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571.
GC/MS-screening analyses of water samples from the Lippe River, Germany, revealed the presence of a wide spectrum of low-molecular weight organic compounds ranging from non-polar constituents like aliphatic hydrocarbons to polar constituents like n-carboxylic acids and phenols. Most of the identified compounds could be attributed to anthropogenic input and are used as plasticizers, flame retardants, pharmaceutical drugs or fragrances. Some of them had rarely been noticed as organic pollutants of aquatic environments before. These are, among others, 9-methylacridine, the plasticizer 2,2,4-trimethyl-1,3-pentandioldiisobutyrate (TXIB), the surfactant 2,4,7,9-tetramethyl-5-decyne-4,7-diol (TMDD), triphenylphosphinoxide and the flame retardant tris(chloropropyl)phosphate. On the other hand, most of the identified trialkyl phosphates, pharmaceutical drugs and synthetic fragrances have been reported in surface waters by several authors so far. Input pathways of the detected compounds were traced back by sampling various input sources of organic matter such as discharges of wastewater and Lippe River tributaries. Several contaminants were ubiquitous in Lippe River water and also occurred in sewage effluent from a municipal sewage treatment plant and in samples from the tributaries. This observation suggests that they are typical sewage derived contaminants and have the potential to be used as anthropogenic molecular markers. 相似文献
572.
573.
Armin Weiß 《Environmental science and pollution research international》1996,3(2):112-114
Atmospheric mixing ratios of chlorinated C1 and C2 hydrocarbons (CHCs) were measured at the mountain Wank (Garmisch-Partenkirchen, Bavarian Alps) in autumn 1992. The data lead to the assumption that at least part of the observed CC14 originates from a source different to the other CHCs measured (C2HCL3, C2C14, CHCl3 and CH3CCl3). The nature of this source is discussed. 相似文献
574.
D.G. Patterson Jr. L.R. Alexander L.T. Gelbaum R.C. O'Connor V. Maggio L.L. Needham 《Chemosphere》1986,15(9-12):1601-1604
We report the response factors of all of the tetrachlorodibenzo-p-dioxins (TCDDs) relative to 2, 3, 7, 3-TCDD by electron-impact ionization mass spectrometry. We used CP SIL 88 capillary column interfaced a ZAB-2F high-resolution mass spectrometer operating at 10,000 resolving power 相似文献
575.
Alcaligenes eutrophus accumulated a terpolyester of 3-hydroxybutyric acid (3HB), 3-hydroxyvaleric acid (3HV), and 4-hydroxyvaleric acid (4HV) during cultivation with 4HV as carbon and energy source under nitrogen starvation. The polyester accumulated by wild-type strains under these conditions contained 4HV at a molar fraction of approximately 5 mol% only. A catabolic pathway of 4HV was postulated, which included the activation of 4HV to 4HV-CoA and a conversion of 4HV-CoA to 3HV-CoA. Tn5::mob-induced mutants were isolated fromA. eutrophus HF39, which were affected in 4HV and/or valeric acid catabolism. Among 83 mutants were 27 4HV-negative or 4HV-leaky mutants; two mutants were identified which accumulated a terpolyester with a molar fraction of 10.1 to 22.7 mol% 4HV. In addition, a further increase in the molar fraction of 4HV in poly(3HB-co-3HV-co-4HV) and a two- to fourfold increase in the PHA synthase activity were monitored in these mutants or others and also in HF39, if the cells were complemented with the hybrid plasmid pHP1014::PP1, which contained the PHA biosynthesis genes ofA. eutrophus H16. Application of mutagenesis plus recombinant DNA techniques resulted in the accumulation of a terpolyester with up to 30 mol% 4HV and with approximately equimolar fractions of 3HB, 3HV, and 4HV. 相似文献
576.
577.
The eutrophication status of rivers is changed to a large degree by discharge of waste waters containing high amounts of phosphates from use of detergents. Sediments from the river Elbe in the port of Hamburg, and upstream from this town, and from some parts of the rivers Trave, Eider, and Schwentine are highly enriched with phosphorus. The phosphorus contents of up to 8300 ppm are about five to tenfold higher than the phosphorus contents of intensively fertilized soils. Phosphates accumulated in sediments are mainly bound as iron phosphates of different composition in a relatively labile binding form from which considerable amounts may be released to the water by various mobilization processes. 相似文献
578.
579.
580.
A comparative analysis of trace element data of human skeletal material from four archaeological sites is presented. We show that the state of histomorphological preservation of bone, which is a measurement for the degree of its diagenetic alteration, closely corresponds to the Sr/Ca and Ba/Ca ratios at an intra-population level. This study challenges the validity of dietary studies that are based on the presently used procedures for sample preparation and subsequent evaluation of strontium and barium concentrations. 相似文献