High-performance Liquid Chromatography—Instrumentation and Techniques

A Multi-step High-Performance Liquid Chromatography (HPLC) Technique for the Extraction and Purification of Medical-Grade Cyclosporine A

“…In a single experiment, the numerous HPLC parameters under evaluation, such as absorbance, retention duration, sample volume, column temperature, and flow rate, were all altered simultaneously. 39,43 The goal of this modification was to develop a detailed final method for detecting, extracting, and purifying CsA from crude form, based on the established optimum conditions of the parameters as stated in this study, especially creating a novel method with optimized purity, recovery time, and loading weight. In high-performance liquid chromatography methods for the detection and extraction of CsA, temperature changes lead to gains in peak width and retention time.…”

Online Coupling of Size Exclusion Chromatography to Capillary Enhanced Raman Spectroscopy for the Analysis of Proteins and Biopharmaceutical Drug Products

“…Capillary optics like a liquid core waveguide (LCW) ,,,− or vertical flow technique ,, were applied as flow cells based on their ability to significantly enhance sensitivity in Raman signal detection of different analytes. , In 1999, Marquardt et al and Dijkstra et al published the online coupling of high performance liquid chromatography (HPLC) to RS by employing an LCW of Teflon AF 2400, a fluoropolymer with a refractive index of 1.29. ,, Since the eluents used in LC provide refractive indices above 1.32, light passing through the liquid core of the capillary is reflected at the critical angle of total internal reflection from the inner surface of the Teflon AF 2400 capillary. This results in an extension of the path length for laser excitation in combination with an internal volume of only a few microliters, and thus, capillary enhanced Raman spectroscopy (CERS) is a convenient technique for increasing the Raman sensitivity ,, in liquid phases and compatible with most LC systems.…”

Chemical Derivatization Processes Applied to Amine Determination in Samples of Different Matrix Composition

“…There are three types of derivatization modes commonly used in chromatography and applied to amine derivatization: pre-column, on-column and post-column derivatization [56][57][58][59][60] . The chemical conversion of amines can also be performed during sample collection and is termed in situ derivatization.…”