SIMPLE GRAPHITE FURNACE ATOMIC ABSORPTION
SPECTROMETRY METHOD FOR DETERMINATION
OF NICKEL IN URINE.
Rocío Castroa, Isel Cortesa,b* and Manuel Leivaa,b
Centro Nacional del Medio Ambiente (CENMA)
Av. Larrain 9975, CP 788-0096 La Reina, Santiago, Chile.
Centro de Química Ambiental.
Facultad de Ciencias, Universidad de Chile,
Casilla 653, Santiago, Chile.
Nickel is normally present at very low levels in biological samples. Graphite furnace
atomic absorption spectrometry techniques (GFAAS) is one of the most useful and
powerful analytical technique for the determination of trace and ultra-trace
elements in biological and clinical samples. The aim of this research was to develop
a simple and fast method for the determination of Ni in urine by GFAAS. Urine
samples were directly collected from children in the north of Chile using properly
identified polyethylene bottles. It were stored to 4°C. For analysis, samples were
placed to room temperature, filtered through a Millipore membrane filter and
diluted with concentrated nitric acid in a clean polyethylene container. Triton X-100
was added and manually shaken for proper mixture. 20µl of the sample were
injected in the furnace of the atomic absorption spectrometer 939/959 Unicam.
Pyrollytically coated graphite furnace and automatic deuterium background
correction were used. The main figures of the developed procedure are described
as: recovery 92,9%; detection limit 0,37 µg/L; quantification limit 1,22 µg/L;
precision as repetibility 0,21 µg/L, linear range from 0,37 to 20,00 µg/L.
In the present study, urine samples from more than 70 Chilean children were
analyzed by the proposed analytical method. Different comparison criteria were
applied to confirm the accuracy of the results such as duplicate analysis of
independent samples and comparison with an independent analytical method based
on preconcentration and flame atomic absorption spectrometry. A good agreement
between both methods was established. The proposed procedure is fast, accurate
and sensitivity and it can be used for routine analysis of nickel in urine samples.