Mercury, fluorimetric determination

There have been several papers concerned with the analytical uses of fluorescence. Thus the determination of lead in blood by atomic fluorescence methods,359 the determination of mercury at picogram l-1 levels in water,380 the use of isocein as a fluorescent reagent for calcium,361 fluorescent reactions of eriochrome red with Be, Mg, Al, In, Ga, and Zn as a method of determination,362 fluorimetric determination of chloroquine363 and of anthracene in anthraquinone,364 and the use of fluorescence methods in the characterization of complex mixtures 365 have been discussed. Readers with criminal tendencies... 

F. Lazaro, M. D. Luque de Castro, and M. Valcarcel, Simultaneous Cat-alytic-Fluorimetric Determination of Copper and Mercury by Flow Injection Analysis. Fresenius Z. Anal. Chem., 320 (1985) 128. 

While detection of cations via porphyrin-ba.sed materials has been explored less than anion sensing, the ability of a porphyrin to coordinate different metals and the unique spectral signatures that result form the basis for metal ion detection. Use of free-base porphyrins in polymer matrices has allowed for the detection of heavy metal ions by Ache et Immobilization of 5,10,15,20-tetrakis(4-N-methylpyridyOporphyrin on Nafion membranes pennitted detection of cadmium and mercury in solution with detection limits of 5 X 10 M and 2 x 10 M, respectively over a 20-minute measuring period. The method is subject to interferences from other metal ions, but the researchers were able to detect several ions simultaneously using pattern-recognition techniques such as principal component analysis. Sol-gel films doped with 5,l0,l5,20-tetra(p-sulfonatophenyDporphyrin have also been used by Ache and coworkers for the fluorimetric determination of mercury in solution, with a detection limit of approximately 7 X 10... 

Thiamin has also been determined using mercury(ii) (Martinez-Lozano et al. 1990). Mercury(ii) is used to oxidize thiamin to the fluorescent thiochrome compound. Based on this reaction, a flow injection method has been developed to analyze thiamin in commercial preparations. A fluorimetric method coupled with flow injection has been developed for determining thiamine based on the oxidation of thiamin to thiochrome by mercury(ii) (Perez-Ruiz et al. 2004). A high mercury(ii) concentration is utilized in this reaction for the largest yield of thiochrome and it produces an enhanced fluorescence emission signal at 440 nm when excited at 356 nm. The fluorescence intensity increases with the concentration of thiamin added, which exhibits outstanding results to determine vitamin Bj. 

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