Determination of arsenic in crude petroleum and liquid hydrocarbons

Total arsenic was determined in crude petroleum and liquid hydrocarbons derived from crude petroleum by extraction with boiling water or boiling aqueous nitric acid (concentration 0.25 to 2.5 M), mineralization of the extracts with concentrated nitric/sulphuric acid, and reduction of the arsenate to arsine in a hydride generator. The arsine was flushed into a helium-DC plasma. The arsenic emission was monitored at 228.8 nm. The total arsenic concentration in 53 crude oil samples ranged from 0.04 to 514 mg L^–1 (median 0.84 mg L^–1). Arsenic was also determined in several refined liquid hydrocarbons and in a commercially available arsenic standard in an organic matrix (triphenylarsine in xylene). The method was checked with NIST 1634b Trace Elements in Residual Fuel Oil. The arsenic concentration found in this standard agreed with the certified value (0.12±0.2 g g^–1) within experimental error. Viscous hydrocarbons such as the fuel oil must be dissolved in xylene for the extraction to be successful. Hydride generation applied to an aqueous not-mineralized extract from an oil containing 1.67 g As mL^–1 revealed, that trimethylated arsenic (520 ng mL^–1) is the predominant arsenic species among the reducible and detectable arsenic compounds. Monomethylated arsenic (104 ng ml^–1), inorganic arsenic (23 ng mL^–1), and dimethylated arsenic (low ng mL^–1) were also detected. The sum of the concentrations of these arsenic species accounts for only 39% of the total arsenic in the sample.On leave from Department of Chemistry, Indian Institute of Technology, New Delhi, India     

Papierchromatographische Nachweis von Histamin in röntgenbestrahlten Histidinlösungen

The Science of Nature -     

The exuberant planet: A global look at the role of utilities in protecting biodiversity

Biodiversity is a critical environmental issue. Biodiverse species as a source of unique genetic information, for example, continues to provide society with lifesaving drugs and important industrial chemicals. Since US utilities are substantial landholders and virtually every aspect of utility operations are in some way tied to environmental/biodiversity issues, it is important and essential that the utility industry step forward as a leader. This paper details the past, present, and future role that utilities have played and need to play in the very important arena of biodiversity.