This manuscript describes a new protocol for determination of Pa/Th/U in marine sediments. It is based on microwave-assisted digestion and represents an important reduction of working time over conventional hot-plate digestion methods, and the use of HClO(4) is avoided. Although Th and U are completely dissolved with a first microwave step, around 40% of (231)Pa remains undissolved, and a short...

The scope of this study was the removal of ammonium by ion exchange from simulated wastewater. The study looks at the effect of organics upon ammonium ion exchange equilibrium uptake. The ion exchangers included a natural zeolite clinoptilolite, and two polymeric exchangers, Dowex 50w-x8, and Purolite MN500. The organic compounds studied included citric acid and a number of proteins. The tradit...

A large scale isolation of a disaccharide from a dialyzable fraction cf Micrococcus Zysodeikticus cell wall is described. This fraction was obtained by degradation of isolated walls with egg white lysozyme. After purification by chromatography on charcoal-Celite 2nd Dowex 1, the compound was characterized by a crystalline heptaacetyl methyl ester. Comparison with synthetic 0-2-acetamido-2-deoxy...

1,9-Diamino-5-azanonane (1, H2N(CH2)4NH(CH2)4NH2), symmetrical “homospermidine,” previously unreported in nature, has now been discovered in sandal (Santalum album L.), where it comprises 0.5-1.5% of the weight of the dried leaves. The new polyamine is conveniently isolated from an aqueous extract of the leaves by ion-exchange 1^) uring a routine examination of the amino acids from an ethanolic...

Abstract The copolymerization of glycidyl cinnamate (GC) as a hitherto non‐polymerizable, photoreactive epoxide structure to aliphatic polyether copolymers is described, using the monomer‐activated ring‐opening polymerization (MAROP). Ethoxyethyl ether (EEGE) and GC are copolymerized employing triisobutylaluminum ( i ‐Bu 3 Al) catalyst tetraoctylammonium bromide (NOctBr 4 ) an initiator. amount...

The extraction of the exopolymeric matrix is a prerequisite to properly assessing the composition of the biofilm. Several extraction methods have already been developed, however, no universal method has yet been adopted because the compromise between high yields of extraction and minimum cell lysis is difficult to establish. In fact, most of the extraction methods promote leakage of intracellul...

The presence of amino acid nitrogen in the non-protein nitrogen fraction of blood plasma was first established in 1912 by Van Slyke and Meyer (1). Chemical, microbiological, and chromatographic techniques have subsequently been employed to determine many of the individual amino acids which contribute to the total or-amino nitrogen as currently measured by the ninhydrin-CO2 method of Hamilton an...

The extraction of the exopolymeric matrix is a prerequisite to properly assessing the composition of the biofilm. Several extraction methods have already been developed, however, no universal method has yet been adopted because the compromise between high yields of extraction and minimum cell lysis is difficult to establish. In fact, most of the extraction methods promote leakage of intracellul...

We describe a mechanized method for determining total estrogens in plasma during the last trimester of pregnancy. This method involves rapid enzymic hydrolysis, automatic extraction (in a tube) with cyclohexane/ethyl acetate, purification of the extracted material by anion-exchange chromatography on a disposable "mini-column" of Dowex AG1 X 2 (acetate form), and continuous-flow fluorometric qua...