Coal, fly ash, slag, and combustion gases from a large cyclone-fed power plant 870 MW(e) were analyzed for a suite of elements. Mass balance calculations show that the sampling and analyses were generally adequate to describe the flows of these elements through the plant. Most Hg, some Se, and probably most Cl and Br were discharged to the atmosphere as gases.

Data obtained via tandem mass spectrometry are reported for ions derived from several explosives and related compounds. Electron impact ionization, isobutane chemical ionization, and negative chemical ionization methods were used to form ions from each of the compounds studied. These compounds include o-, m-, and p-nitrotoluene; m-dinitrobenzene; 2,4-dinitrotoluene; 2,4,6-trinitrotoluene; 2,4-dinitrophenol; picric acid; 1,3,5-trinitro-1,3,5-triazacyclohexane (RDX); 1,3,5,7-tetranitro-1,3,5,7-tetra-azacyclooctane (HMX); nitroglycerin; pentaerythritol tetranitrate (PETN); and ethylene glycol dinitrate (EGDN). For a given ionization method each class of compounds (that is, nitrobenzenes, heterocyclic nitramines, and nitrate esters) shows common decompositions. This promises to facilitate rapid screening for particular types of explosives by the neutral loss scanning procedure. Of the three ionization methods employed, electron impact ionization is least suitable for analysis of explosives by tandem mass spectrometry. Positive and negative chemical ionization methods, in contrast, tend to generate the types of ions most useful for analysis by tandem mass spectrometry.

No abstract

An ion exchange separation followed by a spectrographic determination has been developed for certain of the rare earths present in uranium compounds. This method permits the determination of dysprosium, erbium, europium, gadolinium, neodymium, samarium, and ytterbium at concentrations as low as 0.01 to 1 ppm. Hydrofluoric acid solutions of uranium containing the rare earth elements, with yttrium as an internal standard, were passed through a cation exchanger. The negatively charged uranium fluoride complex passed through the column while the rare earths were retained. After the residual uranium was completely removed by eluting with 2.5 M hydrofluoric acid, the resin bed was ignited, and the resulting ash analyzed spectrographically for the individual rare earth elements. Other cations which separate with the rare earths were easily separated, when necessary, by standard, wet chemical, group separations The standard deviation for the method was about 10%.

No abstract

No abstract