RESEARCH ARTICLE
Flow Markers in Microreactors: A Generally Applicable Chromatographic Method for Monitoring Flow Rates During Reactions
Pieter J. Nieuwland, Kaspar Koch, Jan C.M. van Hest, Floris P.J.T. Rutjes*
Article Information
Identifiers and Pagination:
Year: 2010Volume: 4
First Page: 61
Last Page: 67
Publisher ID: TOCENGJ-4-61
DOI: 10.2174/1874123101004010061
Article History:
Received Date: 25/09/2009Revision Received Date: 19/01/2010
Acceptance Date: 20/01/2010
Electronic publication date: 5/5/2010
Collection year: 2010
open-access license: This is an open access article distributed under the terms of the Creative Commons Attribution 4.0 International Public License (CC-BY 4.0), a copy of which is available at: https://creativecommons.org/licenses/by/4.0/legalcode. This license permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Abstract
Microreactors have found widespread use for continuous flow synthesis and reaction optimization. Flow rates are critical factors with respect to the latter application because they are used to set screening parameters such as reaction time and stoichiometric ratios. However, the set flow values of pumps for nanoliter to microliter volume reactors are quite often not sufficiently accurate. In this paper we present a generally applicable chromatographic method to analyze flow rates during microreactor reaction screening. By adding flow markers to all reactant and reagent flows and performing conventional GC analysis on all samples, an accurate flow rate was calculated. The deviation between the set flow values and the measured flow rates was shown for a standard continuous flow experiment. The implications of this deviation for reaction optimization were demonstrated via a model Swern-Moffatt oxidation reaction, which showed that accurately measured flow rates are critical for correct data interpretation.
