Doxycycline and Methacycline Analyzed by 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 peak pair. Peaks: 1. Methacycline 2. Doxycycline * Impurities in doxycycline […]

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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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Limonin in Orange Juice Analyzed by HPLC – AppNote

Reproducible Separation from Sample Matrix Peaks An Orange Juice Sample was spiked at the level of 250 ppm of Limonin and filtered (MicroSolv Tech Corp. 0.45μm Nylon Syringe Filter)  before injection. Several Peaks from to the Juice Sample Matrix were separated (peaks1–5), the Limonin peak was well separated from the other Peaks and was easy […]

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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 […]

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Oleic Acid & Elaidic Acid – AppNote

Advantages of shape selectivity in cis/trans separations The separation of cis and trans isomers by Reversed Phase can be challenging, as the two compounds often have little difference in hydrophobicity. In cases such as these, additional selectivity mechanisms may be necessary to obtain resolution. Furthermore, they cannot be resolved by MS because they have the […]

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Serum Corticosterone Concentrations Determination by HPLC – AppNote

Serum Corticosterone Concentrations are of clinical significance in Adrenal dysfunction. Its measurement is sometimes used to diagnose apparent mineral Corticoid Excess Syndrome. It can also be used as a bio marker of malignancy in Adrenal Tumors. Using the Cogent UDC Cholesterol Column allows the simultaneous measurement of the two main Estrogen fractions, Estrone and Estradiol […]

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