Radiochemical analysis of 41Ca and 45Ca

A review on speciation of iodine-129 in the environmental and biological samples

“…Gamma and X-ray spectrometry have been used to measure 129 I in thyroid, urine, seaweed, and nuclear waste by using HpGe or plenary Si detector [104][105][106][117][118]. This is based on the counting the 39.6 keV γ-ray or 29.46+29.48 keV (58.1%) X-rays.…”

“…This is based on the counting the 39.6 keV γ-ray or 29.46+29.48 keV (58.1%) X-rays. Due to the low counting efficiency of gamma detector (< 2%), low γ-ray abundance (7.5%), and high background, a detection limit of 20-200 mBq was obtained [104,[117][118] depending on the level of interfering radionuclide. In addition, due to the low energy of X-γ rays (29-40 keV) and normally big sample used (50 -500 g), elaborative self-absorption correction has to be carried out in order to obtain accurate results.…”

“…In this method, iodine has to be separated from the sample matrix as well as other radionuclides before counting. A detection limit of 10 mBq has been reported [117].…”

Critical comparison of radiometric and mass spectrometric methods for the determination of radionuclides in environmental, biological and nuclear waste samples

“…41 Ca is also used as a tracer in the biomedical research [145], which requires a very sensitive determination of 41 Ca because of the small sample size normally available. 41 Ca decays to the ground state of 41 K by pure electron capture, emitting X-rays and Auger electrons of very low energy (3.3 keV, 11.7%), which makes it possible, although difficult, to be measured by X-ray spectrometry [146] and LSC [19,[147][148]. X-ray spectrometry is a simple method, but it is insensitive due to the low counting efficiency (< 0.08%) of X-ray spectrometry for 41 Ca and the low abundance of X-rays from 41 Ca (11.4% for 3.31 keV K α X-ray).…”

41Ca and Accelerator Mass Spectrometry to Monitor Calcium Metabolism in End Stage Renal Disease Patients

“…The advantage of combining a marker such as 41 Ca (low noise) with a technique with attomole sensitivity, such as accelerator mass spectrometry (AMS), 6 is that excellent signal/noise ratios can be obtained from nanogram quantities of isotopes administered (4 -12 ). 41 Ca has a half-life of 104 000 years and decays by electron capture to the naturally occurring and stable isotope 41 K, emitting x-rays and electrons of very low energy (Ͻ3.6 keV) in the process (13,14 ). For biological experiments, 41 Ca is typically prepared by irradiating calcium samples with neutrons in a nuclear reactor.…”