure. Despite being up to four orders of magnitude less abundant than their amino acid precursors, they sensitively reflect mitochondrial lactate overflow and pharmacodynamic adaptation, offering objective assessment of adherence.</p>

New blood biomarkers reveal how faithfully diabetes patients take metformin

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The Czech Academy of Sciences (CAS) was established by Act No. 283/1992 Coll. as the Czech successor of the former Czechoslovak Academy of Sciences. It is set up as a complex of 54 public research institutions.

Czech Academy of Sciences

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

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

Organomation, founded in 1959, designs and manufactures high-quality nitrogen evaporators and extraction systems. Known for innovation and durability, their lab instruments are used globally for efficient sample preparation with strong customer support.

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KNAUER Eurokat H Ion Exclusion/Ligand Exchange Columns (USP L17)

The Eurokat H ionic form is especially designed for the analysis of organic acids and even complex mixtures of acids, sugars and alcohols as well as sugar alcohols.

<p class="cke-user_style-important"><strong>Organic acids and alcohols</strong></p><p><strong>The Eurokat H ionic form </strong>is especially designed for the analysis of <strong>organic acids</strong> and even <strong>complex mixtures of acids</strong>, <strong>sugars</strong> and <strong>alcohols</strong> as well as <strong>sugar alcohols</strong>. It is a <strong>cation exchange</strong> material with 8 % cross linkage of the styrenedivinylbenzene copolymer. Best results are acieved with aqueous eluents and small amounts of anorganic acids, recommended eluent 0.005 M sulfuric acid. The usage of up to 10 % organic content in the mobile phase is possible.</p><h5><strong>Properties</strong></h5><ul><li><strong>Sulfonated cross-linked styrenedivinylbenzene copolymer </strong>phase for the determination of organic acids, carbohydrates and alcohols</li><li><strong>H-form, 8 % cross linkage</strong></li><li>Cation exchanger, extremly long lasting lifetime when correctly handled, best results with aqueous eluents and small amounts of anorganic acids, recommended eluent 0,01 N sulfuric acid, usage of up to 10 % organic content in the mobile phase is possible</li></ul><h5><strong>Technical Data</strong></h5><ul><li>Sulfonated cross-linked styrenedivinylbenzene copolymer with 8 % cross linkage in the ionic form H, available in 10 μm particle size, pressure stable up to maximum 100 bar</li></ul><h5><strong>Recommended application areas</strong></h5><ul><li>Eurokat H is especially designed for the analysis of organic acids and even complex mixtures of acids, sugars and alcohols as well as sugar alcohols. Due to a differing separation process we recommend the use of these type of columns only in 8 mm ID or 4 mm ID.</li></ul><p><img src="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/KNAUER_Eurokat_H_Chromatogram_e2c6665a1f.webp" alt="KNAUER: Eurokat H Chromatogram" srcset="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/thumbnail_KNAUER_Eurokat_H_Chromatogram_e2c6665a1f.webp 245w," sizes="100vw" width="690" height="281"></p><blockquote><p><strong>Tip:</strong> Eurokat columns are characterized by an extremely long lifetime if handled properly. Especially pressure shocks and organic solvent contents of more than 10 % in the mobile phase should be avoided absolutely.</p></blockquote><h3><strong>KNAUER Ion Exclusion and Ligand Exchange Columns</strong></h3><p><strong>Separation of organic acids, carbohydrates, alcohols on sulfonated cross-linked styrenedivinylbenzene copolymer</strong></p><ul><li><strong>Modifications</strong><ul><li>Eurokat H</li><li>Eurokat Ca</li><li>Eurokat Pb</li><li>Eurokat Na</li></ul></li><li><strong>High Temperature Methods:</strong> Up to 90 °C</li><li><strong>Method Development: </strong>Optional up to 10 % organic solvent</li><li><strong>Chemically stable: </strong>pH 1–12</li><li><strong>Sustainability:</strong> Aqueous eluents protect the environment and are cost-effectiv</li><li><strong>User Friendly:</strong> Simple and robust methods for daily analysis. Versatile in its use.</li><li><strong>Simplicity:</strong> Easy purchase via our online store with fast delivery.&nbsp;</li></ul><h4><strong>Characteristics&nbsp;</strong></h4><p>Eurokat high performance polymer phases were especially developed for the separation of organic acids, carbohydrates, alcohols and even complex mixtures of these compounds. Eurokat is a sulfonated cross-linked styrenedivinylbenzene copolymer available in several ionic forms (H, Ca and Pb). This particular cation exchanger is characterized by an outstanding density of functional groups, making it the ideal choice for your ion exclusion, size exclusion and ligand exchange chromatography.</p><h4><strong>Choice of chromatographic conditions&nbsp;</strong></h4><p>The Eurokat stationary phase is designed to be applicable to a wide range of diverse chromatographic conditions. All Eurokat columns can be used at temperatures up to 90 °C with no organic solvents. The best separation of sugars can be achieved using between 60 to 90 °C. To extend separation performance, it is possible to connect up to three columns of Eurokat in series. Eurokat columns require no organic solvents and thus are environmentally friendly.&nbsp;</p><h4><strong>Stability&nbsp;</strong></h4><p>Eurokat polymer columns are extremely stable over the whole pH range. This is one striking advantage compared with silica-based phases which have a limited lifetime at pH extremes, especially in the higher pH range. Most importantly, Eurokat phases show extraordinary column lifetime stability and are not affected by aqueous solvents.&nbsp;</p><h4><strong>Application areas&nbsp;</strong></h4><ul><li>Carbohydrates and organic acids in softdrinks and fruit juices&nbsp;</li><li>Sugar substitutes</li><li>Food preservatives</li><li>Dairy products</li><li>Urine analytic (Uric acid, Hippuric acid)</li><li>Monitoring of fermentation processes</li></ul><p><img src="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/KNAUER_Principle_of_ligand_exchange_mechanism_a5b7c21c43.jpg" alt="KNAUER: Eurokat - Principle of ligand exchange mechanism" srcset="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/thumbnail_KNAUER_Principle_of_ligand_exchange_mechanism_a5b7c21c43.jpg 245w," sizes="100vw" width="1382" height="570"></p>

KNAUER Eurokat Pb & Ca Ion Exclusion/Ligand Exchange Columns (USP L34 / USP L19)

The ionic forms Ca and Pb are best suited for the analysis of smaller carbohydrates like mono- and disaccharides and sugars up to a degree of polymerization (DP) of 4. 

<p class="cke-user_style-important"><strong>Analysis of mono- and disaccharides</strong></p><p><strong>The ionic forms Ca and Pb</strong> are best suited for the analysis of smaller carbohydrates like <strong>mono- and disaccharides </strong>and <strong>sugars up to a degree of polymerization (DP) of 4</strong>. It is a cation exchange material with 6 % cross linkage of the styrenedivinylbenzene copolymer. Best results are achieved with aqueous eluents, recommended eluent is pure deionized water. The usage of up to 10 % organic content in the mobile phase is possible.</p><h5><strong>Properties</strong></h5><ul><li><strong>Polymer phase for the determination of mono- and disaccharides</strong></li><li><strong>Pb (USP L34) form, 6 % cross linkage</strong></li><li>Cation exchanger, extremely long lasting lifetime when correctly handled, best results with aqueous eluents, recommended eluent is pure deionized water, usage of up to 10 % organic content in the mobile phase is possible</li></ul><h5><strong>Technical Data</strong></h5><ul><li>Sulfonated cross-linked styrenedivinylbenzene copolymer with 6 % cross linkage in the ionic form Pb, available in 10μm particle size, pressure stable up to maximum 100 bar</li></ul><h5><strong>Recommended application areas</strong></h5><ul><li>Especially designed for the analysis of small carbohydrates up to DP 4</li></ul><p><img src="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/KNAUER_Eurokat_Pb_Ca_Chromatogram_2054f70e49.webp" alt="KNAUER: Eurokat Pb &amp; Ca Chromatogram" srcset="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/thumbnail_KNAUER_Eurokat_Pb_Ca_Chromatogram_2054f70e49.webp 245w," sizes="100vw" width="690" height="271"></p><blockquote><p><strong>Tip:</strong> Eurokat columns are used at high temperatures. During equilibration it is very important to have an eye on the backpressure and to start with very low flow rates and increase them only slowly and stepwise after the column has adapted to the temperature.</p></blockquote><h3><strong>KNAUER Ion Exclusion and Ligand Exchange Columns</strong></h3><p><strong>Separation of organic acids, carbohydrates, alcohols on sulfonated cross-linked styrenedivinylbenzene copolymer</strong></p><ul><li><strong>Modifications</strong><ul><li>Eurokat H</li><li>Eurokat Ca</li><li>Eurokat Pb</li><li>Eurokat Na</li></ul></li><li><strong>High Temperature Methods:</strong> Up to 90 °C</li><li><strong>Method Development: </strong>Optional up to 10 % organic solvent</li><li><strong>Chemically stable: </strong>pH 1–12</li><li><strong>Sustainability:</strong> Aqueous eluents protect the environment and are cost-effectiv</li><li><strong>User Friendly:</strong> Simple and robust methods for daily analysis. Versatile in its use.</li><li><strong>Simplicity:</strong> Easy purchase via our online store with fast delivery.&nbsp;</li></ul><h4><strong>Characteristics&nbsp;</strong></h4><p>Eurokat high performance polymer phases were especially developed for the separation of organic acids, carbohydrates, alcohols and even complex mixtures of these compounds. Eurokat is a sulfonated cross-linked styrenedivinylbenzene copolymer available in several ionic forms (H, Ca and Pb). This particular cation exchanger is characterized by an outstanding density of functional groups, making it the ideal choice for your ion exclusion, size exclusion and ligand exchange chromatography.</p><h4><strong>Choice of chromatographic conditions&nbsp;</strong></h4><p>The Eurokat stationary phase is designed to be applicable to a wide range of diverse chromatographic conditions. All Eurokat columns can be used at temperatures up to 90 °C with no organic solvents. The best separation of sugars can be achieved using between 60 to 90 °C. To extend separation performance, it is possible to connect up to three columns of Eurokat in series. Eurokat columns require no organic solvents and thus are environmentally friendly.&nbsp;</p><h4><strong>Stability&nbsp;</strong></h4><p>Eurokat polymer columns are extremely stable over the whole pH range. This is one striking advantage compared with silica-based phases which have a limited lifetime at pH extremes, especially in the higher pH range. Most importantly, Eurokat phases show extraordinary column lifetime stability and are not affected by aqueous solvents.&nbsp;</p><h4><strong>Application areas&nbsp;</strong></h4><ul><li>Carbohydrates and organic acids in softdrinks and fruit juices&nbsp;</li><li>Sugar substitutes</li><li>Food preservatives</li><li>Dairy products</li><li>Urine analytic (Uric acid, Hippuric acid)</li><li>Monitoring of fermentation processes</li></ul><p><img src="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/KNAUER_Principle_of_ligand_exchange_mechanism_a5b7c21c43.jpg" alt="KNAUER: Eurokat - Principle of ligand exchange mechanism" srcset="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/thumbnail_KNAUER_Principle_of_ligand_exchange_mechanism_a5b7c21c43.jpg 245w," sizes="100vw" width="1382" height="570"></p>

KNAUER Eurokat Na Ion Exclusion/Ligand Exchange Columns

The ionic form Na is best suited for the analysis of sugars oligomers up to a degree of polymerization (DP) of 8. 

<p class="cke-user_style-important"><strong>Analysis of sugar oligomers</strong></p><p><strong>The ionic form Na</strong> is best suited for the analysis of <strong>sugars oligomers</strong> up to a <strong>degree of polymerization (DP) of 8</strong>. It is a cation exchange material with <strong>6 % cross linkage of the styrenedivinylbenzene copolymer</strong>. Best results are achieved with aqueous eluents, recommended eluent is pure deionized water. The usage of up to 10 % organic content in the mobile phase is possible.&nbsp;</p><h5><strong>Properties</strong></h5><ul><li><strong>Polymer phase for the determination of sugar oligomers</strong></li><li><strong>Na form, 6 % cross linkage</strong></li><li>Cation exchanger, extremly long lasting lifetime when correctly handled, best results with aqueous eluents, recommended eluent is pure deionized water, usage of up to 10 % organic content in the mobile phase is possible</li></ul><h5><strong>Technical Data</strong></h5><ul><li>Sulfonated cross-linked styrenedivinylbenzene copolymer with 6 % cross linkage in the ionic form Na, available in 10 μm particle size, pressure stable up to maximum 100 bar</li></ul><h5><strong>Recommended application areas</strong></h5><ul><li>Especially designed for the analysis of sugar oligomers, separates carbohydrates up to DP 8</li></ul><p><img src="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/KNAUER_Eurokat_Na_Chromatogram_7d3d81fa52.webp" alt="KNAUER: Eurokat Na Chromatogram" srcset="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/thumbnail_KNAUER_Eurokat_Na_Chromatogram_7d3d81fa52.webp 188w," sizes="100vw" width="686" height="568"></p><blockquote><p><strong>Tip:</strong> Eurokat columns are typically used with 100 % aqueous eluents. For storage, please avoid microbial growth by flushing the Eurokat column with 0.45 µm filtered ultrapure water and storing it at 4 °C.</p></blockquote><h3><strong>KNAUER Ion Exclusion and Ligand Exchange Columns</strong></h3><p><strong>Separation of organic acids, carbohydrates, alcohols on sulfonated cross-linked styrenedivinylbenzene copolymer</strong></p><ul><li><strong>Modifications</strong><ul><li>Eurokat H</li><li>Eurokat Ca</li><li>Eurokat Pb</li><li>Eurokat Na</li></ul></li><li><strong>High Temperature Methods:</strong> Up to 90 °C</li><li><strong>Method Development: </strong>Optional up to 10 % organic solvent</li><li><strong>Chemically stable: </strong>pH 1–12</li><li><strong>Sustainability:</strong> Aqueous eluents protect the environment and are cost-effectiv</li><li><strong>User Friendly:</strong> Simple and robust methods for daily analysis. Versatile in its use.</li><li><strong>Simplicity:</strong> Easy purchase via our online store with fast delivery.&nbsp;</li></ul><h4><strong>Characteristics&nbsp;</strong></h4><p>Eurokat high performance polymer phases were especially developed for the separation of organic acids, carbohydrates, alcohols and even complex mixtures of these compounds. Eurokat is a sulfonated cross-linked styrenedivinylbenzene copolymer available in several ionic forms (H, Ca and Pb). This particular cation exchanger is characterized by an outstanding density of functional groups, making it the ideal choice for your ion exclusion, size exclusion and ligand exchange chromatography.</p><h4><strong>Choice of chromatographic conditions&nbsp;</strong></h4><p>The Eurokat stationary phase is designed to be applicable to a wide range of diverse chromatographic conditions. All Eurokat columns can be used at temperatures up to 90 °C with no organic solvents. The best separation of sugars can be achieved using between 60 to 90 °C. To extend separation performance, it is possible to connect up to three columns of Eurokat in series. Eurokat columns require no organic solvents and thus are environmentally friendly.&nbsp;</p><h4><strong>Stability&nbsp;</strong></h4><p>Eurokat polymer columns are extremely stable over the whole pH range. This is one striking advantage compared with silica-based phases which have a limited lifetime at pH extremes, especially in the higher pH range. Most importantly, Eurokat phases show extraordinary column lifetime stability and are not affected by aqueous solvents.&nbsp;</p><h4><strong>Application areas&nbsp;</strong></h4><ul><li>Carbohydrates and organic acids in softdrinks and fruit juices&nbsp;</li><li>Sugar substitutes</li><li>Food preservatives</li><li>Dairy products</li><li>Urine analytic (Uric acid, Hippuric acid)</li><li>Monitoring of fermentation processes</li></ul><p><img src="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/KNAUER_Principle_of_ligand_exchange_mechanism_a5b7c21c43.jpg" alt="KNAUER: Eurokat - Principle of ligand exchange mechanism" srcset="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/thumbnail_KNAUER_Principle_of_ligand_exchange_mechanism_a5b7c21c43.jpg 245w," sizes="100vw" width="1382" height="570"></p>

Products from category IEX HPLC columns focused on Consumables distributed by KNAUER - page 1

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New blood biomarkers reveal how faithfully diabetes patients take metformin

Steroidal hormones and neurosteroids – novel therapeutic strategies in bacterial infections

EU Regulation 396/2005: Pesticide Residue Testing and the Critical Role of QuEChERS Evaporation in Food Safety