Tazobactam USP Assay with HPLC – AppNote

Alternate L1 Column used for the USP Assay Method of Tazobactam This USP Tazobactam Assay is easily performed and the five injection overlay below demonstrates Run to Run consistency and Precision. The Peak Efficiency is very good and Peak Tailing guidelines are easily met with RSD values well below 2.0%. This demonstrates a good alternate […]

Read More

Memantine HCL Analyzed by ELSD- AppNote

An NMDA Receptor Antagonist for Alzheimer’s Disease This simple isocratic Method requires no use of derivatization or other additives for keeping the peak shape of this Tricyclic Amine symmetrical.  This Method displays excellent Repeatability of the data with %RSD values of <0.12 for the Retention Times. Peak: 1. Diluent 2. Memantine HCL Method Conditions: Column: […]

Read More

Ifosfamide Assay with HPLC- AppNote

A Reliable Assay for Detection of a Chemotherapeutic   This simple Isocratic Method may be used to quantitate this important drug.  The Method maintains consistent and reliable results as the Peak values were measured for week-long intervals.  The %RSD for Retention Times for both standards and sample were less than 0.7%. Peak: Ifosfamide Method Conditions: […]

Read More

Fluorouracil Assay with HPLC- AppNote

A Reliable Assay for Detection of a Chemotherapeutic   This simple Isocratic Method may be used to quantitate this important drug.  The Method maintains consistent and reliable results as the Peak values were measured for week-long intervals.  The %RSD for Retention Times for both standards and sample were less than 0.07%. Peak: Fluorouracil Method Conditions: […]

Read More

Gemcitabine Assay with HPLC- AppNote

A Reliable Assay for Detection of a Chemotherapeutic   This simple Isocratic Method may be used to quantitate this important drug.  The Method maintains consistent and reliable results as the Peak values were measured for week-long intervals.  The %RSD for Retention Times for both standards and sample were less than 0.3%.   Peak: Gemcitabine Method […]

Read More

Desloratadine Assay with HPLC – AppNote

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

Read More

Fluphenazine HCl USP Tablet Assay with HPLC – AppNote

Alternate L7 Column used for the USP Assay Method of Fluphenazine HCl Tablets This USP Fluphenazine HCl Tablet Assay is easily performed and the five injection overlay below demonstrates Run to Run consistency and Precision. The Peak Efficiency is very good and Peak Tailing guidelines are easily met with RSD values of 0.2%. This demonstrates […]

Read More

Hydrocortisone USP Assay with HPLC – AppNote

Alternate L1 Column used for the USP Assay Method of Hydrocortisone This USP Hydrocortisone Assay is easily performed and the five injection overlay below demonstrates Run to Run consistency and Precision. The Peak Efficiency is very good and Peak Tailing guidelines are easily met with RSD values of 0.5%. This demonstrates a good alternate Column […]

Read More

RSA-Pro X Improves Quantitation Precision with HPLC – AppNote

RSA-Pro X™ – Hydrolytically Stable Glass Vials & Low Volume Glass Inserts Silanol groups (Si-OH) on the surface of glass has been known to cause not only empirical quantitative loss but also inaccurate quantitation, vial to vial and run to run over time.  Silanol sites are very reactive and can produce among other things, imprecise […]

Read More

Does the HSQ Kit Qualify Quaternary HPLC Pumps? – FAQ

Yes, the HSQ Kit™ will work on many types of pumps; from single, binary, and also quaternary pumps.  For Gradient Qualification Tests, the base method is called “GRDAB” for “Gradient, pump A/B*”, where the “*” designates that the B fluid circuit is “visualized” with the addition of the Gradient Visualization Solution (GVS). For ternary or […]

Read More

Lipophilic Peptides Analyzed with HPLC – AppNote

Simple Gradient for Non-Polar Peptides  In this Method, we demonstrate the Retention of several Hydrophobic Peptides without the use of a typical Reversed Phase Column. Peak: 1. Gly-Tyr ( Glycyl-L-tyrosine ) 2. Val-Tyr-Val ( Valyltyrosylvaline ) 3. Met enkephalin ( Metenkefalin ) 4. Leu enkephalin 5. Angiotensin II Method Conditions: Column: Cogent Diamond Hydride™, 4μm, […]

Read More

Cytarabine Assay with HPLC- AppNote

A Reliable Assay for Detection of a Chemotherapeutic   Cytarabine belongs to the category of chemotherapy called antimetabolites. Antimetabolites are very similar to normal substances within the cell. When these substances are incorporated into the cellular metabolism, they are unable to divide. Antimetabolites are cell-cycle specific and target cells at very specific phases in the […]

Read More

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 […]

Read More

Retention of a Polypeptide Analyzed with HPLC- AppNote

Semaglutide, a Human Glucagon-like Peptide This simple isocratic Method demonstrates good Retention of a Hydrophilic Peptide where Retention is increased in Aqueous conditions.   Peak: Semaglutide Method Conditions: Column: Cogent Diamond Hydride™, 4μm, 100Å. Catalog No.: 70000-75 Dimensions: 4.6 x 75mm Mobile Phase: 60:30 DI Water with 0.1% Formic Acid / Acetonitrile. Injection vol.: 1µL […]

Read More

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 […]

Read More

Sulfonamide Antibiotics Analyzed with HPLC- AppNote

Everyday Reliable & Precise Method This Method offers great Resolution of a mixture of four Sulfa drugs.  These Antibiotics are commonly used in both veterinary medicine and also employed to fight disease in honey bees.  The importance of quantification is vital, as residues are often found in honey samples and are of concern to customers […]

Read More

Triton X-100 Assay with HPLC- AppNote

A Sensitive Assay for Detection of a Non-ionic Surfactant  Triton X-100 is used in the sample purification steps of various materials as well as for cleaning apparatus in pharmaceutical manufacturing.  Due to the toxic nature of Triton X-100, a sensitive method for its detection and quantification is very important to identify any residual amounts. This simple […]

Read More

Moxifloxacin Hydrochloride Analyzed with HPLC – AppNote

Simple and Precise Retention of a Polar Antibiotic  Moxifloxacin Hydrochloride requires the addition of buffers as well as ion pair reagents to aid in retention on regular Reversed Phase Columns per the current USP Method. In this simple isocratic Method, we retain this polar compound with good Run-to-Run Precision.  (%RSD = 0.22, SD below 0.004.)  This […]

Read More

Tetracycline USP Assay with HPLC- AppNote

USP Method for Tetracycline This USP Tetracycline 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 0.4%. This demonstrates a good Alternate Column for your USP Method.   Peak: Tetracycline Method Conditions: […]

Read More

Topiramate, Retention of a Sulfonate Drug by LCMS – AppNote

Retention of the Sulfonate Drug Topiramate The structure of Topiramate leads us to think due to the Amino group and negative Log P value of -0.8, it will not be retained in Reversed Phase HPLC. However, in this Method, the compound is well retained. Peak: Topiramate 340.1062 m/z (M + H)+ Method Conditions: Column: Cogent […]

Read More

Dexamethasone and Prednisone Assay with HPLC- AppNote

Analysis of Corticosteroids This simple isocratic Method demonstrates good separation of two similar synthetic Glucocorticoids.  This analysis for corticosteroids may serve well for quantitation in pharmaceutical preparations.  This Method would easily translate to LCMS. Peak: 1. Prednisone 2. Dexamethasone  Method Conditions: Column: Cogent Bidentate C18™, 4µm, 100Å Catalog No.: 40018-75 Dimensions: 4.6 x 75mm Mobile […]

Read More

Felodipine Extended-Release Tablets USP Assay – AppNote

USP Method for Felodipine ER Tablets This method presents the USP Felodipine Extended-Release Tablet assay using the Cogent RP C18. As shown in the chromatogram with a five injection overlay, the peak efficiency is superb and USP peak tailing guidelines are easily met with the Cogent RP C18™ column.  This demonstrates a great alternative Column […]

Read More

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 […]

Read More

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 […]

Read More

Dimethylolpropionic Acid – AppNote

Hydrophilic acid retention on the Cogent Diamond Hydride™  Dimethylolpropionic Acid is a unique diol molecule with both hydroxyl and carboxyl functionality and presents several challenges in chromatographic analysis. Traditional reversed phase mode may not be viable due to the high hydrophilicity of this organic acid. Also, by lacking chromophores it can be difficult to detect […]

Read More

Analysis of a Local Anesthetic Lidocaine, Aminoethylamide – AppNote

Method Development for a Local Anesthetic (A Case Study) An analyst was using a Cogent Diamond Hydride™ Column for evaluating Lidocaine methods and although they had good retention of the compound, they did not meet the required 0.3 – 0.5 AU when 0.1 mg/mL Lidocaine sample was injected for both 2μL and 10μL injection volumes. […]

Read More

Psychoactive Compounds Analysis in Cannabinoids – AppNote

Cannabinoid Separation Method Due to the number of expanding products of homeopathic extracts from Hemp, there is an equally increasing necessity to accurately analyze and separate the numerous compounds from these natural samples. While Cannabidiol has been extracted for multiple natural remedies, there is also numerous unwanted psychoactive constituents and related compounds that may also […]

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

Ketorolac Separation with LCMS – AppNote

Analgesic agent There is a need for analysis of the Active Pharmaceutical Ingredient (API) in Ketorolac Tablet formulations in order to evaluate two different extraction protocols. The use of Ethanol as the extraction solvent was explored initially but DI Water was observed to produce superior extraction efficiency. The chromatograms show how the compound can be […]

Read More

Nitrofurantoin Capsule Analyzed with HPLC – AppNote

Isocratic Separation of API from USP internal standard The USP assay method for the active pharmaceutical ingredient (API) found in Nitrofurantoin Capsules, uses a Phosphate Buffer and is not compatible with Mass Spectrometry. In this AppNote, using the Cogent Bidentate C18 Column, Formic Acid is used as the Mobile Phase additive, as such, the method […]

Read More

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, […]

Read More

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 […]

Read More

Resveratrol Capsule – AppNote

Isocratic Separation of Isomers In this easy isocratic method, the cis and trans isomers of Resveratrol are separated using a near-UHPLC stationary phase. The Cogent Bidentate C18 2.o™ Column produces excellent efficiency for both analyte peaks. The sample used here is an actual capsule formulation, demonstrating the suitability of the column for real-world samples. With […]

Read More

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: […]

Read More

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 […]

Read More

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: […]

Read More

Doxycycline and Methacycline Analyzed with HPLC – AppNote

Simple Isocratic Method for API and Main Impurity Formulations of Doxycycline may contain a Methacycline Impurity.  As such, it is crucial for analytical methods to be able to separate these two peaks. Using this simple isocratic Method, the baseline resolution is obtained for this pair. Peaks: 1. Methacycline 2. Doxycycline * Impurities in doxycycline standard […]

Read More

Peonidin-3-Glucoside Analyzed by LCMS – AppNote

LC-MS method for Anthocyanin- Fruit or Vegetable Extracts In this analysis, the presence of Peonidin-3-O–Glucoside was confirmed in two out of four extracts. The peaks were symmetrical and retained beyond the dead volume. Due to the MS detection and comparison of the retention time, it was possible to find the peak for Peonidin-3-O-Glucoside among many […]

Read More

Glycosidic Flavonoids Analyzed with HPLC – AppNote

Separation of Diosmin, Eriocitrin, and Naringin In this method, three Glycosidic flavonoid standards are separated with good resolution. The Cogent Bidentate C18 2.o™ Column produces high efficiency peaks with reproducible retention (see figure overlay). Separation is also observed for a small impurity peak, eluting between peaks 1 and 2. This separation of standards could be […]

Read More

Limonin in Orange Juice Analyzed by LC-MS – AppNote

Separation from Matrix Peaks with Reproducible Results Analysis of Limonin in Spiked Orange Juice was performed using a simple isocratic method with MS detection. Analysis at 471.2 m/z allowed for detection of only the Limonin peak without interference of the juice matrix. When the Filtered, Unspiked Orange Juice was injected, a small peak for Limonin […]

Read More

Oral OTC Anesthetic Analyzed with HPLC – AppNote

Isocratic HPLC Method for Phenol in Oral OTC Products This Method shows how an assay of Phenol can be readily performed with a simple isocratic Mobile Phase. Phenol is the active ingredient in this common Over-The-Counter oral spray solution, which is intended for treatment of sore throat. A number of inactive ingredients are present in […]

Read More

Docusate Sodium Analyzed with HPLC – AppNote

A Simple Gradient with Good Separation    The official USP assay method for Docusate Sodium tablets calls for a Mobile Phase of 50% 7mM Ammonium Acetate / 50% Acetonitrile at 40°C. However, retention for the API and the System Suitability compound Methyl Paraben were found to be low using these conditions. This Method not only […]

Read More

Hydroxytryptophan (5-HTP) Analyzed with HPLC- AppNote

Separation from Vitamin B6 Pyridoxine (Vitamin B6) is often added to formulations of 5-Hydroxytryptophan (5-HTP), as it assists in the conversion of 5- HTP to Serotonin. Therefore, it is of interest to separate these two compounds for an HPLC assay Method of this combination formulation. The Method shown provides good resolution between the two peaks […]

Read More

Doxylamine Succinate Tablet Analyzed with HPLC – AppNote

Shorter Run Time than USP Method The USP Assay Method for Doxylamine Succinate tablets uses Triethylamine and Sodium Lauryl Sulfate in the Mobile Phase. These reagents are slow to fully load onto the Column, resulting in long run times and poor Robustness. This Method uses Trifluoroacetic Acid to get an excellent Peak Shape. An overlay […]

Read More

Ketotifen Analyzed with HPLC – AppNote

API with a Tertiary Amine can have a Great Peak Shape The tertiary amine group of Ketotifen makes it a challenging compound to analyze in HPLC.  In addition to good peak shape for this API, another peak can be identified which is baseline resolved from the main peak of interest. This Method is suitable for […]

Read More

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 […]

Read More

Nucleoside Analogs Analyzed with HPLC – AppNote

Polar and Non-Polar Anticancer Prodrugs Analyzed in the Same Run In this Method, we display Retention of both polar and nonpolar compounds in a simple Isocratic run. Adjustment of the aqueous to organic ratio can be used to make either the polar or more hydrophobic compounds elute first. In the example presented, the more hydrophobic […]

Read More

Quinine Sulfate and Impurity Analysis with HPLC – AppNote

API Separation from Impurity without Ion-Pair Reagents The USP Method for Quinine Sulfate requires a Resolution of not less than 1.2 from its main impurity, Dihydroquinine. In the USP Method, the ion pair agents Methanesulfonic Acid and Diethylamine are used in the Mobile Phase. Ion pair agents are often needed to reduce peak tailing of […]

Read More