Microfluidic derivatisation technique for determination of gaseous molecular iodine with GC-MS

Xiaobing Pang; Lucy J Carpenter; Alastair C Lewis

doi:10.1016/j.talanta.2015.01.041

Microfluidic derivatisation technique for determination of gaseous molecular iodine with GC-MS

Talanta. 2015 May:137:214-9. doi: 10.1016/j.talanta.2015.01.041. Epub 2015 Feb 10.

Authors

Xiaobing Pang¹, Lucy J Carpenter², Alastair C Lewis²

Affiliations

¹ Wolfson Atmospheric Chemistry Laboratories, Department of Chemistry, University of York, York YO10 5DD, UK; Key Laboratory for Aerosol-Cloud-Precipitation of China Meteorological Administration, Nanjing University of Information Science and Technology, Nanjing 210044, China. Electronic address: pangxbyuanj@gmail.com.
² Wolfson Atmospheric Chemistry Laboratories, Department of Chemistry, University of York, York YO10 5DD, UK; National Centre for Atmospheric Science, University of York, York YO10 5DD, UK.

PMID: 25770627
DOI: 10.1016/j.talanta.2015.01.041

Abstract

Gaseous molecular iodine (I2) is an important source of reactive iodine in the marine atmosphere, but the sources of I2 are not well understood due to the lack of an easily accessible, sensitive and robust technique for analysis. In this study a microfluidic derivatisation technique combined with GC-MS has been developed to measure gaseous I2. Good linearity in the range of 0.2-416 ppb and low detection limits varying from 6 to 25 ppt for different derivatisation reagents have been achieved, which is a substantial improvement in sensitivity compared with the spectrophotometric method (detection limit of 1.20 ppb) in our previous study [L.J. Carpenter, S.M. MacDonald, M.D. Shaw, R. Kumar, R.W. Saunders, R. Parthipan, J. Wilson, J.M.C. Plane, Nature Geoscience, 6 (2013) 108-111]. The microfluidic technique was employed to quantify I2 produced from the heterogeneous reactions of potassium iodide solution and ozone. Good agreement was observed between the results of the microfluidic technique and the simulation of a coupled surface water-air kinetic model in the amount of I2 produced on the ozonolysis of iodide solutions.

Keywords: GC–MS; Gaseous molecular iodine; Iodide; Microfluidic derivatisation technique; Ozonolysis.