High Throughput Mode Liquid Microjunction Surface Sampling Probe

Journal Article · Thu Jan 01 04:00:00 EST 2009 · Analytical Chemistry

DOI:https://doi.org/10.1021/ac901098d· OSTI ID:963923

Van Berkel, Gary J ^[1]; Kertesz, Vilmos ^[1]; King, Richard C. ^[2]

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1. ORNL
2. PharmaCadence

A simple and automated spot sampling operation mode for a liquid microjunction surface sampling probe/electrospray ionization mass spectrometry (LMJ-SSP/ESI-MS) system is reported. Prior manual and automated spot sampling methods with this probe relied on a careful, relatively slow alignment of the probe and surface distance (< 20 m spacing) to form the probe - to - surface liquid microjunction critical to successful surface sampling. Moreover, sampling multiple spots required retraction of the surface from the probe and a repeat of this careful probe - to - surface distance alignment at the next sampling position. With the method described here, the probe was not positioned as close to the surface, the exact probe - to - surface positioning was found to be less critical (spanning distances from about 100 300 m), and this distance was not altered during the sampling of an entire array of sample spots. With the probe positioned within the appropriate distance from the surface, the liquid microjunction was formed by letting the liquid from the sampling end of the probe extend out from the probe to the surface. This was accomplished by reducing the self-aspiration liquid flow rate of the probe to a value less than the volume flow rate pumped into the probe. When the self-aspiration rate of the probe was subsequently increased, analytes on the surface that dissolved at the liquid microjunction were aspirated back into the probe with the liquid that created the liquid microjunction and electrosprayed. Presented here are the basics of this new sampling mode, as well as data that illustrate the potential analytical capabilities of the device to conduct high-throughput quantitative analysis.

• Research Organization: Oak Ridge National Laboratory (ORNL)
• Sponsoring Organization: ORNL work for others
• DOE Contract Number: AC05-00OR22725
• OSTI ID: 963923
• Journal Information: Analytical Chemistry, Journal Name: Analytical Chemistry Journal Issue: 16 Vol. 81
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
ALIGNMENT
FLOW RATE
LIQUID FLOW
MASS SPECTROSCOPY
MICROANALYSIS
POSITIONING
PROBES
SAMPLING
SURFACE PROPERTIES
liquid microjunction surface sampling probe/electrospray ionization mass spectrometry