Thermogravimetric analysis and gas chromatography of rare earth chelates of trifluoroacetylpivaloylmethane

Anti-inflammatory and immunosuppressive effect of flavones isolated from Artemisia vestita

“…Their structures were identified as pectolinarigenin (1), jaceosidin (2), cirsilineol (3), cirsimaritin (4), hispidulin (5), quercetin (6), 6-methoxytricin (7), acacetin (8), and apigenin (9) (Fig. 2) after comparing with the previous data (Brieskorn and Riedel, 1977;Huang et al, 2007;Liu and Mabry, 1981;Morita et al, 1973;Mues et al, 1979;Nagao et al, 2002;Ren et al, 1998;Tanaka et al, 1968;Zhang et al, 2006).…”

Complex thermoanalytical studies on volatile rare earth element β-diketonates

“…It is known that the presence of coordination water in the compound causes the melting temperature to decrease [4]. This regularity is preserved in the Ln(PTA)3.nH20 series; the temperature decrease is less for monohydrates than for dihydrates ( Table 1).…”

“…In this connection, the most typical problems in studies of their physical and chemical properties are the thermal stability and volatility. The data from the literature are incomplete [4,5], which was the reason for this paper, which combines the results of earlier published articles [6][7][8] and new results.The following materials were studied: REE tris chelates, with common formula LnL3.nH20, where Ln stands for any REE, L = trifluoroacetylacetone (TFA), hexafluoroacetylacetone (HFA), pivaloyltrifluoroacetone (PTA), dimethylheptafluoroacetonedione (FOD) and dipivaloylmethane (DPM); and REE tetrakis chelates, containing an alkali metal cation, with common formula Na[LnL4]. …”

Total-effluent gas chromatography-mass spectrometry

“…These chelates, which could be determined by gas chromatography, were quite volatile. Shigematsu et al (6) and Tanaka et al (4) have reported the gas chromatography of anhydrous chelates of the lanthanides with l,l,l-trifluoro-5,5-dimethyl-2,4hexanedione, H(PTA).…”

“…of column types and column packings are now used, extending from conventional packed columns to open tubular capillary columns, support coated capillary columns, and, more recently, to packed capillary columns. Open tubular capillary columns have been extensively employed in the high resolution analyses of the extremely complex hydrocarbon mixtures frequently encountered in petroleum analysis (2) and in other organic geochemical investigations (for example, 3,4) and in flavor and fragrance analyses. However, it is only relatively recently that their full potential in biochemical and biomedical analyses has been recognized; for example, No-votny and Zlatkis (5) have explored the use of high resolution wall-coated glass capillary columns for the separation of a wide range of oxygenated molecules.…”