Bismuth determination design

Figure S.2 shows a schematic diagram of the automatic hydride/vapour-generator system designed by P.S. Analytical. This has been widely used to determine hydrideforming elements, notably arsenic, selenium, bismuth, tellurium and antimony, in a wide range of sample types. To provide a wide range of analyses on a number of matrices the chemistry must be very well defined and consistent. Goulden and Brooksbank s automated continuous-flow system for the determination of selenium in waste water was improved by Dennis and Porter to lower the detection levels and increase relative precision [10, 11]. The system described by Stockwell [9] has been specifically developed in a commercial environment using the experience outlined by Dennis and Porter.

Choosing divalent and trivalent cations and determining the composition is the most important in designing the multicomponent bismuth molybdate catalyst system. Catalytic activities of typical tri- and tetracomponent bismuth molybdate catalysts having multiphase structure were reported for the oxidation of propylene to form acrolein (35, 36, 40-43, 97, 98). A typical example of the activity test is shown in Fig. 6. Summarizing the results shown in Fig. 6 and reported previously (30, 43, 44), the following trends are generally found. 

Fig. 4.8 FIA assembly for continuous generation of hydrides and transport to the quartz cell of the atomic absorption spectrometer, designed for the determination of bismuth traces. (Reproduced from [4] with permission of the American Chemical Society).

Solution properties. Little work has been done on determining physical properties of the solutions. The available results indicate that the. mall amount of dissolved material does not appreciably affect the phy. ical properties of density, viscosity, heat capacity, and vapor pressure. I or design purposes, the properties of pure bismuth can probably be used with. safety. 

---