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Title: Determination of selenium in blood by pseudo-cyclic instrumental neutron activation analysis

Conference · · Transactions of the American Nuclear Society; (United States)
OSTI ID:5596374
;  [1]
  1. Dalhousie Univ., Halifax, Nova Scotia (Canada)

There is increasing interest in understanding the role of selenium in human and animal metabolism. Analytical methods are being developed in several laboratories for the determination of total selenium in whole blood, serum, urine, soft and hard tissues, food, water, etc. The levels of selenium in human blood are generally too low for direct determination by most analytical techniques except neutron activation analysis (NAA). Selenium has six stable isotopes that produce seven nuclides on thermal neutron activation. Among these nuclides, {sup 77m}Se and {sup 75}Se are most suitable for measurement by instrumental NAA (INAA). The 264.6-keV gamma ray of {sup 75}Se is free from interference and is commonly employed. The use of this long-lived nuclide generally requires lengthy irradiations at a high neutron flux, decay, and counting periods that could take up to 2 to 3 weeks of experimental time. Obviously, it is a time-consuming and expensive procedure and may not be suitable for routine analysis of a large number of samples for selenium in blood. Alternatively, the short-lived {sup 77m}Se nuclide can be used in routine INAA to considerably reduce the total experimental time and cost. Although the conventional INAA procedure involving a one-shot irradiation-decay-counting scheme can be used, precision and detection limit can be significantly improved by using cyclic INAA (CINAA). In CINAA, a sample is irradiated for a short time and is rapidly transferred to a detector for counting for a short period. The entire process is immediately repeated for an optimum number of cycles. If several days are allowed to elapse between repetitions of the irradiation-decay-counting cycles, then the technique is called pseudo-cyclic INAA (PCINAA). A PCINAA method has been developed in this laboratory for the determination of selenium in human whole blood and serum samples.

OSTI ID:
5596374
Report Number(s):
CONF-910603-; CODEN: TANSA
Journal Information:
Transactions of the American Nuclear Society; (United States), Vol. 63; Conference: Annual meeting of the American Nuclear Society (ANS), Orlando, FL (United States), 2-6 Jun 1991; ISSN 0003-018X
Country of Publication:
United States
Language:
English