Organic matrices, antimony

Methods applicable to the determination of trace quantities of antimony in organic matrices, except for neutron activation analysis, require the matrix to be destroyed before the antimony is measured. Wet oxidations using nitric, sulfuric, and perchloric acids have been used for samples of blood and tissue (3), and low temperature ashing has been used for samples of filter paper and ion exchange resins (4). 

Nickel is often used as matrix modifier in the determinations of arsenic and selenium. Nickel stabilizes arsenic up to about 1700 K, and selenium up to about 1500 K. This is presumably due to the formation of thermally stable nickel arsenide and nickel selenide. Nickel can also be used to stabilize bismuth, antimony, and tellurium. In addition, copper, silver, molybdenum, palladium, and platinum salts have been proposed as stabilizers for these elements. Palladium and platinum are the most suitable matrix modifiers for both inorganically and organically bound tellurium. Pretreatment temperatures up to 1320 K can be used. The effect of different matrix modifiers on the determination of antimony are shown in Figure 74. Without matrix modifiers the losses of antimony begin at 1000 K. Palladium, molybdenum, and nickel are the most suitable to stabilize antimony and with these modifiers pretreatment temperatures up to about 1600 K can be used. 

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