Chemistry Reference
In-Depth Information
CHAPTER
35
Nickel
*
CATHERINE KLEIN AND MAX COSTA
ABSTRACT
1 PHYSICAL AND CHEMICAL PROPERTIES
IARC, the International Agency for Cancer Re-
search, concluded in 1990 that nickel compounds
were human carcinogens, and most animal data
in
vivo
and genetic toxicology data
in vitro
before that
time suggested that the insoluble particulate nickel
species were the most carcinogenic; however, more
recent human epidemiology and experimental data
are pointing to the water-soluble nickel compounds
as perhaps of equal hazard. Accumulating molecular
and genetic toxicology data show that soluble NiCl
2
can, in fact, be mutagenic and genotoxic, especially
when cells are chronically exposed for long durations
up to several weeks to allow suffi cient nickel uptake.
On reconsideration of the previous experimental stud-
ies with shorter 24-48-hour acute exposures to the
insoluble nickel compounds
in vitro
, it is likely that
those actual nickel exposures were, in fact, of much
longer duration than previously thought because of
the unlikely removal of adherent nickel particles from
the cell surfaces.
This chapter briefly reviews some of the most
recent work on nickel uptake, metabolism, envi-
ronmental and occupational exposures, and human
disease epidemiology. Other resourceful reviews on
nickel include Costa
et al
. (2001), Costa (2002), and
Lu
et al
. (2005). The newest information on the mo-
lecular mechanisms of nickel's action in biological
systems is briefl y summarized herein, and the read-
er is specifi cally directed to Chapter 5 for additional
details.
*
Revised and updated from the chapter by Tor Norseth, 1986 edi-
tion of this Handbook
Nickel (Ni): atomic weight, 58.71; atomic number,
28; density, 8.9; melting point, 1453°C; boiling point,
2732°C; silver-white malleable metal; exists as oxida-
tion states of 0, +1, +2, and +3. Predominate compounds
of interest include nickel oxide, nickel hydroxide,
nickel subsulfi de, nickel sulfate, nickel chloride, and
nickel carbonyl. Nickel carbonyl [Ni(CO)
4
] is a vola-
tile, colorless liquid (boiling point 43°C) that decom-
poses at temperatures >50°C. Nickel salts of strong
acids and organic acids are soluble in water, whereas
salts of weak inorganic acids are insoluble. Nickel is
resistant to corrosion by air, water, and alkali. These
desirable properties, along with its metallic shine and
inexpensive costs, have made Ni metal alloys popu-
lar choices for use in body piercing jewelry (Vilaplana
et al
., 1991).
2 METHODS AND PROBLEMS
OF ANALYSIS
Routine measurements of nickel and nickel com-
plexes in a variety of matrices, including biological
samples (e.g., urine, blood), workplace atmospheres,
soil, water, and food crops can be obtained by analytical
methods, including mass spectrometry (MS), nuclear
magnetic resonance (NMR), infrared spectroscopy (IR),
UV-Vis spectroscopy, and EPR (electron paramagnetic
spin resonance) (reviewed in Chandra and Kumar,
2005). Some advanced mass spectrometry methods
that have been applied to study nickel complexes
include MALDI (matrix-assisted laser desorption/
