2,4-Pentanedione, complexes with 1,1,1-trifluoro-, complex

Beryllium has been determined [764] in non saline waters and in sea water at oceanic levels of 2.30pM. Two ml of 0.1M EDTA, 2ml of 1.0M sodium acetate, 1.0ml of benzene and lOOpl of l,l,l-trifluoro-2-4-pentanedione were added sequentially to 150ml samples. Following liquid-liquid extraction using detailed handling procedures, the organic phase was mixed with 1.0ml of 1.0M sodium hydroxide (de-emulsifier), washed several times with distilled water and the resultant beryllium l,l,l-trifluoro-2,4-pentanedione complex analysed by gas chromatography with electron capture detection. 

Tetrakis anionic complexes have been isolated with certain lanthanides, such as Eu(III), Tb(III), and Gd(III). The structure of the complex, (NH4)Eu(F3AA)4, HF3AA = l,l,l-trifluoro-2,4-pentanedione, has been completed recently ), but the complete data for the 8-coordin-ate species are not yet available. 

The major breakthrough that transformed metal chelate GC into a useful analytical technique was the introduction of fluorinated beta-diketone ligands, which formed complexes of greater volatility and thermal stability. Trifluoroacetylacetone (l,l,l-trifluoro-2,4-pentanedione—HTFA) and hexafluoro-acetylacetone (l,l,l,5,5,5-hexafluoro-2,4,-pentanedione—HHFA) are the fluorinated ligands most frequently employed. HTFA extended the range of metals that may be gas chromatographed with little or no evidence of decomposition to include Ga3+, In3+, Sc3+, Rh3+ and V4+. An example of a recent application is the analysis for beryllium in ambient air particulates. After filter sampling and extraction/chelation, packed column GC with electron capture detection allowed ppm level beryllium quantitation in collected particulates which corresponded to levels of 2-20 x 10 5 pg/m3 in the sampled air. 

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