188
(2003). The sampling protocol includes (a) removing the dinginess from the attic
surface, (b) collecting the corpuscular dust form the attic surface using plastic brush
and (c) transferring the collected dust in polyethylene bags. The representative
sample from one house was obtained collecting the dust from five to ten attics,
depending of the house condition.
The soil samples brought in the laboratory were subjected to cleaning and
homogenization, drying at room temperature, or in a drying room at 40 °С, to a
constantly dry mass. Then the samples were passed through а 2 mm sieve and finally
were homogenized by grinding in a porcelain mortar until reaching a final size of
the particles of 125 μm. Following the physical preparation, the samples were
chemically prepared by wet digestion, applying a mixture of acids in accordance
with the international standards (ISO 14869-1: 2001).
For digestion of attic dust and soil samples, open wet digestion with mixture of
acids was applied. Precisely measured mass of dust samples (0.5 g) was placed in
Teflon vessels, and 5 mL concentrated nitric acid (HNO 3 ) was added, until the
brown vapours came out from the vessels. Nitric acid is very suitable oxidant for
digestion of environmental samples. For total digestion of inorganic components,
5–10 mL hydrofluoric acid was added. When the digest became clear solution, 2 mL
of HClO 4 was added. Perchloric acid was used for total digestion of organic matter.
After 15 minutes cooling the vessels, 2 mL of HCl and 5 mL of H 2 O were added for
total dissolve of metal ions. Finally, the vessels were cooled and digests quantitatively transferred to 50 mL calibrated flasks. In this way, the digested soil and sediment samples were prepared for determining the contents of the different elements
using atomic emission and mass spectrometry.
PerkinElmer SCIEX ELAN DRC II (Canada) inductively coupled plasma mass
spectrometer (ICP-MS, with quadrupole as single detector) was used for measurement of the concentration trace elements, while for the major elements’ content
determination, atomic emission with inductively coupled plasma (ICP-AES, Varian
715ES) was applied. For this study, reagents with analytical grade, namely, nitric
acid, trace pure (Merck, Germany); hydrofluoric acid, p.a. (Merck, Germany); perchloric acid, p.a. (Merck, Germany); hydrochloric acid, p.a. (Merck, Germany); and
redistilled water, were used for the preparation of all solutions. Standard solutions
of metals were prepared by dilution of 1000 mg/L solutions (11355-ICP multielement standard). For each element analysed, previous optimization of the instrumental conditions was performed.
6.7.3 Data Processing Methods
After the instrumental analysis, the values obtained contain the contents of the
elements, initially co-transformed and normalized. The processing of numerous
variables with a heterogeneous distribution structure is often complex and requires
careful processing. On the other hand, there is significant deviations from the norR. Šajn et al.
(2003). The sampling protocol includes (a) removing the dinginess from the attic
surface, (b) collecting the corpuscular dust form the attic surface using plastic brush
and (c) transferring the collected dust in polyethylene bags. The representative
sample from one house was obtained collecting the dust from five to ten attics,
depending of the house condition.
The soil samples brought in the laboratory were subjected to cleaning and
homogenization, drying at room temperature, or in a drying room at 40 °С, to a
constantly dry mass. Then the samples were passed through а 2 mm sieve and finally
were homogenized by grinding in a porcelain mortar until reaching a final size of
the particles of 125 μm. Following the physical preparation, the samples were
chemically prepared by wet digestion, applying a mixture of acids in accordance
with the international standards (ISO 14869-1: 2001).
For digestion of attic dust and soil samples, open wet digestion with mixture of
acids was applied. Precisely measured mass of dust samples (0.5 g) was placed in
Teflon vessels, and 5 mL concentrated nitric acid (HNO 3 ) was added, until the
brown vapours came out from the vessels. Nitric acid is very suitable oxidant for
digestion of environmental samples. For total digestion of inorganic components,
5–10 mL hydrofluoric acid was added. When the digest became clear solution, 2 mL
of HClO 4 was added. Perchloric acid was used for total digestion of organic matter.
After 15 minutes cooling the vessels, 2 mL of HCl and 5 mL of H 2 O were added for
total dissolve of metal ions. Finally, the vessels were cooled and digests quantitatively transferred to 50 mL calibrated flasks. In this way, the digested soil and sediment samples were prepared for determining the contents of the different elements
using atomic emission and mass spectrometry.
PerkinElmer SCIEX ELAN DRC II (Canada) inductively coupled plasma mass
spectrometer (ICP-MS, with quadrupole as single detector) was used for measurement of the concentration trace elements, while for the major elements’ content
determination, atomic emission with inductively coupled plasma (ICP-AES, Varian
715ES) was applied. For this study, reagents with analytical grade, namely, nitric
acid, trace pure (Merck, Germany); hydrofluoric acid, p.a. (Merck, Germany); perchloric acid, p.a. (Merck, Germany); hydrochloric acid, p.a. (Merck, Germany); and
redistilled water, were used for the preparation of all solutions. Standard solutions
of metals were prepared by dilution of 1000 mg/L solutions (11355-ICP multielement standard). For each element analysed, previous optimization of the instrumental conditions was performed.
6.7.3 Data Processing Methods
After the instrumental analysis, the values obtained contain the contents of the
elements, initially co-transformed and normalized. The processing of numerous
variables with a heterogeneous distribution structure is often complex and requires
careful processing. On the other hand, there is significant deviations from the norR. Šajn et al.