Benzodiazepines in Urine Analyzed using RP and ANP – AppNote

Two Types of Retention Modes are Described in this Application Note Four Compounds were well retained and separated in both HPLC Modes shown in Figures A and B; however, the Retention Order was changed depending on the Gradient used. It is worth noticing that the peak intensities were three times higher when using Gradient “A” […]

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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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Benzylpiperazine (BZP) – AppNote

Analysis in Hair Samples using LCMS An analytical protocol was developed for analysis of Benzylpiperazine in human hair samples. The elucidation of the chromatographic method was challenging due to the polar nature of BZP. The limits of detection / quantification for this method were determined to be 0.05 ng / mg for Benzylpiperazine in hair […]

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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, BPA Analyzed with HPLC – AppNote

Toxic Substance Found in Consumer Products Analyzed with HPLC Bisphenol A (BPA) is a challenging compound for analysis with HPLC. Monitoring of this environmental and health toxicant is a necessary process for surveillance as well as risk assessment. As shown in the 5 Chromatograms overlaid below, this Method produces Peak Shapes that are Symmetrical and […]

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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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Bradykinin Analyzed with LCMS – AppNote

The Peptide Bradykinin Analyzed in Saliva Samples A simple, sensitive, and specific Gradient Method was developed for the Quantification of Bradykinin (BDK) in Saliva. In addition to the intact Peptide, the Gradient applied in the developed Method was designed to analyze its impurities and metabolites. Robustness of this Method, against small modifications in pH, flow […]

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Brazilian Tree Bark Analyzed with 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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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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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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Cancer Prodrug Analyzed with HPLC – AppNote

Separation Achieved with Shape Selectivity and Hydrophobic Interaction This Method provides an example of Reversed Phase Separation containing a number of related compounds. The properties of the solutes are listed in the Table below. When comparing the properties of Compounds 2 and 3, it is interesting to note that 2 is more hydrophobic than 3 […]

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Cannabis Metabolite Analyzed with LCMS – AppNote

THC Metabolite Found in Urine Matrix Analyzed The extraction procedure using an SPE technique allows for successful detection of this Cannabis metabolite with this Method. It is worth noting that the Retention of this Compound was achieved using Methanol rather than Acetonitrile as the Organic component in the Mobile Phase. Peak: (l)-9-Carboxy-11-Nor-Delta-9-Tetrahydrocannabinol, m/z 345.2060 [M+H]+ […]

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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 HPLC – AppNote

Compounds of the Carotenoid Family Retained These compounds are very lipophilic and often have subtle differences in structure. Resolution of these compounds can be difficult with a standard Reversed Phase C8 or C18 Column because of these Similarities. The Cogent C30 Column on the other hand can further differentiate by analyte Shape in addition to […]

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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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Cefprozil E & Z Isomers Analyzed with HPLC – AppNote

LCMS Compatible Method The USP Assay Method for Cefprozil uses a phosphate-based Mobile Phase, which is not compatible with LCMS. In this Method, only Formic Acid is needed in the Mobile Phase. The Method meets the isomer resolution criterion of not less than 2.5 with an average calculated value of 4.4. The tailing factor was […]

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Celecoxib Analyzed with HPLC – AppNote

Impurities Method with Improved Peak Shape Celecoxib is Separated from an Impurity in this simple Gradient Method. The Peak shape obtained for this API shows good Peak Symmetry. In addition, the Method shows good repeatability from run to run. The API Retention time %RSD from five runs was 0.025%. Figure A shows the excellent Precision […]

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Cetirizine Tablet Analyzed with HPLC – AppNote

Efficient and Symmetrical Peak of API from Zyrtec® Tablet This Application Note shows how very Efficient Peaks can be achieved for Cetirizine from a tablet formulation and how the API Peak can be well Retained with excellent Symmetry. Even with ion pairing in Reversed Phase Methods, a Peak with acceptable Efficiency and Symmetry could be […]

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Cetylpyridinium Chloride Analyzed with HPLC – AppNote

Excellent Peak Shape for a Cationic Compound Commonly found in Household Products This Method demonstrates the potential to avoid Peak Tailing or Band Broadening with cationic compounds due to interaction with Silanols on the surface of Reversed Phase Column. Tailing can cause interference with Quantitation of a nearby Peak of interest as well. Since Cetylpyridinium […]

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Chenodeoxycholic Acid in Urine Analyzed with LCMS – AppNote

Chenodeoxycholic Acid (CDCA) Separation in LCMS The presence of an important bile acid, Chenodeoxycholic Acid, in human urine was detected using a simple Mobile Phase with the Method below. In addition to being simple and easy, it also provides a fast Equilibration between runs even while using a Gradient, for higher throughput. Peak: Chenodeoxycholic Acid […]

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Chlorhexidine Analyzed with HPLC – AppNote

Rapid, Reliable Assay without Ion Pairing Agents Chlorhexidine contains numerous amine functional groups that can have a detrimental effect on Peak Shape in HPLC. The USP Assay Method uses Triethylamine as an Ion Pairing Agent in the Mobile Phase for this reason. The Method developed in this Application Note uses only Formic Acid as the […]

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Chlormequat & Mepiquat Analyzed with LCMS – AppNote

Plant Growth Regulators CQ & MQ Retained and Separated Analysis of Chlormequat and Mepiquat can be challenging since they are extremely hydrophilic and are only weakly Retained in Reversed Phase HPLC which makes their Separation difficult. In addition, these compounds are Retained too strongly in Normal Phase (Non Polar Solvents) Chromatography. Due to this situation, […]

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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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Ciprofloxacin Analyzed With LCMS – AppNote

Retention with Good Peak Shape for this Polar Compound This Method illustrates how the MS compatible HPLC UV Methods described in various application notes can be successfully adapted for LCMS. The Peak Shape for this polar compound meets the System Suitability specification for the USP Tailing Factor. Peak: Ciprofloxacin 332.1405 m/z (M+H)+ Method Conditions Column: […]

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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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Citric, Aconitic & Maleic Acids Analyzed with LCMS – AppNote

Low Molecular Weight Organic Acids Low mass Acids were retained and Separated in this Method with the Aqueous Normal Phase mode of HPLC. The Method was able to resolve the three compounds in 10 minutes. Limits of Detection (LOD) for them ranged from 0.05 to 24 micromolar. Peaks: 1. Maleic Acid 115.0031 m/z (M-H)- 2. […]

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Clindamycin Antibiotic Tablet Analyzed with HPLC – AppNote

Separation of API from Excipients  The Stability and Robustness of this Method makes it an excellent choice for QC of this semi-synthetic antibiotic which is structurally related to Lincomycin. The Chromatogram shown below of Clindamycin is from a complex Pharmaceutical Formulation but note the excellent Peak Shape for it and the Separation from the Excipients. […]

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Clopidogrel Analyzed with HPLC – AppNote

LCMS Compatible Separation of API from Degradants Although Clopidogrel, commonly known as Plavix, retains well in Reversed Phase, its Degradants showed low Retention even at high water content. Therefore this Method the compounds are retained on the basis of polarity. This Method uses MS compatible Solvents and provides good Retention and separation between the API […]

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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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Cogent Diamond Hydride 2.o HPLC Column Retention Time Precision – AppNote

This Graph shows a Study Investigating the Day to Day Retention Time Precision with two test solutes on the Cogent Diamond Hydride 2.o™ HPLC Column. Peaks: Blue Trace: Phenylalanine Red Trace: Phenylglycine Many factors can affect Column Robustness and lifetime, so it is not possible to define specific values for those parameters. Mobile Phase: —A: DI […]

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Cogent UDA HPLC Column Use – Extended AppNote

Ion exchange chromatography can be a useful tool available to the analytical chemist. In this separation mode, an ionized moiety on the stationary phase interacts electrostatically with an oppositely charged analyte. There are several types of ion exchange that can be used, such as strong anion exchange, weak anion exchange, strong cation exchange, and weak […]

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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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Comparison of Extracts in Jaboticaba Fruit Powder with LCMS – AppNote

Phenolic Compounds Separated with HPLC with LCMS This simple Analytical Method was used to determine the content of very potent compounds present in Jaboticaba extracts and quantified some its Phenolic contents in fermented/non-fermented fruit; estimated by using standard addition. It is important to know the quantitation of compounds before and after fermentation to optimize the […]

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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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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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Corticosterones Analyzed with LCMS – AppNote

Serum Corticosterones Concentration Determinations Serum Corticosterone Concentrations are of clinical significance in Adrenal dysfunction. Its measurement is sometimes used to diagnose apparent mineral Corticoid Excess Syndrome. It can also be used as a bio marker of malignancy in Adrenal Tumors. Using this Method allows the simultaneous measurement of the two main Estrogen fractions, Estrone and Estradiol […]

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Cough Syrup Ingredient Analysis with HPLC – AppNote

Separation of Antitussives, Analgesics, Decongestants, and Preservatives Cold and cough formulations may contain a number of components such as antitussives (Dextromethorphan), decongestants (Pseudoephedrine, Guaifenesin), analgesics (Acetaminophen), and preservatives (Methyl Paraben, Propyl Paraben, Benzoic Acid). The method illustrates good separation between a variety of these compounds, also that symmetric Peak shapes can be obtained in each […]

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Cyanidin-3-O-Glucoside Analyzed in Fruit – AppNote

Analysis in Fruit and Vegetable Extracts In this analysis of proprietary fruit & vegetable extracts, the presence of Cyanidin-3-O-Glucoside was confirmed in three out of four extracts. The peaks were Symmetrical and Retained beyond the dead volume. The Method after validation can be used to quality control of commercial fruit extracts as well in studies […]

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Cyanuric Acid and Melamine Analyzed with LCMS – AppNote

Simple Gradient Method with MS Detection This Method by LCMS detection eliminates derivatization which may be necessary with GCMS Methods.  Reversed Phased Methods may run into poor separation of the small and very polar Melamine, resorting to ion pairing reagents to improve separation.  The use of these ion pairing reagents counterintuitively results in ionization suppression […]

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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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