Talanta 81 (2010) 722–726 Contents lists available at ScienceDirect Talanta journal homepage: www.elsevier.com/locate/talanta Short communication Miniaturised centrifugal solid phase extraction platforms for in-field sampling, pre-concentration and spectrometric detection of organic pollutants in aqueous samples Josiane P. Lafleur, Andrien A. Rackov, Scott McAuley, Eric D. Salin ∗ Department of Chemistry, McGill University, 801 Sherbrooke St W., Montreal, Qc, Canada H3A 2K6 article info Article history: Received 24 August 2009 Received in revised form 4 December 2009 Accepted 7 December 2009 Available online 16 December 2009 Keywords: Centrifugal microfluidics Absorbance Fluorescence PAH Solid phase extraction In situ detection abstract Great variations in pollutant concentrations are observed in the environment and pre-concentration is often required to detect trace contaminants in water samples. This paper presents a novel solid phase- extraction device integrated onto a centrifugal microfluidic platform for rapid on-site pre-concentration and screening of organic contaminants in aqueous samples. In-column fluorescence and absorbance measurements are obtained directly from an analyte trapped on the top of a solid phase extraction microcolumn. Results are presented for the representative fluorophore fluorescein and the polycyclic aromatic hydrocarbon anthracene. An absolute detection limit of 20 ng was obtained for anthracene using a simple light emitting diode for fluorescence excitation. One of the main advantages of this device is that only a simple motor is needed to induce liquid flow, making simultaneous on-site extraction and measurement of multiple samples easy while minimizing sample losses and contamination. © 2010 Elsevier B.V. All rights reserved. 1. Introduction Many toxic or potentially harmful pollutants are released into the environment every day as a direct consequence of human activity. Polycyclic aromatic hydrocarbons (PAHs), which are widespread by-products of incomplete combustion, are an example of organic pollutants ubiquitous in the environment. Their presence in our environment predates the industrial era due to such natural causes as forest fires and volcanic eruptions. Their concentrations have increased dramatically as a consequence of the burning of fos- sil fuels, resulting in increased contamination of water resources. Many PAHs are toxic to aquatic life and several have carcinogenic properties. Anthracene is one of the 16 PAHs selected by the US Environmental Protection Agency (EPA) as priority pollutants [1]. New analytical tools that can rapidly screen organic pollutants with minimal sample handling are required in order to assess and monitor their fate and impact. A recent review by Li and Lin [2] demonstrates the growing interest in applying microfluidic tech- nologies to environmental analysis. Microfluidic systems are a tool of choice for the analysis of pollutants in the environment because several steps of a chemical analysis can be performed rapidly and directly on the microfluidic platforms. Sample transportation to the ∗ Corresponding author. Tel.: +1 514 398 6236; fax: +1 514 398 3797. E-mail address: eric.salin@mcgill.ca (E.D. Salin). laboratory becomes unnecessary, minimizing analysis time, sample losses and contamination. Microfluidic devices that use centrifugal force to drive the flow of liquids have recently been developed for environmental analy- ses. LaCroix-Fralish et al. [3] recently developed a micro-analytical system for the detection of nitrite and Cr(VI) to demonstrate the potential of centrifugal microfluidic systems for on-site (field) anal- ysis of water samples. Lafleur and Salin [4] also recently introduced a miniature centrifugal solid phase-extraction (SPE) device for the rapid determination of trace metals in water by Laser Ablation (LA) Inductively Coupled Plasma Mass Spectrometry (ICP-MS). SPE is one of the most commonly used sample preparation techniques for the extraction and pre-concentration of analytes in environmental samples [5]. Since the concentration of PAHs can range from less than 1 ppt in pure groundwater to greater than 1 ppm in heavily contaminated sewage, extraction and pre- concentration are often necessary [6]. PAHs can be extracted by SPE using a reversed phase C 18 stationary phase column followed by elution with a toluene–methanol mixture [7]. The collected eluate is then analyzed using the appropriate method. However, fluores- cence and absorbance measurements could be performed directly on the sorbent material. This has the advantage of reducing the number of sample preparation steps, thereby minimizing risks of sample loss and contamination and reducing analysis time. The elimination of the elution steps also reduces the use of organic solvents which are detrimental to health and the environment. 0039-9140/$ – see front matter © 2010 Elsevier B.V. All rights reserved. doi:10.1016/j.talanta.2009.12.001