Serum cesium

There are many examples of relatively straightforward use of ICP-MS for the analysis of biological fluids. Antimony has been measured in blood after a 14 1 dilution [236]. Cesium serum levels were found to be elevated in patients with alcohol dementia but not in Alzheimer s disease patients [237]. Cobalt levels in rat serum depended on the form of cobalt [238] ingested. Bismuth levels were measured in human blood and urine by using a direct injection nebulizer [239]. Lead was measured in the blood and blood plasma of smelter workers and the general population [240]. The measurement of trace elements in serum by ICP-MS has been compared to results from neutron activation analysis and proton-induced x-ray emission [241]. Semiquantitative analysis can also be used to obtain a rapid screening of samples [242]. 

Kumar et al. 1989 Study of groups of depressed, manic, recovered, and normal individuals no differences in hair, whole blood, serum, or urine levels of cesium. 

Fig. 1 (on p. 152). HP-Ge spectrum of a multielement standard (serum doped with chromium, iron, cobalt, zinc, selenium, rubidium, antimony, and cesium) irradiated 7 times for approximately 7 h at a neutron flux of 1.77-10 n-cm -s and counted for 12 h, 18 days after the end of the irradiation. The figure illustrates the excellent resolution of modern radioactivity counting equipment. As soon as their energies differ by some 5 keV, photopeaks are sufficientiy resolved to allow the calculation of their number of counts as in the case of the 563.2 and 569.3 keV and the 795.8 and 801.9 keV gamma ray photopeaks of Xs (indicated by i ). Only when their energies differ only by 2 or 3 keV, they largely overlap as exemplified by the 602.7 keV and 604.7 keV photopeaks, respectively of Sb and Xs (indicated by s ). 

Versieck, J. Hoste. J., Barbier. F., Michels, H. and De Rudder, J. (1977). Simultaneous determination of iron, zinc, selenium, rubidium and cesium in serum and packed blood cells by neutron activation analysis. Clin. Chem. 23,1301. 

In addition to varying the substrates, other authors have worked on the conditions in order to extend the scope of the reaction. In particular, MW [127] and ultrasound [128] irradiations have been applied successfully, decreasing considerably the reactions times. On the other hand, different catalysts have been used substituting the classical secondary or tertiary amines [129], for example, L-proline [130], imidazole [131], cesium carbonate (Cs COj) [132], amine-functional polysiloxanes (AFPs) [133], MgAa mixed oxide as a heterogeneous solid base catalyst [134], ZnO (under solvent-free conditions) [135], bovine serum albumin (BSA) [136], and guanidine-based IL [137]. 

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