Alizarin garnet

Structure of (a) alizarin garnet R, and (b) its metal-ligand complex with AP+. 

Acid chrome red, acid anthracene red, acid alizarine red, anthracene chrome red, acid alizarine garnet, azo alizarine Carmoisine, chrome fast Bordeaux, cbrome fast garnet, chromotropes, diamond red, eriochrome red, eriochrome Bor- deaux, omega chrome red, oxychrome garnet, palatine chrome red, eriochrome olive, palatine chrome violet, anthracene chrome violet, acid chrome blue, azi chrome blue, chrome fast blue, chromotrope blue, omega chrome blue. 

Figure 27-9 Some fluorometric chelating agents for metal cations. Alizarin garnet R can detect AP at levels as low as 0.007 pg/mL. Detection of F with alizarin garnet R is based on quenching of the fluorescence of the AP" complex. Flavanol can detect Sn + at the 0.1 pg/mL level.

Challenge Problem. The following volumes of a standard 10.0-ppb F solution were added to four 10.00-mL aliquots of a water sample 0.00, 1.00, 2.00, and 3.00 mL. Precisely 5.00 mL of a solution containing an excess of the strongly absorbing Al-acid Alizarin Garnet R complex was added to each of the four solutions, and they were each diluted to 50.0 mL. The fluorescence intensity of the four solutions were as follows ... 

Acid-Alizarin Garnet R (AAGR or 2,4,2 -Trihydroxy- azobenzene-5 -sodium sulfonate) 470 575 4 X 10-8 to 9 X 10-8... 

A fluorometric analysis results in the collection of two spectra, the excitation spectrum and the emission spectrum. The excitation spectrum should be the same as the absorption spectrum obtained spectropho tome trie ally. Differences may be seen due to instrumental factors, but these are normally small, as seen in Fig. 5.45, which shows the absorption and excitation spectra for Alizarin garnet R, a fluorometric reagent for aluminum ion and fluoride ion. The longest wavelength absorption maximum in the excitation spectrum is chosen as the excitation wavelength this is where the first monochromator is set to excite the sample. It would seem reasonable to choose the wavelength that... 

Figure 5.45 Absorption and fluorescence spectra of the aluminum complex with acid Alizarin garnet R (0.008%) Curve A, the absorption spectrum Curve B, the fluorescence excitation spectrum Curve C, the fluorescence emission spectrum. (From Guilbault, used with permission.)...

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