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 […]

Read More

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 […]

Read More

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 […]

Read More

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 […]

Read More

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 / […]

Read More

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 […]

Read More

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 […]

Read More

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 […]

Read More

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 […]

Read More

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. […]

Read More

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 […]

Read More

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 […]

Read More

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. […]

Read More

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 […]

Read More

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 […]

Read More

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 […]

Read More

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 […]

Read More

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: […]

Read More

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 […]

Read More

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 […]

Read More

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: […]

Read More

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 […]

Read More

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 […]

Read More