FLAME SPECTROSCOPY

1
??????? ??????????????

• ?????????? ?? ????? ??????? ?? ??????? ??
  ?????????? ????? ?????? ?? ????????????,
  ????????? ??? ???????????????? ??
  ????????????????? ??????? ?? ??????????? ????????
  ??? ?? ??????? ?? ????? ???????? ?? ????????.

2
(No Transcript)
3
???????????

• ? ?????????? ?? ?????????? ?? ????? ?? ??? ???
  ???????? ??
• ????????? ?? ????? ??????? ?? ?????????? ??
  ????????? ??
• ?????????? ?? ????????? ?? ???? ?? ?????? ??
  ????? ?? ????? ?????

??????? ?? ????????
-???? ??????? ?? ?? ????? ???????? ?? ????????,
??? ??????????? ????????? ???????? ?? ????????
??? ??? ??????? ??? ?? ??????? ?? ???????????
(?.?. ??????????? ?? ???? ?? ????????
?????????? ?????). ??? ????????? ?? ????
????????? ?? ????????? ???????? ????? ??
????????? ?? ????????????? ???????.
-????????? ?? ??? ??????? ? ?????????????? ??
?????? ?? ???????????? ?????, ??? ? ???
?????????????? ?? ???????? ???? ?? ????? ??
??????????, ?.?., ?? ??????????????? ?? ????????
4
??????? ?? ????????? ???????????
????????? ?? ??????? ?? ????? ???? ?? ???????? ??
????? ? ????? ?????????? ????? ??? ??????????? ??
????????????? ??????? ?? ???????????? ?????????.
????????? ??????? ?? ??? ?? ?????????
????????????? ????????? ? ?????? ?? 671 nm
for ??????, 589 nm for ??????? and 767 nm
for ??????.
5
????????? ?? ?????????? ????? ?? Li, Na ? ?
6
????????? ???????
??????? X

• ?????????? ??????? ?? ????? ???????
  ?fingerprint-??????? ?? ??? ???????

7
????????? ???????

• ???????
• ??????? ?????????? ?? ??????? ?? ?????? ???????
  ?? ????????? ?? ????? ???????, ????? ??? ????????
  ???? ?? ?? ?????? ??? ???????

??????? ?? ??????????
(????? ???? ???????? ?? ?????? ????????? X)
???????? ??? ?? ?????? ????????? X
8
???????? ???????

• ??????? 2
• ??????????????? ?? ????? ??????? ?? ?????????? ??
  ??????? ? ?????????????? ?? ???????????? ??
  ????????

??????? ?? ?????????? ?? ???????
1 Std 2
????????? X ?? ??? ?? ???????? ????????????? ??
?????????? 2
9
?????? ?? ??????? ?? ????? ??????? ??? ?? ??
??????????? ???????? ?? ???????? ?????? ??
1- ????????????? ?? ????????
2- ????????? ?? ????????? ?????? ????????? ?
????????????? ???????? ?? ???????.
?????? ???
-?????? ?? ??????????? ????? ?? ???????? ?
??????? ???.
??. ??? ??????? ?? 2500 k0,???? 0.017 ?? ???????
?? ???????????!
??? ???? ???? 10-7 ?? ??????? ?? ???????????.
-?? ??????????? ?? ????????????? ?? ????????? ?
?????? ?? ????????????? ?????
10
                                                
                           lt TDgt
11
???????????? ?? ?????????? ?????? ???????????
1-?????? ?? ??????????? ????? ?? ???????? ?
?????? ???. ?? ???, ????????? ???? ?? ??
???????????? ???? ????????? ?????? Li, K, Na, ?
?????????????? Mg, Ca, Ba
2-???????? ? ???????? ??????? ?? ????????.
3- ???????? ???????????? ?? ??????? ????????.
4-????????? ?? ??????? ?????? ?? ?????????? ? ??
? ????? ????? ????????????.
12
?????????? ?? ???????? ?????? ???????????

• 1-?????? ????????.
• 2- ????????????
• 3- ????????.
• 4- ?????.

13
                                                
                           lt TDgt
14
1-????????
a-??????????? ?? ??????????.
b- ????? ?? ????????? ???????? ?? ?? ??
????????? ???????
??????????? ? ???????? ??
??????????? ? ?????
?????????????
? ???? ???? ????????? ?? ??? ? ?????????? ??
?????????? ?? ???? ????? ??? ?????? ????????????
?? ????? ?? ???????
???? ?????????? (????????) ???????? ???
?????????????, ??? ?? ???? ?? ???? ?????????? ???
? ?? ????? ?? ????? ?????
????? ??? ????? ?? ???????? ? ????? ?? ??????????
?? ?????? ?? ????????? ??? (???????? ??? ??????
?????) ?? ???????? ?? ??????.
??????? ?? ??????? ??? (?????? ?????)-????????
(????????)--???????? ?? ????? ?? ???????-????????
??? ??????? ???? ?? ????????? ??????? ???
???????? ?? ??????????? ? ??????????? ?? ???????
?? ?????????? ??? ?? ?????????
15
                                                
                           lt TDgt
16
                                                
                           lt TDgt
17
?? ???????
?? ??????? ?????????? ?? ???????? ? ?????? ??
????????? ??????? ??? ? ????????? ?? ???????????
?? ??????????, ?? ?? ? ?? ?????????? ??
???????!!!
????????????? ?? ???????? ?????? ?? ???????
??????/????????, ?? ? ?? ????????? ?? ????????.
18
?? ?????? ?? ?, Na, Li i Ca, ???? ????? ??
??????????? ? ?? ??????????? ?? ? lt 2000 K, a na
T gt 2500 K ?? ??????? ??????????.
????????????? ?? ???????? ???? ?? ????
???????????
? ??????? ?????? ?? ?????????? ???????????, ?? ??
? ??????????.
2- ????????????
? ??????? ???? ??? ??? ?????? ??? ???????????
???? ????? ?????????? ??????? ??????? ?? ???????
??? ???????? ? ?? ?????? ?? ?????????? .
19
?????? ?????????

• Device measures the concentration of a element in
  a sample by measuring the intensity of its
  emission spectrum
• Parts
• Pump
• Burner
• Nebulizer
• Photodetector
• readout

!
0.000
20
???????? ?? ???????

• ???? ?? ?????? ?? ?????? ?????????
• ???? ? ??????????? ????

std1 std2 std 3 ukn
c2g/L c4g/L c6g/L c?
!
0.000
21
Pocedure

• To use a flame photometer
• Zero with distilled water
• ?????? ?? ??????????????? ?? ??????? ??????????
  ????????, each more concentrated than the next
  (0.010)

!
0.010
Conc 1 g/L
22
Pocedure

• To use a flame photometer
• Zero with distilled water
• Measure the concentration of several standard
  solutions, each more concentrated than the next
  (0.010, 0.020)

!
0.020
Conc 4 g/L
23
Pocedure

• To use a flame photometer
• Zero with distilled water
• Measure the concentration of several standard
  solutions, each more concentrated than the next
  (0.010, 0.020, 0.030

!
0.030
Conc 6 g/L
24
Pocedure

• To use a flame photometer
• Zero with distilled water
• Measure the concentration of several standard
  solutions, each more concentrated than the next
  (0.010, 0.020, 0.030)
• Measure unknown (0.026)

!
0.026
Conc ?
25
Pocedure

• To use a flame photometer
• Zero with distilled water
• Measure the concentration of several standard
  solutions, each more concentrated than the next
  (0.010, 0.020, 0.030)
• Measure unknown (0.026)
• Compare unkn to stds using calibration curve

!
0.000
Conc ?
26
std1 std2 std 3 ukn
c2g/L c4g/L c6g/L c?
e0.010 e0.020 e0.030 e0.026
Calibration Curve
.04
.03
Emission Of standards
.02
.01
8
2
6
4
Conc of standards (g/L)
27
ATOMIC ABSORPTION SPECTROSCOPY

• atoms in the vapor state are subjected to
  external source of radiation which produces one
  line or beam of monochromatic light with single
  wavelength.
• This wavelength is a resonance one for the atoms
  and that will be absorbed by them.

All elements can be determined by this technique.

INSTRUMENT FOR ATOMIC ABSORPTION
3- Atomizer
1- Source of radiation
2- Chopper
6- Read out meter
4-Monochromator
5- Detector
28
(No Transcript)
29
                                                
                           lt TDgt
30
1- Source of radiation Hollow cathode lamp
is a tube with a front quartz window contains
an anode of tungsten and a cylindrical cathode
, the material of which is the same element of
the sample to be determined.
The glass tube is filled with neon or argon at
a pressure of 1 to 5 tore.
When a low potential is applied between the two
electrodes ionization of the gas occurs
ions move rapidly to the cathode
31
                                                
                           lt TDgt
32
                                                
                           lt TDgt
33
                                                
                           lt TDgt
34
2-The chopper
its function is to fluctuate the source output.
It is a circular disc divided into four quarters
two are mirrored and two are opened.
The disc rotates at high constant speed, when
the mirrored quarter in front of the lamp, it
reflects the radiation
the second moment the open in front of the lamp
and the radiation passes to the sample being
absorbed by it and reaches the detector in
pulses.
The detector converts the radiation to
alternating current signal and amplified it.
The radiation coming from the flame itself and
from atoms excited by the flame will reach the
detector continuously and converted to direct
current signal which can be suppressed and
eliminated.
This process is known by modulation of the
source output.
35
                                                
                           lt TDgt
36
3- Atomizer
a- Flame atomizer
b- Flameless or non flame atomizer
It is a graphite furnace heated electrically up
to 6000oC and contains a ribbon or boat in
which one can inject the sample.
Upon heating the furnace
the sample is ashen, then atomized by action of
heat.
Advantages of non flame atomizer
-The sample volume is small .
- No need for fuel -oxidant mixture.
- Unusual high sensitivity
- No flame noise.
-Solid sample can be used directly.
- Heat distribution is uniform and temperature
is steady.
37
4- Monochromator
Grating to eliminate other resonance lines
from the source or other radiation from the flame
or sample
Schematic of an atomic-absorption experiment
                                                  
                   
38
(No Transcript)