Journal
JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY
Volume 25, Issue 1, Pages 30-36Publisher
SPRINGER
DOI: 10.1007/s13361-013-0749-z
Keywords
Nanoelectrospray; nano-ESI; Quantitation; Mass-limited analysis
Funding
- William R. Wiley Environmental Molecular Sciences Laboratory (EMSL) intramural program
- National Institutes of Health: the National Institute of General Medical Sciences [8 P41 GM103493-10]
- National Institutes of Health: National Cancer Institute [1R33CA155252]
- US DOE's Office of Biological and Environmental Research
- DOE [DE-AC05-76RLO 1830]
- NATIONAL CANCER INSTITUTE [R33CA155252] Funding Source: NIH RePORTER
- NATIONAL INSTITUTE OF GENERAL MEDICAL SCIENCES [P41GM103493] Funding Source: NIH RePORTER
Ask authors/readers for more resources
Electrospray ionization mass spectrometry (ESI-MS) at flow rates below similar to 10 nL/min has been only sporadically explored because of difficulty in reproducibly fabricating emitters that can operate at lower flow rates. Here we demonstrate narrow orifice chemically etched emitters for stable electrospray at flow rates as low as 400 pL/min. Depending on the analyte concentration, we observe two types of MS signal response as a function of flow rate. At low concentrations, an optimum flow rate is observed slightly above 1 nL/min, whereas the signal decreases monotonically with decreasing flow rates at higher concentrations. For example, consumption of 500 zmol of sample yielded signal-to-noise ratios similar to 10 for some peptides. In spite of lower MS signal, the ion utilization efficiency increases exponentially with decreasing flow rate in all cases. Significant variations in ionization efficiency were observed within this flow rate range for an equimolar mixture of peptide, indicating that ionization efficiency is an analyte-dependent characteristic for the present experimental conditions. Mass-limited samples benefit strongly from the use of low flow rates and avoiding unnecessary sample dilution. These findings have important implications for the analysis of trace biological samples.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available