Remdesivir and GS-441524 a ProDrug – AppNote

Retention of polar and non-polar drug compounds in ANP Remdesivir, an antiviral drug, and GS-441524, a pro-drug converted in the body as a ribonucleotide analog, is as a mixture that may be difficult to analyze in routine chromatographic analysis. As GS-441524 is polar, is makes it more difficult to retain in typical Reversed Phase conditions. […]

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Dicloxacillin and Ampicillin, an Antibiotic Mixture Analyzed with HPLC – AppNote

Ampicillin and Dicloxacillin were retained with minimal amounts of buffer concentration and with good run-to-run precision in this HPLC method that can be readily transferred to LCMS. The combination of both drugs presents a mixture of polar and non-polar antibiotics that may incur difficulties to retain on conventional HPLC columns in Reversed Phase. This drug mixture […]

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Hydroxychloroquine Sulfate – AppNote

Hydroxychloroquine Sulfate presents a few Complexities to Routine Chromatographic Analysis. The Amine Groups also interact with lone-Silanols, causing Peak Tailing on regular Silica Columns. In typical Reversed Phased Modes, Buffers are needed in higher concentrations to aid in retention, as well as Ion Pair Reagents. These additives can hinder coupling in Mass Spectrometry and also […]

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Ethyl Glucuronide Analysis with LCMS – AppNote

Method Optimization in Separation of Ethyl Glucuronide and Ethyl Sulfate Ethyl Glucuronide and Ethyl Sulfate are compounds that are not well-retained or separated using Reversed Phase Columns due to their hydrophilicity thus requiring high water concentrations in the Mobile Phase. To avoid the use of high water content Mobile Phases, HILIC columns were sought as […]

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Chlorpheniramine Maleate Organic Impurities Analyzed with HPLC – AppNote

Separation demonstrated in real commercial formulation extracts Use of the Cogent Bidentate C8™ Column allows for high resolution baseline separation of six specified impurities of Chlorpheniramine Maleate (Fig. A). Fig. B shows how the method can be applied to a real-world formulation, spiked with the N-oxide impurity to demonstrate resolution from the API peak. Currently, […]

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Dehydroepiandrosterone (DHEA) Capsule Separation with HPLC – AppNote

Excellent separation from matrix excipients Pharmaceutical formulations may contain a number of excipients that can potentially interfere with a chromatographic analysis. However, using the Cogent Bidentate C8 Column, the DHEA peak is well-resolved from the others, the latter of which all elute as a large peak in the solvent front portion of the run. The […]

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Sucralose – AppNote

Common Artificial Sweetener Sucralose does not exhibit significant UV absorption, hence detection of this analyte may be suited to Refractive Index (RI) as an alternative. Both approaches are shown in this application note, where UV and RI detector modules where attached in series. The relatively high concentration used in this example allowed for adequate detection […]

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Oleic Acid & Elaidic Acid – AppNote

Advantages of shape selectivity in cis/trans separations The separation of cis and trans isomers by Reversed Phase can be challenging, as the two compounds often have little difference in hydrophobicity. In cases such as these, additional selectivity mechanisms may be necessary to obtain resolution. Furthermore, they cannot be resolved by MS because they have the […]

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5 Phenolic Compounds Separated by LCMS – AppNote

Commercial Rice Extract A commercial rice extract was analyzed and peaks were assigned based on retention times and m/z values for the compounds of interest using the Cogent Phenyl Hydride Column . After method validation the developed procedure can be used to evaluate the quality of rice and to develop the best extraction procedure. Peaks: […]

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Spiked Hesperidin Extract Analyzed with LCMS – AppNote

Eriocotrin, Hesperidin, Naringin, Diosmin In this method, the Hesperidin extract was spiked with three glycosidic flavonoids. The Cogent Phenyl Hydride Column was used to separate the main component of the extract (Hesperidin) and three standards. The MS detection helped to distinguish between the Naringin peak of the standard and a small impurity peak (peak marked […]

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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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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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Lansoprazole Capsule Analyzed with HPLC – AppNote

Separation from matrix peaks Lansoprazole is separated from several Matrix Components in this simple assay method. The Mobile Phase is LC-MS compatible so the method could be applied to more complex samples such as plasma. Five runs are shown in the figure to illustrate the repeatability of the data. Peak:Lansoprazole Method Conditions Column: Cogent Bidentate […]

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Propranolol in Urine Analyzed by LCMS – AppNote

Excellent peak shape for basic compound The developed method permitted analysis of Propranolol in urine after simple sample preparation. The analysis is performed at a high concentration of Acetonitrile (Acetone may be used as well). The peak shape obtained for this basic compound was excellent. The method could be easily applied to analysis of Propranolol […]

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β-Carotene Capsule Analyzed with HPLC – AppNote

Separation from Matrix Peaks Beta-carotene may be taken as a dietary supplement in capsule form. In this case, a wide variety of Matrix Peaks were observed in the chromatographic data. It is possible that some of these peaks are various isomers of all-trans ß-carotene or other similar carotenes. In any case, resolution was obtained from […]

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Vardenafil (Levitra®) Analyzed with HPLC – AppNote

LC-MS Compatible Assay Method Vardenafil in a tablet formulation can be readily assayed with this LC-MS compatible gradient method. The peak tailing factor was close to unity. The compound has several amine groups which can produce tailing with ordinary HPLC Columns that have a number of surface Silanols. The MS-compatible Mobile Phase means that the […]

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Nonylphenol Analyzed with HPLC – AppNote

Separation of Isomer Peaks Nonylphenol is a very hydrophobic compound and is suitable for analysis by Normal Phase. It is produced commercially by Acid-catalyzed Alkylation of Phenol with a mixture of nonenes. Therefore a variety of product isomers are possible, with different branching of the C9 group and position of the chain on the ring. […]

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Metronidazole Topical Cream Analyzed with HPLC – AppNote

Retention for Highly Polar API This API has very little Hydrophobic character and is not readily retained by Reversed Phase. The Peak that was obtained had excellent efficiency and symmetry. Three runs are shown in the figure in order to illustrate the repeatability of the data. Peak: Metronidazole Method Conditions Column: Cogent Diamond Hydride™, 4µm, […]

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Separation of Nucleotides – AppNote

AMP, NAD, NADP, and GTP on UDA Column Nucleotides are not well retained under Reversed Phase conditions due to their highly polar nature (the presence of one or more Phosphate groups). In this method, weak cation-exchange interactions can provide additional retention/selectivity along with the ANP retention of the Hydride surface. Peaks: 1. AMP – Adenosine […]

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Separation of Adenine Nucleotides – AppNote

Separation of AMP, ADP, ATP with HPLC The figure shows a separation of three energy nucleotides. All three are baseline separated in order of increasing polarity as is expected when ANP chromatography is used. It is worth noting that the retention of nucleotides increased as the buffer concentration was increased (data not shown). 16.0mM concentration […]

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Separation of Inosine Nucleotides – AppNote

IMP, IDP, and ITP Analyzed with HPLC The figure shows the optimized separation of ITP (Inosine 5’-monophosphate), IDP (Inosine 5’-diphosphate) and IMP (Inosine 5’-triphosphate) in the order of increasing Phosphate content similar to anion exchange. The presence of at least one impurity near ITP and possibly a second near IMP precluded accurate determination of peak […]

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Red Bull Energy Drink Analysis – AppNote

Separation of Taurine and Caffeine with LC-MS A method combining Solid Phase extraction with high performance liquid chromatography–electrospray ionization tandem Mass Spectrometry was developed for the highly sensitive and accurate screening of Caffeine and Taurine in energy drinks. The matrix pretreatment by SPE sample extraction was essential in the analysis of Taurine. The matrix did […]

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Valaciclovir & Degradants Analyzed with LCMS – AppNote

Separation of Valaciclovir from two Degradants The anti-viral Herpes drug Valaciclovir and its degradation products are analyzed using Aqueous Normal Phase HPLC with MS detection. The Method development was completed using UV detection, where excellent Separation between the Prodrug Valaciclovir and its active converted degradant, Acyclovir, was observed. The Method transfer from UV to MS […]

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Effexor Capsule Analyzed with HPLC- AppNote

Reducing Tailing for Venlafaxine with HPLC The USP assay Method for Venlafaxine capsules uses Triethylamine and Phosphoric Acid in the Mobile Phase, both of which are incompatible with LC-MS. The system suitability for Venlafaxine tailing factor is 2.0, indicating the compound has a tendency for tailing. Here a sharp symmetrical peak is observed using Formic […]

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Tandem LCMS approach to Metabolite Profiling – Poster

Hydrophilic and Hydrophobic Molecules In a Single Line Injection Presented at the Metabolomics Society meeting in Amsterdam, June 2010; below is the introduction from the poster or you can download and view the entire poster by clicking on the link below. INTRODUCTION: A tandem liquid chromatography (LC) setup has been developed to analyze a larger […]

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Tapentadol HCl Tablet Analyzed with HPLC – AppNote

Assay Method for the Analgesic Nucynta Tapentadol can be a problematic compound for HPLC analysis due to the Amine functional group. Tertiary amines are often particularly difficult to obtain a good peak shape using Reversed Phase methods. Peak tailing has been reported in several published papers in the literature. With this Method, a sharp Peak […]

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Tizanidine HCl Tablet Analyzed with HPLC – AppNote

Separation Method for Tizanidine Compatible with LC-MS Tizanidine has numerous amine functional groups and can be a challenge for analysis with HPLC. The USP method uses Phosphate in the Mobile Phase which is not compatible with LC-MS. This Method however uses Formic Acid as the Mobile Phase additive and produces a sharp, symmetrical peak. The […]

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Morphine Sulfate Tablet Analyzed with HPLC- AppNote

Excellent Peak Shape for Tertiary Amine Morphine can be a very problematic compound for analysis with HPLC. It has a tertiary amine and has a tendency to tail under some conditions. USP assay methodology uses phosphates, alkylsulfonates, or other LC-MS incompatible agents in the Mobile Phase. This Method uses only Formic Acid and can be […]

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Urea Analyzed with HPLC – AppNote

Retention of Urea, a Highly Polar Compound Urea is very difficult to retain by conventional HPLC methods. It is highly polar and therefore shows little or no Reversed Phase retention. However, this Method shows how it can be readily retained past the solvent front using a simple isocratic Mobile Phase. Furthermore, the Peak shape for […]

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Streptomycin Analyzed with HPLC – AppNote

Retention of a Highly Polar Antibiotic Streptomycin is very polar and difficult to retain with Reversed Phase methods using conventional Columns. In this Method, retention is achieved with Separation of the Streptomycin from two impurities found in the Standard Solution. Furthermore, the numerous amine groups do not cause tailing of Peak shape as with standard […]

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Caffeine in Coffee Analyzed with HPLC- AppNote

Unique Retention Mode Affords Superior Specificity Although Caffeine retains well in Reversed Phase, it is found to be difficult to obtain a well-resolved Peak free of interference from other matrix peaks with a complex sample such as coffee. In this Method, most of the matrix peaks elute near the void volume and do not interfere […]

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Glycolic Acid Analyzed with HPLC – AppNote

Analysis in Urine Samples An enzymatic Method is widely used for the determinations of Glycolic Acid in various products, but it suffers from instability and very high cost of the enzyme (Glycolate Oxidase). The LCMS analysis presented here is rapid, simple, selective, and suitable for routine analyses of urine samples. It offers numerous advantages including […]

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Coricidin HBP Day Tablet Analyzed with HPLC- AppNote

Formulation of Guaifenesin and Dextromethorphan HBr This Method shows the separation of two active ingredients in a formulation of Guaifenesin and Dextromethorphan. Dextromethorphan often exhibits tailing in many HPLC methods, but here an excellent Peak shape is observed. This Method is suitable for routine assay of these compounds in combination formulations. A change in wavelength […]

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Furazolidone Analyzed with HPLC – AppNote

Improved Specificity Compared to USP Assay Method The USP Assay Method for Furazolidone is performed by UV Spectrophotometry. This HPLC Method provides more Robustness and Specificity for the analysis. Separation of Furazolidone from the structurally similar compound Nitrofurantoin is shown in the figure. Nitrofurantoin can be used as an internal standard to obtain more robust […]

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Trimethobenzamide Analyzed with HPLC – AppNote

Separation of Trimethobenzamide with a Simple Isocratic Method  The USP Assay Method of Trimethobenzamide is performed by titration. This alternative HPLC approach is fast, easy, and reliable. It has many advantages over the titration Method, including ease of automation and less operator-dependent results. This simple isocratic Method provides sufficient Retention of the API to allow […]

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Pyrilamine Maleate Analyzed with HPLC – AppNote

Separation of Pyrilamine with a Simple Isocratic Method Pyrilamine is a challenging compound to analyze with HPLC because it contains several amine groups that can contribute to peak tailing. In this Method, an excellent Peak shape is obtained for Pyrilamine with a simple isocratic Mobile Phase. Data is shown for two lots of Columns in […]

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Prednisone Analyzed with HPLC – AppNote

Isocratic Method for Prednisone Tablets  This Method uses the Mobile Phase specified in the USP Method for Assay of Prednisone tablets. The resolution between the API and the Acetanilide Internal Standard meets the system suitability. Resolution was found to be superior compared to standard C18 HPLC Columns. In addition, this Method also produces excellent precision […]

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Alprazolam Analyzed with HPLC – AppNote

Robust Separation of API from USP Internal Standard The USP Assay Method for Alprazolam uses a bare Silica Column and a complex Mobile Phase consisting of Acetonitrile, Chloroform, Butyl Alcohol, and Acetic Acid. In this Method, a simple LCMS compatible Mobile Phase is used and produces excellent Peak shapes for both the API and its […]

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Stability Testing of Tetracycline HCl Capsules – AppNote

Robust, high-throughput Separation of API from its Degradation Products Figure A shows the chromatogram obtained from a single injection of the degraded Tetracycline capsule extract. Tetracycline is well-resolved from its three main degradation products, the identities of which were confirmed by individual standards under non-degrading conditions. Amine-containing analytes such as these often require the use […]

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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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Substituted Phenols Analyzed with LCMS – AppNote

Separation by Functional Groups Two proprietary compounds, which are precursors for a catalyst or Prodrugs are analyzed using a C18 Column under Normal Phase conditions. Separation of the two compounds is extremely reproducible (%RSD 0.1) and is very easy. The amount of moisture in your Mobile Phase is not an issue with this Method. Peaks: […]

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pH Gradient to Separate Vitamins – AppNote

Separation of Ascorbic Acid, Riboflavin, Pyridoxine, & Thiamine This LCMS compatible Method shows excellent Separation and Retention for all four analytes. If the analysis were done by Reversed Phase, LCMS incompatible ion pair agents would likely be required to get this type of separation. Ascorbic Acid was found to have better Retention near neutral pH […]

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Vancomycin Analyzed with HPLC- AppNote

Retention of a Highly Polar Antibiotic As a highly polar compound, Vancomycin is difficult to retain with Reversed Phase Methods. In this Method the compound retains very well as illustrated in the Figure. In addition, the repeatability of the analysis, which is demonstrated by the overlay of five consecutive runs, is excellent. The Mobile Phase […]

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Histamine Analyzed with HPLC – AppNote

LCMS Compatible Method for the Separation of Histamine As a Heterocyclic primary amine, Histamine is a very polar compound and is difficult to retain on a Reversed Phase Column. This Method provides adequate Retention and a symmetrical Peak shape for this challenging compound without the use of ion pairing reagents in the Mobile Phase. The […]

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