Electrospray and nanospray ionization of discrete samples in droplet format
US8431888B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jun 18, 2010 |
| Grant date | Apr 30, 2013 |
| Priority date | — |
| Expiry date | Jun 18, 2030 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB01L3/502784
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
Droplets or plugs within multiphase microfluidic systems have rapidly gained interest as a way to manipulate samples and chemical reactions on the femtoliter to microliter scale. Chemical analysis of the plugs remains a challenge. It has been discovered that nanoliter plugs of sample separated by air or oil can be analyzed by electrospray ionization mass spectrometry when pumped directly into a fused silica nanospray emitter nozzle. Using leu-enkephalin in methanol and 1% acetic acid in water (50:50 v:v) as a model sample, we found carry-over between plugs was <0.1% and relative standard deviation of signal for a series of plugs was 3%. Detection limits were 1 nM. Sample analysis rates of 0.8 Hz were achieved by pumping 13 nL samples separated by 3 mm long air gaps in a 75 μm inner diameter tube. Analysis rates were limited by the scan time of the ion trap mass spectrometer. The system provides a robust, rapid, and information-rich method for chemical analysis of sample in segmented flow systems.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.