Neutron activation analysis of stable heavy metals as multiple markers in nutritional monitoring

Abstract

A method is reported by which instrumental neutron activation analysis of various heavy metal elements has been applied to the monitoring of nutrient intake of laboratory animals. Some data are presented illustrating reproducibility. The scope of the method may be expanded by utiliza-

Dysprosium Chloride as a Nonabsorbable Gastrointestinal Marker for Studies of Stable Isotope-Labeled Triglyceride Excretion in Man

“…The %RSD for each set of standards was always better than 5% and ranged from 1.79% to 4.4%. These findings are consistent with previously published reports [5,10].…”

“…Dy content of subsamples taken from each sample of dry powdered stool was determined by neutron activation analysis DyCl 3 as Nonabsorbable Marker for 13 C-Lipid Absorption according to the method of Gray and Vogt [10]. Briefly, samples and a series of Dy-spiked fecal standards were irradiated in the fast pneumatic irradiation port of the University of Missouri research reactor (MURR) for five seconds.…”

“…Recently, however, several groups have shown that a number of lanthanide (rare earth) elements administered as simple inorganic salts exhibit negligible gastrointestinal (GI) absorption in man [3,5,9]. Because these nonabsorbable elements are present in very low amounts in human foods and the concentration of these elements can be measured with a high degree of accuracy in feces [3,5,10], only trace quantities need be administered. This reduces the potential for the marker to interfere with the absorption of the nutrient of interest.…”

“…Of the lanthanide elements, dysprosium (Dy) administered as DyCl 3 is particularly useful for this purpose [3,5]. Dysprosium in stool can be accurately quantitated using neutron activation [10], ICP-MS [3,5] or AAS [11]. Oral administration of a small dose of DyCl 3 concurrently with the stable-isotope-labeled mineral/ trace element permits accurate assessment of fecal excretion of the latter by laboratory analysis of small samples one or two stools for the ratio (labeled mineral/trace element)/Dy.…”

Dysprosium, Cerium and Chromium Marker Determination by Instrumental Neutron Activation Analysis

“…(Luckey et al 1915(Luckey et al , 1971(Luckey et al , 1919a (Carew 1973) prompted this investigation into the possibility of its measurement by INAA. It was therefore decided to develoo an analvtical procedure for these three elements, although other markers are possible and have been proposed (Gray and Vogt 1974 A"or-6.02x1023xq06 (1) M Upon removal from the reactor, the induced activity decays in the usual fashion with characteristic decay constant )t ()t:ln2lTt,"…”