Spark source mass spectrometry detection limits

Because GDMS can provide ultratrace analysis with total elemental coverage, the technique fills a unique analytical niche, supplanting Spark-Source Mass Spectrometry (SSMS) by supplying the same analysis with an order-of-magnitude better accuracy and orders-of-magnitude improvement in detection limits. GDMS analy-... 

Table 8.60 shows the main features of GD-MS. Whereas d.c.-GD-MS is commercial, r.f.-GD-MS lacks commercial instruments, which limits spreading. Glow discharge is much more reliable than spark-source mass spectrometry. GD-MS is particularly valuable for studies of alloys and semiconductors [371], Detection limits at the ppb level have been reported for GD-MS [372], as compared to typical values of 10 ppm for GD-AES. The quantitative performance of GD-MS is uncertain. It appears that 5 % quantitative results are possible, assuming suitable standards are available for direct comparison of ion currents [373], Sources of error that may contribute to quantitative uncertainty include sample inhomogeneity, spectral interferences, matrix differences and changes in discharge conditions. 

Actinide metal samples are characterized by chemical and structure analysis. Multielement analysis by spark source mass spectrometry (SSMS) or inductively coupled argon plasma (ICAP) emission spectroscopy have lowered the detection limit for metallic impurities by 10 within the last two decades. The analysis of O, N, H by vacuum fusion requires large sample, but does not distinguish between bulk and surface of the material. Advanced techniques for surface analysis are being adapted for investigation of radioactive samples (Fig. 11) ... 

Tipton et al. [22] spectrophotometrically analyzed normal tissues from autopsied humans from throughout the world and found less than 0.1 ppm indium. In dried blood plasma, indium was not detected by spark source mass spectrometry (0.07 ppm detection limit) [23]. Neutron activation analysis of human hair determined there to be less than 2.8 ppm indium present [2]. Estimates of dietary intake of indium for humans in the United States range from 8 pg/day [24] to 10 xg/day [25],... 

Spark-source mass spectrometry can detect all elements, with sensitivities often as good as 1 ng/g. Residual gases in the vacuum system restrict detection limits for carbon, oxygen, and nitrogen to... 

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