Dewi Erisa Nainggolan : Kajian Pelapukan Geokimia R C Tanah Andisol Di Desa Tongkoh Kecamatan Tiga Panah Kabupaten Karo, 2007.
USU Repository © 2009
5. KlPO
4
6. Larutan standar 1000 ppm
7. Larutan standar 10 ppm
Prosedur :
1. Place 1 g of soil passing a 100 mesh screen in a platinum
evaporating dish 2.
Add 10 ml of HNO
3
, heat dish slowly 3.
Evepotrate the contents to dryness and ingite the residu in a muffle furnace at 500
C for 30 minutes 4.
Cool the dish 5.
Add 5 ml of 18 N H
2
SO
4
and 10 ml of HF and stir the mixture with platinum strring rod
6. Heat the dish slowly inb fume hood of sand-bath until the H
2
SO
4
has fumed strongly for 30 minutes 7.
Cool the dish 8.
Fill it about ¾ full wuth H
2
O and evaporate the contents to strong fuming of H
2
SO
4
again for 30 minutes 9.
Allow the dish to cool add 10 to 20 ml of H
2
O and place the dish on water bath for 10 minutes
10. Filter the solution into a 100 ml volumetric flash, washing the filter
paper with hot water 11.
Allow the flask to cool, and bring the solution to volume with H
2
O 12.
Transfer an aliquot containing from 0.001-0.3 mg og Mn to a 100 ml beaker and add 2 ml of HNO
3
, 5 ml 0f 85 H
3
PO
4
and about 0.3 g of KIO
4
13. Cover the beaker with a watch caustiously bring the solution to a
boil on a hot plate, and continue to boil the solution gently for at least 5 minutes after the color develops
14. Cool the beaker to room temperature, transfer the solution to a 50
ml volumetric flask and bring with H
2
O. mix the contents of the flask thourghly
15. Measure the light transmittance at 540 m
6. Natrium NaO
Bahan-bahan
a. Zinc uranyl acetate
b. Ethyl alcohol 95
c. Anhydrous ether or acetone
d. Standard Na solution
Prosedur 1.
Decompose 0.5 g of soil in HF and HClO
4
and silute the residue to 50 ml
2. Transferan aliquot 20 ml containing no more than 8 mg of Na to
a small acid washed beaker
Dewi Erisa Nainggolan : Kajian Pelapukan Geokimia R C Tanah Andisol Di Desa Tongkoh Kecamatan Tiga Panah Kabupaten Karo, 2007.
USU Repository © 2009
3. Evaporate the solution to dryness
4. Cool the beaker and add 1 ml of water and 10 ml of yranyl zinc
acetate solution 5.
Stir the contents thoroughly and allow the beaker to stand for not less than 30 minutes over night is satisfactory
6. Filter the solution by suction through a porous porcelain of fritted
glass crucible of medium porousty using 2 ml of reagent to transfer the precipate
7. Wash thr precipate and the crucible with five to ten 2 ml portions
of alcohol followed by to 2 ml portions of anhydrous ether or acetone
8. Dissolves the precipate by washing it with 100 to 200 ml of cold
water, depending on the amount the present 9.
Wash the crucible with alcohol and ether and then reweigh it as before
10. The difference in weight by 0.01495 to obtain the weight pf Na in
the aliquot taken
7. Kalium K
2
O Penetapan Kalium dalam HCl 25
Bahan-bahan Larutan standard Kalsium 100 ppm K
Dipipet 50 ml larutan standard baku 1000 ppm K kedalam labu ukur 500 ml, ditambah 62,5 ml larutan HCl 25 , dipenuhkan dengan air destilasi hingga tanda
garis. Larutan seri standard ; 0-1-2-5-10-20-30 ppm K
Dipipet 0-1-2-5-10-20-30 ml larutan standard 100 ppm K, masing-masing dimasukkan ke dalam labu ukur 100 ml, ditambah 12,5 ml larutan HCl 25
dipenuhkan hingga tanda garis dengan air destilasi Alat-alat
Atomic Adsorbtion Spectrophotometer Cara kerja
Larutan seri standard 1-20 ppm K, larutan blanko dan larutan contoh filtrat HCl 25 . Diukur dan dibaca “absorbance” pada alat AAS Atomic Absorbtion
Spectrophotometer Perhitungan
Dari hasil pengukuran “absorbance” seri standard, dibuat garfik kurva, yang mana kepekatan larutan seri standard 0-20 ppm sebagai absis dan “absorbance”
sebagai ordinat. Kepekatan larutan contoh dibaca pada grafik.
Dewi Erisa Nainggolan : Kajian Pelapukan Geokimia R C Tanah Andisol Di Desa Tongkoh Kecamatan Tiga Panah Kabupaten Karo, 2007.
USU Repository © 2009
K
2
O = K-garfik x 1001000 x 1,4 x 100 x 100 berat contoh tanah kering 105
C g x 100 dihitung dua desimal
8. Besi Ferum Fe
