Biodegradation of 1080: Testing soils in south-eastern Australia for sodium fluoroacetate-degrading micro-organisms

Sodium fluoroacetate (1080) is a vertebrate poison commonly used for the control of vertebrate pests in Australia. Long-term environmental persistence of 1080 from baiting operations has likely nontarget species and environmental impacts and is a matter of public concern. Defluorinating micro-organisms have been detected in soils of Western and central Australia, and Queensland, but not in south-eastern Australia. The presence or absence of defluorinating micro-organisms in soils from south-eastern Australia will assist in determining whether long-term environmental persistence of 1080 is or is not occurring. Soils from the Central West Slopes and Plains and Central Tablelands of New South Wales were sampled to investigate the presence and capability of 1080 defluorinating soil micro-organisms. Thirty-one species of micro-organisms were isolated from soils from each site after 10 days incubation in a 20 mM 1080 solution. Of these, 13 isolates showed measurable defluorinating ability when grown in a 1080 and sterile soil suspension. Two species, the bacteria Micromonospora, and the actinomycete Streptosporangium, have not been previously reported for their defluorinating ability. These results indicate that defluorinating micro-organisms are present in soils in south-eastern Australia, which adds weight to other studies that found that 1080 is subject to microbiological degradative processes following removal from the bait substrate. Soil micro-organism defluorination, in combination with physical breakdown and uptake by plants, indicates that fluoroacetate in soils and natural water ways is unlikely to persist. This has implications for the better informed use of 1080 in pest animal management programmes in south-eastern Australia.

A new hydrometallurgical process for extracting rare earths from apatite using solvent extraction with P-350

In this paper, a new process is proposed to recover rare earths from nitric acid leaching of apatite without interfering with the normal route for fertilizer production using solvent extraction with dimethyl heptyl methyl phosphonate CH3P(O)(OC8H17)(2) (P-350, B). In the present work, the leaching conditions are studied. In selected condition, apatite was dissolved in 20% (v/v) nitric acid solution at 60-70 degrees C while agitating. The most suitable acidity for extraction is 0.4 M HNO3. More than 98% of rare earths in apatite can be recovered using countercurrent extraction process with six stages when phase ratio = 0.5, and defluorination is unnecessary. The influences of phase ratio, stage number, acidity and salting-out agent on extractabilities Of P-350 are studied. The results show that rare earths can be separated with P-350 from Ca, P, Fe and other impurities. Mixed rare earth oxides (REO) of which purity is more than 95% with yield over 98% can be obtained.

Determination of fluoroacetate and fluoride in blood serum by capillary zone electrophoresis using capacitively coupled contactless conductivity detection

Fluoroacetate is a highly toxic species naturally found in plants and in commercial products (compound 1080) for population control of several undesirable animal species. However, it is non-selective and toxic to many other animals including humans, and thus its detection is very important for forensic purposes. This paper presents a sensitive and fast method for the determination of fluoroacetate in blood serum using capillary electrophoresis with capacitively coupled contactless conductivity detection. Serum blood samples were treated with ethanol to remove proteins. The samples were analyzed in BGE containing 15 mmol/L histidine and 30 mmol/L gluconic acid (pH 3.85). The calibration curve was linear up to 75 mu mol/L (R(2) = 0.9995 for N = 12). The detection limit in the blood serum was 0.15 mg/kg, which is smaller than the lethal dose for humans and other animals. Fluoride, a metabolite of the fluoroacetate defluorination, could also be detected for levels greater than 20 mu mol/L, when polybrene was used for reversion of the EOF. CTAB and didecyldimethylammonium bromide are not useful for this task because of the severe reduction of the fluoride level. However, no interference was observed for fluoroacetate.

Determination of fluoroacetate and fluoride in blood serum by capillary zone electrophoresis using capacitively coupled contactless conductivity detection

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Zero-valent iron mediated degradation of ciprofloxacin - Assessment of adsorption, operational parameters and degradation products

The zero-valent iron (ZVI) mediated degradation of the antibiotic ciprofloxacin (CIP) was studied under oxic condition. Operational parameters such as ZVI concentration and initial pH value were evaluated. Increase of the ZVI concentration from 1 to 5 g L−1 resulted in a sharp increase of the observed pseudo-first order rate constant of CIP degradation, reaching a plateau at around 10 g L−1. The contribution of adsorption to the overall removal of CIP and dissolved organic carbon (DOC) was evaluated after a procedure of acidification to pH 2.5 with sulfuric acid and sonication for 2 min. Adsorption increased as pH increased, while degradation decreased, showing that adsorption is not important for degradation. Contribution of adsorption was much more important for DOC removal than for CIP. Degradation of CIP resulted in partial defluorination since the fluoride measured corresponded to 34% of the theoretical value after 120 min of reaction. Analysis by liquid chromatography coupled to mass spectrometry showed the presence of products of hydroxylation on both piperazine and quinolonic rings generating fluorinated and defluorinated compounds as well as a product of the piperazine ring cleavage.

Synthese und Evaluierung von [18 F]-Fluormethyltosylat als prosthetische Gruppe für die 18 F-Fluormethylierung von ZNS-Liganden für die PET

Die 11C-Methylierung von Radioliganden ist eine weit verbreitete Markierungsstrategie für PET-Liganden. Aber die kurze Halbwertszeit des Kohlenstoff-11 von 20,3 Minuten limitiert seinen Nutzen. Daher ist die 18F-Fluoralkylierung eine Möglichkeit, Fluor-18, das eine Halbwertszeit von 109,8 Minuten hat, in Target-Moleküle einzuführen. Während die 18F-Fluorethylierung eine weitverbreitete Markierungsstrategie ist, wird die 18F-Fluormethylierung bisher nur selten angewendet. Eine Ursache dafür ist die geringe Stabilität der 18F-Fluormethylgruppe in vivo. Durch Substitution des Wasserstoffs in der 18F-Fluormethylgruppe durch Deuterium kann deren Stabilität jedoch deutlich erhöht werden. Dadurch kann die 18F-Fluormethylierung eine wichtige Synthesestrategie für ZNS-Liganden sein, bei denen große strukturelle Varianz zum Einführen des Fluor-18 nicht möglich ist. rnAls prosthetische Gruppen zur 18F-Fluormethylierung wurden [18F]Fluormethyltosylat und [18F]Fluor-[d2]methyltosylat mit radiochemischen Ausbeuten bis zu 50% synthetisiert. Die Reaktionsbedingungen der 18F-Fluormethylierung mit d2-[18F]FMT und die Abtrennung der Radioliganden wurden an einer Modellverbindungen und den drei Zielstrukturen [18F]Fluor-[d2]methylharmol, [18F]Fluor-[d2]methyl-MH.MZ und [18F]Fluor-[d2]methylflumazenil optimiert. Es konnten radiochemischen Ausbeuten zwischen 25 und 60% erzielt werden. rnMit allen drei ZNS-Liganden wurden Kleintier-PET-Studien durchgeführt. Das d2-[18F]FMH zeigte eine schnelle und 1,5fach höhere Anreicherung im Hirn innerhalb der ersten fünf Minuten als die Vergleichssubstanz [18F]FEH. Für d2-[18F]FM-MH.MZ wurde in vivo eine höhere spezifische Anreicherung des Radiotracers im frontalen Cortex beobachtet als bei der 18F-fluorethylierten Vergleichssubstanz. Für das [18F]Fluor-[d2]methylflumazenil konnte keine Aufnahme ins Hirn festgestellt werden, sondern es kam zur vollständigen Zersetzung des Radioliganden durch Defluorierung. d2-[18F]FMH und d2-[18F]FM-MH.MZ waren bei physiologischen Bedingungen zu mehr als 90% stabil.rn

Fluorine-18-labeled estrogens, progestins and corticosteroids for receptor-based imaging of breast tumors and target areas of the brain

Estrogens can be labeled with the positron-emitting radionuclide fluorine-18 (t$\sb{1/2}$ = 110 min) by fluoride ion (n-Bu$\sb4$N$\sp{18}$F) displacement of a 16$\beta$-trifluoromethanesulfonate (triflate) derivative of the corresponding estrone 3-triflate, and purification by HPLC. That sequence has been used to synthesize the 11$\beta$-methoxy 1 and 11$\beta$-ethyl 2 analogues of the breast tumor imaging agent, 16$\alpha$-($\sp{18}$F) fluoro-17$\beta$-estradiol (FES). Tissue distribution studies of 1 and 2 in immature female rats show high selectivity for target tissue (T, uterus) vs non-target (NT, muscle and lung), with T/NT ratios being 43 and 17 at one hour after injection for 1 and 2, respectively. The parent estrogen FES has previously been shown to display an intermediate value for tissue selectivity.