Fluorine determinations in biological materials by instrumental neutron activation analysis

Conference · Wed Jan 01 04:00:00 EST 1992 · Transactions of the American Nuclear Society; (United States)

OSTI ID:7202445

Demiralp, R; Guinn, V P; Becker, D A

Exploratory studies were carried out at the University of California, Irvine on several freeze-dried human diet materials and on two freeze-dried vegetation materials - all prospective reference materials. The University of California, Irvine equipment includes a 250-kW TRIGA Mark 1 reactor, 2.5 {times} 10{sup 12} n/cm{sup 2}{center dot}s thermal flux, 3-s sample transfer time, and a typical 18% Ge(Li)/4,096-channel gamma-ray spectrometer with a detector resolution of 3.3 keV at 1,332 keV. In these exploratory studies, it was found that it was not feasible to measure fluorine with adequate precision or accuracy at fluorine concentrations much less than {approximately}100 ppm. These initial studies, however, defined the magnitudes of the various difficulties. One good outcome of these studies was the demonstration that the otherwise excellent Teflon-mill brittle-fracture method for homogenizing freeze-dried biological samples was not suitable if fluorine was to be determined. Abrasion of the Teflon increased the fluorine content of a human diet sample about sevenfold (compared with similar treatment of the same material in an all-titanium mill).

• OSTI ID: 7202445
• Report Number(s): CONF-920606--
• Conference Information: Journal Name: Transactions of the American Nuclear Society; (United States) Journal Volume: 65
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400101 -- Activation
Nuclear Reaction
Radiometric & Radiochemical Procedures
560300* -- Chemicals Metabolism & Toxicology
63 RADIATION, THERMAL, AND OTHER ENVIRON. POLLUTANT EFFECTS ON LIVING ORGS. AND BIOL. MAT.
ACTIVATION ANALYSIS
BIOLOGICAL MATERIALS
CHEMICAL ANALYSIS
CHEMICAL COMPOSITION
FLUORINE COMPOUNDS
GAMMA SPECTROMETERS
HALOGEN COMPOUNDS
MATERIALS
MEASURING INSTRUMENTS
NEUTRON ACTIVATION ANALYSIS
PLANTS
SAMPLE PREPARATION
SPECTROMETERS