Mass spectrometry of technetium at the subpicogram level

Abstract

We have developed a method to determine >10* atoms of **Tc or *7Tc and 5 X 10* atoms of **Tc by negative thermal ionization mass spectrometry. Interferences from Isobaric Impurities or hydrocarbons are equivalent to 5 X 10* atoms of technetium or less. Lanthanum oxide Ion enhancers In conjunction with Ca(N03)2 are added to single, zone-refined rhenium filaments to achieve Ionization efficiencies that are >2% for the formation of Tc04~.

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 %).…”

“…TIMS with multiple ion collectors is generally the method of choice for isotope ratio measurements with high precision (down to 0.002 %). 99 Tc levels from 10 -9 g down to less than 10 -15 g (6×10 6 atoms) have been successfully measured with ionization efficiencies of more than 2 % using negative thermal ionization [118]. However, the interferences from iodine (I -) and the complex molecule molybdenum fluoride trioxide (MoFO 3 -) are the main problems in analysis of environmental samples using TIMS.…”

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

“…The long half-life of 99 Tc (0.211 My) and low specific activity (6.3 × 10 8 Bq/g) makes mass spectrometry a sensitive method for the determination of 99 Tc, AMS [192][193][194], TIMS [195][196] and ICP-MS [46][47][48][49][50][51][52][53]197] have been used for the determination of 99 Tc. In AMS, the separated TcO 4 -is mixed with Al or Nb to prepare a target, the sputtered TcO -ions is then stripped to TcO 14+ , separated in mass spectrometry, and measured by a gas ionization chamber.…”