3,3′-Diaminobenzidine Analyzed with LCMS – AppNote

Retention and Separation is Easy with this Method 3,3′-Diaminobenzidine (DAB) is a very challenging compound for analysis using HPLC with a UV detector. It is highly polar and hence difficult to retain when Reversed Phase HPLC Columns are used. Moreover, when there are a significant number of Silanol Groups present on the surface of the […]

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Acrylamide HPLC Analyzed with HPLC – AppNote

Easy & Precise Retention of a Very Polar Compound  Acrylamide can be difficult to retain with conventional Reversed Phase Methods due to its polar nature. With this Method however, Retention is readily achievable using a simple, Isocratic Mobile Phase. The overlay of two Chromatograms using two different lots of HPLC  Columns in the Figure below […]

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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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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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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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DMAP, 4-Dimethylaminopyridine Analyzed with HPLC – AppNote

Analyzing the Catalyst, DMAP, 4-Dimethylaminopyridine with HPLC This AppNote shows a rapid, reliable, Isocratic Reversed Phase, HPLC Method that was developed for the Analysis of an important Catalyst for many applications and industries: 4-Dimethylaminopyridine (DMAP). Peak: DMAP Method Conditions Column: Cogent Diamond Hydride™, 4μm, 100Å Catalog No.: 70000-7.5P Dimensions: 4.6 x 75mm Mobile Phase: —90:10 Solvent A / […]

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EDTA Analysis with HPLC – AppNote

EDTA does not have a significant Chromophore, so to achieve UV Detection, in the Method shown below we used a pre-Column reaction of a Solution of Ferric Chloride with the Sample. The resulting EDTA/Fe3+ has significant UV Absorbance making this a very Sensitive Method. Ethylenediaminetetraacetic acid is extremely difficult to analyze by itself however in […]

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EDTA Analyzed with HPLC – AppNote

Very Sensitive Method for Measuring Ethylenediaminetetraacetic Acid EDTA does not have a significant Chromophore, so to achieve UV Detection, this Method uses a Pre-Column reaction of a solution of Ferric Chloride with the sample. The resulting EDTA / Fe3+ has significant UV Absorbance making this a very sensitive Method. With this Method, Peak Shapes and […]

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Glyphosate Analyzed by LCMS – AppNote

Retention of an Extremely Polar Compound A reliable Method for the determination of Glyphosate is presented. This Method provides very reproducible Retention and fast equilibration even when a Gradient analysis is used. The use of LCMS detection avoids time-consuming derivatization of this compound which is lacking a chromophore for UV detection. The Method shown, with […]

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Herbicide and Metabolites by LCMS – AppNote

Glufosinate, N-Acetylglufosinate, and Glufosinate Propanoic Acid Analysis of these Compounds can be problematic with other methods and poor peak shape may occur. In contrast, the Peaks obtained in this method are very sharp and symmetrical and can be applied to food products containing these types of Compounds. Peaks: 1. Glufosinate m/z 180.0431 [M-H]– 2. N-Acetylglufosinate […]

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Herbicides & Metabolite Analyzed with LCMS – Extended AppNote

Glufosinate, N-Acetylglufosinate, Glufosinate Propanoic Acid, Diquat  & Paraquat Two primary metabolites of Glufosinate are N-Acetylglufosinate and Glufosinate Propanoic Acid. Due to the potentially toxic nature of these Herbicides, analysis of their metabolites in a variety of sample matrices may be required. However, all three compounds are quite Polar and therefore difficult to retain with conventional […]

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Histamine in Red Wine Analyzed with LCMS – AppNote

Demonstrating Low Histamine Content in Red Wine Samples Two Red Wine samples were tested for Histamine using the Cogent Diamond Hydride Column in an LCMS method. The wine shown in Figure B was claimed to have virtually no Histamine but had no analytical evidence to support it. The claim was verified using this simple LCMS […]

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Hydrophobic Compounds Analyzed With HPLC – AppNote

Shorter Analysis Time For separations requiring a less hydrophobic Stationary Phase, Cogent C8 can be used successfully as demonstrated in the Chromatograms. The Retention on the C8 Column is lower when compared with a C18 Column under the same Mobile Phase conditions, but since the Efficiency is excellent the separation goals can be achieved in […]

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Metaldehyde in Slug Pellets Analyzed by LCMS – AppNote

Pesticide Formulation As Metaldehyde is a non-UV absorbing compound, other detection methods needed to be investigated besides conventional UV-HPLC. LC-MS was found to be a well-suited analysis by searching for the EIC corresponding to the [M+H]+ ion. Good retention and peak shape were observed for this analyte using the Cogent Bidentate C18 2.o™ Column. Peak: […]

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Morphine Sulfate Tablet HPLC Method Transferred to Near UHPLC – AppNote

Standard 4um Particle Size Transferred to 2.o™ This application illustrates how methods developed using the 4µm Cogent Diamond Hydride Columns may be adapted for Cogent Diamond Hydride 2.o™ phases. Morphine shows slightly higher retention on the 2.o™ Column (average 7.311 min vs. 5.588 min). The efficiency is almost twice as high when using the smaller […]

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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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Normal Phase HPLC with a C18 Column – AppNote

C18 Column Produces Good Chromatography with a Hexane / Ethyl Acetate Mobile Phase A Cogent Bidentate C18 HPLC Column was used to Separate four proprietary Phenolic Compounds (precursors for a catalyst or prodrugs) under Normal Phase Conditions. The separation shown is extremely reproducible (%RSD 0.2) and the solvents do not need to be dried before […]

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Organic Alcohols Analyzed with HPLC – AppNote

Separation of 1-Phenyl-2-Propanol and 2-Phenyl-1,2-Propanediol In this Method, Separation is obtained between two structurally similar Organic Alcohols. The Method illustrates the type of Retention and Selectivity that can be obtained for these kinds of compounds. Furthermore, the Mobile Phase Solvents are simple to prepare and LCMS compatible. The overlay of the 5 Figures demonstrates how […]

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Organic Bases and Isomers at a Low pH – AppNote

Separation of Four Amine Containing Test Solutes The four test solutes selected for this application are both well-retained and well-resolved. In particular, the separation between the two isomers is readily accomplished, which may be difficult to achieve in Reversed Phase. This Method uses only Formic Acid as the Mobile Phase additive and is LCMS compatible. […]

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Phenylglycine & Phenylalanine Analyzed with HPLC – AppNote

Analysis using a Simple Mobile Phase. In this Method two important amino acids: L-(+)–alpha-phenylglycine and L-phenylalanine, were Separated. C18 Columns used today which may be present in every Analytical Laboratory may not be able to Retain underivatized Amino Acids. They usually elute at or near the “void volume” with other polar compounds. Peaks: 1. L-(+)-Alpha-Phenylglycine […]

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Polycyclic Aromatic Hydrocarbons Analyzed with HPLC – AppNote

Analysis of PAH by Reversed Phase HPLC Polycyclic Aromatic Hydrocarbons (PAH) determination in soil, food, air, body fluids etc. has been a topic of interest for routine Quality Control or Screening Analyses. This Method offers good Resolution, reproducible Retention Time and Peak Shape for these compounds. In addition to the main components, small peaks due […]

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Prep HPLC in Normal Phase on C18 Column – AppNote

“Prep up” in NP with a Step Gradient and “Check Purity” in RP on the Same Column Two compounds with similar Polarity but different Function Groups, that can be typically Resolved in Isocratic Reversed Phase conditions, are more Separated using this Method with Normal Phase Conditions (non Polar Solvents); without the characteristic hassles associated with […]

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Pyrilamine & 4-Amino-3-Chloropyridine – AppNote

Unique Selectivity on an Amide Stationary Phase The Cogent Amide Column offers unique selectivity that may not be readily attainable with other phases. Two test solutes shown in this application note (Pyrilamine and 4-Amino-3-Chloropyridine) were baseline separated on the Cogent Amide Column (Figure A), but  they co-eluted with no resolution on a different Cogent Column […]

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Retain Highly Polar Compounds with LCMS – AppNote

Analysis of Amino-Caproic Acid by a Simple LCMS Method 6-Amino-N-Caproic Acid is an active pharmaceutical ingredient used in massive thrombolysis and proteolysis secondary to metastatic carcinoma of the prostate. It is also a potent in vitro inhibitor of fibrinolysis. After oral administration 6-Amino-N-Caproic Acid enhances the uptake of labeled Fibrinogen in both the Walker and […]

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Separation of Polar Solutes with HPLC – AppNote

Niacin, Riboflavin, Folic Acid, Pyridoxine, Metformin, Thiamine The Cogent Diol Column is a good addition to the TYPE-C™ Silica line of HPLC stationary phases. Here, a variety of common polar analytes are well-retained and separated. Peaks: 1. Ascorbic acid 2. Niacin 3. Riboflavin 4. Folic acid 5. Pyridoxine 6. Metformin 7. Thiamine Method Conditions Column: […]

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Shape and Size Selectivity of HPLC Columns – AppNote

Separation of Planar Molecules in HPLC using the Cogent UDC-Cholesterol Column When comparing Cogent UDC-Cholesterol™ and Cogent Bidentate C18™ Columns, the Cholesterol phase is generally less hydrophobic under the conditions in this Application Note. However from the two Chromatograms shown, a very interesting property of the Cholesterol Phase can be observed; the Cholesterol Column exhibits […]

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Shikimic Acid Analysis by LCMS- AppNote

Ingredient for Production of Oseltamivir The method shown in this application note assures both high specificity and high sensitivity for Shikimic Acid, a synthetic ingredient for the production of the pharmaceutical Oseltamivir marketed as Tamiflu®. Using this LCMS friendly method allows for a 10-100 fold increase in sensitivity over some other methods. Also note that […]

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Shikimic Acid in Red Wine Analyzed with LCMS – AppNote

Red Wine Varietal Determined by Quantity of Shikimic Acid This Application Note presents a Method for the analysis of Shikimic Acid in Red Wine. The main advantage of using this Method is its high Specificity (mass accuracy) of this compound, the short analysis time, fast Equilibration time between runs thus more throughput, and high Repeatability […]

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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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Tetrahydrocannabinol Analyzed with HPLC – AppNote

The Psychoactive Component THC in Cannabis  Tetrahydrocannabinol (THC) has several isomeric forms, which may account for the extra Peaks observed in the Chromatogram below. Although their identities could not be confirmed, these Peaks can be Separated from the main Peak using this Method. The compound is quite hydrophobic and therefore a relatively high organic content […]

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Transfer HPLC Method to UHPLC with Hydrophobic Compounds – AppNote

Separation of Hydrophobic Compounds with HPLC & UHPLC This AppNote shows separation of analytes within a range of hydrophobicity. A simple gradient is used to elute all the compounds and baseline separation is obtained for the critical pair (peaks 4 and 5) and the least hydrophobic compound is adequately retained. A comparison is shown in […]

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Tryptamine Analyzed with HPLC – AppNote

Simple and Fast Analyses of an Important Biogenic Amine Using this Method to analyze Tryptamine produces excellent Peak Shape and Reproducible Retention Times as shown. It is very polar and very difficult to Retain when using standard C18 Columns. The baseline in this Chromatogram appears to be noisy but it is due the low UV […]

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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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Urea Analyzed with HPLC- AppNote

Fast, Reproducible Method In this Method Urea was retained when a 100% DI Water Mobile Phase was used. DI Water can be used as the complete Mobile Phase without fear of phase “de-wetting” and subsequent loss of retention time. This Method has the advantage of being very simple, without time consuming derivatization or reaction steps […]

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Zinc-EDTA Complex – AppNote

No Ion Pair Agents Needed Using conventional analytical methods, retention of metal–EDTA complexes is accomplished using Ion Pair Reversed Phase Chromatography. However, the Ion Pair Agents used in the Mobile Phase are not compatible with Mass Spectrometry. In this AppNote, only Formic Acid is needed in the Mobile Phase in order to obtain retention of […]

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