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

Abstract EN

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 2.0×10−7 M to 2.0×10−5 M.

Moreover, the relative standard deviation (RSD) was 1.63 % (n=5) for 2.0×10−6 M l-tyrosine, and its detection limits (3σ) were 1.81×10−7 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%.