title: A new microfluidics-based droplet dispenser for ICPMS.
abstract: In this work, a novel droplet microfluidic sample introduction system for inductively coupled plasma mass spectrometry (ICPMS) is proposed and characterized. The cheap and disposable microfluidic chip generates droplets of an aqueous sample in a stream of perfluorohexane (PFH), which is also used to eject them as a liquid jet. The aqueous droplets remain intact during the ejection and can be transported into the ICP with >50% efficiency. The transport is realized via a custom-built system, which includes a membrane desolvator necessary for the PFH vapor removal. The introduction system presented here can generate highly monodisperse droplets in the size range of 40-60 μm at frequencies from 90 to 300 Hz. These droplets produced very stable signals with a relative standard deviation (RSD) comparable to the one achieved with a commercial droplet dispenser. Using the current system, samples with a total volume of <1 μL can be analyzed. Moreover, the capabilities of the setup for introduction and quantitative elemental analysis of single cells were described using a test system of bovine red blood cells. In the future, other modules of the modern microfludics can be integrated in the chip, such as on-chip sample pretreatment or parallel introduction of different samples.
authors.affiliation: Laboratory of Organic Chemistry, and ‡Laboratory of Inorganic Chemistry, Department of Chemistry and Applied Biosciences, ETH Zurich , 8093 Zurich Switzerland.
authors.forename: Pascal E
authors.initials: PE
authors.lastname: Verboket
authors.forename: Olga
authors.initials: O
authors.lastname: Borovinskaya
authors.forename: Nicole
authors.initials: N
authors.lastname: Meyer
authors.forename: Detlef
authors.initials: D
authors.lastname: Günther
authors.forename: Petra S
authors.initials: PS
authors.lastname: Dittrich