OBJECTIVE
1. To deter determin minee the concent concentrat ration ion of Iron and Cadmium Cadmium in Water spinac spinach h plant plant tissue tissue by using AAS 2. To determine the weight and weight percent of Iron and Cadmium that present in the th e Water Water plant tissue.
ABSTRACT
The experiment conducted is to find if there is a present of Iron and Cadmium in plant tissue. The sample was undergoes acid digestion to conert it to solution for the instrument use. The AAS was used in order to determine the concentration of Iron and Cadmium in the water spinach. At the end! the result will be compared between both of the instruments.
INTRODUCTION
Atomic Atomic Absor Absorpti ption on spectr spectrosc oscopy opy "AAS# "AAS# is the techni techni$ue $ue for determ determine ine the compos compositi ition on elemental elemental of an analyte by its electromagnet electromagnetic ic or mass spectrum. spectrum. This techni$ue techni$ue can be used to analy%e concentration of oer &2 different metals in a solution. Atomic Absorption Absorption happens when a ground state atom absorbed light radiation at a specific waelength and is transferred to an excited state. The amount of light energy absorbed at specific waelength increase as the number of atoms of the selected element in the light path increases. There are ' important basic components in AAS which are the light sources! the atomi%er! the monochromator! the detector and readout. The light source use in AAS is (ollow Cathode )amp "(C)#! which hae specific light. It proided light energy for excitation. The atomi%er is the flame itself. In this component! the li$uid sample is conerted into a mist by a process called nebuli%ation. The samples will be sent to flame for atomi%ation to occur. The process of atomi%ation cause the metal in sample to atomi%ed and undergoes a transition from ground state to excited state by absorbing the light from (C). The emitted light from will pass to monochromator. The monochromator will select the desired waelength! so that the desired light passes through the monochromator and eliminate
all insignificant light. The detector! *hotomultiplier Tube "*+T# will detect the light and the readout will read and conert the signal into readable result. Acid digestion method is a procedure to conert the sample into solution so that it can be introduced to the AAS. Acid digestion method is carried out by using ,itric acid "(,-# and also hydrogen peroxide "(2-2#. The sample will be dissole in nitric acid with the help of high temperature. Then! the hydrogen peroxide is added to aid the oxidation properties of nitric acid.
Iron "/e# and Cadmium "Cd# is a transition metal. These two metals is considered as a trace metal because it is expected to hae a low amount of concentration in the samples. Iron "/e#! is good to human as it help the formation of haemoglobin in our blood! maintaining body temperature! and increase the brain function. The deficits of Iron in body cause anaemia! insomnia and problem with en%yme system. -n the other hand! Cadmium seres a bad reputation to human health. Cadmium poisoning is one of the bad effects of cadmium introduction to human body. +oreoer! Cadmium also causes 0idney damage! fragile bones! omiting and een the worst! death to the person who consumed it.
EXPERIMENTAL PROCEDURE
A# SA+*) **AATI-,
The egetable was cut and put dried in and oen of 1134C for 5 hours. The dried egetables were cut into pieces. About grams of egetable was weighed and placed in 2'3 ml bea0er. 2363 ml of nitric acid "(,-# was added into the bea0er and was allowed to stand -ernight. The sample was heated until red fume came out. Then it was cooled.1 ml of peroxide "(2-2# was added into the cooled sample. The sample was reheated till concentrate. It was then filtered into 2'3ml olumetric flas0. The sample was diluted with distilled water and transferred into bottles
7# **AATI-, -/ STA,8A8 1. **AATI-, -/ 13 **+ -/ STA,8A8 S-)9TI-, /- AAS A,8 ' m) of 133 ppm stoc0 solution of Iron : Cadmium was pipette into '3 m) olumetric flas0 by using pipette. The olumetric flas0 was filled with distilled water until the calibration mar0. The olumetric flas0 contained solutions were labeled as 13 p pm /e;: Cd2;.
2. **AATI-, SIS -/ STA,8A8 S-)9TI-, /- AAS 2.1
CADMIUM SERIES STANDARD
Standard series of Cadmium range from 3 ppm! 3.2 ppm! 3.5 ppm! 3.& ppm! 3.< ppm and 1.3 ppm were made by using standard addition method. 3 m)! 1.3 m)! 2.3 m)! .3 m)! 5.3 m) and '.3 m) of 13 ppm Cadmium standard were pipetted and transfer into '3 m) of each olumetric flas0. 13 m) of Water samples were added into each olumetric flas0 contained standard series. All of the olumetric flas0s were then diluted with distilled water until the calibration mar0. 2.2
IRON SERIES STANDARD
Standard series of Iron range from 3 ppm! 1.3 ppm! 1.' ppm! 2.3 ppm! 2.' ppm and .3 ppm were made by using standard addition method. 3 m)! '.3 m)! =.' m)! 13.3 m)! 12.' m) and 1'.3 m) of 13 ppm of Iron standard were pipetted and transfer into '3 m) of each olumetric flas0. 13 m) of Water spinach samples were added into each olumetric flas0 contained standard series. All of the olumetric flas0s were then diluted with distilled water until the calibration mar0.
.
RESULT
C-,C,TATI-, I-, CA8+I9+
A7S-7A,C"y1 # I-, CA8+I9+
>-)9+"x1 # I-, CA8+I9+
7lan0 1 1.' 2 2.'
3.3?2 3.1= 3.1&1 3.1<2 3.231 3.22
3 ' ml =.' ml 13 ml 12.' ml 1' ml
7lan0 3.2 3.5 3.& 3.< 1
3.3=3 3.13= 3.15 3.1<2 3.21< 3.25?
3 1 ml 2 ml ml 5 ml ' ml
Calculation@ )east s$uare method@ C-,C,TATI -, /e Cd
A7S-7A,C "y1# /e Cd
7lan0 1 1.' 2 2.'
3.3?2 3.1= 3.1&1 3.1<2 3.231 3.22 yD 3.??&
IRON
7lan0 3.2 3.5 3.& 3.< 1
3.3=3 3.13= 3.15 3.1<2 3.21< 3.25? yD 3.?&?
>-)9+ "x1#
11
1B1
/e
Cd
/e
Cd
/e
Cd
3 ' ml =.' ml 13 ml 12.' ml 1' ml
3 1 ml 2 ml ml 5 ml ' ml
D '3
D 1'
3 2' '&.2' 133 1'&.2' 22' xxD '&2.'
3 1 5 ? 1& 2' xxD ''
3 3.&<' 1.23=' 1.<2 2.'12' .5' xyD ?.'=
3 3.13= 3.2<& 3.'5& 3.<=2 1.2' xyD .3'&
iron 0.25 f(x) = 0.02x + 0.12 R² = 1
0.2 0.15
Linear ()
0.1 0.05 0 0.5
1
1.5
2
2.5
(∑ x )( ∑ y ) xy D ""xy# 6
N
( 50 ) (0.996 )
=9.57
=
-
6
1.2=
(∑ x ) xx D "xx# E
2
N
(50 )2 =
'&2.' E
D 15'.<
mD
∑ xy ∑xx
6
3
3.5
4
4.5
5
5.5
1.27
D
55145.83
D 3.33<=
c=
∑ y 1 m (∑ x 1 ) − N N
¿
0.996 6
−
( )
0.0087 50 6
=0.0935 Concentration of Chromium in plant tissue@
CD
(V s )( b ) ( Vt ) ( m)
(10 ) (0.0935 ) D ( 10 ) (0.0087 ) D 13.=' ppm
CADMIUM
cadmium 0.3 0.25
f(x) = 0.04x + 0.07 R² = 1
0.2
Linear ()
0.15 0.1 0.05 0 0.5
1
1.5
2
2.5
(∑ x )( ∑ y ) xy D ""xy# 6
N
( 15 ) (0.969 )
=3.056-
=
6
3.&'
(∑ x ) 2 xx D "xx# E
N
(15 )2 =
'' E
D 1=.'
6
3
3.5
4
4.5
5
5.5
∑ xy ∑xx
mD
0.6335
D
17.5
D 3.3&2
c=
∑ y 1 m (∑ x 1 ) − N N
¿
0.969 6
−
( )
0.0362 15 6
= 0.071 Concentration of cadmium in !ant ti""ue
CD
(V s )( b ) ( Vt ) ( m)
( 10 ) (0.071 ) D ( 10 )( 0.0362) D1.?& ppm
*ercent weight of iron@ 3.331 gram per litre D 1 ppm D13.=' x 3.331 D 3.313=' *ercent of iron D
mass of iron ∈ the sample x 100 mass of sample
0.01075
D
2.0
x 100
= 0.5375 %
*ercent weight of cadmium@ 3.331 gram per litre D 1 ppm D1.?&? x 3.331 D 3.331?& *ercent of cadmium D 0.00196
D
2.0
= 0.098 %
x 100
mass of iron ∈ the sample x 100 massof sample
DISCUSSION
In this experiment! we used wet digestion methods for sample preparation. It is for elemental analysis that inoles the chemical degradation of sample matrices in solution! usually with a combination of acids to increase solubility as it has been done on day 2 and allow to stand oernight. The arious acid and Fux treatments are carry out at high temperatures in specially designed essels that help to minimi%e contamination of the sample with substances in the air! the local enironment! and from the essel walls. Sample may be loss due to adsorption onto the essel walls! olatili%ation! and coextraction! but these can be reduced by procedural modiGcations. The use of closed systems! where the digestion reaction is completely isolated from the surroundings! may help to reduce both contamination and sample loss. /or this experiment! the sample was coered with aluminium foil. Standard addition methods are particularly useful for analy%ing complex samples in which the li0elihood of matrix effects is substantial. A standard addition method can ta0e seeral forms. -ne of the most common forms is spi0ing method as we had use it in preparing standard. ach solution was diluted to mar0ed point be fore measuring or analy%ing it. The least s$uare method is a typical calibration graph where I hae plotted in calculation area for both sample chromium and cadmium respectiely. The sample was inHected into the atomic absorption spectroscopy and the result was obtained. Absorbance ersus olume graph was plotted and the linear e$uation and 2 was calculated in +icrosoft excel and as well as manually which had been shown.
/or analysis using /lame AAS! the concentration of Iron "/e# and Cadmium "Cd# can be determined by measuring the absorbance. The samples was undergoes standard addition method. 13 m) of water sample is added into each standard. The purpose of standard addition method is to eliminate matrix interference. -ther than that! it is used widely for the trace element detection as trace element is present in low concentration. /rom the experiment! the Iron and Cadmium concentration are
ppm and
ppm respectiely.
CONCLUSION
The amount of concentration of iron and cadmium can be determined by using AAS and IC*6 -S. /rom the experiment! the amount of Iron and Cadmium by using AAS is 13.=' ppm and 1.=' ppm respectiely.
REFERENCE
Cadmium.org "n.d#. Cadmium exposure and human health. etrieed at 22nd 8ecember 2315 from http@::www.cadmium.org:pgn.phpJidmenuD'
Ingle! K.8. Kr.! Crouch! S..! "1?<<#. Spectrochemical analysis. nglewood Cliffs! ,ew Kersey@ *rentice6(all! Inc.
Lrisha +cCoy! +S. "2315#. Cadmium Toxicity. etrieed at 22nd 8ecember 2315 from http@::medicine.med.nyu.edu:conditions6we6treat:conditions:cadmium6toxicityMris0
-rganicfacts.net "n.d#. Health benefits of Iron. etrieed at 22nd 8ecember 2315 from https@::www.organicfacts.net:health6benefits:minerals:health6benefits6of6iron.html
S0oog! 8.A.! West! 8.+.! (oller! /.K.! N Crouch! S.. "2335#. Fundamental of analytical chemistry. "
S0oog! 8. A.! (oller! /. K.! N ,ieman! T. A. "1??<#. Principles of instrumental analysis. *hiladelphia@ Saunders College *ub.
O9STI-, 1. 7riefly explain other method of digestion that is aailable for sample treatment in atomic absorption or atomic emission spectroscopy 6 Sample preparation can be performed by simple dilution or heating for pre6concentration or partial or total dissolution. (oweer to achiee most sample preparation! it is necessary to add reagent to the sample and to apply enough energy to brea0 some bond and the structure of solids.
2. xplain what are standard addition method and the purpose of this method 6 The standard addition method is the method to determine the concentration where by the sample was added together with the standard.
. 7riefly discuss why different hollow cathode lamps "(C)# were used for different element and how cathode lamp wor0s. 6 The cathode is a hollowed out cylinder constructed entirely or in part of metal whose spectrum is to be produced. The anode and cathode are sealed in a glass cylinder filled with noon or argon. The glass cylinder has a $uart% or u glass window for optimum transmittance of emitted radiation.
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