1,4-Benzodiazepines in Urine Analyzed with ANP – AppNote

1,4-Benzodiazepine compounds from Urine Samples were analyzed successfully after Solid Phase Extraction (SPE). —Four available Compounds (shown below) were well retained and separated. The procedure could be used for determination of this class of compounds in urine samples and other body fluids. Peaks: 1. Temazepam 301.0739 m/z [M+H]+ 2. Diazepam 285.0790 [M+H]+ 3. Nordiazepam 271.0633 […]

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10 Phenolic Acids Analyzed with LCMS – AppNote

Compounds Shown were Extracted from Commercial Rice. Commercial Rice Extract 3 was spiked with ten standards and analyzed. The Cogent Phenyl Hydride Column was an excellent choice to use for analysis of Phenolic Compounds with Reversed Phase HPLC. The Retention and Separation of all nine available standards was possible using the Method below.   Peaks: […]

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3-Hydroxy-3-Methylglutaric acid, HMG in Urine Analyzed with HPLC – AppNote

Important Biomarker for Diabetes and HMG Disorder is well retained with HPLC. A selective, specific, and sensitive HPLC method with LCMS Analysis has been developed for the determination of 3-hydroxy-3-methylglutaric acid (a.k.a. Meglutol) in urine samples. The method can be also used in the analysis of plasma samples after precipitation of plasma proteins with Acetonitrile. […]

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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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4-(Methylamino)butyric Acid Analyzed with HPLC- AppNote

A gamma-Aminobutyric Acid (GABA) Derivative  This challenging polar compound is easily retained in this simple Method where repeatability of the data is excellent with %RSD<0.1 for the Retention Times. Peak: 4-(Methylamino)butyric Acid Method Conditions: Column: Cogent Diamond Hydride™, 4μm, 100Å Catalog No.: 70000-15P-2 Dimensions: 4.6 x 150mm Mobile Phase: —A: DI Water with 0.1% Formic […]

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4’-Aminoacetophenone Analysis with HPLC – AppNote

4’-Aminoacetophenone Retained in Acidic Conditions This Method investigated 4’-Acetaminophenone Retention and Analysis. Adequate Retention and Sensitivity was the result and could be useful in Analysis of the Metabolites of this class of Anti-tumor Agents in body fluids (Plasma or Urine) during or after Chemotherapy. Peak: 4’-Aminoacetophenone Method Conditions Column: Cogent Bidentate C18™, 4μm, 100Å Catalog […]

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5 Phenolic Compounds Separated by LCMS – AppNote

Commercial Rice Extract A commercial rice extract was analyzed and peaks were assigned based on retention times and m/z values for the compounds of interest using the Cogent Phenyl Hydride Column . After method validation the developed procedure can be used to evaluate the quality of rice and to develop the best extraction procedure. Peaks: […]

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Acetaminophen & Impurity Analyzed with HPLC – AppNote

APAP Drug Substance Analysis with HPLC This Method has been developed for determination of Acetaminophen as a Drug Substance. The Separation was achieved on a C18 Column using Gradient Elution. The Method shown here has excellent Reproducibility of Acetaminophen for 5 consecutive Chromatograms shown had 0.03% RSD. This could be used for Quality Control of […]

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Acetaminophen Impurities Method with HPLC – AppNote

Acetaminophen – Alternate USP Method Acetaminophen and two of its major impurities were analyzed using a simple Mobile Phase. The Peak Shapes are very good and the Repeatability was good (%RSD = 0.01). Peaks: 1. 4-Aminophenol 1.072 minutes 2. Acetaminophen 4.668 minutes 3. 4-nitrophenol 7.588 minutes Method Conditions: Column: Cogent Bidentate C18™, 4µm, 100Å Catalog […]

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Acetone as the Organic Mobile Phase Component – AppNote

“Green” Substitute for Acetonitrile in LCMS Method of 17 Amino Acids Acetone has a high UV absorbance “cutoff” and therefore is generally unsuitable for HPLC with UV Detection. However, this is not a problem when using LCMS or Evaporative Light Scattering Detectors (ELSD) such as the Shimadzu Prominence or the Corona CAD. Acetone can be […]

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Acetyl-L-Carnitine in Plasma Analyzed with LCMS – AppNote

Spiked Plasma Samples with Acetyl-L-Carnitine The Method in this Application Note was designed to be suitable for the routine analysis of Plasma Samples obtained from animal and human Pharmacokinetic studies in which Acetyl-L-Carnitine (ALC) is administered. The calibration curve prepared for the Plasma Samples showed good Linearity (R2 = 0.999) and the Precision was good […]

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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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Advantage of Using Cogent TYPE-C Columns for Drugs of Abuse – Extended AppNote

Heroin, MDMA, Morphine, Hydromorphone and 6-MAM Analyzed with LCMS Analysis of Drugs of Abuse encompasses a wide variety of compounds, including controlled substances, prescription drugs, and even over-the-counter formulations. These drugs can be problematic to analyze due to several problems. First, many have similar structures (e.g. morphine and hydromorphone), making adequate selectivity difficult to obtain […]

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Aegeline in Protein Sport Mix – AppNote

LC-MS analysis of harmful substance in food supplement The data demonstrates the use of the Cogent Bidentate C18 2.o™ Column for analysis of dietary supplement samples. Isolation of the Aegeline peak is readily obtained with an extracted ion chromatogram (EIC) in the positive ion mode. Chromatographically, the peak is well retained and highly symmetrical. The […]

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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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Alprazolam Analyzed with HPLC – AppNote

Robust Separation of API from USP Internal Standard The USP Assay Method for Alprazolam uses a bare Silica Column and a complex Mobile Phase consisting of Acetonitrile, Chloroform, Butyl Alcohol, and Acetic Acid. In this Method, a simple LCMS compatible Mobile Phase is used and produces excellent Peak shapes for both the API and its […]

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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 Analyzed Orthogonally with HPLC – AppNote

Orthogonal Analysis to USP Assay Method for Validation The USP Assay Method for the antibiotic Amoxicillin is performed in Reversed Phase. Analysis by an Orthogonal Retention mode is very useful and can be readily done by Aqueous Normal Phase (ANP) mode of HPLC, using solvents common to both. A benefit of this Method is the […]

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Amoxicillin USP Assay with HPLC – AppNote

Alternate L1 Column used for the USP Assay Method for Amoxicillin This USP Amoxicillin Assay is performed and a five injection overlay shows Run to Run consistency and Precision. The Peak Efficiency is very good and Peak Tailing guidelines are easily met with RSD values less than 0.3%. This demonstrates a good alternate Column for […]

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Amoxicillin, USP Method with HPLC – AppNote

Robust Analysis of Amoxicillin, Antibiotic with HPLC The USP Assay Monograph 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 […]

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Analysis of Alpha and Beta-Acids in Hops with HPLC – AppNote

Robust, Precise Method for Beer Analysis with HPLC The effectiveness of this Method is evident from the fact that data obtained were in a good agreement with the literature values. This Method also has the added bonus of good Precision (%RSD =0.1 and below). Calibration Curves for Alpha and Beta Acids in Beer showed good […]

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Analysis of Clopidogrel with LCMS – AppNote

Analysis of the API and Degradants A Sensitive, Selective, and rapid LCMS Method was developed for the simultaneous Quantification of Clopidogrel (Plavix®) and degradants. This Method can be used for the determination of Clopidogrel in commercial tablets for Quality Control with an application for content uniformity test. The Method is also stability-indicating as it is […]

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Analysis of Harmful Substances in Dietary Supplements – Extended AppNote

Dietary Supplements have had, in notable cases, ingredients added to them that have been implicated in serious health issues and even death. Two such pernicious compounds are Aegeline and 1,3-Dimethylamylamine. These two can be readily separated from the dietary supplement matrix using the Cogent Bidentate C18 2.o™   and Cogent Diamond Hydride™ Columns by LCMS […]

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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 Litchi Seed Extracts – Extended AppNote

Hypoglycin A and Methylenecyclopropylglycine are two compounds found in the extract of Litchi Seeds that studies have shown to be toxic. Methylenecyclopropylglycine inhibits the synthesis of fatty acids from Glucose, and therefore undernourished children are more at risk since their Glucose reserves are low. This study used LCMS with a Cogent Diamond Hydride™ Column to […]

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Analysis of MDMA in Plasma Samples with LCMS – AppNote

Methylenedioxymethamphetamine Analyzed 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 GCMS Detection [1]. Matrix effects were of minor extent and reproducible and hence should not compromise Quantification. The Method can be used for Forensic […]

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Analysis of Nucleotides – AppNote

ATP & AMP Separated in Aqueous Normal Phase (ANP) The chromatogram below shows an example of the separation possible with this Method for three Adenosine analytes using an Aqueous Normal Phase (ANP) Gradient. Peaks: 1. Adenosine-3’,5’-Cyclic Monophosphate 2. Adenosine 5’-Monophosphate (AMP) 3. Adenosine 5’-Triphosphate (ATP) Method Conditions Column: Cogent Diamond Hydride™, 4μm, 100Å Catalog No.: […]

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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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Anatoxin-a, ANTX-A Analyzed with LCMS – AppNote

Potent Neurotoxin Analyzed without Derivatization Anatoxin-a or ANTX-A is a low molecular weight compound with a secondary amine which can be difficult to retain with most Reversed Phase HPLC Columns. This Application Note illustrates a very simple Method for Retention of Anatoxin-a which does not require pre-Column or post Column Derivatization as with other Methods. […]

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Antibiotic Keflex Analyzed with 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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Application Notes – AppNotes Listed by Compound

This list of links to Application Notes on this Site, showcase Methods of Separation for each of the compounds below and the Cogent Column used.  Not all of our Application Notes are listed below and to find other Applications, call our Customer Service Department at 1-732-380-8912 between 9-5 EST or use our Click To Chat […]

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Arginine, Lysine and Histidine Analyzed with LCMS – AppNote

Basic Amino Acids In Synthetic or Human Urine Can be Analyzed A “Cleanup” procedure for the isolation of the Basic Amino Acids in Urine was developed in this Method and no derivatization procedure was used. Three Basic Amino Acids were Separated using an inverse gradient or Aqueous Normal Phase (ANP) Chromatography. The advantages of this […]

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Aspartic Acid & Arginine Analyzed with LCMS- AppNote

Reduced Sample Prep and Handling Two amino acids are adequately Retained and can be easily quantified in this Method with very little Sample Prep. There is no need for any Pre-Column or Post Column derivatizing due to Mass Spectrometric Detection can detect these molecules and Aqueous Normal Phase (ANP) HPLC can Retain in their ionized […]

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Aspirin & Salicylic Acid Analyzed with HPLC- AppNote

Excellent Peak Shape For a Very Difficult Compound This Method is easy to prepare, use, reproduce and a good Separation of Aspirin from its major hydrolysis product, Salicylic Acid is achieved. Peaks: 1. System Peak 2. Aspirin (Acetylsalicylic Acid) 3. Salicylic Acid Method Conditions Column: Cogent Bidentate C18™, 4μm, 100Å Catalog No.: 40018-75P Dimensions: 4.6 x […]

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Asymmetric Dimethylarginine ADMA – AppNote

LCMS Method with Plasma Samples ADMA has a very narrow concentration distribution in the general population. For this reason, the method of analysis of this compound in body fluids (Plasma, Urine) should have a very high precision and accuracy to generate clinically useful results. The analysis of ADMA in Plasma Samples shown in the figure […]

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Atenolol Tablet Analyzed with HPLC – AppNote

Quick Analysis without Ion Pair Agents The USP Assay Method for Atenolol uses Heptane Sulfonate and Dibutyl Amine in the Mobile Phase, which are slow to load and remove from a Reversed Phase HPLC Column. These reagents are added to improve the Peak Tailing, which must be not more than 2.0. The Method in this […]

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Atorvastatin Drug Product Analyzed with HPLC

API Well Separated from Degradation Product Using this Simple Linear Gradient, Atorvastatin is well separated from its main degradation Product. The degradant is formed under acidic conditions and therefore its Separation is important for Stability Indicating Methods for pharmaceutical formulations of Atorvastatin. For Methods requiring non-degrading conditions, it is important to choose diluent and Mobile […]

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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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ATP, UDP-Glucose UDP-Galactose Separation from Red Blood Cells – AppNote

Separation of Nucleotides  In this application, we present an easy-to-use protocol for sensitive detection and quantification of nucleotides in red blood cell extracts.  Retention times were very reproducible with %RSD around 0.4. The desired separation between UDP-Glu and UDP-Gal was achieved, all other nucleotides eluted later and did not interfere with the analysis. ATP represents […]

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Atropine Analyzed with a Gradient Method – AppNote

No Ion Pair Reagent Necessary Chromatographic separation and quantification methods of Atropa Alkaloids are often described in the literature and the method of choice is usually Ion-Pair Chromatography (IPC), which requires long equilibration times and it is not very robust. This method shows a symmetrical peak for Atropine using a simple Gradient Method that does […]

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Avoid Sample Cleanup for Food and Beverages – Extended AppNote

3 Methods to Avoid Sample Cleanup with Histamine, Limonin & Folic Acid Food and beverage analysis is complicated by the complex nature of the sample. In many cases, extensive sample cleanup techniques such as Solid Phase Extraction (SPE) may be required to avoid problems associated with the sample matrix. In this Application Note, three strategies […]

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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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Baclofen Analyzed with 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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Barbiturates Analyzed with LCMS – AppNote

Standard Solutions in Human Urine Spiked with Barbiturates After minimal sample preparation (dilute-and-shoot approach), spiked urine samples were analyzed using a C18 Column. The analysis was based on a Separation of Standards [1]. The obtained Peaks were Symmetrical (As<1.05) and Efficient (> 106 pl/m). No shift in retention Times was observed after the samples were diluted […]

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Basic Compound Adsorption Study with Time Dependence in Vials – AppNote

Comparing Cetylpyridinium Chloride Adsorption in Glass Autosampler Vials This Study investigated the effect of Analyte loss due to Adsorption by hydroxyl groups (aka Silanols) on the glass surface of Autosampler Vials over Time. It is well known that the surface of standard, including industry leading Borosilicate Glass Vials are populated with Silanols and Basic Analytes […]

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Basic Compound Concentration and Adsorption Study in Autosampler Vials – AppNote

Comparing Cetylpyridinium Chloride Adsorption on RSA Glass v. Standard Autosampler Vials In this study, the importance of Analyte Concentration is demonstrated when dealing with Adsorption during analyses of Basic Solutes. Using conventional glass of an industry leading supplier, the basic test analyte Cetylpyridinium Chloride showed notable loss to Adsorption with the Vial at the lower […]

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