D.E. Ryan

The elemental composition of street dust from large and small urban areas related to city type, source and particle size

Abstract Twenty-six elements have been determined in street dust from London (U.K.), New York (U.S.A.), Halifax (Canada), Christchurch (N.Z.) and Kingston (Jamaica). The cities divide into two groups, London and New York (large urban) and Halifax, Christchurch and Kingston (small urban). The elements fall into two groups, those that originate mainly from soil (e.g. Al, K, Na, Th, Ce, La, Sm and Ti), and those (e.g. Ca, Cd, Pb, Cr, Zn, Cu and Au) that primarily originate from other sources, including cement, tyre wear, car emissions and salt. The first group of elements are in lower concentration in London and New York than in the other cities, while the reverse holds for the second group of elements. The concentrations of most elements increase with decrease in the size of the dust particles. The metals, Cd, Pb, Cu, Zn, Mn and Fe were sequentially extracted from the dust into five fractions, exchangeable metal, carbonate bound metal, MnFe oxide bound metal, organic bound metal and the residue.

Rapid multielement neutron activation analysis with a slowpoke reactor

Abstract The SLOWPOKE nuclear reactor meets many modern elemental analysis requirements; rapid multielement analysis of most types of samples is possible. The variable neutron flux (maximum 10 12 n cm -2 s -1 ) is stable, homogeneous and reproducible from day to day over a period of months. Sensitivities for 78 elements analyzed by neutron activation, with short irradiation and counting periods, have been determined; the conditions allow rapid multielement analysis with short sample turn-round time. Examples of the application of the technique to complex practical samples are given.

Multi-element analysis of blood for trace metals by neutron activation analysis

Fourteen elements can be rapidly determined in whole blood by the neutron activation analysis procedure described. Three of these (Ag, Cl, Se) are measured after a 10-s irradiation and eleven others (Al, Ba, Br, Ca, Cu, I, Mg, Mn, Mo, Rb, V) are determined by a 180-s irradiation of a 1-cm3 sample of whole blood after destruction of organic matter and removal of sodium by hydrated antimony pentoxide. A further 13 elements (As, Au, Co, Cr, Cs, Fe, Hg, K, Na, Ni, Sb, Sc, Zn) are determined after overnight irradiation in the SLOWPOKE reactor.

The elemental composition and sources of house dust and street dust

Abstract The elemental compositions of house dust, street dust and soil have been determined for 26 elements on material collected in Christchurch, New Zealand. The elements Hf, Th, Sc, Sm, Ce, La, Mn, Na, K, V, Al and Fe may be considered to be soil-based and contribute about 45–50% to house dust and 87% to street dust. The elements which are enriched (>3 times) in the dusts relative to the levels found in local soils, are Br, Cu, Cl, Pb, Zn, Cr, Ca, Co, As and Sb in house dust, and Zn, Cr, Cu and Pb in street dust.

The rapid determination of total bromine and iodine in biological fluids by neutron activation

Total bromine and iodine are instrumentally determined in 1 mL samples of body fluids by neutron activation under a boron shield at normal concentration levels. No sample treatment is necessary. Bromine is determined by its 80Br nuclide (617.0 keV; T1/2 = 18.0 min) and iodine by its 128I nuclide (442.7 keV;T1/2 = 25.0 min). The method is rapid; four bromine and two iodine determinations can be done in one hour. Bromine and iodine can be detected down to 14 micrograms/dL (1.75 mumol/L) and 2.9 micrograms/dL (0.23 mumol/L), respectively.

Substituted hydrazones as tridentate chelating agents

Abstract The compositions and stabilities of the metal chelates of two new tridentate ligands, pyridinc-2-aldehyde-2-quinolylhydraxonc and pyridinc-2-aldehyde-2-thiazo-lylhydrazone are reported. Cationic bis-chelates, which have been reported with similar ligands, are not formed during chelation with these ligands. The copper reaction, in which both mono- and bis-chelates are formed, is discussed in detail.

Thiobenzoylphenylhydroxylamine: potential analytical reagent

Abstract Thiobenzoylphenylhydroxylamine has been prepared and its reactions with metal ions compared to those of its oxygen analogue, benzoylphenylhydroxylamine. Acid dissociation constants and a few formation constants in 1:1 dioxane-water are reported. The thio compound is more reactive, more acidic, and forms chelates of generally greater stability.

Elemental Anomalies at the Cretaceous-Tertiary Boundary, Woodside Creek, New Zealand

Iridium and 26 other elements were determined in shale from the Cretaceous-Tertiary boundary at the locus classicus (for iridium anomalies) at Woodside Creek, New Zealand. Iridium, gold, copper, cobalt, chromium, nickel, arsenic, molybdenum, and iron were enriched in the basal 2 millimeters of the 8-millimeter shale parting as compared with the rest of the stratigraphic column. No other shale partings in the column had anomalous concentrations of any element when the data were expressed on a carbonate-free basis. The boundary material showed striking compositional similarities with the Stevns Klint Danish boundary shale. Elemental concentrations were in general much higher in the New Zealand material than in nonboundary shales from elsewhere in the world. The high concentration of iridium (153 nanograms per gram) in the basal layer of the boundary, together with the enrichment of other siderophile elements supports the idea of an extraterrestrial source for much of the material. The iridium/gold ratio of 2.1 is also in accordance with such a source. The iridium content of the basal layer is higher than for any other marine boundary shale obtained on land. The integrated iridium value is 187 nanograms per square centimeter of boundary surface.

Analytical applications of peroxyoxalate chemiluminescence

Abstract Peroxyoxalate chemiluminescence can be applied to the determination of hydrogen peroxide and aromatic hydrocarbon fluorophores in a static system. Hydrogen peroxide causes a linear response in the range 10 -6 –10 -1 M when bis(2,4,6-trichlorophenyl) oxalate is used with perylene as the fluorophore. As the intensity of chemiluminescence from different aromatic hydrocarbons varies substantially, there is a degree of selectivity in their determination. If metal chelates are employed as fluorophores, trace metal analysis is possible.

Spectrophotometric determination of palladium with pyridine-2-aldehyde-2-quinolylhydrazone

Abstract A new, sensitive colorimetric procedure for the determination of microgram quantities of palladium(II) with pyridine-2-aldehyde-2-quinolylhydrazone is described. The reaction is practically instantaneous and not sensitive to variations in salt concentration. The platinum group metals do not interfere, and the analysis is possible with milligram amounts of these metals present.