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

<div><div>Researchers led by <a target="_blank" rel="noopener noreferrer" href="https://kudova.group.uochb.cz/en">Eva Kudová</a> 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 Staphylococcus aureus.</div></div><div>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.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.These findings support the idea that rationally designed steroid-based molecules could act as antibiotic adjuvants, helping existing drugs overcome bacterial resistance.<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"><blockquote><h4>Original Article</h4><h4><a target="_blank" rel="noopener noreferrer" href="https://www.sciencedirect.com/science/article/pii/S0223523426001613?via%3Dihub">Steroidal hormones and neurosteroids - novel therapeutic strategies in bacterial infections: Design, synthesis, and biological evaluation</a></h4>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;Eur. J. Med. Chem., 2026, 308, 118716<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><h6>licensed under <a target="_blank" rel="noopener noreferrer" href="https://creativecommons.org/licenses/by/4.0/">CC-BY 4.0</a></h6></blockquote><h4>Abstract</h4>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 Staphylococcus aureus. Structure-activity relationship analysis identified compounds 13 and 16 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 13 significantly downregulated S. aureus 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.<h4>Instrumentation</h4><h5>Structural characterization</h5><ul><li>AVANCE III 400 MHz NMR spectrometer (Bruker)</li><li><a target="_blank" rel="noopener noreferrer" href="https://lcms.labrulez.com/library?mainauthorItems=3&amp;search=LTQ+Orbitrap+XL">LTQ Orbitrap XL HRMS</a> (Thermo Fisher Scientific, ESI)</li></ul></div>

Steroidal hormones and neurosteroids – novel therapeutic strategies in bacterial infections

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.<h4>New biomarkers for metformin use</h4>A team led by Tomáš Čajka from the Laboratory of Translational Metabolism at IPHYS analyzed plasma samples from 637 patients with type 2 diabetes treated with metformin and 143 non-diabetic controls using advanced metabolomics and lipidomics. Among 614 detected metabolites, they identified five from the group of N-lactoyl-amino acids (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.<h4>A sensitive “fingerprint” of the drug’s effect</h4>N-Lactoyl-amino acids are formed in cells by combining lactate and amino acids, thus reflecting the metformin-induced changes in cellular energy metabolism. “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,” emphasizes T. Čajka.<h4>Metabolomics in practice and international collaboration</h4>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 Clinical and Experimental Medicine in Prague and the West Coast Metabolomics Center (University of California, Davis) also participated in the study.The results demonstrate that advanced metabolomics approaches developed at IPHYS within the CarDia project can find highly practical applications both in clinical studies and in personalized monitoring of treatment in patients with diabetes.<blockquote><h4>The original article</h4><h4><a target="_blank" rel="noopener noreferrer" href="https://ascpt.onlinelibrary.wiley.com/doi/10.1002/cpt.70205">Untargeted Metabolomics Identifies N-Lactoyl-Amino Acids as Dose-Responsive Plasma Biomarkers of Metformin Adherence in Type 2 Diabetes</a></h4>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 HaluzikClin Pharmacol Ther, 119: 1057-1069<a target="_blank" rel="noopener noreferrer" href="https://doi.org/10.1002/cpt.70205">https://doi.org/10.1002/cpt.70205</a><h6>licensed under <a target="_blank" rel="noopener noreferrer" href="https://creativecommons.org/licenses/by/4.0/">CC-BY 4.0</a></h6></blockquote><h4>Abstract</h4>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.

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 Eurospher II 100 C18 Prep HPLC Columns (USP L1)

Stationary phase Eurospher II 100 C18 Prep HPLC is the most often used stationary phase in reversed phase mode

Classical Reversed Phase columns for HPLC and UHPLC (USP L1)Most often used stationary phase in reversed phase mode. Silica gel based columns with C18 modification are available with or without endcapping. Classically endcapped phases are slightly more hydrophobic and unpolar than the not endcapped phases.<h5>Properties</h5><ul><li>Separation mechanism: Hydrophobic interaction</li><li>Ultra pure, spherical high performance HPLC phase based on silica gel</li><li>Unpolar, monomeric C18 (Octadecyl) modification, endcapped, with 16 % carbon content (~ 50 % endcapping).</li></ul><h5>Key features</h5><ul><li>High-class HPLC phase perfectly suited to take on routine analyses as well as the most ambitious chromatography tasks, classical C18 phase with ca. 50 % endcapping and resulting 16 % carbon content, outstanding mechanical and chemical stability.</li></ul><h5>Recommended application areas</h5><ul><li>acidic, basic and neutral analytes in reversed phase mode, for example sulphonamides</li><li>anabolic steroids</li><li>anti-psychotics</li><li>beta blocker</li><li>sudan dyes</li><li>phenols and preservatives</li></ul><img src="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/KNAUER_C18_non_endcapped_6e4fce9989.webp" alt="KNAUER: C18 Non-endcapped" srcset="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/thumbnail_KNAUER_C18_non_endcapped_6e4fce9989.webp 245w," sizes="100vw" width="682" height="420"><blockquote>Tip: Caution! Never use classical C18 phases with 100 % aqueous mobile phase. The hydrophobic C18 chains will collapse</blockquote>Stationary phase Eurospher II 100 C18 is provided in these column types: analytical, semi-preparative and preparative.Eurospher II 100 C18 Preparative Standard Columns are available with these parameters:<ul><li>Column length (mm): 50, 150, 250</li><li>Column ID (mm): 20, 30, 50</li><li>Particle size (µm): 5, 10, 15</li></ul>Eurospher II 100 C18 Preparative dAX Columns with dynamic axial compression are available with these parameters:<ul><li>Column length (mm): 50, 150, 250</li><li>Column ID (mm): 25, 30, 50</li><li>Particle size (µm): 5, 10, 15</li></ul><h3>KNAUER Preparative HPLC Columns</h3>The right choice for all dimensions from semi-prep to batch chromatography to SMB.<ul><li>Modifications: Reversed Phase, HILIC, Normale Phase</li><li>Max. Pressure: 400–600 bar</li><li>Column Inner Diameter (ID): 16–50 mm in our shop, more on request</li><li>Column Brands: Eurospher, Eurospher II</li><li>Safe Investment: Robustness and durability based on superior technology</li><li>Application: Easy upscaling, as all materials are available from ultra high performance to preparative scale HPLC. You can also use our upscaling calculator.</li><li>Customizable: Standard flanged hardware &amp; dAX hardware with static or dynamic axial compression available</li></ul><img src="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/KNAUER_Preparative_HPLC_Columns_31bc2477c3.webp" alt="KNAUER: KNAUER Preparative HPLC Columns" srcset="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/thumbnail_KNAUER_Preparative_HPLC_Columns_31bc2477c3.webp 221w," sizes="100vw" width="1024" height="724"><h5>Preparative HPLC columns can be offered with two different hardware types:</h5><ul><li>Versatile standard flanged hardware for nearly any application task in batch chromatography</li><li>dAX Hardware with static and dynamic axial compression for an extended lifetime and multi-column chromatography like SMB processes</li></ul>

KNAUER Eurospher II 100 C18A Prep HPLC Columns (USP L1)

C18A phases can be operated under 100 % aqueous conditions without destroying the stationary phase, what is not recommended for classical C18 phases

C18A columns for polar reversed phase applications with 100 % aqueous mobile phase (USP L1)C18 stationary phase for the analysis of more polar and hydrophilic compounds in reversed phase mode (USP L1). Silica gel based columns with C18 modification with hydrophilic endcapping. Because of their modification, C18A phases can be operated under 100 % aqueous conditions without destroying the stationary phase, what is not recommended for classical C18 phases caused by their hydrophobicity.<h5>Properties</h5><ul><li>Separation mechanism: Hydrophobic and polar interaction</li><li>Ultra pure, spherical high performance HPLC phase based on silica gel</li><li>Polar, monomeric C18 (Octadecyl) modification, polar endcapping, with 10 % carbon content (~ 50 % endcapping).</li></ul><h5>Key features</h5><ul><li>C18 A phase with alternative, more polar selectivity, suited for the use with pure aqueous mobile phases, 50 % endcapping and resulting 10 % carbon content, outstanding mechanical and chemical stability, suited for analytical as well as semi preparative and preparative applications</li></ul><h5>Recommended application areas</h5><ul><li>Polar endcapped C18 phase for water soluble and polar analytes, 100 % aqueous eluents for analysis of very polar compounds:<ul><li>basic pharmaceutical ingredients</li><li>water soluble vitamins</li><li>catecholamines</li><li>as well as organic acids.</li></ul></li></ul><img src="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/KNAUER_C18_A_6f4b0c3063.webp" alt="KNAUER: C18A" srcset="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/thumbnail_KNAUER_C18_A_6f4b0c3063.webp 245w," sizes="100vw" width="690" height="428"><blockquote>Tip: With an endcapping the influence of nonderivatized silanol groups can be minimized. The endcapping reagent is generally a smaller silane than used for derivatisation. This treatment reduces the unwanted interaction of polar or charged analytes (acids, bases ect.) because the amount of available silanol groups is reduced.</blockquote>Stationary phase Eurospher II 100 C18A is provided in these column types: analytical, semi-preparative and preparative.Eurospher II 100 C18A Preparative Standard Columns are available with these parameters:<ul><li>Column length (mm): 50, 150, 250</li><li>Column ID (mm): 20, 30, 50</li><li>Particle size (µm): 5, 10, 15</li></ul>Eurospher II 100 C18A Preparative dAX Columns with dynamic axial compression are available with these parameters:<ul><li>Column length (mm): 50, 150, 250</li><li>Column ID (mm): 25, 30, 50</li><li>Particle size (µm): 5, 10, 15</li></ul><h3>KNAUER Preparative HPLC Columns</h3>The right choice for all dimensions from semi-prep to batch chromatography to SMB.<ul><li>Modifications: Reversed Phase, HILIC, Normale Phase</li><li>Max. Pressure: 400–600 bar</li><li>Column Inner Diameter (ID): 16–50 mm in our shop, more on request</li><li>Column Brands: Eurospher, Eurospher II</li><li>Safe Investment: Robustness and durability based on superior technology</li><li>Application: Easy upscaling, as all materials are available from ultra high performance to preparative scale HPLC. You can also use our upscaling calculator.</li><li>Customizable: Standard flanged hardware &amp; dAX hardware with static or dynamic axial compression available</li></ul><img src="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/KNAUER_Preparative_HPLC_Columns_31bc2477c3.webp" alt="KNAUER: KNAUER Preparative HPLC Columns" srcset="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/thumbnail_KNAUER_Preparative_HPLC_Columns_31bc2477c3.webp 221w," sizes="100vw" width="1024" height="724"><h5>Preparative HPLC columns can be offered with two different hardware types:</h5><ul><li>Versatile standard flanged hardware for nearly any application task in batch chromatography</li><li>dAX Hardware with static and dynamic axial compression for an extended lifetime and multi-column chromatography like SMB processes</li></ul>

KNAUER Eurospher II 100 C18H Prep HPLC Columns (USP L1)

C18H stationary phase with a special, high efficiency or polymeric unpolar endcapping style. Suited for the use of mobile phase in an extended pH range from typically pH 1–12. 

Hydrophobic / pH stable C18H Columns for more unpolar analytes in Reversed Phase (USP L1)C18H stationary phase with a special, high efficiency or polymeric unpolar endcapping style. Because of the high carbon content and the protection of the Silica gel these materials are also suited for the use of mobile phase in an extended pH range from typically pH 1–12.While a high endcapped C18H phase is characterized mostly by the high carbon content. A polymeric endcapped phase also provides an increased steric selectivity.<h5>Properties</h5><ul><li>Separation mechanism: Hydrophobic interaction</li><li>Ultra pure, spherical high performance HPLC phase based on silica gel</li><li>Nonpolar, monomeric C18 (Octadecyl) modification, high efficiency endcapping with 17 % carbon content (~ 99 % endcapping)</li></ul><h5>Key features</h5><ul><li>Nonpolar C18 phase with high efficiency endcapping and 17 % carbon content, resulting in higher pH stability in the range of 1–12, outstanding mechanical and chemical stability, suited for analytical as well as semi preparative and preparative applications.</li></ul><h5>Recommended application areas</h5><ul><li>Recommended alternative to Kromasil 100 C18, for acidic, basic and neutral analytes in reversed phase mode with extended pH range.</li></ul><img src="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/KNAUER_C18_H_c5531f7d87.webp" alt="KNAUER: C18H" srcset="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/thumbnail_KNAUER_C18_H_c5531f7d87.webp 226w," sizes="100vw" width="687" height="475"><blockquote>Tip: All analytical KNAUER columns can be used in reversed flow direction for example for cleaning. Please refer to our Column care and use documents on the website for further information about storage conditions and cleaning procedures.</blockquote>Stationary phase Eurospher II 100 C18H is provided in these column types: analytical, semi-preparative and preparative.Eurospher II 100 C18H Preparative Standard Columns are available with these parameters:<ul><li>Column length (mm): 50, 150, 250</li><li>Column ID (mm): 20, 30, 50</li><li>Particle size (µm): 5, 10, 15</li></ul>Eurospher II 100 C18H Preparative dAX Columns with dynamic axial compression are available with these parameters:<ul><li>Column length (mm): 50, 150, 250</li><li>Column ID (mm): 25, 30, 50</li><li>Particle size (µm): 5, 10, 15</li></ul><h3>KNAUER Preparative HPLC Columns</h3>The right choice for all dimensions from semi-prep to batch chromatography to SMB.<ul><li>Modifications: Reversed Phase, HILIC, Normale Phase</li><li>Max. Pressure: 400–600 bar</li><li>Column Inner Diameter (ID): 16–50 mm in our shop, more on request</li><li>Column Brands: Eurospher, Eurospher II</li><li>Safe Investment: Robustness and durability based on superior technology</li><li>Application: Easy upscaling, as all materials are available from ultra high performance to preparative scale HPLC. You can also use our upscaling calculator.</li><li>Customizable: Standard flanged hardware &amp; dAX hardware with static or dynamic axial compression available</li></ul><img src="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/KNAUER_Preparative_HPLC_Columns_31bc2477c3.webp" alt="KNAUER: KNAUER Preparative HPLC Columns" srcset="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/thumbnail_KNAUER_Preparative_HPLC_Columns_31bc2477c3.webp 221w," sizes="100vw" width="1024" height="724"><h5>Preparative HPLC columns can be offered with two different hardware types:</h5><ul><li>Versatile standard flanged hardware for nearly any application task in batch chromatography</li><li>dAX Hardware with static and dynamic axial compression for an extended lifetime and multi-column chromatography like SMB processes</li></ul>

KNAUER Eurospher II 100 C18P Prep HPLC Columns (USP L1)

KNAUER´s most unpolar C18P phase with excellent shape selectivity. It features polymeric, high efficiency endcapping of 99 % and 20 % carbon content, exceptional pH stability in the range of 1–12.

C18P columns with trifunctional modifications (USP L1): Hydrophobic and stearic interactionsKNAUER´s most unpolar C18P phase with excellent shape selectivity. It features polymeric, high efficiency endcapping of 99 % and 20 % carbon content, exceptional pH stability in the range of 1–12, and outstanding mechanical and chemical stability.<h5>Properties</h5><ul><li>Separation mechanism: Hydrophobic and stearic interaction</li><li>Ultra pure, spherical high performance HPLC phase based on silica gel</li><li>Unpolar, trifunctional C18 (Octadecyl) modification, high efficiency endcapping, with 20 % carbon content (~ 99 % endcapping)&nbsp;</li></ul><h5>Key features</h5><ul><li>KNAUER´s most unpolar C18 phase, polymeric, high efficiency endcapping of 99 % and 20 % carbon content, higher pH stability in the range of 1-12, outstanding mechanical and chemical stability, suited for analytical as well as semi preparative and preparative applications.</li></ul><h5>Recommended application areas</h5><ul><li>Alternative selectivity to standard C18; stationary phase in Eurospher II C18 family with the highest carbon load; fully endcapped; excellent shape selectivity and pH stability.</li></ul><img src="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/KNAUER_C18_P_f093126fa9.webp" alt="KNAUER: C18P" srcset="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/thumbnail_KNAUER_C18_P_f093126fa9.webp 245w," sizes="100vw" width="278" height="174"><blockquote>Tip: Not all C18 phases are comparable! When replacing an existing column, always have a close look at the characteristics like carbon load, pore size and specific surface area.</blockquote>Stationary phase Eurospher II 100 C18P is provided in these column types: analytical, semi-preparative and preparative.Eurospher II 100 C18P Preparative Standard Columns are available with these parameters:<ul><li>Column length (mm): 50, 150, 250</li><li>Column ID (mm): 20, 30, 50</li><li>Particle size (µm): 5, 10, 15</li></ul>Eurospher II 100 C18P Preparative dAX Columns with dynamic axial compression are available with these parameters:<ul><li>Column length (mm): 50, 150, 250</li><li>Column ID (mm): 25, 30, 50</li><li>Particle size (µm): 5, 10, 15</li></ul><h3>KNAUER Preparative HPLC Columns</h3>The right choice for all dimensions from semi-prep to batch chromatography to SMB.<ul><li>Modifications: Reversed Phase, HILIC, Normale Phase</li><li>Max. Pressure: 400–600 bar</li><li>Column Inner Diameter (ID): 16–50 mm in our shop, more on request</li><li>Column Brands: Eurospher, Eurospher II</li><li>Safe Investment: Robustness and durability based on superior technology</li><li>Application: Easy upscaling, as all materials are available from ultra high performance to preparative scale HPLC. You can also use our upscaling calculator.</li><li>Customizable: Standard flanged hardware &amp; dAX hardware with static or dynamic axial compression available</li></ul><img src="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/KNAUER_Preparative_HPLC_Columns_31bc2477c3.webp" alt="KNAUER: KNAUER Preparative HPLC Columns" srcset="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/thumbnail_KNAUER_Preparative_HPLC_Columns_31bc2477c3.webp 221w," sizes="100vw" width="1024" height="724"><h5>Preparative HPLC columns can be offered with two different hardware types:</h5><ul><li>Versatile standard flanged hardware for nearly any application task in batch chromatography</li><li>dAX Hardware with static and dynamic axial compression for an extended lifetime and multi-column chromatography like SMB processes</li></ul>

KNAUER Eurospher II 100 C8 & C8A Prep HPLC Columns (USP L7)

C8 is a silica gel based stationary phase in reversed phase mode with alternative selectivity compared to C18 phases. 

Classical and hydrophilic/aqueous C8 columns for HPLC and UHPLC (USP L7)C8 is a silica gel based stationary phase in reversed phase mode with alternative selectivity compared to C18 phases. Compared to C18 phases, these columns show less retention due to the lower hydrophobicity.<ul><li>Ultra pure, spherical high performance HPLC phase based on silica gel</li><li>Monomeric C8 (Octyl) modification, standard endcapping, with 10 % carbon content (~ 50 % endcapping)</li></ul><h5>Properties</h5><ul><li>Separation mechanism: Hydrophobic interaction(lower compared to C18 phases)</li></ul><h5>Key features</h5><ul><li>Classical C8 phase, standard 50 % endcapping and 10 % carbon load, outstanding mechanical and chemical stability, suited for analytical as well as semi preparative and preparative applications.</li></ul><h5>Recommended application areas</h5><ul><li>Similar selectivity to C18 phase but less retention due to the lower hydrophobicity; useful for determination of:<ul><li>Water soluble vitamins</li><li>Steroids</li><li>Catecholamines</li><li>Sedatives</li></ul></li></ul><img src="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/KNAUER_C8_rp_non_endcapped_3f7727d3fd.webp" alt="KNAUER: C8 RP Non-endcapped" srcset="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/thumbnail_KNAUER_C8_rp_non_endcapped_3f7727d3fd.webp 148w," sizes="100vw" width="304" height="321">Hydrophilic C8A phase offers an alternative, more polar selectivity. It is suited for highly polar reversed phase applications with up to 100 % aqueous mobile phases.&nbsp;<img src="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/KNAUER_C8_A_e1f371165e.webp" alt="KNAUER: C8A" srcset="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/thumbnail_KNAUER_C8_A_e1f371165e.webp 198w," sizes="100vw" width="473" height="373"><blockquote>Tip: Caution! Even for short term storage all buffer solutions have to be rinsed from the column to prevent crystallization effects.</blockquote>Stationary phases Eurospher II 100 C8 and C8A are provided in these column types: analytical, semi-preparative and preparative.Eurospher II 100 C8 and C8A Preparative Standard Columns are available with these parameters:<ul><li>Column length (mm): 50, 150, 250</li><li>Column ID (mm): 20, 30, 50</li><li>Particle size (µm): 5, 10, 15</li></ul>Eurospher II 100 C8 and C8A Preparative dAX Columns with dynamic axial compression are available with these parameters:<ul><li>Column length (mm): 50, 150, 250</li><li>Column ID (mm): 25, 30, 50</li><li>Particle size (µm): 5, 10, 15</li></ul><h3>KNAUER Preparative HPLC Columns</h3>The right choice for all dimensions from semi-prep to batch chromatography to SMB.<ul><li>Modifications: Reversed Phase, HILIC, Normale Phase</li><li>Max. Pressure: 400–600 bar</li><li>Column Inner Diameter (ID): 16–50 mm in our shop, more on request</li><li>Column Brands: Eurospher, Eurospher II</li><li>Safe Investment: Robustness and durability based on superior technology</li><li>Application: Easy upscaling, as all materials are available from ultra high performance to preparative scale HPLC. You can also use our upscaling calculator.</li><li>Customizable: Standard flanged hardware &amp; dAX hardware with static or dynamic axial compression available</li></ul><img src="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/KNAUER_Preparative_HPLC_Columns_31bc2477c3.webp" alt="KNAUER: KNAUER Preparative HPLC Columns" srcset="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/thumbnail_KNAUER_Preparative_HPLC_Columns_31bc2477c3.webp 221w," sizes="100vw" width="1024" height="724"><h5>Preparative HPLC columns can be offered with two different hardware types:</h5><ul><li>Versatile standard flanged hardware for nearly any application task in batch chromatography</li><li>dAX Hardware with static and dynamic axial compression for an extended lifetime and multi-column chromatography like SMB processes</li></ul>

KNAUER Eurospher II 100 C4 Prep HPLC Columns (USP L26)

C4 stationary phases (USP L26) are often used in reversed phase mode for different application areas. 

C4 columns for Reversed Phase in HPLC and UHPLC (USP L26)C4 stationary phases (USP L26) are often used in reversed phase mode for different application areas.&nbsp;They are suitable for:<ul><li>Hydrophobic Interaction Chromatography (HIC mode)</li><li>Analysis of biomolecules like proteins and peptides</li></ul><img src="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/KNAUER_C4_3f3adfbdb4.webp" alt="KNAUER: C4" srcset="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/thumbnail_KNAUER_C4_3f3adfbdb4.webp 78w," sizes="100vw" width="200" height="400"><h3>KNAUER Preparative HPLC Columns</h3>The right choice for all dimensions from semi-prep to batch chromatography to SMB.<ul><li>Modifications: Reversed Phase, HILIC, Normale Phase</li><li>Max. Pressure: 400–600 bar</li><li>Column Inner Diameter (ID): 16–50 mm in our shop, more on request</li><li>Column Brands: Eurospher, Eurospher II</li><li>Safe Investment: Robustness and durability based on superior technology</li><li>Application: Easy upscaling, as all materials are available from ultra high performance to preparative scale HPLC. You can also use our upscaling calculator.</li><li>Customizable: Standard flanged hardware &amp; dAX hardware with static or dynamic axial compression available</li></ul><img src="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/KNAUER_Preparative_HPLC_Columns_31bc2477c3.webp" alt="KNAUER: KNAUER Preparative HPLC Columns" srcset="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/thumbnail_KNAUER_Preparative_HPLC_Columns_31bc2477c3.webp 221w," sizes="100vw" width="1024" height="724"><h5>Preparative HPLC columns can be offered with two different hardware types:</h5><ul><li>Versatile standard flanged hardware for nearly any application task in batch chromatography</li><li>dAX Hardware with static and dynamic axial compression for an extended lifetime and multi-column chromatography like SMB processes</li></ul>

KNAUER Eurospher II 100 DNPH Prep HPLC Columns (USP L1)

Silica gel based columns with C18 modification with special endcapping, designed for DNPH analysis.

DNPH columns for polar reversed phase applications with 100 % aqueous mobile phase (USP L1)C18 stationary phase for the analysis of more polar and hydrophilic compounds in reversed phase mode (USP L1). Silica gel based columns with C18 modification with special endcapping, designed for DNPH analysis. Because of their modification, DNPH phases can be operated under 100 % aqueous conditions without destroying the stationary phase, what is not recommended for classical C18 phases caused by their hydrophobicity.These phases are ideal for the analysis of:<ul><li>DNPH-derivates of aldehydes and ketones</li></ul><img src="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/KNAUER_DNPH_7020417932.webp" alt="KNAUER: DNPH" srcset="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/thumbnail_KNAUER_DNPH_7020417932.webp 245w," sizes="100vw" width="690" height="428"><h3>KNAUER Preparative HPLC Columns</h3>The right choice for all dimensions from semi-prep to batch chromatography to SMB.<ul><li>Modifications: Reversed Phase, HILIC, Normale Phase</li><li>Max. Pressure: 400–600 bar</li><li>Column Inner Diameter (ID): 16–50 mm in our shop, more on request</li><li>Column Brands: Eurospher, Eurospher II</li><li>Safe Investment: Robustness and durability based on superior technology</li><li>Application: Easy upscaling, as all materials are available from ultra high performance to preparative scale HPLC. You can also use our upscaling calculator.</li><li>Customizable: Standard flanged hardware &amp; dAX hardware with static or dynamic axial compression available</li></ul><img src="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/KNAUER_Preparative_HPLC_Columns_31bc2477c3.webp" alt="KNAUER: KNAUER Preparative HPLC Columns" srcset="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/thumbnail_KNAUER_Preparative_HPLC_Columns_31bc2477c3.webp 221w," sizes="100vw" width="1024" height="724"><h5>Preparative HPLC columns can be offered with two different hardware types:</h5><ul><li>Versatile standard flanged hardware for nearly any application task in batch chromatography</li><li>dAX Hardware with static and dynamic axial compression for an extended lifetime and multi-column chromatography like SMB processes</li></ul>

KNAUER Eurospher II 100 Phenyl Prep HPLC Columns (USP L11)

Phenyl stationary phases (USP L11) in reversed phase mode with alternative selectivity for aromatic and moderately π-π interaction polar analytes

Phenyl columns for Reversed Phase in HPLC and UHPLC &nbsp;(USP L11)Phenyl stationary phases (USP L11) in reversed phase mode with alternative selectivity for:<ul><li>Aromatic and moderately π-π interaction polar analytes</li><li>Mixtures with varying polarity and aromaticity</li></ul>The polarity is similar to C8 modification but with different selectivity for polar aromatics, polycyclic aromatic hydrocarbons, fatty acids etc. Phenyl phases with a classical slightly hydrophobic endcapping or without endcapping.<h5>Properties</h5><ul><li>Separation mechanism: π-π interactions</li><li>Ultra pure, spherical high performance HPLC phase based on silica gel</li><li>Phenyl modification (Phenylpropyl), 12 % carbon content</li></ul><h5>Key features</h5><ul><li>Classical phenyl phase with 12 % carbon load, outstanding mechanical and chemical stability, suited for analytical as well as semi preparative and preparative applications.</li></ul><h5>Recommended application areas</h5><ul><li>Alternative selectivity for aromatic and mode rately pi-pi interaction polar analytes or mixtures with varying polarity and aromaticity.</li></ul><img src="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/KNAUER_Phenyl_df9b20c77a.webp" alt="KNAUER: Phenyl" srcset="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/thumbnail_KNAUER_Phenyl_df9b20c77a.webp 90w," sizes="100vw" width="306" height="528"><blockquote>Tip: For UHPLC columns like Eurospher II 2 μm particle size, samples and eluents should be filtered through a 0.2 μm instead of a 0.45 μm membrane filter. Frits at column inand outlet have smaller pores than classical HPLC columns and block more easily.</blockquote>Stationary phase Eurospher II 100 Phenyl is provided in these column types: analytical, semi-preparative and preparative.Eurospher II 100 Phenyl Preparative Standard Columns are available with these parameters:<ul><li>Column length (mm): 50, 150, 250</li><li>Column ID (mm): 20, 30, 50</li><li>Particle size (µm): 5, 10, 15</li></ul>Eurospher II 100 Phenyl Preparative dAX Columns with dynamic axial compression are available with these parameters:<ul><li>Column length (mm): 50, 150, 250</li><li>Column ID (mm): 25, 30, 50</li><li>Particle size (µm): 5, 10, 15</li></ul><h3>KNAUER Preparative HPLC Columns</h3>The right choice for all dimensions from semi-prep to batch chromatography to SMB.<ul><li>Modifications: Reversed Phase, HILIC, Normale Phase</li><li>Max. Pressure: 400–600 bar</li><li>Column Inner Diameter (ID): 16–50 mm in our shop, more on request</li><li>Column Brands: Eurospher, Eurospher II</li><li>Safe Investment: Robustness and durability based on superior technology</li><li>Application: Easy upscaling, as all materials are available from ultra high performance to preparative scale HPLC. You can also use our upscaling calculator.</li><li>Customizable: Standard flanged hardware &amp; dAX hardware with static or dynamic axial compression available</li></ul><img src="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/KNAUER_Preparative_HPLC_Columns_31bc2477c3.webp" alt="KNAUER: KNAUER Preparative HPLC Columns" srcset="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/thumbnail_KNAUER_Preparative_HPLC_Columns_31bc2477c3.webp 221w," sizes="100vw" width="1024" height="724"><h5>Preparative HPLC columns can be offered with two different hardware types:</h5><ul><li>Versatile standard flanged hardware for nearly any application task in batch chromatography</li><li>dAX Hardware with static and dynamic axial compression for an extended lifetime and multi-column chromatography like SMB processes</li></ul>

KNAUER Eurospher II 100 HILIC Prep HPLC Columns

Based on ultra-pure Silica gel, zwitterionic HILIC phases are ideal for the analysis of polar and ionizable compounds. Stronger interaction of more polar compounds with stationary aqueous layer.

Zwitterionic and polar columns for HILIC applicationsBased on ultra-pure Silica gel, zwitterionic HILIC phases are ideal for the analysis of polar and ionizable compounds. Stronger interaction of more polar compounds with stationary aqueous layer.Faster elution of nonpolar compounds is possible due to minor hydrophobic interactions. Retention increases with the charge of the analyte.<h5>Recommended for the analysis of hydrophilic compounds like:</h5><ul><li>Polar organic acids and bases</li><li>Natural polar compounds</li><li>Nucleosides</li><li>Oligonucleotides</li><li>Amino acids</li><li>Peptides</li><li>Water soluble vitamins</li></ul><h5>Properties</h5><ul><li>Separation mechanism: Hydrophilic and weak electrostatic interactions</li><li>Ultra pure, spherical high performance HPLC phase based on silica gel</li><li>Zwitterionic modification: Ammonium – sulfonic acid</li><li>7 % carbon content</li></ul><h5>Key features</h5><ul><li>Modern HILIC phase with zwitterionic modification on the basis of ammonium- sulfonic acid. Outstanding mechanical and chemical stability.</li></ul><h5>Recommended application areas</h5><ul><li>Especially suited for the separation of hydrophilic, polar and ionic analytes which are poorly retained on reversed phase columns; behavior is the other way round on Eurospher II HILIC compared to RP which makes it an ideal tool to enhance chromatographic separations for these molecules.</li></ul><img src="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/KNAUER_HILIC_b9c3bffc20.webp" alt="KNAUER: HILIC" srcset="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/thumbnail_KNAUER_HILIC_b9c3bffc20.webp 147w," sizes="100vw" width="439" height="465"><blockquote>Tip: HILIC applications are well-suited for coupling with MS detection. The high organic content of the applied mobile phases are qualified well for evaporation in the MS´s ionization source.</blockquote><h3>KNAUER Preparative HPLC Columns</h3>The right choice for all dimensions from semi-prep to batch chromatography to SMB.<ul><li>Modifications: Reversed Phase, HILIC, Normale Phase</li><li>Max. Pressure: 400–600 bar</li><li>Column Inner Diameter (ID): 16–50 mm in our shop, more on request</li><li>Column Brands: Eurospher, Eurospher II</li><li>Safe Investment: Robustness and durability based on superior technology</li><li>Application: Easy upscaling, as all materials are available from ultra high performance to preparative scale HPLC. You can also use our upscaling calculator.</li><li>Customizable: Standard flanged hardware &amp; dAX hardware with static or dynamic axial compression available</li></ul><img src="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/KNAUER_Preparative_HPLC_Columns_31bc2477c3.webp" alt="KNAUER: KNAUER Preparative HPLC Columns" srcset="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/thumbnail_KNAUER_Preparative_HPLC_Columns_31bc2477c3.webp 221w," sizes="100vw" width="1024" height="724"><h5>Preparative HPLC column hardware</h5>Preparative HPLC columns can be offered with two different hardware types:<ul><li>Versatile standard flanged hardware for nearly any application task in batch chromatography</li><li>dAX Hardware with static and dynamic axial compression for an extended lifetime and multi-column chromatography like SMB processes</li></ul>

KNAUER Sepapure oliGO 120-3 Column

KNAUER Sepapure oliGO 120-3 column for oligonucleotide analysis in RP and IP-RP modes with UHPLC performance and low back pressure.

The KNAUER Sepapure® oliGO 120-3 is a high-performance HPLC/UHPLC column optimized for oligonucleotide analysis in both reversed-phase (RP) and ion-pair reversed-phase (IP-RP) modes.The column is based on hybrid silica with advanced endcapping and hydrophobic modification, ensuring stable interactions, high reproducibility, and long lifetime, even under demanding conditions.With 3 µm particles, the column delivers UHPLC performance while maintaining low back pressure, allowing use even on standard HPLC systems.It is ideal for:<ul><li>identification</li><li>quantification</li><li>quality control (QC) of oligonucleotides.</li></ul><img src="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/KNAUER_Sepapure_oli_GO_120_3_Column_3_e306727053.jpg" alt="KNAUER: Sepapure oliGO 120-3 Column" srcset="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/thumbnail_KNAUER_Sepapure_oli_GO_120_3_Column_3_e306727053.jpg 245w," sizes="100vw" width="882" height="478"><h4>Key Features</h4><ul><li>Optimized for oligonucleotides</li><li>Supports RP and IP-RP modes</li><li>UHPLC performance with low back pressure</li><li>3 µm particles for high resolution</li><li>18% carbon load</li><li>Wide pH range (1.5–10)</li><li>High chemical stability</li><li>Compatible with standard HPLC systems</li><li>High reproducibility and robustness</li><li>Suitable for extreme pH and temperature conditions</li></ul><h3>Technical Specifications</h3><h4>General</h4><ul><li>Separation modes: RP / IP-RP</li><li>Endcapping: Yes</li><li>USP classification: L1</li><li>Connection: 1/16"</li></ul><h4>Column Parameters</h4><ul><li>Particle size: 3 µm</li><li>Pore size: 120 Å</li><li>Surface area: 300 m²/g</li><li>Carbon load: 18%</li></ul><h4>Operating Conditions</h4><ul><li>pH range: 1.5 – 10</li><li>Max pressure: 413 bar</li><li>Max temperature: 60 °C</li></ul><h3>Technology Advantages</h3><h4>Low Back Pressure</h4><ul><li>enables UHPLC performance on HPLC systems</li><li>protects instrumentation</li><li>reduces wear and clogging</li><li>minimizes oligonucleotide aggregation</li></ul><h4>IP-RP Optimization</h4><ul><li>ideal pH range: 7.0 – 9.5</li><li>combines hydrophobic and ionic interactions</li><li>enables high-resolution separation</li></ul><h4>Cost-effective Hardware</h4><ul><li>no need for inert hardware</li><li>optimized for routine analytical use</li><li>tested with no impact on performance</li></ul><h4>Typical Applications</h4><ul><li>Oligonucleotide analysis</li><li>Biopharmaceutical QC</li><li>Polar molecule analysis</li><li>Method development (extreme pH/temperature)</li></ul>

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

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