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Journal of Analytical Methods in Chemistry
Volume 2012 (2012), Article ID 520248, 5 pages
Research Article

Quenching-Chemiluminescence Determination of Trace Amounts of l-Tyrosine Contained in Dietary Supplement by Chemiluminescence Reaction of an Iron-Phthalocyanine Complex

1Department of Biomolecular Functional Engineering, Faculty of Engineering, Ibaraki University, 4-12-1 Nakanarusawa, Hitachi, Ibaraki 316-8511, Japan
2Faculty of Symbiotic Systems Science, Cluster of Science and Technology, Fukushima University, Kanayagawa 1, Fukushima 960-1296, Japan

Received 18 November 2011; Revised 22 January 2012; Accepted 23 January 2012

Academic Editor: Jianxiu Du

Copyright © 2012 Takao Ohtomo et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.


The chemiluminescence (CL) signal immediately appeared when a hydrogen peroxide solution was injected into an iron-phthalocyanine tetrasulfonic acid (Fe-PTS) aqueous solution. Moreover, the CL intensity of Fe-PTS decreased by adding L-tyrosine. Based on these results, the determination of trace amounts of L-tyrosine was developed using the quenching-chemiluminescence. The calibration curve of L-tyrosine was obtained in the concentration range of 2 . 0 × 1 0 7  M to 2 . 0 × 1 0 5  M. Moreover, the relative standard deviation (RSD) was 1.63 % ( 𝑛 = 5 ) for 2 . 0 × 1 0 6  M L-tyrosine, and its detection limits (3σ) were 1 . 8 1 × 1 0 7  M. The spike and recovery experiments for L-tyrosine were performed using a soft drink. Furthermore, the determination of L-tyrosine was applied to supplements containing various kinds of amino acids. Each satisfactory relative recovery was obtained at 98 to 102%.