Acetaminophen Impurities Method – AppNote

Acetaminophen and two of its major impurities were analyzed using the Cogent Bidentate C18 Column and a simple Mobile Phase. The Peak Shapes were very high. The Repeatability of the Results was extremely good (%RSD = 0.01). Peaks: 1. 4-aminophenol 1.072 minutes 2. Acetaminophen 4.668 minutes 3. 4-nitrophenol 7.588 minutes t0: 0.9 minutes Method Conditions: […]

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Alprazolam (Xanax®) HPLC Method Transferred – AppNote

Benefit of 2.2um Column Analyzing Alprazolam by HPLC In this AppNote, we show that a transfer from a 4µm to 2.2µm Column, higher efficiency is observed with the smaller particle size Column. This can be very useful for analyses requiring detection at low concentrations. The Peak shape is very sharp using the 2.2um Column (Figure. […]

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Amikacin & Tobramycin – AppNote

Highly Polar Antibiotic Separation These two Antibiotic agents present a considerable challenge to chromatographers. As highly hydrophilic compounds, they are generally poorly retained by conventional Reversed Phase methods that rely on an analytes hydrophobicity. In addition, they exhibit very low UV absorption and therefore more sophisticated detection methods are often required. In this application, an […]

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Amiloride and Triamterene in Urine – AppNote

LCMS Method for Spiked Urine Sample This application note describes the separation of two important  drugs for treatment of hypertension and congestive heart failure. Both compounds have numerous amine groups, which can contribute to Peak tailing in some instances. However, the Peak shapes observed here are both symmetrical and very efficient. This is accomplished using […]

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Amlodipine, Valsartan, and Hydrochlorothiazide Tablet USP Assay – AppNote

This AppNote demonstrates the USP Method for Amlodipine, Valsartan, and Hydrochlorothiazide Tablets working with the Cogent RP C18. As shown in the Chromatograms, the Peak efficiency is superb and USP Peak tailing guidelines are easily met with the Column. This demonstrates a great alternative Column for easy plug and play with this USP Method. Method […]

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Amoxicillin, USP Method – AppNote

Robust Analysis of Amoxicillin, Antibiotic by HPLC The USP assay 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 Assay […]

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An Analysis of Local Anesthetic Dyclonine HCL by HPLC – AppNote

A Reproducible Method for Detection of Dyclonine Hydrochloride using Reversed Phase HPLC A rapid, sensitive, and reproducible method has been developed for detection of Dyclonine HCL. The data below, (overlay of 20 injections) illustrates how the compound can be adequately retained and detected using HPLC, with both excellent peak shape and run-to-run precision. Using a […]

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Analysis of a Local Anesthetic Lidocaine, Aminoethylamide – AppNote

Method Development for a Local Anesthetic (A Case Study) An analyst was using a Cogent Diamond Hydride™ Column for evaluating Lidocaine methods and although they had good retention of the compound, they did not meet the required 0.3 – 0.5 AU when 0.1 mg/mL Lidocaine sample was injected for both 2μL and 10μL injection volumes. […]

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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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Analysis of MDMA in Plasma Samples by LCMS – AppNote

MDMA – Analyzed by HPLC with MS Under the described conditions, MDMA was retained and eluted as a symmetrical peak. The sensitivity of the method is very good and  comparable to that reported with GC-MS detection [1]. Matrix effects were of minor extent and reproducible and hence should not compromise quantification. The method can be […]

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Antibiotic Keflex Analysis by HPLC – AppNote

Analysis of Polar Antibiotic Main Active Ingredient: Cephalexin Monohydrate Cephalexin Monohydrate, commercially known as Keflex, is a semi synthetic Cephalosporin antibacterial drug, analysis of which is of great interest to scientists from many research fields. There is a need for a rapid, efficient and inexpensive analytical method to be applied for analysis of formulations during […]

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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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Baclofen Analysis by HPLC – AppNote

Very Polar API Retained with Precision This compound has two ionizable functional groups (an amine and a carboxylic acid), which makes it quite suitable for retention using this method. A simple gradient produced a very sharp peak for this analyte. These method conditions can be applied to the routine analysis of Baclofen tablet formulations. Peak: […]

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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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Brazilian Tree Bark Analysis by LCMS – AppNote

Identification of Quercetin, Rutin, and “Compound 1” in a Brazilian Tree Bark Over one quarter of natural medicines have been discovered in rainforests, and therefore analytical study of the indigenous flora and fauna is necessary. The Amazonian rainforest in Brazil is the most biodiverse region in the world. A Brazilian tree bark extract (Brownea Grandiceps) […]

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Chlorpheniramine Maleate Organic Impurities Analyzed by 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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Ciprofloxacin LC-MS Compatible Assay – AppNote

Antibiotic Tablet Ciprofloxacin has several amine groups and therefore is susceptible to peak tailing in Reversed Phase methods. The USP assay method for Ciprofloxacin tablets uses Triethylamine as an Ion Pair Agent to reduce tailing and in addition, Phosphoric Acid is included in the Mobile Phase. These conditions make the USP method incompatible with MS […]

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Coricidin HBP Night® Tablet – AppNote

Acetaminophen, Dextromethorphan, and Chlorpheniramine This method demonstrates the potential of the Cogent Phenyl Hydride 2.o™ Column for analysis of amine-containing analytes in a real formulation. Chlorpheniramine and Dextromethorphan can often be problematic in terms of peak tailing due to the tertiary amines, but this column and method produces excellent peak shapes for both compounds in this […]

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Cyclobenzaprine Hydrochloride USP Assay – AppNote

This method demonstrates the USP Cyclobenzaprine Hydrochloride Extended-Release Capsules Assay. As shown in the Chromatograms, the peak efficiency is superb and USP peak tailing guidelines are easily met with the Cogent RP C18 5μm column. This demonstrates a great alternative column for easy plug and play and this UPS Assay Method. Method Conditions: Column: Cogent […]

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Dehydroepiandrosterone (DHEA) Capsule Separation by 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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