Desorption electrospray ionization lipids

Dill A, Ifa D, Manicke N, Zheng O, Cooks R (2009) Mass spectrometric imaging of lipids using desorption electrospray ionization. J Chromatogr B 877 2883-2889. doi 10.1016/j. jchromb.2008.12.058... 

Ellis S, Wu C, Deeley J, ZhuX, Truscott R, Panhuis J, Cooks R, Mitchell T, Blanksby S (2010) Imaging of human lens lipids by desorption electrospray ionization mass spectrometry. J Am Soc Mass Spectrom 21 2095-2104. doi 10.1016/j.jasms.2010.09.003... 

Girod M, Shi Y, Cheng J, Cooks G (2010) Desorption electrospray ionization imaging mass spectrometry of lipids in rat spinal cord. J Am Soc Mass Spectrom 21 1177-1189. doi 10.1016/j. jasms.2010.03.028... 

Paglia, G Ifa, D.R., Wu, C Corso, G., Cooks, R.G. (2010) Desorption Electrospray Ionization Mass Spectrometry Analysis of Lipids after Two-dimensional High-Performance Thin-Layer Chromatography Partial Separation. Anal. Chem. 82 ... 

Eberlin, L.S., Liu, X., Ferreira, C.R., Santagata, S., Agar, N.Y., and Cooks, R.G. 2011, Desorption electrospray ionization then MALDI mass spectrometry imaging of lipid and protein distributions in single tissue sections, Anal. Chem., 15 8366-8371. 

In recent years, TLC was successfully combined with different ionization techniques, matrix-assisted laser desorption/ionization (MALDI), ESI, atmospheric pressure chemical ionization (APCI), desorption electrospray ionization (DESI), electrospray-assisted laser desorption ionization (ELDI), and LDI for identification and quantification of organic and biomolecules. In this section, the interfacing of TLC techniques with MALDI-ESI/MS, DESI-MS, ELSI-MS, and LDI-MS will be described, performance will be discussed, and selected applications in the separation and identification of lipids, gangliosides, dyes, drugs, and medicinal compounds will be presented. 

Gonzalez-Serrano AF, Felipe A, Pirro V, et al. Desorption electrospray ionization mass spectrometry reveals lipid metabolism of individual oocytes and embryos. PLoS One. 

Dill, A.L., Ifa, D.R., Manicke, N.E., Onyang, Z. and Cooks, R.G. (2009) Mass spectro-metric imaging of lipids using desorption electrospray ionization. J. Chromatogr. B 877, 2883-2889. 

The dynamic development of mass spectrometry has had a huge impact on lipid analysis. Currently, a variety of suitable mass spectrometers is available. In principal, a mass spectrometer consists of an ion source, a mass analyzer, and an ion detector. The typical features of each instrument (Fig. 2) result mostly from the types of ion source and mass analyzer. To date, the ionization techniques apphed to lipid analysis include Electrospray Ionization (ESI or nano-ESI), Atmospheric Pressure Chemical Ionization (APCI), Matrix-Assisted Laser Desorption/Ionization... 

Nearly all known ionization methods of mass spectrometry (including electron impact, laser desorption and fast atom bombardment) were already successfully applied to lipids. However, many ionization techniques are not very suitable for the analysis of complex PL mixtures as they provide considerable amounts of fragment ions. Therefore, only three soft-ionization methods play nowadays a major role in lipid analysis. Beside atmospheric pressure chemical ionization (APCI) (Byrdwell 2001), electrospray ionization (ESI) (Pulfer and Murphy... 

Figure 9.2 The basic components of a mass spectrometer. All mass spectrometers consist of an ion source linked to a mass analyser then to a detector. The important ion sources and mass analysers for biological mass spectrometry are listed. There are many other potential ion sources and mass analysers used generally in mass spectrometry, but only the indicated are of use in the analysis of biological macromolecules and amphiphilic lipids, and also in proteomics FAB fast atom bombardment MALDI matrix-assisted laser desorption and ionization ESI electrospray ionization ToF time of flight FTICR fourier transform ion cyclotron resonance MS/MS tandem mass spectrometry.

Although several technologies have been used in lipidomics to identify, quantify, and understand the structure and function of lipids in biological systems, it is clear that the progress of lipidomics has been accelerated by the development of modern mass spectrometry (e.g., electrospray ionization (ESI) and matrix-assisted laser desorption/ionization). Mass spectrometric analysis of lipids plays a key role in the discipline. Therefore, this book is focused on the mass spectrometry of lipids that has occurred in these years. Other technologies for analysis of lipids, particularly those with chromatography, can be found in the book entitled Lipid Analysis Isolation, Separation, Identification and Lipidomic Analysis written by Drs William W. Christie and Xianlin Han. Readers who are interested in classical techniques and applications of mass spectrometry for analysis of lipids should refer to Dr Robert C. Murphy s book entitled Mass Spectrometry of Lipids. 

Electrospray ionization and atmospheric pressure chemical ionization are popular as ionization techniques, for qualitative and quantitative LC—MS analysis of lipids [63—65]. Based on flieir ionization mechanisms, ESI is more suitable for ionization of polar and ionic compounds and is capable of ionizing both small and large biomolecules. APCI can ionize less polar and neutral compounds more efficiently than ESI. Consequently, APCI—MS coupled to LC is the most used tool for TAG identification, because of the full compatibility with common NARP LC conditions, easy ionization of nonpolar TAGs, and the attainment of both protonated molecules [M + H]+ and fragment ions [M - - H — RzCOOH]. On the other hand, ESI is usually employed for the more-polar phospholipids. However, ESI or matrix-assisted laser desorption—ionization (MALDI) have been used for TAGs, as well [66,67]. 

DESI is performed by directing electrosprayed-charged droplets onto a surface for analysis under atmospheric conditions. The collision of the charged droplets with the surface leads to the ionization and desorption of the analyte (35). Then, the ions produced in the gas phase are sampled by an atmospheric interfaced mass analyzer. DESI has been used to create two-dimensional images related to the distribution of lipid species in human tissues (36). 

---