Ni , Zn , Pd and Pt tetra(pentafluorophenyl)porpholactone (TFPL) were synthesized and identified by their optical and mass spectra. The lactone ring was produced from the parent free-base porphyrin using silver nitrate and oxalic acid with a yield of 73%, and the metals were inserted by standard procedures from metal salts. The compounds show intense Soret Bands in the region 390-420 nm. The longest wavelength visible absorbance peaks, in the region 572-608 nm, are weaker than the Soret peaks by a factor of only ~3 for the Ni , Pd , and Pt complexes but a factor of ~10 for the free-base and Zn complexes. As found with other metalloporphyrins the Ni complex is dark, Zn shows fluorescence and Pd and Pt complexes show strong phosphorescence. The Pd complex also shows a weak fluorescence not quenched by oxygen. The phosphorescence lifetimes of Pd and Pt complexes of TFPL in 3-methylpentane at 77 K are, respectively, ~1 ms and ~70 μs, about 60% that of the TFPP complexes. The wavelengths of phosphorescence emission, 733 nm and 758 nm for PtTFPL and PdTFPL, respectively, are sufficiently red-shifted so that these pressure sensitive luminophors can be included in the same pressure sensitive paint (PSP) as Eu complexes, whose emission at ~615 nm can serve as a temperature sensor. The fluorescences of Mg , Zn , and Y(TFPP) show weak origin bands, making them suitable as unquenched references for PSP.
Direct extraction methods for the quantitation of sterols and steryl esters (SE) in foods, beverages and concentrates as free sterols (trimethylsilane ether derivatives) by gas chromatography with flame ionization detection (GC/FID) are introduced. Theoretical correction factors are used for sterol quantification relative to the internal standard, Epicoprostanol. Conversion of the acylglycerols, when present, into FFA eliminates the timeconsuming acylglycerol extraction step and reduces the GC run time since no higher molecular weight acylglycerols need to elute from the column. Accuracy and precision of analytical data are important when formulating food products with sterols or SE to ensure a formulation will meet health claims, while at the same time minimizing costly over formulation. Method accuracy was determined by complete recovery of sterol and SE concentrates as free sterols with subsequent analysis of foods and beverages formulated with sterol and SE concentrates. Triplicate analysis over 5 days demonstrated repeatability for the alkaline saponification and acid extraction with alkaline saponification methods. A relative standard deviation of \5% demonstrates the repeatability of the methods. Replicate analysis of a common sample by two laboratories and replicate analysis of a common sample by multiple analysts demonstrated reproducibility of the methods.
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