One of the impediments to the direct injection of undiluted biological
fluids in GF AAS, especially viscous liquids like blood, is the
poor repeatability of the dispensed volume generating poor repeatability
of the atomic absorption signal. Therefore, sample dilution is necessary,
and consequently the choice of suitable diluents (nature and concentration)
and dilution factors. In thisway, 0.1% (v/v) Triton X-100,water and
0.2% (v/v) nitric acid were studied as diluents, while dilution factors
ranging from 3 to 10 for blood and 1.5 to 5 for urine were investigated
(Fig. 1). Those choices were based on previous similar studies found in
the literature [16]. For these tests, all sample solutions were spiked
with 50 μg L−1 of Sn, after the sample dilution