Category: ARTICLES, APPNOTES, FAQ
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Acceptable wavelength band width for HPLC detectors when performing an HPLC Performance Qualification - Tech Information
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Add 10 micro molar EDTA or medronic acid to mobile phase for better peak shapes - Tips & Suggestions
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Analyte retention decreases with mobile phase water content using the Cogent Bidentate C18 HPLC column has anything happened to the column - Tech Information
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Analyze phosphorylated compounds with the Cogent Diamond Hydride column - Tips & Suggestions
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Analyzing metformin in plasma samples how do I obtain reproducible results and peak shapes - FAQ
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Aqueous Normal Phase ANP ballistic gradients compared to same in HILIC - Tips & Suggestions
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Aqueous Normal Phase ANP defined & compared to Reversed Phase & Normal Phase definitions HPLC
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Are polypropylene screw top vials and caps free of metals sodium potassium magnesium and calcium - FAQ
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Are polypropylene vials suited to avoiding adsorption issues with proteins compared to glass - FAQ
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Are septa in autosampler vial caps self sealing inert and compatible with organic solvents - FAQ
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Are the Chemical Solutions kits compliant with the latest USP-NF chapter revisions for 857 and 1857 - FAQ
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Are the Cogent TYPE-C Silica based stationary phases available for sale as bulk materials - FAQ
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Are the MicroSolv AQ brand of syringe filter membranes supported by extra membranes in the plastic housing - FAQ
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Are there any solvents that I cannot use with the knitted reactor coils KRC and knitted delay tubes KDT - FAQ
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Are there HPLC columns that could be used to separate both polar and nonpolar compounds in a single run - FAQ
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Are there inherent problems with autosampler vials that have a filter built into the cap - FAQ
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Assuring retention of polar compounds in an Aqueous Normal Phase ANP gradient in positive ion mode LCMS - Tips & Suggestions
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Autosampler vials sold by MicroSolv will fit properly in your instruments - Tech Information
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Avoid loss of concentration of heparin with HPLC when using syringe filters - Tips & Suggestions
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Basic compound functional group dependent adsorption study in RSA autosampler vials - AppNote
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Blocked HPLC column from proteins from the sample matrix can be recovered - Tips & Suggestions
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Buffer concentration can affect ANP retention of acids in HPLC Analyses - Tips & Suggestions
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Can amber or clear polypropylene vials be sterilized with autoclaving or ethylene oxide - FAQ
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Can an autosampler needle pierce the Zone Free sealing film and will it reseal afterwards - FAQ
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Can I choose HPLC mobile phase percentages other than those used in the HSQ Spreadsheet - FAQ
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Can I expect a more predictable retention time with Silica-C columns than with ordinary silica - FAQ
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Can I sterilize screw caps for autosampler vials that have silicone rubber with PTFE septa - FAQ
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Can I use a PEEK finger tight fitting on stainless steel tubing - Can I use a SS fitting on PEEK tubing in HPLC - FAQ
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Can I use a silica or Silica-C guard column with an analytical column of a different phase - FAQ
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Can I use heat to remove the polyimide coating on Zero Flow capillaries without damaging the inner coating - FAQ
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Can I use phosphoric acid or sodium phosphate with the Cogent Diamond Hydride HPLC column - FAQ
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Can I use the certified HPLC column supplied in the HSQ Kit for UHPLC performance qualification - FAQ
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Can I use the Cogent Diamond Hydride column without mobile phase additives like formic acid - FAQ
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Can I use the holmium oxide solution in a UV instrument that calls for Starna or NIST cuvettes - FAQ
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Can I use the MicroSolv Window Maker to remove polyimide from wires or solid core glass fiber - FAQ
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Can I use trifluoroacetic acid TFA to improve the chromatographic performance in LCMS - FAQ
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Can I use vial 95025-VN-05C with crimp cap 95025-08-1S in an oven at 105C for approximately 1 month - FAQ
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Can the HSQ or PQ qualification kits be used with Waters equipment and Empower chromatography data software - FAQ
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Can the MicoSolv Window Maker be used to remove the polyimide from the tips of capillaries - FAQ
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Can the U-2D Micro-Sample management system be used in SPE manifold for 96-well plates - FAQ
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Can the Window Maker heating modules be used with either US or European voltage units - FAQ
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Causes of high baseline noise with Cogent Diamond Hydride HPLC column - Tips & Suggestions
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Changing retention times of amino acids in biological extracts using ammonium acetate in HPLC methods. - Troubleshooting.
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Citric acid retention and peak shape has changed compared to data from a previous run what happened - FAQ
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Compatibility guidelines for safety coated mobile phase reservoir bottle use - Tips & Suggestions
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Considerations for keeping gases dissolved in solution when using sparging stones - Tips & Suggestions
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Could your PEEK tubing have contaminants via manufacturing processes from previous extrusion runs - FAQ
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Determining Efficiency of HPLC methods comparing 4um v 2.o HPLC columns - Tips & Suggestions
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Differences between the linearity solutions in the HSQ qualification kit - Tech Information
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Difficulties with wavelength accuracy readings while performing a PQ of an HPLC - Tips & Suggestions
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Direct silicon to carbon bonds on Cogent TYPE-C HPLC columns produce longer column lifetimes
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Do Cogent TYPE-C Silica columns have a partial positive charge and if so is retention for basic compounds reduced because of this - Tech Information
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Do different retention times for peaks in the Resolution Test Mixture on different systems impact the integrity of my data - FAQ
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Do I need any special fittings to use the Cogent Column Filter with my current HPLC column - FAQ
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Do Tanaka Plots for HPLC apply to columns used with Aqueous Normal Phase ANP methods - FAQ
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Do the MicroSolv mobile phase delivery bottle caps have holes to insert tubing through - FAQ
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Do you offer autosampler vials or caps for use with the Beckman PACE MDQ or other CE systems - FAQ
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Does deactivation process of RSA-Pro X autosampler vials add any chlorides to the glass surface - FAQ
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Does MicroSolv sell bared fused capillaries for CZE that are completely UV-transparent - FAQ
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Does the Hichrom brand column coupler work with the Partisil and Partisphere HPLC columns - FAQ
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Eliminating shoulder peaks in an HPLC method using Cogent RP C18 columns - Tips & Suggestions
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For sugars analyzed by LCMS sodium acetate is recommended for sensitivity of Na adducts - Tips & Suggestions
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For the separation of polar intermediates in reversed phase HPLC which C18 column do you recommend - FAQ
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Ghost peaks appearing in results using a gradient with TFA which can degrade with time - Tips & Suggestions
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High pressure develops after flushing a Cogent Diamond Hydride column with acetonitrile cause and solution - FAQ
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How are your polypropylene vials and inserts for LCMS different from those of other manufacturers - FAQ
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How can Cogent TYPE-C HPLC columns offer faster results compared to other type of silica based columns - FAQ
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How can I fix poor peak shape for phosphorylated compounds in aqueous normal phase ANP methods - FAQ
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How can I improve accuracy and precision when separating polar compounds by HPLC using Aqueous Normal Phase ANP - FAQ
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How can I make changes to locked cells in the Excel spreadsheet that comes with the HSQ qualification kit - FAQ
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How can I restore my Diamond Hydride HPLC column after I ran out of mobile phase and air was accidently introduced into it - FAQ
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How do I avoid distorted peak shapes when using a basic mobile phase pH for the analysis of a lipophilic amine - FAQ
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How do retention and efficiency of asymmetric dimethylarginine ADMA compare using 4um vs 2.o Diamond Hydride columns - AppNote
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How do RSA autosampler vials compare against silanized vials for pharma applications - FAQ
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How do the terms nano capillary and micro LC differ in terms of column ID and typical flow rates - FAQ
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How does ammonium fluoride affect HPLC and LCMS data if using Aqueous Normal Phase ANP methods - FAQ
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How does the shorter column supplied in the HSQ kit affect the data compared to the longer column from the PQ Kit - FAQ
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How long will it take for chloroform to degrade the plastic safety coating on the mobile phase bottles if the bottle is broken during a fall - FAQ
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How often do I need to do the conditioning procedure for a new Diamond Hydride column - FAQ
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How similar fittings for chromatography can differ from different brands in HPLC - Tech Information
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How tight should an autosampler vial cap be to prevent push through of the septa during injection - FAQ
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How to choose a suitable mobile phase additive for negative ionization mode LCMS - Tips & Suggestions
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How to define custom plate measurements for the U-2D Micro-Sample Management System in the Waters Acquity console software - How to
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How to eliminate retention time drift in LCMS with Aqueous Normal Phase ANP methods - Tips & Suggestions
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How to improve peak shapes, retention & carryover for polar compounds with the Cogent Diamond Hydride™ column - Tips & Suggestions
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How to prepare 10mM ammonium acetate buffer 90:10 in acetonitrile for HPLC and LCMS - Tips & Suggestions
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How to prepare 16mM ammonium acetate buffer 90:10 in acetonitrile for HPLC - Tips & Suggestions
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I am not observing any peaks for succinic acid or alpha-ketoglutarate with the Cogent Diamond Hydride column - Tips & Suggestions
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I currently use a glass filter why should I use the HSQ Kit solutions instead for qualification - FAQ
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I see a strange saw tooth type of pattern in the UV baseline using my Cogent HPLC column what is it and how can I fix it - FAQ
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Identify used U-2D inserts for multiple projects or in small sample sets - Tips & Suggestions
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If an analyte is only soluble at basic pH can you use a basic mobile phase for my method - FAQ
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If I use a buffer at pH 9 at 30 to 35C with the Zero Flow capillaries what lifetime should I expect from them - FAQ
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In a cap that contains a butyl rubber with a PTFE septa which direction does the PTFE membrane face - FAQ
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In order to prevent gas venting from an autosampler vial cap should I use snap or crimp or a screw cap - FAQ
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Injection Technique for Aqueous Samples using Cogent TYPE-C Columns in ANP - Tips & Suggestions
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Is the Excel template included in the Chemical Solutions Qualification kits CFR Part 21.11 compliant - FAQ
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Is the Holmium Oxide Solution intended as a stand alone product or solely as a replacement solution for the HSQ Kit - FAQ
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Is the power cable supplied with the MicroSolv Window Maker or is it a separate accessory - FAQ
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Is the software for the MicroSolv HPLC PQ Kit supplied on CD or can it be downloaded - FAQ
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Is there a difference in chromatography performance between clear and amber RSA vials - FAQ
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Is there a difference in the properties of different colors of rubber in vial cap septa - FAQ
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Is TYPE-C Silica a high purity support and have a low metal content silica like Type B silica - FAQ
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Issues arising from changes in mobile phase with acids to one with ammonium salts. Tips & Suggestions
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LFER studies compared to Log D data in describing the Aqueous Normal Phase ANP retention - Tips & Suggestions
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Lower retention is observed when functional group in a compound is ionized - Tips & Suggestions
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Mobile Phase recommendation Cogent Diamond Hydride columns for use with serum samples in Aqueous Normal Phase LCMS - Tips & Suggestions
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Modify selectivity in an ANP method of HPLC using different mobile phase pH - Tips & Suggestions
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My LCMS source was getting white film on it and at the same time the background noise was very low so is my Diamond Hydride column bleeding packing material - FAQ
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My method uses an standard type-B silica based HPLC column is there a Cogent TYPE-C column equivalent substitute - FAQ
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My retention times are changing after storing my buffer and what could be causing this and tips to help avoid issues - FAQ
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Peaks are broad and non symmetrical in LCMS method using Reversed Phase columns - Tips & Suggestions
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Polar and non polar peptides analyzed by LCMS with an Aqueous Normal Phase ANP method - Tips & Suggestions
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Restoring the initial results with a method for analyzing AMP ADP ATP UDP and GPT in biological extracts - Tips & Suggestions
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Should I use methanol as the organic solvent in HPLC when using Aqueous Normal Phase ANP - FAQ
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Silicone rubber in septa for autosampler vials vary in the way it is made - Tech Information
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Since Cogent TYPE-C columns can be used in Reversed Phase or Normal Phase what do you suggest to switch these solvent systems which are not miscible - FAQ
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Solvents and solutions that should be avoided when using PEEK filters fittings or tubing - Tech Information
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Solving baseline problems in ANP methods with the Cogent Diamond Hydride column - Tips & Suggestions
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The best way to avoid with ion suppression issues in LCMS if you need to use an ion-pair agent - Primer
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The differences in ion content between clear and amber borosilicate glass vials - Tech Information
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The effect of ionic strength of the mobile phase additive for HPLC columns in Aqueous Normal Phase - Tips & Suggestions
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To obtain greater sensitivity than Na adducts for sugars could you add ammonia NH4 instead - FAQ
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Troubleshooting problems with poor HPLC runs before the examining the column - Tips & Suggestions
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Two gradients to use for analysis of hydrophilic and or hydrophobic molecules in the same Aqueous Normal Phase ANP method - Tips & Suggestions
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Type of gradient to use for analysis of hydrophilic and hydrophobic molecules in the same HPLC or LCMS run - Tips & Suggestions
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Understanding some of the differences between HILIC columns and TYPE-C columns - Tips & Suggestions
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Use a low concentration of salt in your mobile phase to avoid ion suppression and build up on your inlet source - Tips & Suggestions
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Using ammonium acetate or formate in an acetonitrile based HPLC mobile phase for Aqueous Normal Phase ANP - Tips & Suggestions
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Using an Aqueous Normal Phase ANP method will sodium ions interfere with succinate when analyzing sodium succinate - FAQ
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Using methanol instead of acetonitrile in an HPLC method should be done with caution - Tips & Suggestions
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Using temperature changes for separations of terpenoids with the Cogent Bidentate C18 and UDC-Cholesterol HPLC columns - Tips & Suggestions
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Using the wavelength calibration solution holmium oxide for HPLC UV detector performance qualification - Tips & Suggestions
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Using triethylamine TEA in Aqueous Normal Phase ANP methods for simple sugars - Tips & Suggestions
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Vials are listed as 12 x 32mm but my autosampler accepts a maximum diameter of 11.8mm will they fit - FAQ
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Viscosity changes will affect these parameters in capillary electrophoresis - Tips & Suggestions
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What are some common sources of variance during sample preparation in an analytical application - FAQ
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What are some notable examples of journal articles that feature Aqueous Normal Phase ANP methods in metabolomics studies - FAQ
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What are some of the advantages of using Cogent TYPE-C prep and semi-prep HPLC columns - FAQ
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What are the differences between 33 and 51 expansion glass and which should I choose - FAQ
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What are the main differences between Cogent Amide columns and other brands of Amide - FAQ
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What are the size and materials of the mobile phase delivery bottle caps and O-rings - FAQ
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What are the temperature specifications of the autosampler vial storage box and cap for 4ml vials - FAQ
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What is the advantage or disadvantage of using Certified autosampler vials compared to MicroSolv vials - FAQ
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What is the best way to attach the inlet of the knitted reactor coil KRC tubing to the outlet of a tee with a PEEK finger tight fitting that will hold high back pressure - FAQ
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What is the chemical compatibility of the Chemical Resistant Sealing Mats for U-2D Micro-Sample Management System - FAQ
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What is the chemical structure of the ligand in the Cogent DIOL HPLC stationary phase - FAQ
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What is the compatibility of Cogent TYPE-C Silica HPLC columns with UHPLC instruments - FAQ
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What is the difference between ferrules made of stainless steel vs stainless steel and PEEK hybrids - FAQ
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What is the difference between related compounds and related substances in pharmaceutical HPLC - FAQ
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What is the difference between the Beta Tools and other similar pliers on the market - FAQ
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What is the difference between weak and strong cation exchange for Ion Exchange columns - FAQ
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What is the durability of the SOLVFIL when used with standard mobile phases and buffered mobile phases - FAQ
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What is the effect of extra column volume for different HPLC instruments on the same method - FAQ
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What is the elution order for analytes in the Resolution Test Mixture supplied in the HSQ kit - Tech Information
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What is the functional difference between the MRQ and the Max Recovery autosampler vials - FAQ
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What is the highest amount of vacuum pressure that can be applied to the 47mm 0.45um nylon Filter Discs Membranes - FAQ
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What is the inside diameter of the opening of your Luer Lock syringes catalog number 58901-S - FAQ
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What is the main difference between ordinary and LCMS compatible polypropylene vials - FAQ
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What is the maximum concentration of ammonium fluoride to use in a mobile phase to avoid column damage - Tips & Suggestions
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What is the maximum loading capacity mass injection volume that can be used for a semi prep Cogent TYPE-C HPLC column - FAQ
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What is the maximum salt concentration to use with Cogent TYPE-C HPLC columns with HPLC or LCMS - FAQ
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What is the most effective way to clean HPLC columns after or before use - Tips & Suggestions
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What is the pH range of 316 stainless steel laboratory tubing fittings and sparging stones - FAQ
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What is the purpose of the Resolution Test Mixture supplied in your Qualification Kits - FAQ
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What is the purpose of using isopropanol IPA as part of the mobile phase solvent in ANP methods - FAQ
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What is the recommended sparging stone pore size to use for carbonating applications - FAQ
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What makes non-coated Mobile Phase Reservoir Bottles suitable for use in various temperature environments - FAQ
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What maximum flow rate can I use for a PTFE 10m 0.75mm ID Knitted Reactor Coil KRC with isopropanol - FAQ
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What precautions are used in the assembly of your vial and cap kits to prevent contamination - FAQ
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What pressure should I expect with a Diamond Hydride 2.o HPLC column at flow rates from 0.2 to 2.0mL / min - FAQ
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What special care should I take to protect my HPLC columns when I am equilibrating them - FAQ
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What tubing is suitable for use in a knitted reactor coil KRC system utilizing isopropanol or concentrated HCl or concentrated NaOH or copper or luminol - FAQ
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What type of tubing do I use to connect the guard column holder to analytical columns - FAQ
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What will the pressure be with a mobile phase of 90% methanol and 10% DI water with a 4.6 x 250mm Cogent TYPE-C HPLC column - FAQ
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When I run gradients on my HPLC and switch from one gradient to another my baseline shows as negative and if I auto zero it becomes positive for the remainder of the run but when I start again it is negative - Primer
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Which acid or base additive should I choose for positive or negative ion mode in LC-MS - FAQ
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Which Cogent TYPE-C column do you recommend for the separation of positional isomers by HPLC or LCMS - FAQ
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Which column coupler do you recommend for pairing HPLC columns with guard columns- Tech Information
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Which column do you suggest for Cocaine & metabolite Ecognin separation - Tips & Suggestions
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Which crimp cap is most commonly used for residual solvent testing by the pharmaceutical industry - FAQ
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Which crimp caps and septa are suitable for use with Solid Phase Micro Extraction SPME vials - FAQ
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Which HPLC column ID dimensions are the Hichrom brand guard column holders cat no 82000-GH compatible with - FAQ
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Which parameters can be determined with the supplied solutions in the MicroSolv PQ Excel template - FAQ
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Which type of vial do you recommend to use with the U-2D Micro Sample Management inserts - FAQ
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Why am I observing broad split peaks in Aqueous Normal Phase ANP when using acetonitrile and methanol diluents - FAQ
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Why are environmental conditions such as temperature relative humidity that are not specified on the CofA for the UV Calibration Kit - FAQ
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Why are the same size autosampler vials listed as 2mL 1.8mL or 1.5mL by different suppliers - FAQ
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Why do I see large intermittent pressure spikes in HPLC runs and can it be a defective column - FAQ
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Why does the metal content of a silica particle contribute to the peak shape of my chromatogram in HPLC - FAQ
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Why you should use temperature control with the UDC-Cholesterol column - Tips & Suggestions
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Will I see any differences in my HPLC chromatography if I change to AQ syringe filters - FAQ
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Working with ammonium acetate and LCMS requires attention to cleaning - Tips & Suggestions
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