Abstract
A method for speciation and determination of low levels of dissolved iron in rainwater was established by coupling reverse flow injection analysis with a 2-m liquid waveguide capillary cell and spectrophotometric detection. Ferrozine solution was injected into a sample stream to form an Fe(II)-ferrozine complex with Fe(II), and the absorbance of this complex was detected at both 562 nm and 625 nm with a reference wavelength at 700 nm. Fe(III) was analyzed in the same manner after being reduced to Fe(II) by ascorbic acid. The optimum conditions and the interference of Cu(I), Ni(II) and Co(II) were investigated. The limits of detection were 0.1 nM for Fe(II) and 0.2 nM for Fe(III), while the linear ranges were 0.4 – 200 nM for Fe(II) and 0.8 – 287 nM for Fe(III) at 562 nm, and can be extended to higher concentrations with the detection at a less sensitive wavelength of 625 nm. The sample throughput was 6 h−1, and the total sample volume consumed was 10 mL. This method has been successfully applied to analyze dissolved iron in rainwater of Xiamen from August to November, 2008. The lowest level of iron in rainwater was observed during typhoon events. By adopting reverse flow injection analysis coupled with liquid waveguide long path length capillary cell, the reagent consumption was low and the sensitivity was enhanced. The other advantages of this method are high sample throughput, wide linear dynamic range and high selectivity for Fe(II).
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.