Domoic Acid Analyzed by LCMS – AppNote

Determination without Derivatization To date, 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. […]

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Domoic Acid in Seafood Samples Analyzed by LCMS – AppNote

Domoic Acid (DA) From Seafood Without Derivatization Several Seafood and Plankton samples were tested for Domoic Acid (DA) which, as a highly polar compound, is poorly Retained on most Reversed Phase Columns. This developed Method based on HPLC and MS detection does not require derivatization of Domoic Acid. The concentration of this potent toxin varied […]

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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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Domoic Acid, Amino Acids, & Ornithine Analyzed with LCMS – AppNote

LC-MS Analysis without Analyte Derivatization The potent toxin, Domoic Acid is a highly polar compound which is poorly retained on most Reversed Phase Columns. In this Method , not only was Domoic Acid well Retained but also two isobaric compounds (L-Asparagine and Ornithine) were Retained and Separated. In addition, the Peak obtained for Aspartic Acid […]

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Doxapram HCL Analyzed with HPLC – AppNote

Easy, Rapid Isocratic Assay of A Polar Compound Automating a Method is a distinct advantage over the official USP Method for Doxapram which is by Titration. Not only will this Method save time and money, but will reduce errors. Simple to perform, the Mobile Phase can be quickly prepared without errors. A highly Symmetrical Peak […]

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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 […]

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Effexor Capsule Analyzed with HPLC- AppNote

Reducing Tailing for Venlafaxine with HPLC The USP assay Method for Venlafaxine capsules uses Triethylamine and Phosphoric Acid in the Mobile Phase, both of which are incompatible with LC-MS. The system suitability for Venlafaxine tailing factor is 2.0, indicating the compound has a tendency for tailing. Here a sharp symmetrical peak is observed using Formic […]

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Efficiency of ANP Measured – AppNote

Aqueous Normal Phase (ANP) Efficiency Measured with Sorbitol, Glucose & Uracil Figure A is an excerpt from a study that investigated analyses of Glucose and Sorbitol on TYPE-C Silica based HPLC Columns and found that the efficiency of ANP is better than observed with HILIC. A Cogent Diamond Hydride Column (2.1 x 150mm with a […]

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Ethambutol Analyzed with LCMS- AppNote

Retention of Hydrophilic Analyte in a Drug Product Click HERE for Column Ordering Information. When Ethambutol is analyzed on many C18 Columns, it strongly interacts with residual Silanol groups in the Stationary Phase. These interactions normally cause excessive Retention and severe Peak broadening. In this LCMS Method, Formic Acid is all that is required for […]

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Ethanolamine Analyzed with LCMS – AppNote

Retention & Analysis of Hydrophilic, Ethanolamine from Plasma In this Application Note, the Chromatograms show Ethanolamine sufficiently retained using either the Gradient or Isocratic Methods. The advantages of using these Methods are fast equilibration between runs when Gradient analysis is required and due to the high organic content of the Mobile Phase, the Ionization efficiency […]

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Famotidine Tablet Analyzed with HPLC – AppNote

API Separation from Matrix Component This Method for Analysis of Famotidine Tablets is easy to perform and produces a Symmetrical Peak Shape for the API. This compound has numerous amines which can be problematic in terms of Peak Shape with conventional Columns. Separation from a component from the tablet extract matrix is obtained as well, […]

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Fenfluramine & Phentermine Analyzed with HPLC – AppNote

Assay for Anti-Obesity Combination Capsule & Tablet This Application  Note illustrates Separation of similar compounds in the Phenethylamine class of compounds; Fenfluramine & Phentermine. These two compounds in particular were once used as APIs in the same formulation. The data shows how these Phenethylamines can be easily Retained and Separated with an Isocratic Mobile Phase […]

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Fluconazole Tablet Analyzed with HPLC – AppNote

Assay Method for Amine Containing API This Application Note shows a simple Gradient Method for Assay of Fluconazole Tablets. In Reversed Phase HPLC, notable tailing was observed due to the two heterocyclic amine groups. Use of Aqueous Normal Phase (ANP) HPLC produced a sharp Peak for this API. Data from three different Column lots is […]

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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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Fluoxetine Orthogonal Assay Method – AppNote

Simple Methods Without the Use of Ion-Pairing Agents Unlike the USP assay method, Ion Pair Agents are not needed in this application. Both figures show how good Peak symmetry can be achieved either in the Reversed Phase (RP, Figure A) or Aqueous Normal Phase (ANP, Figure B) mode with only Formic Acid as the Mobile […]

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Folic Acid Analyzed by LCMS – AppNote

Minimized Sample Prep & Increased Sensitivity for Vitamin B9 A sensitive and reliable Method was developed for the determination of Folic Acid (FA) and can be used in many applications including complex sample matrices without the Solid-Phase Extraction clean up. Since the method uses LC-MS (negative-ion) it provides sensitivity as well as great selectivity. The […]

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Folic Acid Content in Fortified Cereals Analysis with HPLC – AppNote

Online Cleanup of Sample or Matrix Components This application note demonstrates an effective means of separating and resolving Folic Acid from undesired matrix components in cereal extracts without the use of SPE or other sample cleanup techniques. SPE is normally performed to remove compounds from the matrix which would co-elute with Folic Acid before injection […]

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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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Gabapentin Drug Product Analysis by LCMS – AppNote

Isocratic Retention with LCMS Gabapentin was retained successfully with a very symmetrical peak. Two different Mobile Phases were used and the advantage of the Mobile Phase used in Figure A is shown to be that Isopropanol present in the solvent A helps clean the Column which can be useful if biological samples containing lipids are […]

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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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Galactose-1-Phosphate Analyzed with LCMS – AppNote

Potential Clinical Screening Method for Galactosemia This Method is useful as a quantitative screening or routine clinical test to detect infants suspected of having a defect of Galactose Metabolism. It can also be used to monitor blood levels of Galactose-1-Phosphate in children with Galactosemia who are on a lactose-free diet. Peak: Galactose-1-phosphate, 259.0224 m/z (M-H)– […]

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Glutamine and Lysine Analyzed by LCMS – AppNote

Two Isobaric Amino Acid as Biomarkers Found in Saliva The Chromatogram below shows an interesting aspect of analyzing real patient samples for a pair of metabolites: Glutamine and Lysine. Figure A represents 7 samples taken from patients with cancer; Figure C shows injections of samples from 7 patients with pancreatitis while Figure B represents 7 […]

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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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Glyburide and Metformin Analyzed with HPLC – AppNote

Separation of “Highly Polar” and “Non-Polar” Compounds in one Isocratic run In this Method, the polar compound, Metformin, and the nonpolar compound Glyburide, can be retained on the same Stationary Phase (see A & B). Depending on the Mobile Phase composition either Metformin or Glyburide can be retained longer. Method Conditions Column: Cogent Bidentate C18™, […]

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Glycolic Acid Analyzed with HPLC – AppNote

Analysis in Urine Samples An enzymatic Method is widely used for the determinations of Glycolic Acid in various products, but it suffers from instability and very high cost of the enzyme (Glycolate Oxidase). The LCMS analysis presented here is rapid, simple, selective, and suitable for routine analyses of urine samples. It offers numerous advantages including […]

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Glycosidic Analyzed with LCMS – AppNote

Cyanidine-3-Hexoside, Luteolin 7-O-Glucoside & Malvidin Dihexoside Click HERE for Column Ordering Information. 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 […]

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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 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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Histamine Analyzed with HPLC – AppNote

LCMS Compatible Method for the Separation of Histamine As a Heterocyclic primary amine, Histamine is a very polar compound and is difficult to retain on a Reversed Phase Column. This Method provides adequate Retention and a symmetrical Peak shape for this challenging compound without the use of ion pairing reagents in the Mobile Phase. The […]

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Histamine and Methylhistamine Analyzed with LCMS – AppNote

No Derivatization Required for Detection or Retention with this Method Various Assay Methods for Histamine (HA) and / or its metabolite, Methylhistamine (MHA), in biological samples, have been developed. However, most of them require post-Column (for detection purposes) or pre-Column (to achieve retention) Derivatization. The Method in this Application Note provides Separation and Detection of […]

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Histamine Content in Red Wine Using IPA – AppNote

Use Isopropyl Alcohol for Improved Peak Shape of Histamine  This Method for Red Wine Analysis is simple, fast, robust and does not require derivatization like many other HPLC Methods.  When Isopropanol (IPA) was not used in the A Solvent, the Histamine Peak was highly Symmetrical in the standard (Compare Figure C and D) but distorted […]

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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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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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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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Hydromorphone Tablet Analyzed with HPLC – AppNote

Alternative to USP Method for this Opioid The USP Method for Hydromorphone Tablet Assay calls for the use of Sodium Dodecyl Sulfate (SDS) in the Mobile Phase. In addition to not being LCMS compatible, adding it is time consuming to load and unload from the HPLC column. Often the columns are permanently altered and cannot […]

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Hydrophilic Vitamins Analyzed with LCMS – AppNote

Different Mobile Phase for LCMS from a UV Method was Needed Hydrophilic Vitamin analyses were developed using UV detection. However, when the same Method and Mobile Phase was tried with MS Detection, the Peak intensities were very low and Peak Shape for Pyridoxine was not acceptable (see Red Peaks in Figures below). The Mobile Phase […]

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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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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 […]

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Impurities Determination in Metformin HCL Formulation – AppNote

Simple Separation of API from Melamine and Cyanoguanidine A simple Method was developed for the analysis of the widely prescribed anti-diabetic drug Metformin Hydrochloride and for determination of two impurities, Cyanoguanidine and Melamine, in tablet formulations. In addition, to Accurate Mass all three compounds, the Peaks were confirmed by injections of standards. The USP specified […]

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Isobaric Metabolites in Urine Analyzed with LCMS – AppNote

A Simple and Reproducible LCMS Method This Method demonstrates the ability to separate a wide variety of polar metabolites using Mass Spectrometry for detection. When monitoring the EIC at 133 m/z, seven Peaks were positively detected in a Urine sample by comparison with standards or by using accurate mass. Although primarily focused on the analysis […]

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Isotretinoin in Human Plasma Analyzed with LCMS – AppNote

Isocratic, LCMS Method for Isotretinoin in Human Plasma Method development for Isotretinoin was first performed with a Reference Standard, on an HPLC with a Diode Array, UV Detector. The final, Method (Isocratic) was then transferred to an LCMS for analysis of the active ingredient in Human Plasma. The potential matrix effect on the ionization of […]

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Ketoconazole Analyzed with HPLC – AppNote

Lipophilic Ketoconazole Retained using Aqueous Normal Phase HPLC Ketoconazole is a significantly lipophilic molecule (log P ~ 3.8) and is not generally suitable to ordinary Methods based on Hydrophilic Retention (HILIC). However, in this Method it is well retained using Aqueous Normal Phase (Inverse Gradient), therefore it is an Orthogonal Assay Method. This can be […]

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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 […]

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L-a-phenylglycine Antibiotic Analysis with HPLC – AppNote

Comparison using Cogent Silica-C™ and UDC-Cholesterol™ HPLC Columns In this Method, a non-modified, silica-hydride HPLC Column, Cogent Silica-C, produces good Retention of the important amino acid L(+)-α-Phenylglycine with an Isocratic Mobile Phase. In addition the Retention Times are extremely Reproducible (%RSD 0.2). The same Method using a Cogent UDC-Cholesterol Column (UDC), silica-hydride with an 11 […]

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L-Theanine in Green Tea Analyzed with HPLC – Extended AppNote

L-Theanine in Green Tea L-Theanine does not have significant UV absorption, but detection at a low wavelength (200 nm) was found to be suitable. With an expected sample concentration of around 10ppm, a calibration curve in the range 2–200 ppm would be appropriate. The data showed good linearity in the studied range, with a line […]

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