4’-Aminoacetophenone Analysis with HPLC – AppNote

4’-Aminoacetophenone Retained in Acidic Conditions This Method investigated 4’-Acetaminophenone Retention and Analysis. Adequate Retention and Sensitivity was the result and could be useful in Analysis of the Metabolites of this class of Anti-tumor Agents in body fluids (Plasma or Urine) during or after Chemotherapy. Peak: 4’-Aminoacetophenone Method Conditions Column: Cogent Bidentate C18™, 4μm, 100Å Catalog […]

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Acetaminophen & Impurity Analyzed with HPLC – AppNote

APAP Drug Substance Analysis with HPLC This Method has been developed for determination of Acetaminophen as a Drug Substance. The Separation was achieved on a C18 Column using Gradient Elution. The Method shown here has excellent Reproducibility of Acetaminophen for 5 consecutive Chromatograms shown had 0.03% RSD. This could be used for Quality Control of […]

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Acetaminophen Impurities Method with HPLC – AppNote

Acetaminophen – Alternate USP Method Acetaminophen and two of its major impurities were analyzed using a simple Mobile Phase. The Peak Shapes are very good and the Repeatability was good (%RSD = 0.01). Peaks: 1. 4-Aminophenol 1.072 minutes 2. Acetaminophen 4.668 minutes 3. 4-nitrophenol 7.588 minutes Method Conditions: Column: Cogent Bidentate C18™, 4µm, 100Å Catalog […]

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Advantage of Using Cogent TYPE-C Columns for Drugs of Abuse – Extended AppNote

Heroin, MDMA, Morphine, Hydromorphone and 6-MAM Analyzed with LCMS Analysis of Drugs of Abuse encompasses a wide variety of compounds, including controlled substances, prescription drugs, and even over-the-counter formulations. These drugs can be problematic to analyze due to several problems. First, many have similar structures (e.g. morphine and hydromorphone), making adequate selectivity difficult to obtain […]

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Aegeline in Protein Sport Mix – AppNote

LC-MS analysis of harmful substance in food supplement The data demonstrates the use of the Cogent Bidentate C18 2.o™ Column for analysis of dietary supplement samples. Isolation of the Aegeline peak is readily obtained with an extracted ion chromatogram (EIC) in the positive ion mode. Chromatographically, the peak is well retained and highly symmetrical. The […]

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Amoxicillin, USP Method with HPLC – AppNote

Robust Analysis of Amoxicillin, Antibiotic with HPLC The USP Assay Monograph Method for Amoxicillin often yields poor Peak shapes and low Method reproducibility with L1 Columns based on ordinary Silica. In contrast, the Figures shown here illustrate the high degree of reproducibility obtained from use of the Cogent Bidentate C18 L1 Column, following the USP […]

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Analysis of Alpha and Beta-Acids in Hops with HPLC – AppNote

Robust, Precise Method for Beer Analysis with HPLC The effectiveness of this Method is evident from the fact that data obtained were in a good agreement with the literature values. This Method also has the added bonus of good Precision (%RSD =0.1 and below). Calibration Curves for Alpha and Beta Acids in Beer showed good […]

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Analysis of Isobaric Opioids by LCMS – AppNote

Separation of Isobaric Drugs Morphine and Hydromorphone are Isobaric Drugs (the same m/z value) that can be separated using the Cogent Bidentate C18 2.o™ Column. Multiple samples (n=5) were prepared and analyzed. The results showed great reproducibility (RSDs < 3%). The detection limits were 50 to 500 times lower than that required by immunoassays. Peaks: […]

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Aspirin & Salicylic Acid Analyzed with HPLC- AppNote

Excellent Peak Shape For a Very Difficult Compound This Method is easy to prepare, use, reproduce and a good Separation of Aspirin from its major hydrolysis product, Salicylic Acid is achieved. Peaks: 1. System Peak 2. Aspirin (Acetylsalicylic Acid) 3. Salicylic Acid Method Conditions Column: Cogent Bidentate C18™, 4μm, 100Å Catalog No.: 40018-75P Dimensions: 4.6 x […]

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Atorvastatin Drug Product Analyzed with HPLC

API Well Separated from Degradation Product Using this Simple Linear Gradient, Atorvastatin is well separated from its main degradation Product. The degradant is formed under acidic conditions and therefore its Separation is important for Stability Indicating Methods for pharmaceutical formulations of Atorvastatin. For Methods requiring non-degrading conditions, it is important to choose diluent and Mobile […]

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Atorvastatin HPLC Method Transfer to UHPLC – AppNote

Transfer to “near-UHPLC” 2.2um Column, for the API Atorvastatin This Application Note demonstrates how data obtained on a 4μm Cogent Bidentate C18 Column (Figure B) can be adapted for a 2.2μm Column (Figure A). The retention times of both analytes are very comparable in each figure. This Method produces excellent Separation of the API and […]

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Atropine Analyzed with a Gradient Method – AppNote

No Ion Pair Reagent Necessary Chromatographic separation and quantification methods of Atropa Alkaloids are often described in the literature and the method of choice is usually Ion-Pair Chromatography (IPC), which requires long equilibration times and it is not very robust. This method shows a symmetrical peak for Atropine using a simple Gradient Method that does […]

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Avoid Sample Cleanup for Food and Beverages – Extended AppNote

3 Methods to Avoid Sample Cleanup with Histamine, Limonin & Folic Acid Food and beverage analysis is complicated by the complex nature of the sample. In many cases, extensive sample cleanup techniques such as Solid Phase Extraction (SPE) may be required to avoid problems associated with the sample matrix. In this Application Note, three strategies […]

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Barbiturates Analyzed with LCMS – AppNote

Standard Solutions in Human Urine Spiked with Barbiturates After minimal sample preparation (dilute-and-shoot approach), spiked urine samples were analyzed using a C18 Column. The analysis was based on a Separation of Standards [1]. The obtained Peaks were Symmetrical (As<1.05) and Efficient (> 106 pl/m). No shift in retention Times was observed after the samples were diluted […]

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Benzonatate Excipients & Degradants Analyzed with HPLC – AppNote

A Simple, Linear Gradient for a Challenging Drug Product This Gradient Method will produce a good separation of Benzonatate from excipients and degradants in a USP Capsule Formulation. Benzonatate contains a secondary amine group, which can cause peak tailing. Peak:  Benzonatate Method Conditions Column: Cogent Bidentate C18™, 4μm, 100Å Catalog No.: 40018-75P Dimensions: 4.6 x […]

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Benzophenone Analyzed with HPLC – AppNote

Isocratic Method Retains Benzophenone with Efficiency and Precision Benzophenone, a hydrophobic non ionic compound, was selected to illustrate the excellent Reversed Phase HPLC capabilities of this Cogent TYPE-C Silica Hydride Stationary Phase. The Reproducibility, Efficiency and Peak Symmetry of this Method is excellent, as presented in each figure below, which represents ten consecutive injections with […]

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Bi-Est® Method Transfer – AppNote

4μm to Near-UHPLC – Separation of Hormones: Estriol, Estradiol, and Progesterone Separation of three components of a hormone replacement formulation is demonstrated in this Application Note using the Cogent Bidentate C18 2.o™ Column. The two figures demonstrate how comparable retention can be obtained for both the near-UHPLC column as well as the standard 4μm Column, […]

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Bisacodyl Tablet Analyzed with HPLC – AppNote

Separation of API from Matrix Peaks from an Over The Counter Tablet This Method for Analysis of a Bisacodyl Tablet formulation Separates the API from several small matrix Peaks. These Peaks must be Resolved from the main Peak in order to ensure accurate Quantitation. The data below illustrates the separation potential of the this Method […]

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Bisphenol A, S, & F Analyzed with HPLC – AppNote

Separation of Epoxy Resins Found in Consumer Products & Food Many consumer products are using Bisphenol A (BPA) alternatives in recent years due to health concerns regarding toxicity of these compounds.  An analytical HPLC method is shown in this AppNote to distinguish amongst these various Bisphenol compounds potentially in chemicals and foods. Excellent resolution was […]

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Caffeine Content in Coffee Analyzed with HPLC – AppNote

Espresso, Regular, and De-Caffeinated Coffee Caffeine Content Caffeine is separated from other matrix components in three common Coffee beverages in this AppNote. A shot of Espresso (Figure A) had the highest content, followed by regular drip Coffee (Figure B) as expected. In De-Caffeinated Coffee, Caffeine is extracted from the coffee beans but even after numerous […]

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Capsaicin in Topical Solution Analyzed with HPLC – AppNote

Separation of Capsaicinoids in an OTC Formulation A  formulation of Capsaicins is used as a topically applied solution for Arthritis pain relief. Analyzing Capsaicin and a similar compound, Dihydrocapsaicin is required. The Method illustrates the ability to resolve structurally similar Capsaicinoids from a pharmaceutical formulation. Peak Shapes and Efficiencies are excellent for both Peaks. Furthermore, […]

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Carisoprodol & Meprobamate Analysis by LCMS – AppNote

Analysis of Closely Related Compounds It has been reported that for the quantitation of Meprobamate and Carisoprodol, (in biological samples plasma, urine, hair etc) by LCMS, excessive analysis time and complex sample treatment (derivatization, solid or liquid phase extraction) may be required. The Method in this AppNote shows a rapid way to quantitate both drugs […]

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Carotenoids Analyzed with SFC – AppNote

Separation in Super Critical Fluid using a Bidentate C18 Column Cogent TYPE-C Silica™ Stationary Phases with the unique hydrophobic, Silica Hydride Surface and a very wide range of Selectivities, can be used for Supercritical Fluid Chromatography (SFC). In HPLC, Cogent TYPE-C Columns are known to retain many polar compounds in the Aqueous Normal Phase (ANP) […]

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Carvone and Loratadine Analyzed with HPLC – AppNote

Linear Gradient In Normal Phase Mode on a C18 Column for Selectivity Carvone and Loratadine have similar Polarity but in this Method, they can be separated while maintaining significant Retention (k > 2). When the Mobile Phase of 95% Hexane and 5% Dichloromethane is used, the Loratadine is infinitely retained. This Normal Phase Analysis shown […]

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Cefpodoxime Proxetil Analyzed with HPLC – AppNote

USP Assay Method an Antibiotic Prodrug The USP Assay Method for Cefpodoxime Proxetil specifies a Resolution of not less than 2.5 between the two epimers of the Prodrug. Using this Method, the average Resolution was calculated to be 2.8. In addition, the R-epimer tailing factor must be not more than 1.5 where this Method meets […]

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Codeine and Hydrocodone in Blood Analyzed with LCMS – AppNote

LCMS Separation of isobaric Drugs Found in Urine Codeine and Hydrocodone which are Isobaric Drugs (i.e. the same m/z value) were separated using this AppNote. Multiple Samples (n=5) were prepared and analyzed. The results showed excellent Reproducibility (RSDs < 2.5%). The Method in this AppNote, after validation, can be used in Forensic Toxicological Laboratories to […]

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Comparison of 4um vs. 2.2um Columns – Extended AppNote

Easy Method Transfer from 4µm to 2.2µm HPLC Columns. The Bidentate C18™ is an excellent choice for Reversed Phase Applications. In addition to the standard 4µm material, a near UHPLC 2.o™ (2.2um) Phase is also available. These 2.2µm Columns provide inherently superior Efficiency than a larger particle size. Because the same C18 ligand is used […]

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Dantrolene Sodium Analyzed with HPLC with UV – AppNote

Dantrolene Sodium has several amine groups that can interact with lone-silanols causing problematic peak tailing when analyzed with conventional HPLC columns. By utilizing a Bidentate C18™ Column with its Silica Hydride™ surface, challenging compounds like Dantrolene can be readily retained with symmetrical peak shape. Peak:  Dantrolene Sodium Method Conditions: Column: Cogent Bidentate C18™, 4μm, 100Å […]

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Digoxin Analyzed with HPLC – AppNote

Forced Degradation Method Digoxin had several Sugar Residues that can be hydrolyzed in acidic conditions. In this Forced Degradation Method, six degradants are observed. Some of these Peaks are likely the various hydrolyzed forms, including the Aglycone Digoxigenin. The Method is capable of Separating a wide variety of Degradants. Figure A shows the Chromatogram of […]

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Dipyridamole Analyzed with HPLC – AppNote

Several Tertiary Amines on a Molecule that is Easily Retained This Method for the Analysis of Dipyridamole USP Tablet Formulation is easy to do. Note the excellent Resolution from capsule excipients, along with the excellent Peak shape for this complex, difficult molecule.   Peaks: 1. Dipyridamole 2. Tablet Excipients Method Conditions Column: Cogent Bidentate C18™, 4μm, […]

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Docusate Sodium Analyzed with HPLC – AppNote

A Simple Gradient with Good Separation    The official USP assay method for Docusate Sodium tablets calls for a Mobile Phase of 50% 7mM Ammonium Acetate / 50% Acetonitrile at 40°C. However, retention for the API and the System Suitability compound Methyl Paraben were found to be low using these conditions. This Method not only […]

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Etodolac Tablet Analyzed with HPLC – AppNote

An Assay Method for Etodolac Tablets The USP Assay Method for  Etodolac tablets uses a Phosphoric Acid based Mobile Phase which is not LCMS compatible. The Method in this Application Note is more versatile since it can be used for HPLC or LCMS. The Gradient can be adjusted if lower Retention is required. Data from […]

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Fenofibric Acid Capsule Analyzed with HPLC – AppNote

Simple Isocratic LCMS Compatible Assay Method The USP Assay Method for Fenofibric Acid uses a Phosphate buffer which is incompatible with MS detection. In this isocratic Method, only Formic Acid is needed in the Mobile Phase. The Peak Efficiency and Symmetry are excellent and the run-to-run precision is reliable and robust, as the 10 Chromatograms […]

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Fioricet Analyzed with HPLC – AppNote

Gradient Separation of Acetaminophen, Caffeine, and Butalbital In this Method, a simple Reversed Phase gradient is used to separate the three components of a Fioricet tablet. Figure A shows the five-run overlay obtained from the gradient. Figure B shows a “zoomed in view” so that the Butalbital Peak can be seen clearly. Peaks: 1. Acetaminophen […]

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Forced Degradation of Atorvastatin by LCMS – AppNote

Separation of API from its Lactone Degradation Product Atorvastatin is separated from its main Degradation product in this Method with a simple linear Reversed Phase Gradient. With the use of LCMS, the identity of the Degradant can be confirmed from its m/z value. The Degradation is an intramolecular Fischer esterification, which is catalyzed under Acidic […]

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Furazolidone Analyzed with HPLC – AppNote

API and Related Compounds Separation Furazolidone was Separated from related compounds in a commercially available pharmaceutical preparation. Excellent Peak shape and Selectivity from the related compounds was achieved with this Robust Method making it a great choice for QC applications even when using aggressive Mobile Phases that include acids. Molecular weight of Furazolidone is 225.16. […]

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Furosemide Analyzed with HPLC – AppNote

Furosemide & Related Compound with Improved Peak Shapes Furosemide and its related compound can be a difficult molecule to chromatograph with conventional L1 (C18) Columns due to Silanol activity. With this Method, the Peak shape of Furosemide and its related Compound A is excellent and baseline Resolution is achieved between this specified impurity and Furosemide. […]

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Glimepiride Tablet Analyzed with HPLC – AppNote

Isocratic Assay Method for a Diabetes Drug In this study, an Isocratic, HPLC Method for Glimepiride Analysis in a tablet formulation is presented. The USP Assay Method for this drug calls for a Phosphate Buffer and is therefore not LCMS compatible. This Method uses Formic Acid instead and produces a Symmetrical, well-Retained Peak. Therefore the […]

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Glipizide Analyzed with HPLC – AppNote

Separation of API from Acid Degradation Products This Method illustrates the capabilities to separate several Glipizide Degradants that are formed under acidic conditions. Good separation is obtained as well as Sharp, Symmetric Peak shapes for each compound. The Retention times show good repeatability as well, as demonstrated in the Figure overlays. Also, the Mobile Phase […]

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Glyburide and Metformin Analyzed with HPLC – AppNote

Separation of “Highly Polar” and “Non-Polar” Compounds in one Isocratic run In this Method, the polar compound, Metformin, and the nonpolar compound Glyburide, can be retained on the same Stationary Phase (see A & B). Depending on the Mobile Phase composition either Metformin or Glyburide can be retained longer. Method Conditions Column: Cogent Bidentate C18™, […]

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Glycosidic Flavonoids Analyzed with HPLC – AppNote

Separation of Diosmin, Eriocitrin, and Naringin In this method, three Glycosidic flavonoid standards are separated with good resolution. The Cogent Bidentate C18 2.o™ Column produces high efficiency peaks with reproducible retention (see figure overlay). Separation is also observed for a small impurity peak, eluting between peaks 1 and 2. This separation of standards could be […]

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Hesperidin Analyzed with HPLC – AppNote

LC-MS compatible method This method for analysis of Hesperidin produces an excellent analyte peak and shows separation from what appears to be two impurity peaks. The gradient method is LC-MS compatible and can be applied to many types of Hesperidin-containing samples such as citrus fruit extracts. The overlay of five runs shown in the figure […]

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Hormone Replacement HPLC Methods – Extended AppNote

Ethinylestradiol, Norethisterone Acetate, Estriol, Estradiol, Progesterone, Separation in Hormone Replacement Formulations. Often, these formulations have multiple active ingredients present, therefore HPLC is an appropriate technique in obtaining the necessary specificity for a Quantitative Assay. This Method can retain the Hormones by conventional Reversed Phase HPLC and can also differentiate among the compounds by shape. The […]

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Ibuprofen Assay Method Reproducibility with HPLC – AppNote

Extremely Precise, Assay Method This Assay Method for a common Ibuprofen formulation demonstrates Reproducibility and Robustness as the Figure below shows an overlay of four Chromatograms with different Columns lots (%RSD < 1). An important aspect of Column Selection for a Method is that the Retention behavior is consistent across numerous manufacturing batches. This is […]

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Indomethacin Capsule Analyzed with HPLC – AppNote

Simple Assay Method  This method for analysis of Indomethacin capsules is easy to perform and uses an LC-MS compatible Mobile Phase. The API peak that was obtained shows excellent efficiency and the data is very reproducible, as illustrated by the overlay of five runs shown in the figure. Peak: Indomethacin Method Conditions Column: Cogent Bidentate […]

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Isotretinoin in Human Plasma Analyzed with LCMS – AppNote

Isocratic, LCMS Method for Isotretinoin in Human Plasma Method development for Isotretinoin was first performed with a Reference Standard, on an HPLC with a Diode Array, UV Detector. The final, Method (Isocratic) was then transferred to an LCMS for analysis of the active ingredient in Human Plasma. The potential matrix effect on the ionization of […]

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Lamotrigine Analyzed with HPLC – AppNote

USP Assay Method for a Very Polar Compound The USP Assay Method for Lamotrigine uses a relatively low pH of 2.0. These conditions may promote hydrolysis of the bonded phase in many L1 Columns, but the unique chemistry of the Cogent Bidentate C18 Column (L1) is very rugged and shows no loss of Retention for […]

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