A microfluidic lab-on-chip derivatisation technique for the measurement of gas phase formaldehyde

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A microfluidic lab-on-chip derivatisation technique has been optimized to achieve a rapid, automated and sensitive determination of ambient gaseous formaldehyde when used in combination with GC-MS. The method used a Pyrex micro-reactor comprising three inlets and one outlet, gas and fluid splitting and combining channels, mixing junctions, and a 2.0 m long, 620 mm internal diameter reaction micro-channel. The micro-reactor integrated three functions, that of: (1) mixer and reactor, (2) heater, and (3) preconcentrator. The flow rates of the gas sample and derivatisation solution and the temperature of the micro-reactor were optimized to achieve a near real-time measurement with a rapid and high efficiency derivatisation step following gas sampling. The enhanced phase contact area-to-volume ratio and the high heat transfer rate in the micro-reactor resulted in a fast and high efficiency derivatisation reaction. Calibration showed good linearity in the range of 26 to 331 ppb with correlation coefficients R-2 = 0.988 and 0.997 for PFPH and PFBHA derivatives. For low gas phase formaldehyde mixing ratios (
Original languageEnglish
Pages (from-to)2013-2020
JournalAnalytical methods
Issue number7
Publication statusPublished - 1 Jul 2012

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