1,4-Benzodiazepines in Urine Analyzed using RP and ANP – AppNote

The analyses of 1,4-Benzodiazepines using the Cogent Diol Column from Urine Samples after Solid Phase Extraction using two types of Retention Modes are shown in this Note. Four Compounds were well retained and separated in both HPLC Modes shown in Figures A and B; however, the Retention Order was changed depending on the Gradient used. It […]

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1,4-Benzodiazepines in Urine by ANP – AppNote

1,4-Benzodiazepines from Urine Samples were analyzed using a Cogent Diamond Hydride 2.o HPLC Column 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]+ […]

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

Important Biomarker for Diabetes and HMG Disorder is well retained by 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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Acetone as the Organic Mobile Phase Component – AppNote

“Green” substitute for separation of amino acids Caution: Acetone and Amines can react When working with Acetone as an HPLC solvent it is important to note that primary amines could react with Acetone to form imines. However, to achieve this reaction the mobile phase would most likely need to be free of water and or […]

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

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 in a chromatographic separation. Second, a good number of […]

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Alprazolam (Xanax®) HPLC Method Transferred – AppNote

Benefit of 2.2um Column Analyzing Alprazolam by 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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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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Analysis of Litchi Seed Extracts – 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 LC-MS with a Cogent Diamond Hydride™ Column to […]

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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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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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Avoid Sample Cleanup for Food and Beverages – 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 by 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 Analysis by 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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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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Brazilian Tree Bark Analysis by LCMS – AppNote

Identification of Quercetin, Rutin, and “Compound 1” in a Brazilian Tree Bark Over one quarter of natural medicines have been discovered in rainforests, and therefore analytical study of the indigenous flora and fauna is necessary. The Amazonian rainforest in Brazil is the most biodiverse region in the world. A Brazilian tree bark extract (Brownea Grandiceps) […]

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