Dantrolene Sodium Analyzed with HPLC with UV – AppNote

Dantrolene Sodium has several amine groups that can interact with lone-silanols causing problematic peak tailing when analyzed with conventional HPLC columns. By utilizing a Bidentate C18™ Column with its Silica Hydride™ surface, challenging compounds like Dantrolene can be readily retained with symmetrical peak shape. Peak:  Dantrolene Sodium Method Conditions: Column: Cogent Bidentate C18™, 4μm, 100Å […]

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Neomycin Sulfate Analyzed with LCMS – AppNote

Neomycin presents a number of challenges to routine Chromatographic Analysis. It lacks Chromophores and therefore is difficult to detect using conventional HPLC techniques and retention in traditional Reversed Phase mode may not be viable due to its high polarity.  However, use of the Cogent Diamond Hydride Column in conjunction with a Mass Spec helps circumvent […]

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Glycosidic Analyzed with LCMS – AppNote

Cyanidine-3-Hexoside, Luteolin 7-O-Glucoside & Malvidin Dihexoside Observed in Mesquite Flour extracts, these compounds are Glycosidic Flavones and Anthocyanins. The Glycoside Moieties impart polar characteristics to the analytes, which makes them amenable to Retention by the Aqueous Normal Phase (ANP). In this Application Note, the Cogent Phenyl Hydride Column was used to obtain Chromatographic Separation. The […]

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Hydrophobic and Hydrophilic Peptides Analyzed with HPLC – AppNote

Simultaneous Separation using a Capillary Column The studied analytes comprised some very Hydrophobic and Hydrophilic Peptides with diverse isoelectric points (pI) and thus served as useful probes to explore the potential of this App Note in this field of Bioanalysis. The figure shows how these Peptides of widely disparate physicochemical properties could be separated in […]

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Domoic Acid Separation with LCMS without Derivatization – AppNote

Several analytical methods have been developed for the quantitative determination of Domoic Acid (DA). However, many of the methods require tedious and labor-intensive derivatization of this compound in order to detect it. A new method based on HPLC and MS detection which does not require derivatization has been developed. A simple linear gradient and typical […]

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Octreotide Analyzed with LCMS – AppNote

Retained Isocratically or With a Gradient This cyclic Octapeptide can be retained with simple Isocratic Mobile Phase conditions of 50:50 Solvent A / Solvent B (see Figure I). In addition, use of a Gradient produces a sharper Peak if desired (Figure II). Note, that the Gradient starts at an unusually high percent of Water (50%) […]

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Sugars, Sugar Alcohols & Amino Acids Separation with LCMS – AppNote

Glucose, Mannitol, Aspartic Acid, Alanine and Arginine Metabolomics analysis encompasses a vast array of molecules with disparate hydrophobic/hydrophilic properties. Many  of these analytes are in fact quite polar and problematic to retain by conventional Reversed Phase Chromatography. The Cogent Diamond Hydride Column is quite well-suited to their separation. This application demonstrates this property through the […]

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Tramadol Separation with Enhanced LCMS – AppNote

LC-MS Compatible HPLC Method for Tramadol  Tramadol can be retained by Reversed Phase HPLC  but some reported methods require Phosphate buffer additives in the Mobile Phase, which means incompatibility with LC-MS. In contrast, this Method uses Formic Acid as the Mobile Phase additive. An advantage this method has is that it produces enhanced signal-to-noise compared […]

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Fructose and Glucose in Coca-Cola Analyzed with HPLC & RI – AppNote

Separation of Polar Sugars in Coca Cola© The high sugar content of soda beverages can be observed in this Chromatographic separation of Fructose and Glucose in cola. The two Sugars are retained and separated with the use of the Cogent Amide Column. Data from reference standards is also shown for peak identity confirmation. A preconditioning […]

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Prasugrel Analyzed with HPLC – AppNote

Comparison of Diamond Hydride to C18 HPLC Column Prasugrel has a tertiary Amine and therefore tails in many Reversed Phase methods and conventional HPLC columns. Figure A shows how a sharp and symmetrical peak can be easily obtained with the Cogent Diamond Hydride Column using an MS-compatible Mobile Phase. Figure B shows the peak that […]

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Histamine Analysis in Tuna by LCMS – AppNote

LC-MS method without derivatization A small amount of Histamine was found in a Tuna sample (Figure A) after an extraction procedure and analysis using the Cogent Diamond Hydride Column and MS detection. In Figure B, a Tuna sample was spiked before the extraction procedure at a level of 0.5 mg/L and Figure C shows the […]

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Tizanidine HCl Tablet with Precision – AppNote

Excellent Run to Run Precision Tizanidine has several amine groups which can present problems to chromatographers. Residual silanols on the surface of ordinary Silica-based Columns can electrostatically interact with these groups, causing peak tailing. The Cogent Amide Column, used in the Application Note is virtually free of residual silanols and therefore a symmetrical peak shape […]

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Galactose and Sucrose – AppNote

Retention and Separation of Mono and Disaccharides This application demonstrates the ability of the Cogent Amide Column to retain two highly polar test solutes. Sucrose, for example, has a log P of -3.7 and hence would be unlikely to retain in Reversed Phase. Excellent separation is obtained here for these Mono and Disaccharides. The noisy […]

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Fluoxetine (Prozac®) – AppNote

Excellent Retention and Peak Shape with Amide Column Fluoxetine can have a tendency to tail in some HPLC methods due to its secondary amine group. However, peak shape with the Cogent Amide Column was found to be highly symmetrical without the aid of ion pairing agents. This allows the method conditions to be adapted to […]

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Ribose and Xylose – AppNote

Sugars can be difficult to analyze with HPLC due to their polarity. Columns with amine ligands are often used for retention of simple sugars like Ribose and Xylose, but they have a number of drawbacks. The amine group can form Schiff bases with Aldehydes in the sample, resulting in irreversible deactivation of the ligand’s retention […]

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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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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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Taurine with HPLC & Refractive Index – AppNote

Retention of Highly Polar Compound The food and beverage industry may need reliable methods for assay for Taurine in their products. However, its analysis is complicated by the lack of chromophores in its structure. LC-MS can be used instead, but many QC labs may not have this instrumentation or might prefer a more simple detection […]

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Method Transfer for Cyclobenzaprine – AppNote

Increased Efficiency: 4 μm to 2.2 μm The two chromatograms compare the retention and efficiency of a Cyclobenzaprine peak using two types of Cogent Diamond Hydride Columns. Figure A uses a near-UHPLC 2.2 µm phase while Figure B uses a standard 4 µm particle size column. The results show consistent retention between the two phases […]

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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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Histamine in Cheese Analyzed by LCMS – AppNote

No Derivatization Required for this Analysis of Histamine A small but measurable amount of Histamine was found in a Cheese sample (Figure A) after an extraction procedure and analysis using the Cogent Diamond Hydride Column with MS detection. Two spiked Cheese samples were also analyzed. In Figure B, the Cheese sample was spiked before the […]

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Warfarin, Hydroxybupropion, and Codeine by LCMS – AppNote

Analysis in Spiked Blood Samples In this application, three pharmaceuticals/metabolites are separated using the Cogent Diol 2.o Column. The blood sample illustrates the suitability of the Column for analysis of more complex matrices. Use of Acetone in the Mobile Phase was found to be appropriate for this LC-MS method. As a less expensive and less […]

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LSD and Codeine – AppNote

LCMS Method for Spiked Urine Sample LSD and codeine may be present in Urine samples and methods are needed for their detection in these matrices. The extracted Ion Chromatograms (EICs) for both analytes are shown in the figure and illustrate excellent chromatographic as well as Mass Spectral Separation. The Method in this AppNote produces high […]

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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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Analysis of Thiopurines – AppNote

Separation using LCMS Gradient Method The Cogent Diamond Hydride Column with gradient elution was used for analysis of Thiopurines. Figure A shows the Peak of 6-TG, which also can be analyzed using Isocratic conditions. Good retention and symmetrical peak shape were obtained under the analysis conditions. Figure B represents two separated Thiopurines (Mono and Di- […]

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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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Tizanidine HCl HPLC Method Transferred to Near UHPLC – AppNote

Use of Near UHPLC Column for Improved Results This challenging compound has several amine groups and can be problematic to analyze with HPLC. Here a good peak shape is obtained using the Cogent Diamond Hydride 2.o Column. The efficiency is higher on the 2.2µm phase compared to a standard 4µm Column, leading to increased sensitivity. […]

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Alprazolam (Xanax®) HPLC Method Transferred – AppNote

Benefit of 2.2um Column Analyzing Alprazolam with 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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Vancomycin HPLC Method Transferred – AppNote

Benefits of using 2.2 µm Column for Vancomycin Analysis The highly polar antibiotic Vancomycin can be readily analyzed with either the standard 4µm Cogent Diamond Hydride or the Cogent Diamond Hydride 2.o Column. Notably higher efficiency is obtained on the smaller particle size Column. This Method is easy to perform and is LCMS compatible. Three […]

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Human Plasma Extract Analyzed by LCMS – AppNote

 Urea, Lactodifucotetraose, Trimethylamine, L-carnitine & Choline Using this Method it is possible to analyze Compounds present in a Human Plasma Samples. The mechanism of retention of these polar compounds on the Column used is unknown at this time. It is possible to Retain and Separate steroids and other Compounds based on the Shape of the […]

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Phosphorylated Sugars Analyzed by LCMS – AppNote

Sucrose-6-phosphate, Glucose-6-phosphate, & Trehalose-6-phosphate Central Metabolic Intermediates in Plants Sugar Phosphates are very highly polar Metabolites and may be difficult to retain using traditional Reversed Phase Methods. In addition, S6P and T6P are Isobaric Compounds so it is very important to separate these two Phosphorylated Sugars for MS Detection. G6P is easily distinguished by its […]

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Uric acid and Metabolites Analyzed by LCMS – AppNote

LCMS Method for Allantoin, 6-Aminouracil, and Uric Acid (UA) The presented method for analysis of UA and its highly polar metabolites is simple and does not require Mobile Phase additives or pre-column derivatization. The Peaks are symmetrical, and the MS signal is not diminished, as is the case when Ammonium Formate or Acetate is used […]

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Milk Extract Analyzed by LCMS – AppNote

Analysis of Composition using LCMS Milk components are polar compounds that are not well retained or resolved by traditional Reversed Phase Chromatography. In addition, many of the compounds do not contain strong chromophores, resulting in low specificity and sensitivity in UV detection. The analysis using the Cogent Diamond Hydride Column and MS detection provides separation […]

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B Vitamins Analysis with HPLC – AppNote

Separation of Five Highly Polar Vitamins The B Vitamins are all highly polar and often ion pair agents are needed in Reverse Phase in order to retain them. However, these agents are incompatible with LCMS and therefore limit the applications of these methods. In this method using the Diamond Hydride Column, good separation is obtained […]

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Uric Acid (UA) Metabolites Analyzed by LCMS – AppNote

Allantoin and 6-Aminouracil The presented method for analysis of UA metabolites in human Urine is very simple and does not require Mobile Phase additives or pre-Column derivatization. The peaks are symmetrical and the MS signal is not diminished as is the case when Ammonium Formate or Acetate is used as the Mobile Phase additive. The […]

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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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Glutathione (GSH) Analyzed by LCMS – AppNote

LCMS Method without Derivatization The major benefit of this analysis method for Glutathione which uses the Cogent Diamond Hydride Column and MS detection is that it is performed without derivatization, unlike other LCMS approaches. A GSH signal of MS is stable after repeated analyses. The unique design of the ESI offers efficient supersoft ionization which […]

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Sorbic and Tartaric Acids in Wine Analyzed by LCMS – AppNote

Minimal Sample Preparation This method doesn’t require complex preparation or extraction of the wine samples. It allows detection of both Acids in a short gradient run, with rapid equilibration of the column after each run. Calibration curves were constructed in the ranges 1–300ppm and 100–3000ppm for Sorbic Acid and Tartaric Acid respectively. Correlation coefficients for […]

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Tropicamide and Homatropine Analyzed with HPLC – AppNote

Separation of Anticholinergic Mydriatic Agents In this Method, Tropicamide and Homatropine are separated with a simple Gradient. Homatropine is significantly hydrophobic yet still retains well. Furthermore, the Separation between these two solutes is good, illustrating the Selectivity capabilities of this Method. Data is shown for two lots of Columns in order to demonstrate the robustness […]

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Terbutaline and Salbutamol Analyzed with HPLC – AppNote

Separation of ß2-Adrenergic Receptor Agonists This Method shows how two structurally similar compounds can be readily separated. This is an important characteristic in many types of HPLC Methods since typical separations often involve impurities, degradants, metabolites, and other groups of compounds that have subtle structural differences. These two compounds for instance were found to coelute […]

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Ranitidine Tablet Analyzed with HPLC – AppNote

Excellent Peak Shape of API From an OTC Tablet Ranitidine has several amine functional groups that can contribute to significant tailing with Reversed Phase Methods. Data shown below uses an extract from a tablet formulation, illustrating how good Peak shape can be obtained. In addition, three Column lots were used to demonstrate the robustness and […]

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Oxybenzone and Octinoxate Analyzed with HPLC – AppNote

Separation of Two APIs in Chap Stick® Extract This Method shows how two common ingredients found in sunscreens and lip balms can be separated. The two compounds are very hydrophobic, so a Mobile Phase Gradient with significant organic content was used in order to avoid excessive retention. Likewise, a highly organic diluent should be used […]

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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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Doxycycline Analyzed with HPLC – AppNote

Forced Degradation Method Using Shape Selectivity Doxycycline is known to epimerize at the C4 and C6 positions in acid conditions. Epimers can be difficult to separate in Reversed Phase due to subtle differences in hydrophobicity. However, this Method differentiates based on shape as well as hydrophobicity and is therefore well suited to this Isomer separation. […]

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Glipizide Analyzed with HPLC – AppNote

Separation of API from Acid Degradation Products This Method illustrates the capabilities to separate several Glipizide Degradants that are formed under acidic conditions. Good separation is obtained as well as Sharp, Symmetric Peak shapes for each compound. The Retention times show good repeatability as well, as demonstrated in the Figure overlays. Also, the Mobile Phase […]

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