Electrospray Ionization(ESI)

Introduction

Electrospray Ionization (ESI) is a soft ionization technique widely used to produce gas-phase ions (without fragmentation) of large, heat-sensitive molecules such as proteins and nucleic acids. This analysis is used for structural characterization. ESI-MS is not only used for determining the molecular weight of protein molecules but also for gaining a deeper understanding of the three-dimensional structure of proteins, non-covalent interactions, and amino acid sequencing.

Although the development of ESI-MS has had a significant impact in the fields of biology and proteomics, its application has extended to a wide range of solutions, including polar organic compounds, inorganic compounds, and organometallic complexes.

Electrospray Ionization Mass Spectrometry (ESI-MS)

It is one of the most important ionization techniques used in the field of LC-MS.

It is an ionization method used to convert compounds from the liquid phase into ions in the gas phase. This is done by passing the liquid sample through a charged needle, resulting in a spray of tiny droplets. The solvent evaporates from these droplets, producing ions that can be analyzed by mass spectrometry.

It is used to analyze large proteins and peptides, as it can handle molecules with high molecular weights. It is also used to analyze organic compounds, including small organic molecules and metabolites.

It is used in applications that require accurate measurements of compound levels in samples.

Features of ESI

High sensitivity: ESI-MS can provide high sensitivity, making it suitable for analyzing compounds in trace amounts.

Analysis of large molecules: It can effectively ionize large compounds such as proteins, making it useful in proteomics and molecular biology.

Liquid phase analysis: ESI-MS allows for the analysis of samples in the liquid phase, facilitating the handling of complex biological samples.

Types of Samples That Can Be Measured

1.      Biological fluids: such as blood, urine, and cellular fluids.

2.      Protein extracts: from sources such as cells and tissues.

3.      Chemical compounds: small and large organic compounds, including drugs and metabolites.