Determination of selenium, arsenic, iodine and bromine in fish, plant and mammalian oils by cyclic instrumental neutron activation analysis

Abstract

The concentrations of arsenic, selenium, iodine and bromine in a series of fish, plant and mammalian oils have been determined by cyclic instrumental neutron activation analysis (CINAA). Crude fish oils contain between 0.047 and 0.151 ~g Se g-l, 2.36-14.5 ~ig As g-~, 2.36-9.63 #g Br g-~ and 0.97-4.76 #gl g-~. Seal oil contains the same four elements, but at levels below the lower end of the fish oil ranges. Iodine, bromine and arsenic were not detected in rapeseed or soybean oils and the concentration of selenium varied from < 0.010 to 0.042 rig g-~. The levels of selenium, iodine and bromine are reduced markedly by hydrogenation of the menhaden oils. The CINAA method yielded results which were in agreement with published values obtained by other methods. The technique was rapid, requiring minimal sample manipulation, and was essentially free from interferences.

Assay of Iodine in Foodstuffs

“…The detection limit of the INAA mode can be moderately improved using cyclic INAA (Elson et al, 1983). Significant improvement of the detection limit is achieved by taking advantage of a high resonance integral for the reaction of 127 I(n,) 128 I (cf.…”

Iodine Content in Fish and Other Food Products from East Africa Analyzed by ICP-MS

“…Several different methods for determining iodine in foodstuff have been used, such as spectrophotometric kinetic assay (Mahesh et al, 1992), semiautomatic method (Moxon and Dixon, 1980), and iodidespecific ion electrode method (van Ryssen et al, 1987). An accurate method for determining small quantities (mg and ng) of iodine in foodstuff is by use of neutron activation analyses (NAA) (Elson et al, 1983;Norman and Iyengar, 1994;Rao and Chatt, 1993), but these methods are relatively time consuming and require extensive sample preparation. Inductively Coupled Plasma-Mass Spectrometry (ICP-MS), which is a rather newly developed technique, has been shown to combine the advantages of high sensitivity and high sample throughput without the need for extensive sample preparation.…”