Volume 71, Issue 11

Environmentally significant phosphorus species in water and phosphorus fractions in sediments are briefly discussed and the methods for their determination are described. One of the most critical analytical steps is the separation of the different forms which, after conversion into orthophosphates, may be determined by a multitude of various techniques. Spectrophotometric methods are often preferred for routine analysis. Several rapid automatic methods for the separation and determination of orthophosphate, linear polyphosphates, cyclic condensed phosphates and lower oxidation state anions of phosphorus, which may exist in natural and waste waters, have been developed. They are mainly based on the use of flow-injection analysis, high-performance liquid chromatography including ion chromatography, capillary electrophoresis and a few of other techniques. These methods have been described and critically evaluated.

Poly(hexano-6-lactone) (PCL*) fibers were degraded under environmental conditions, including soil burial, sea water exposure, and activated sludge exposure. The extent of degradation was examined by weight loss, mechanical properties loss such as tensile strength and ultimate elongation decreases, and visual observations by scanning electron microscopy. The rate of degradation was found to depend on draw ratio and crystallinity of the PCL fibers with surface erosion of amorphous regions more readily than crystalline regions. The life time of highly-drawn PCL fibers when exposed to soil burial and seawater was evaluated from the view point of environmental applications. In terms of degradation mechanism of PCL fiber breakdown biodegradation seems to be the dominant reaction, that is hydrolysis reaction catalyzed by enzyme secreted by microorganisms.

This report is the 17th in a series on spectrochemical methods of analysis issued by IUPAC commission V.4. It is concerned with the principles of laser absorption spectroscopy and its application in the optical wavelength region. The present report has four main sections: fundamentals of laser absorption spectroscopy, Doppler-limited spectroscopy; sub-Doppler laser spectroscopy, and time-resolved laser spectroscopy.