Ultratrace Analysis of Technetium

Abstract

Technetium, trace analysis / Radiometrie methods, mass spectrometry, induetively coupledplasma mass spectrometry / Laser resonance ionization mass spectrometry Abstract For radioecological studies and for the measurement of the boron-8 solar neutrino flux in a geochemical experiment small amounts of technetium have to be determined. The applicability of radiometric methods as well as of mass spectrometry and induetively coupled plasma mass spectrometry for trace analysis of technetium is briefly discussed. In more detail laser resonance ionization mass spectrometry (RIMS) for low-level measurements is presented. Using a three-step, three-colour excitation and ionization scheme an overall detection efficiency of 2 x 10"® was obtained resulting in a detection limit of «10^ atoms (1.6 fg) of technetium. With a reflectron time-of-flight mass spectrometer the sensitivity of RIMS can further be improved by one order of magnitude. By means of a laser ion source, made of extremely pure pyrolytically coated graphite, an enhancement by two Orders of magnitude is possible.

Determination of technetium-99 in environmental samples: A review

“…With the advantages of high sensitivity and short analysis time, MS has been applied in many areas and studied extensively, in recent years for measurement of 99 Tc, especially in low level environmental samples [14][15][16][17][18][19][20][21]112,[117][118][119]]. The first trace-level analysis of 99 Tc using MS was reported by Anderson et al [87].…”

“…Since then, extensive measurement of 99 Tc has been carried out using this technique. So far, several MS techniques, including AMS [14][15][16], RIMS [112,117], TIMS [17,118,119], and the popular ICP-MS [18][19][20][21], have been introduced to determine the concentration of 99 Tc.…”

“…Thermal ionization mass spectrometry (TIMS) and resonance ionization mass spectrometry (RIMS) are two of the more important of these [17,112,[117][118][119]. TIMS with multiple ion collectors is generally the method of choice for isotope ratio measurements with high precision (down to 0.002 %).…”

“…For instance for measurement using RIMS, the separated 99 Tc is electroplated or evaporated onto Re filaments [112]. The source for AMS is normally prepared as oxides, and is pressed in a target holder.…”

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

“…RIMS as a highly selective and sensitive mass spectrometric technique for ultratrace and isotope analysis has been used for the analysis of many radionuclides such as 41 Ca, 90 Sr, 99 Tc, 135 Cs, 210 Pb, 236 U, 238 Pu, 239 Pu, 240 Pu, 242 Pu, and 244 Pu in environmental, biological and waste samples [33,34,[94][95][96][97][98][99][100][101][102][103][104][105]. In RIMS the solid or liquid samples are vaporized and atomized by an atomic beam source (e.g.…”