Pii: S0584-8547(98)00100-1
نویسنده
چکیده
The thermal stabilization characteristics of mercury species (inorganic and organic) in the presence of different chemical modifiers, including PdCl2 + ascorbic acid, (NH4)2PdCl6 + citric acid, (NH4)3RhCl6 + citric acid and a mixture of the last two salts, were investigated. The results indicate that PdCl2 + ascorbic acid can stabilize mercury species upto a temperature of 5008C whereas, with the mixed (NH4)2PdCl6–(NH4)3RhCl6 modifier, mercury can withstand a pyrolysis temperature as high as 9208C and can tolerate much higher concentration of interferents than with palladium or rhodium alone. The integrated absorbance for mercury was also much increased in the presence of the mixed modifier. The characteristic mass, which gives an integrated absorbance of 0.0044 s for mercury, is found to be 59 pg, and the absolute detection limit, based on the variability of the blank (3j), is 38 pg. The proposed (NH4)2PdCl6–(NH4)3RhCl6 mixed modifier has been applied to the determination of low levels of mercury in cosmetics with a recovery range of 97%–103%. q 1998 Elsevier Science B.V. All rights reserved
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