Liquid chromatography-mass spectrometry (LC-MS method) is an analytical chemistry technique that combines the mass analysis capabilities of Mass Spectrometry (MS) with the physical separation capabilities of Liquid Chromatography (or HPLC). Due to the synergistic enhancement of the specific qualifications of each approach, coupled chromatography-MS systems are widely used in chemical analysis.
The ability of liquid chromatography to separate delicate and complicated natural mixtures, whose chemical composition needs to be thoroughly defined, makes the coupling of MS with LC systems appealing. Additionally, the analysis of volatile explosive residues can be done using LC-MS. visit u tech times
Chromatography and mass spectrometry coupling is a well-established chemical analysis technique that dates back to the 1950s. To create tandem separation-mass analysis procedures, A. T. James and A. J. P. Martin first proposed gas chromatography (GC)-MS in 1952. It was theoretically easier to attach the EI or CI ion sources in the MS system since, in GC, the analytes are eluted from the separation column as a gas. They were initially made available for purchase in the 1970s after developing quicker than LC-MS.
To connect LC columns to an EI source, V. L. Tal’roze employed capillaries and created the LC-MS method validation in the 1960s. To increase the liquid flow into the source, McLafferty, in 1973, linked the LC column to a CI source. This interface was only capable of analyzing relatively volatile analytes and non-polar molecules with low molecular masses, unlike the analysis capabilities of GC-MS (below 400 Da). One of the critical problems in the capillary inlet interface was the evaporation of the mobile phase inside the capillary.
Online and offline alternatives were used as coupling alternatives during the early years of LC MS method validation. The method for treating analytes offline took a long time, and sample contamination was always possible. It was soon evident that creating a completely automated online coupling solution for LC-MS was necessary to study complicated mixtures.
Moving Belt Interface
McFadden et al. created the moving-belt interface (MBI) in 1977, made up of a moving belt on which the LC Column effluent is deposited in a band.
Direct liquid introduction interface
The 1980s saw the development of the direct liquid introduction (DLI) interface. The purpose of this interface was to address the issue of liquid evaporation within the capillary inlet interface.
At the University of Houston, Vestal laboratories created the thermospray (TSP) interface in 1983. The interface came up as a result of an extensive research effort to establish an LC-MS interface that could handle high flow rates (1 ml/min) without experiencing the flow split found in DLI interfaces.
FAB based interfaces
The interfaces for (FAB) and (CF-FAB) were created in 1985 and 1986, respectively. While CF-FAB employed a probe tip as a connecting channel, FAB used a porous frit probe. The CF-FAB was the most effective of them as an LC-MS interface and was suitable for the analysis of non-volatile and thermally labile chemicals.
Because it enables fast molecular weight confirmation and structural identification, LC-MS is popular in drug development. With these features, the Creation, testing, and validation of discovery with potential applications are accelerated. Peptide mapping, glycoprotein mapping, lipidomics, natural product dereplication, impurity identification, quantitative bioanalysis, and quality control are highly automated techniques employed in LC-MS applications for drug development.