The sample, in the form of an aerosol, is transported to the plasma, where it is desolvated, vaporised, atomised and excited and/or ionised by the plasma. The excited atoms and ions emit their radiation at a characteristic wavelength. This radiation is detected and can be converted into concentration information.
The ICP-OES has two types of nebulisers: Low-Flow (for general samples) and ultrasonic (for water); as well as two types of spray chambers: Scott and cyclonic.
The samples must be in solution and suitably filtered. The amount of sample required for analysis will depend on the number of elements to be measured, but 10 to 15 mL is generally sufficient.
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Theoretical detection limits for each element and their current availability are shown in the table below. Special conditions are required to measure Hg.
Theoretical detection limits
Element
Theoretical DL (ppb)
Element
Theoretical DL (ppb)
Element
Theoretical DL (ppb)
Ag
7
Hg
61
Rh
44
Al
28
Ho
430
Ru
30
As
53
In
63
S
---
Au
17
Ir
27
Sb
32
B
4.8
K
42.8 ppm
Se
75
Ba
1.3
La
10
Si
12
Be
0.3
Li
850
Sm
43
Bi
24
Lu
1
Sn
25
Ca
10
Mg
0.2
Sr
4
Cd
2.7
Mn
1.4
Ta
25
Ce
48
Mo
7.9
Tb
23
Co
6
Na
69
Te
41
Cr
7.1
Nb
36
Th
65
Cs
42 ppm
Nd
50
Ti
3.8
Cu
5.4
Ni
10
Tl
120
Dy
10
Os
0.4
Tm
5
Er
10
P
76
U
250
Eu
2.7
Pb
42
V
5
Fe
4.6
Pd
44
W
5
Ga
46
Pr
37
Y
3
Gd
14
Pt
30
Yb
1.8
Ge
40
Pu
15
Zn
1.8
Hf
15
Rb
---
Zr
7.1
The samples must be in solution and suitably filtered. The amount of sample required for analysis will depend on the number of elements to be measured, but 10 to 15 mL is generally sufficient.
In the case of solid samples, where an acid attack has to be performed, the Unit has a mill, microwave and digester for sample preparation.
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The fields of application are:
- Agriculture and food: soils, sludge, fertilisers, animal feed, vegetation, food, beverages.
- Biology and clinical: animal tissues and biological fluids such as serum or urine.
- Geology: rocks, soils, sediments and related materials.
- Environment and water: sludge, water, ash, air, dust.
- Organics: petroleum products, oils.
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Unidade de Análise Instrumental
- Edificio de Apoio á Investigación (CACTUS) Lugo
- Campus Lugo s/n, 27002Lugo
- 982 822 816 (Responsable da Unidade)
- 982 822 818