Ni Analysis by Atomic Absorption

Introduction

Nickel is obtained by combusting various nickel- containing ores, such as garnierite, niccolite, pentlandite, etc., and then reducing the oxide using carbon. Ni is a silver-white metal with abundant malleability and ductility, however, since it is extremely stable at ambient temperatures, it is widely used for plating. The alloys of nickel include stainless steel (Ni 8%, Cr 18%, with the main constituent being Fe), cupronickel used for coin (Ni 25%, Cu 75%), white metal used for art objects, musical instruments, tableware, etc. (Ni 10 – 20%, Cu 40 – 70%, Zn 20 – 30%), nichrome used in heating elements (Ni 60 – 80%, Cr 10 – 20%, Mn 1 – 2%), etc. In addition, it is used in a wide range of fields, including electrode materials in Ni-Zn batteries and Ni-Cd batteries, as a catalyst in organic synthesis, etc. Ni is present at the rate of about 143μg/kg in the human body, with its greatest concentration in bones. Since there is almost no absorption of Ni from the intestine, it is presumed that oral toxicity is low, although nickel sulfide and nickel oxide, etc. are carcinogenic and can cause allergies. Nickel alloys used in accessories become ions when in contact with skin, and when they form bonds with biological substances, they act as haptens (weak antigens) showing strong antigenicity. As a result, an immune reaction occurs in the body, causing skin inflammation and other symptoms. Ni has a high melting point and high boiling point, and it cannot be easily atomized. Thus it is one of the elements for which it is difficult to obtain good sensitivity. However, we introduce here an example of high sensitivity analysis using concentration-boosting inside the furnace.

November 25, 2005 GMT