No abstract

The work that is reported here concerns a method that allows the simultaneous determination of cadmium (II) and zinc (II) in aqueous solution by molecular fluorescence spectroscopy using 9-(1',4',7',10',13'-pentaazacyclopentadecyl)-methylanthracene. For this chemosensor, the fluorophore pi-system is insulated from an azacrown donor by one methylene group. A self-quenching mechanism, resulting from an electron transfer from the nitrogens of the azacrown to the excited aromatic system, essentially precludes fluorescence emission. Fluorescence is restored when cadmium (II) or zinc (II) are chelated by the macrocycle. The difference between the emission spectra profiles of the free chemosensor, the cadmium and the zinc chelates is such that the concentration determination of the two metals and the remaining free chemosensor is possible at the nanomolar scale in only one experiment using a multiple linear regression algorithm. Usefulness and convenience of this simple method is proven by steady state and kinetic quantitative determination experiments.

No abstract

The paper describes an integrated luminometer able to perform fluorescence (FL), room temperature phosphorescence (RTP) and chemiluminescence (CL) measurements on seawater samples. The technical details of the instrumentation are presented together with flow injection (FI) manifolds for the determination of cadmium and zinc (by FL), lead (RTP) and cobalt (CL). The analytical figures of merit are given for each manifold and results are presented for the determination of the four trace metals in seawater reference materials (NASS-5, SLEW-2) and Scheldt estuarine water samples.