Nanoflow liquid chromatography

Very low flow electrospray is called nanoelectrospray [26] where the samples are infused into the mass spectrometer at the nanoliter flow rate range. The infusion of a few microliters will result in a stable signal for more then 30 min, using pulled capillaries or chip-based emitters [27]. With infusion, signal averaging allows to improve the limit of detection in tandem mass spectrometry. Nanoelectrospray is particularly important in combination with nanoflow liquid chromatography or chip-based infusion for the analysis of peptides and proteins. 

Natsume, T., Yamauchi, Y, Nakayama, H., Shinkawa, T., Yanagida, M., Takahashi, N., and Isobe, T., A direct nanoflow liquid chromatography—Tandem system for interaction proteomics. Analytical Chemistry 74(18), 4725 733, 2002. 

Mirgorodskaya, E., Braeuer, C., Fucini, P, Lehrach, FI. and Gobom, J. (2005a) Nanoflow liquid chromatography coupled to matrix-assisted laser desorption/ionization mass spectrometry Sample preparation, data anlysis, and application to the analysis of complex peptide mixtures. Proteomics 5, 399-408. 

Watanabe, T., Nakanishi, K., Ozawa, T., Kawasaki, H., Lite, K., et al. (2010) Semi-online nanoflow liquid chromatography/matrix-assisted laser desorption ionization mass spectrometry of synthetic polymers using an octadecylsilyl-modified monolithic silica capillary column. Rapid Commun. Mass Spectrom., 24, 1835-1841. 

Lab-on-a-chip analyzers are now available from several instrument companies. One commercial analyzer allows the analysis of DNA, RNA, proteins, and cells. Another commercial microfluidics device is used for nanoflow liquid chromatography and provides an interface to an elcctrospray mass spectromeu y detector. Lab-on-a-chip analyzers are envisioned for drug screening, for DNA sequencing, and for detecting life forms on I iarth, Mars, and other planets. These devices should become more important as the teehnol-ogy matures. 

Lee, J.Y., Min, H.K. and Moon, M.H. (2011) Simultaneous profiling of lysophospholipids and phospholipids from human plasma by nanoflow liquid chromatography-tandem mass spectrometry. Anal. Bioanal. Chem. 400, 2953-2961. 

Min, J. Z. Kurihara, T Hirata, A. Toyo oka, T. Inagaki, S. Identification of A-linked oligosaccharide labeled with 1-pyrenesulfonyl chloride by quadrupole time-of-flight tandem mass spectrometry after separation by micro- and nanoflow liquid chromatography. Biomed. Chromatogr. 2009, 23, 912-921. 

Deguchi, K., Ito, S., Yoshioka, S., Ogata, I., and Takeda, A., Nanoflow gradient generator for capillary high-performance liquid chromatography, Awa/yficaZ Chemistry 16(5), 1524—1528, 2004. 

One of the major attractions of ESI is its ability to serve as an interface between liquid chromatography and mass spectrometry. There are currently a number of low-flow HPLC systems on the market that are compatible with electrospray, microspray, and nanospray sources. Capillary HPLC systems are interfaced with electrospray conducted in the pL/min flow regime, while nanoflow systems can accommodate nL/min flow rates. When electrospray is coupled with conventional HPLC, it is necessary to accommodate a higher sample flow rate ( 0.1—2mL/min) than normal electrospray can tolerate. To facilitate operation at these higher flow rates, a technique called pneumatically assisted electrospray or ion spray is employed, in which sample nebulization by aflow of gas is used to stimulate a more... 

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