Neutron Activation Analysis Procedure Research Articles

Neutron Activation Analysis for the Detection of Firearm Discharge Residues Collected on Cotton Swabs

Abstract Cotton swabs moistened with 5% HNO3 are frequently used by police investigators to process a suspect’s hands for the presence of gunshot residue. A neutron activation analysis procedure is described for testing these swabs for barium and antimony, which are commonly found in firearm residues. The limitations of the method are also discussed.

A neutron activation analysis procedure for the determination of uranium, thorium and potassium in geologic samples

A neutron activation analysis procedure was developed for the determination of uranium, thorium and potassium in basic and ultrabasic rocks. The three elements are determined in the same 0.5-g sample following a 30-min irradiation in a thermal neutron flux of 2·1012 n·cm−2·sec−1. Following radiochemical separation, the nuclides239U (T=23.5 m),233Th (T=22.2 m) and42K (T=12.36 h) are measured by β-counting. A computer program is used to resolve the decay curves which are complex owing to contamination and the growth of daughter activities. The method was used to determine uranium, throium and potassium in the U. S. Geological Survey standard rocks DTS-1, PCC-1 and BCR-1. For 0.5-g samples the limits of detection for uranium, throium and potassium are 0.7, 1.0 and 10 ppb, respectively.

Mercury pollution of Lake Erie ecosphere

The distribution of mercury in the ecosphere of Lake Erie was monitored using a highly sensitive and reliable neutron activation analysis procedure. A variety of samples from the fauna and flora of the lake as well as those from its immediate environment were analyzed for their mercury content. The results of this survey indicate a widespread distribution of mercury in air particulates; coal samples of the region; sediments, plankton/algae and fish samples from the lake; and in the brain tissues of long-time residents of the Lake Erie Basin.

Neutron Activation Analysis of Inorganic Constituents of Airborne Particulates

The applications of neutron activation analysis for the routine monitoring of airborne inorganic pollutants were investigated. The use of several filter media were studied and two suitable filter materials (Millipore EHWP04700 and Dexter X-1215) were chosen for this investigation. An air sampling procedure was used to obtain several representative samples during the period of monitorinsg. A non-isolative neutron activation analysis procedure involving multiple neutron irradiation and high resolution gamma-ray spectrometry was used to determine the concentrations of 16 elements found in the airborne particulates in samples collected over a 1-year period from the Buffalo, New York area. Differences from previous studies are due to higher filter efficiency and the particular local industrial workup.The findings of this investigation indicate that in the analysis of the elemental composition of air pollutants, neutron activation techniques can compete well with other analytical methods.

Instrumental activation analysis for determining the composition of micro-ingots of multi-constituent alloys

A procedure for the instrumental neutron activation analysis of micro-ingots of alloys containing In, Sb, Au, Ga, Ni, Sn and Bi is proposed. The non-destructive analysis of the irradiated samples is performed by γ-spectrometry techniques including one-crystal scintillation detectors, dual-crystal sum-coincidence scintillation detectors and Ge(Li) semiconductor detectors. As a result, the cumbersome operations of radiochemical separation can be eliminated. The sensitivity of quantitative determinations using scintillation detectors in alloys of the above composition is 10−10 g for indium, gold, antimony and gallium and 10−6 g for nickel and tin. The use of semiconductor detectors yields sensitivities of 10−10 g for indium and gold and 10−9 g for gallium and antimony.

Bestimmung von Si, Cl, K, P, Ca und Al in biologischem Material durch Aktivierungsanalyse mit 14 MeV Neutronen

A neutron activation analysis procedure utilizing 14 MeV neutrons produced by an accelerator is described. The six elements Si, Cl, K, P, Ca and Al are determined in biological material without any chemical separation. For avoiding the interpretation of very complex spectra, the half-life of the nuclides was applied for the measurement as an important characteristic.

A neutron activation analysis method for the determination of Be, Li, B, F, and Pb

A neutron activation analysis procedure that utilizes reactor pulsing, rapid sample transfer and a Cerenkov counter for the determination of Be, Li, B, and F via very short-lived radioisotopic indicators is shown to give analytical sensitivities for these elements of 15μg, 0.0008μg, 1.1μg, and 0.83μg, respectively. Use of a NaI(Tl) counter coupled to the same system enables the detection of 0.4μg of Pb via 0.8 second207mPb.

Application of Neutron Activation Analysis to the Microanalysis of Gold-Containing Pharmaceuticals in Biological Materials

A neutron activation analysis procedure was designed for the microanalysis of gold-containing compounds, which eliminates all prior chemical separation and permits direct qualitative and quantitative analysis for gold in a γ-ray scintillation spectrometer. The method was further applied to the determination of gold in biological tissues at the 5 to 60 mcg. level following administration of gold thioglucose.