Application of an iodide-specific resin to the determination of iodine in biological fluids by activation analysis

Abstract

Foreign ions present (weight excess over P) 0.150 0.152 + 1.33 Ca(20), Fe(10), Cu(15) 0.300 0.295 -1.67 Al(30), Si(30) 0.300 0.296 -1.33 Zn(30), Pb(20) 0.400 0.420 +5.00 Asm(10), Cd(20) 0.250 0.260 +4.00 Se(20), Te(20) 0.200 0.200 0.0 Bi(15), Cu(20) 0.350 0.335 -4.30 W(20), Sb(25), Ge(25) 0.080 0.079 -0.62 Si(15), Ni(10) " Each result is the average of two determinations in good agreement.which the Rhodamine B recovered in the final butanolchloroform phase from the complex after its formation from known amounts of phosphorus was determined fluorimetrically. Allowance for depletion of the Rhodamine B concentration in the final chloroform-butanol phase due to the chloroform extractions, which promote the dissociation of the complex by removal of the excess reagent, was made. The overall cumulative formation constant, A, defined as [RhB-MPC]/[MPC][RhB]3, under these conditions was estimated to be 1.6 ± 0.3 X 1011 liter3 mole-3.Conclusions. High sensitivity is obtained for the determination of phosphorus by the spectrofluorimetric method developed. The sensitivity achieved is higher than that for most other methods based on the formation of molybdophosphoric acid, and compares favorably with that of more complex enzymatic methods. High selectivity is achieved with the optimum conditions established. Of the ions investigated, only arsenic(V) interferes seriously, by formation and extraction of the corresponding Rhodamine B molybdoarsenate; arsenic (III), however, may be tolerated when present in moderate excess with respect to phosphorus.

Determination of Chemical Species of Iodine in Seawater by Radiochemical Neutron Activation Analysis Combined with Ion-Exchange Preseparation

“…The iodine contents in iodine standard solution as KIO 3 and seawater spiked KIO 3 solution were determined by direct extraction after irradiation, and the results are the same as those in the same water but being treated with 0.5 mL of 0.3 mol/L KHSO 3 solution before extraction. UV irradiation was usually used for conversion of organic iodine in seawater to inorganic iodine. ,, It has also been reported that activation in the reactor (irradiation with a strong flux of thermal neutrons and γ-, β-, and X-rays) can rupture irreversibly any organically bound iodine in biological fluid and convert organic iodine to iodide. ,− Byrne et al found that the chemical yield of iodide in the serum spiked with thyroxine was the same as that in serum spiked with KI after irradiation at a neutron flux of 4 × 10 12 n cm -2 s -1 for 4 min. Smith et al also reported that the value of iodine determined as iodide in protein bound iodine after irradiation with reactor neutrons was the same as that determined by chemical ashing decomposition.…”

“…In addition, it has been reported that organic iodine (e.g., thyroxine, protein bound iodine, etc.) was not adsorbed by an anion-exchanged column or can be easily eluted by deionized water. − Thus, this method can also be used to separate I - , IO 3 - , and organic iodine from each other.…”

Determination of iodine in urine by neutron activation analysis. Application of the Szilard-Chalmers effect

“…The iodine in urine samples irradiated by thermal neutrons from a nuclear reactor is chemically activated by the 127 ( , )128 (T1/2 = 25.2 min) reaction. In an effort to develop a semi-automated separation system for iodine analyses in biological fluids Heurtebise et al (7)(8)(9) simply used a specific iodinated resin to separate the iodide-128 from the irradiated biological fluid. Based on the work of Comar and LePoec (10,11) they assumed that neutron activation of their biological liquids ruptures the organic iodine ligand so that the total iodine measurement can be achieved by iodide separation, using anion exchange chromatography.…”

“…6) Assay the 128I activity exactly 25 minutes after the neutron irradiation employing a Ge(Li) detector described previously. 7) Irradiate approximately 5 ml of standard NH4I solution for 30 minutes at the same neutron flux as the urine in the preceding steps. 8) Dilute exactly 2 ml of the standard with water to a 4-ml volume in a polyethylene counting tube in order to obtain the same counting geometry as that employed in step 3.…”

A study of iodine loss during the preparation and analysis of samples using 131I tracer and neutron activation analysis

“…However, few papers describing detailed studies of iodine stability in the preparation and analysis process are available. Belling et al 5,6 studied the recovery of iodine in dry, alkali ash and acid digestion, Zaichick and Zaichick 7 and Ishikawa et al 8 studied the loss of iodine in lyophilisation of biological samples and Heurtebise and Ross 9 and Byrne et al 10,11 investigated the loss of iodine in neutron irradiation. However, in all these papers, the analyte investigated was total iodine in the samples, and no study of the stability of different chemical species of iodine in the sample preparation process was reported.…”