Nanofractionation spotter technology for rapid contactless and high-resolution deposition of LC eluent for further off-line analysis.
The development of a contactless postcolumn spotter technology capable of rapidly and accurately depositing LC eluent onto another platform (e.g., 1536-well microtiter plates) is described. Many detection methodologies are suitable for online analysis, such as mass spectrometry, UV-vis, and fluorescence. In some cases, when online analysis is less suitable, off-line postcolumn analysis is the methodology of choice and usually relies on LC-based fractionation prior to detection (e.g., MALDI-MS, Raman spectrsocopy, biochemical assays). As fractionation generally involves loss in resolution, the technology described here allows high-resolution contactless fractionation by tailoring the fractionation frequency to the chromatographic peaks and mixing in of postcolumn reagents. Droplet ejection at frequencies of at least 6 Hz could be performed in the nanoliter to low microliter range with repeatabilities of ∼6%. Furthermore, multiple droplets can be ejected at the same position thereby allowing adjustment of fractionation volume and speed. The technology was evaluated, optimized, and validated prior to two proof-of-principle demonstrations comprising off-line chemical detection of injected fluorescein and off-line postcolumn biochemical detection of acetylcholine-binding protein ligands, both based on 1536-well plate reader analysis.
BioMolecular Analysis, Department of Chemistry and Pharmaceutical Sciences, and FMI-Bèta-VU, ELE-Bèta-VU (Mechanical and Electronic Engineering), Faculty of Sciences, VU University Amsterdam, De Boelelaan 1083, 1081HV Amsterdam, The Netherlands. j.kool@few.vu.nl
Jeroen
J
Kool
Gerdien
G
de Kloe
Arnoud D
AD
Denker
Klaas
K
van Altena
Marek
M
Smoluch
Dick
D
van Iperen
Tariq T
TT
Nahar
Rob J
RJ
Limburg
Wilfried M A
WM
Niessen
Henk
H
Lingeman
Rob
R
Leurs
Iwan J P
IJ
de Esch
August B
AB
Smit
Hubertus
H
Irth
D000818:Animals; D002352:Carrier Proteins / Q000302:isolation & purification / Q000378:metabolism; D002460:Cell Line; D005591:Chemical Fractionation / Q000295:instrumentation / Q000379:methods*; D002853:Chromatography, Liquid / Q000379:methods*; D019793:Fluorescein / Q000737:chemistry; D007202:Indicators and Reagents / Q000737:chemistry; D013058:Mass Spectrometry; D036103:Nanotechnology / Q000295:instrumentation / Q000379:methods*; D015203:Reproducibility of Results; D013997:Time Factors
C428944:AChBP protein, Lymnaea; D002352:Carrier Proteins; D007202:Indicators and Reagents; D019793:Fluorescein