Xác định lượng vết Asen bằng phương pháp điện hoá hoà tan

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GAG
PLbdEG
PEAP
±>IEb
hO^
KG
A
'J^^NT
( 1 04 03 -
Hoa

pban tieb )
Luan
an pho tien
si
kboa hoc
(7ttM-
".
•
1*1.
-'H
3W-^
Nb5ng ngufdi budng
dan kboa hoc :
Tran
CbUdng Huyen ,
Pbo tien
si
, Pbo giao
sif
Tii Vong Kgbi
, Pho tien si , Pho
gieo
su'
Cbu Xuan Anb , Pbo tien si
Ha-noi
- 1984
mo 'ujG
KI KIEU VA GbU
TXT
trg

1.
MO
±;AU
2 TO]^"G
^LAl^'
TAI
LISU
2.0 / Sd li:Ldc cac pbifdng pbap xac dinbi lu'dng vet esen 5
2.1
/ Tinb chat dien hoa cua asen 12
2.2 / Cac phu'dng pbap dien boa boa tan xac dinh asen
2.5.1
- Pbitdng pbap dien boa boa tan anot 1?
2.^.2
- Pbufdng pbap dien hoa boa tan catot 19
2.3 / Cac van de ngbien ciiu trong luan an nay ' 20
3 GAG PHtfdNG PHAP
I^IGHIEK
CUb
\fl.
i^lJu
'ixl^l:^ TIiUG JNGlxlSk
3-0
/ Cac phu'dng pbap dinb bijfdng ngbien cu'u
3-C.l
- Phu'dng pbap cu'c pbo 23
3.0.2 - Phiidng pbap von-ampe vong 25
3-i / Cae phudng pbap dien boa boa tan
3.1.0 - Ban chat pb\j:dng pbap ' 26
5.1.1

- Nb5ng van de lien quan den giai ttoan lam giau 28
3-1.2
- ATn-Sng van de lien quan clen giai doan boa tan 31
3.2 / Dieu kien tbirc nghiem ' •
3.2.1 - May.thiet bi • . . 36
3.2.2 - Dien ciic 36
3-2.3 - Hoa chat va dung dieb 38
3.2.4
- Ky
tbuat
ghi
^0
3.2.5
-
l^ay
mau va ehuan bi
^1
3.2.6 -
Xi ly
so lieu
tbrfc
ngbiem 41
4 iOi^T
'CQD^
VA
bAiM LlJAl'i
4.0 / Cac dien
cite
so sanb
4.0.1

-
iJien cifc
ealomen va bae
ekorua
.
^
• • -
4.0.2 -
Bien ci:fc cbi
sunfat
5^
. *
4.0.3
-
Pbam
vi
sxl
dung cac dien
cue
so sanb 57
4.1 / Tinb chat dien boa cua asen 59
4.2 /Xac dinh asen
bSng pbu:dng
pbap dien boa boa tan anot
4.2.1 - Cac tin bieu boa tan anot cua dong
67
4.2.2 - Hoa tan anot he
Cu-As 72
4.2.3
-

Hoa tan anot be Cu-Au 73
4.2.4 - Hoa tan anot be
Cu-As-Au
75
4.2.5 -
£'ieu
kien xac dinb asen tbeo be
Gu-As-Au
bS.ng pbtfdng
pbap dien the tbdi gian hoa tan anot 76
4.3
/ Xac dinb asen bang
pbifdng
pbap dien hoa boa tan catot
4.3.1
- Xac dinb asen tbeo he Gu-As
bSng pb^idng
pbap
von-ampe boa tan catot 81
4.3.2
- Xac dinh asen tbeo be
I-Gu-As
bSng pb\:fdng
pbap
von-ampe boa tan catot
,
dung dien
ciic
tbuy
ngan tinb

85
4.3.3
- Xac dinb asen theo he
I-Cu-As
bling
phudng pbap
dien the tbdi gian boa tan catot , dung dien
ci/e mang
tbuy ngan 95
4.4 / Xac dinb asen
bSng pbi:fdng
pbap von-ampe boa tan
xoay cbieu boa tan bae
bai
. 100
4.5
/ So sanb cac
pbiidng
pbap di ngbien
cu'u
.
Ban ve cd ebe 101
5 AP
DbNG
THUG
T^
5.1 / Xac dinb
triic
tien
luldng

vet asen trong cac mau
tbT^c
te 110
5.1.1 - Pban tich boa chat tinh kbiet 113
5-1.2
- Pban tieb
nufde
115
5.1.3 - Pban tieb cac doi
tu:dng
sinb
b9e
116
5.2
/ Xac dinb bam
l-\X6nQ:
asen sau khi cat
dudi
dang
AsH^
119
6
idlT
LUAN 120
TAI
LiSb
THAIV.
ivb.AO 123
— 0 -
1984

E.T
HI^U
VA
CHU^
TAT
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s
SCE
SPbE
T
k
: dien tieb dien
cUc
• • -
,
CTT
: nong do ion esen , dong
,
tbuy ngan trong
xig
dung dich
nong do dang oxi boa trong dung dicb
nong do
kim loai
trong tbuy nga n
h| so khueeh tan cua dang oxi hoa trong dung dicb
he so kbuecb tan cua kim loai trong tbuy ngan
dien the tbdi gian boa tan ( phudng pbap )
the dieu
ci;c ;
bien gidi tin cay
the oxi boa
kbit
tieu ehuan
the
ti2&

song cua song
cu:c
pbo
;'
the
itng
vdi
nUa
tbdi gian cbuyen
the dien pban
the dinh
the
dinh
anot va catot • ' •
bien gidi tin cay bieu dien tbeo
6.6n
vi
tijfdng
doi
tbuy ngan
;
dien
ciic
tbuy ngan tinb ( dang tree )
dien
ci/c
mang tbuy ngan tren
dia
than tbuy tinb
dong boa tan trong

pbiidng
pbap
±)THT
dong boa tan anot va catot trong
phu^dng
pbap BTHT
dong
dinb
dang
khu'
cua chat boat
don^:
dien
dang oxi boa cua chat boat dong dien
dien lu'dng ,
tij:dng ditdng
vdi
ludng
kim loai da bi
ket
tua
tren dien
ciic
; do nbay ve dong dien cua may ghi
: dien
eiic
ealomen bao boa ( dung dicb
KCl
)
: dien cu'c cbi sunfat

: nbiet do dung dicb
Tm
TT
VAHT
T
1
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1
m
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s
sv
t
t
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1
1
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1
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pp^
ppm
nm
ng
(Jig

: dien
cu'c
than mem
a .
: dien
ciic
dia than tbuy tinh ( quay )
:
von-am.pe
boa tan (
pbitdng
pbap )
: dong dien trung binh trong
pb;:rdng
pbap
cu'c phS
: dong kbuecb tan gidi ban trung binh
: bing so
toe
do cua pban
u'ng
dien hoa d dien the
tieu ehuan
: cbieu day cua mang tbuy ngan
*
: toe do ehay cua tbuy ngan trong mao quan cua dien
eiie
giot tbuy ngan
so electron
tham

gia phan
ling
d dien
cu:e
;
so
Ian
tbi nghiem doc lap
ban kinh
gi9t
tbuy ngan
giay
\
sal so binh
pbiidng
trung.
binh bay
do lech ehuan
. •
: so vdi
: tbdi gian
;
cbu ky giot tbuy ngan
: tbdi gian dien pban
: toe do
quet
the
: gia tri trung
binii
cong cua n

Ian
thi ngbiem
: he so cbuyen cua phan u'ng dien
cue
: cbieu day
Idp
kbuecb tan
: tbdi gian cbuyen
=
1.10'^
%
1.10
-4
ol
1.1C~^
m
l.lC
1.10
•9
•o
0
-
1
Md
BAU
J
^ng
ed the dong vat va
thuc
vat c6 asen . Vdi

lUdng
rat nbo , asen
c6
tac dung kieb
tbieb
qua
trirJri
song .
NbUng
neu
vUdt
qua mot
gdi
ban nao do , no trd
tharih
chat doc
.HgUdi
bi ngo doe asen kinh nien se roi loan bo may tieu hoa , cac
niem mac bi hoai va eo the
tu:
vong
. -Asen ehiem -10 i
khoi
a
•
•
lUdng
vo qua dat
,
cbu yeu ton tai

dUdi
dang
sunTua
nbu:
reanga
(
As^S.
)
,
oepimen (
As^S^
) va
mim Ian Ion
vdi quang kim
loai kbae . Khi
Ifehai
tbac
qu|ng ,
pbai cbu y den asen . Asen
dude sU
dung trong y hoc
,^tbuoe
da , san xuat tbuy
tinln ,
v
vat lieu ban dan
v.v.
. Trong nong ngbiep , dan xuat cua asen
lam thuoe
trU

sau cbo cay trong . Trong boa hoc pban tich ,
asen la thanb pban quan trong cua nhieu tbuoc
tbu;
huu
ed quy
nbu : asenazo , berilon IV ,
sunfaxazen , thoron
I
v.v.
.
San
ludng
asen cua the gidi
tu bin nSm
1940 la
46.000
T
/
57
/•
Asen va cae ebe pbam cua no
d^^X^c
san xuat hang nam' ,
bSng
nbieu con
dUdng
kbae nbau , bi thai dan ra song
,
ho , bien .
Xac dinb

ludng
vet cac nguyen to , trong do c6 asen , la
mot trong nbung van de tbdi sU cua boa hoe pban tich nude
ta
nb§m
phuc vu nbieu
cbUdng
trinh phat trien kinh te , kboa hoc
ky tbuat va bao ve moi trudng
.
Be
laioi
viec nay , ehung ta
thudng
dung pbUdng pbap
tr§c
quang , pban tich quang
pbo
pbat
xa
I^oSc
hap tbu nguyen
tu!
.
Phudng pbap dien boa boa tan da
bat
dau phat buy tac dung d mot so phong thi nghiem , nbung
nhin ehung
,
no

chUa dii6c
pho bien rong rai .
Tren the gidi , dien boa boa tan da tr5
tbanlj
mot phudng
pbap pban tieb vet quan trong trong khoang 20
n^m
nay . tfu
diem noi bat cua phudng pbap
nsj
la do nbay rat cao
^
CO the so sanb
d\l6o
vdi do nbay cua
pbudn^
pbUdng pbap kieb boat ndtron
/ 3914,35^^,55
/
ina
trang bi
va ky tbuat lam viec lai kha ddn gian .
I'o
eo the tbUe bien
ngay ca tren cac
m.ay
cue pbo thong
tl!iudng
da eo tai nbieu
pbong tbi ngbiem thuoe cac bo .

Bing
phudng pbap dien hoa boa
tan , ngudi ta da xac dinh dude nbieu nguyen to trong nbieu
doi
tUdng
f
3»14,53
7 • Tuy nbien , viec xac dinh mot so
nguyen to , trong do eo asen , can pbai ngbien
euu Jhem
.
Hien nay , viec xac dinb asen
thUdng
dude tbue bien
bllng
pbUdng pbap
tr4c
quang dung
bae-diaylditbioeacbamat /
1,18,
44,
47
7 - Bo la pbUdng pbap tieu ehuan cua nbieu nude va
nbieu
tS chuc
quoc te
/
18,24,25,47
/
. Bo nbay

-5-10"''^mo
1/1.
TbUc te ngbien cUu va Ung dung trong
nUde mUdi nSm
qua
ehung to la ,
b^ng
phudng pbap dien boa boa tan , cbu yeu la
von-ampe boa tan
,
ehung ta da xac dinb dude nbieu nguyen to
d vung nong do
10"-
lC"\ol/l
, tru asen va vai nguyen to
kbae . Neu ngbien euu thanb cong mot phudng pbap xac dinh
asen c6 do nbay
,
do ebon
loc vao
ed nbu cac phudng pbap xac
dinb
Gu,Pb,Cd,Zn
( cac nguyen to sd trudng cua dien boa boa
tan ) thi ta de dang tboa man nbieu nbu eau
thue
te cua dat
nudc , trong do c6 nbu eau cua cong tac bao
ve^moi
trudng .

3di vay , ehung toi ebon de tai ngbien eUu la :
Xac dinb
lUdng
vet asen
bSng
cae pbUdng pbap dien boa boa tan
Asen
c6
kboi ludng nguyen tu la
74,92
d.v.6.
,
mang.so
tbu tu
:
33 trong bang tuan
bo^n
Mendeleep .
m
thuoe
nb6m
V A , cbu ky 4
, n5.m gilia
Ge va
oe
. Asen eo tinh chat
trung gian giua a kim va kim loai
.
l^-'o
c6 nhieu tinh chat

dien boa
d^c
biet , pban ung dien cue kbong tbuan nghich
.Do
.' \
do , viec xac dinb asen
bSng
phudng pbap dien boa boa tan
kbong giong
nhu
viec xac dinb Cu,Pb,Gd,Zn . Sau khi
khao
sat nhieu he ,
dSe
biet la eac be bae ba
CU-AS-AU
va
I-Gu-As,
a ' a a a a
'
ehung toi
ebon
ra mot pbUdng pbap xac dinh ludng vet asen dap
ung dude cac yeu eau da neu
a
I^o
da dude dung de xac dinh
ham ludng asen trong mot so mau tbue te .
Trong qua trinb ngbien cUu , ehung toi con phat bien
mot so van de eo y nghia cbung trong

linh
vUe pban tich dien
boa boa tan .
00
-
2
T6i^
G
^b M
TAI
LI^U
2.0
/
2£l_l2£^lL-gA^ ^^^^^^
^^^^ ^^^ ^^^-^
l^<JJ^g
^e^
asen
»
Nbung thong tin quan trong ve cae pbUdng pbap bien dai
xac dinh ludng vet eac nguyen to , trong do eo asen , de
dang tim tbay trong eac tai lieu cua
Korenman
I.M.
/
15
/,
BAoracbevxki
lu.
V.

/ ^0
/ va Koch 0.
.^. /
44
/
. Sau phudng
pbap trie quang eo y nghia
nbat
trong viec xac dinb
lUdng
vet
asen da dude mo ta ty my trong cbuyen khao cua
Bavko
A. K.
va Pilipenko A. T.
/
1
7
.
Asen
CO
the
dudc
xac dinh 3 dang xanb cua
pbuc
di da
axit
asenomolipdic
vdi chat
kbu

la
bidrazinsuniat
boae
SnCl^
f
1 7
'
Tinh chat phUc nay tUdng tu tinh chat pbuc di da cua •
Ge
,
Si,
dS.c
biet rat giong
phUc
di da cua P . Trong eac doi
tUdng tu nbien va ky tbuat
,
ham ludng photpho thudng
Idn
bdn asen vai
ebiie
den vai tram
Ian
.
Bdi vay,phudng
pbap nay
trong tbue te pbai di kem vdi mot pbUdng pbap taeh kbae
,
thudng la chiet
hoSc

cat . Gong viec nay cbiem nbieu tbdi gian
va can dung moi bUu cd nbu
GHClv
,
CCl^
v.v.
PbUdng pbap xac dinb ludng vet asen dung tbuoc tbu
bac-
dietylditbiocaebamat la pbUdng pbap tot , dude cong nban la
phudng pbap tieu ehuan cua ISO , SEV , Lien xo ,
hy {
18,
24,25,47 7
v^-v-
•
luan
'kxi sU dung phudng pbap nay lam
pby:dng
pbap doi ehung .
NgUdi
ta
dung kem kim loai khu asen trong moi trUdng
axit thanb asin (
AsH^
) roi bap tbu no
bIng
dung dieb bac-
dietylditbiocacbamat
pha
trong piridin . Pban Ung xay ra nhu

sau :
AsH^
^
6
(C^H-)2NCSSAg —>
6 Ag
-s-
3
(G2,:H^)^NGSSH ^
7
(G2H^)^NGSS
7^As
Kbi
AsH-z
trUde khi vao dung dich hap
fhu
dude dan qua
Idp
3
giay (
bo§c
bong ) tam cbi axetat de lam
sach
vet
H^S
.Gudng
do mau cua dung dicb hap tbu ty
le
vdi nong do asen . Bo
nbay

-5.10"'^
mol/1
- Bung dicb thuoe tbu eo mui
h^e
va rat
doc - No de bi pban buy dudi tac dung cua anb sang va nbiet
do,gay
kbo khan cbo viec bao quan .
Co
tbf
xac dinb asen
bSng pbUdg_pbap
so mau vet tren
giay
7
1 7 •
^ ^ay ^
asen dude
khU
bing kem kim loai trong
moi trudng axit thanb asin
.
Khi nay di qua giay tam cbi
axetat de lam sacb vet
H^S
roi den giay tarn
HgBr^
boae
HgCl^
. Ham ludng asen dUdc danb gia qua viec

stb
sanb
cudng
do mau cua giay tam muoi tbuy ngan Ung vdi mau phan tich va
mau doi cbieu - Cong viec nay lam bing
m§t
thudng , sai so
cbu quan
Idn
. Koch 0- G. £
^^
J kbong xep pbUdng pbap nay
vao hang cac pbUdng pbap
dirib
ludng asen . Tuy theo ludng
asen bi hap tbu tren giay , cae hdp chat
c6
mau kbae nbau
se
d^i6Q.
tao thanb [
\ 7
'-
H(HgBr)^As
- mau vang ,
(HgBr)-,;As
•
mau nau
,
Hg^As^

-
mau
d^ii
. Hien nay cac pbong tbi nghiem
trong nude
sU.
dung bai loai tbiet bi . Gbung kbae nbau cbu
yeu d
each
d|t
giay tam muoi tbuy ngan . PbUdng pbap nay
kbong du do nbay de xac dinh asen trong toe va mau vi bam
ludng asen trong cae doi
titdng
nay qua nbo va ludng mau can
pban tieb qua
Idn
, kbong eo dieu kien cung cap . Kbi pban
tieb
nude ,
pbai dung bang lit va qua giai doan boc bdi rat
au
/
Cac pbUdng pbap kbae it
c6
y nghia trong
tbiie
tien
nude
ta .

Chang ban phudng pbap dung
di
thiol va butylrodamin
bi P va Si can trd .
PbUdng_nba£_auan2_pbo_ba2_tbu_ngu2|n_tU
Binh
luat
Kiecsop la ed
s3
cua pbUdng pbap nay - Tbeo
do
,
moi nguyen tU se bap tbu bUc xa
c6
do dai song ehinh
bing do dai song cua bUe xa ma no phat ra kbi d trang thai
kieb
tbich
.
Cudng do bap tbu ty le vdi nong do nguyen tu
can xac dinb . Be tbUc hien pbUdng pbap nay
,
ve nguyen tac
,
ta pbai c6 moi den rieng cbo moi
nguyen
to can xac dinb . Ca
tot cua den nay dudc ebe tao bing ehinh nguyen to can xac d
dinb . NgUdi ta dUa mot nguyen to nao do den trang thai nguyen
tu bing nbieu each

,
pho bien nbat la dung ngon
lUa
.
Phudng pbap quang pbo hap tbu nguyen tu eo do
ebon
loc cao,
toe do pban tich nbanh nen dUdc sU dung rong rai d cac nude
ti'en
tien . Vdi ngon
lUa
axetylen - kbong kbi va den ca-
tot asen cbo vacb
189,042
nm
,c6
the pbat bien dUdc nong do
asen trong dung dicb thap den
1.10"
%
,
tuc
-lCu^^;;r2C7
•
S
nUde
ta
, cbi
vai pbong tbi ngbiem dau
nganh

va mot
so trUdng dai hoc
Idn
mdi thUc bien
dvl^c
phudng pbap nay vi
tbiet bi rat dit
.
Hdn
nua
, viec
s^
du bo den kbong pbai
de
,
ma tuoi tbo cua moi den lai eo ban .
'
. a a
?^!i^-S_E^ap_quang_pbo_£h8t_xa_nguyen_tu
Nguyen tu kbi dUdc dUa
len
trang thai kieb tbieb
tfhi
pbat xa .
DUa
vao viec ngbien cUu pho vacb cua bUc xa , ta
CO
the dinh tinh va dinh ludng mot nguyen to nao do . Tuy
tbeo tinb chat nguyen to can xac dinb , doi tudng phan tieb
8

,
eau tao tbiet bi ma n,gudi ta dung cac nguon kieb tbieb
kbae
nbau : ngon
lUa
(
2.000
-
3-000
^K
) , bo quang
(4.000-
6.000
"^K
)
,
tia dien ( 10.000 -
^0.000
''K
) , laser
(7-000-
8.000
^K
) . Koch 0. G.
/44
7 cbo biet ,
lUdng
asen thap.
nbit.
CO the pbat hien khi dung nguon ho quang

li
1
(ug -Tbeo
Indicbenko L.
N.
7
10
7 ,c6
the pbat bien dUdc
0;i^03
% As
trong khoang vat nbd vacb
23^,984
ma , eUdng do manh nbat.
Hien nay
5
nUde
ta,cae
may quang pbo eo nguon laser rat
hiem . Vdi eac may quang
pbS
pbat xa thong
tbUdng
dung nguon
bo quang tbi do nbay kbong tboa man de pban tich nbieu doi
tUdng tbue te ma 5 do ham
lUdng
asen cbi vao khoang 1 ppm
-
1 ppb

PbUdng
2i^a£_kich__hoat_ndtron
PbUdng pbap
kieb
boat ndtron la mot trong eac phudng
pbap pban tich pbong xa . 8 pbUdng pbap nay , ngUdi ta bien
cae nguyen
t6
can xac dinh
tbanli
cac dong vi pbong xa nban
tao nbd eac pban Ung bat nban kbi cbieu mau ngbien cUu
bBng
cac bat
•
electron
,
ndtron , proton , hat nban
heli
v.v.
CO nSng
ludng cao va tiep sau do , do do pbong xa cua ehung .
Phudng 'pbap nay eo do nbay rat cao ( 0,01 ppm - 0,1 ppb )
/"
15,20,44
7
•
KHi
cbieu mau bing dong ndtron 10
n-em'^^.s"

, gidi ban dUdi cua sU xac dinb asen la 2 ng
/"
44
7
•
i^9
-^
nbay nay tboa man nbu eau xac dinh asen trong bau bet cac doi
tudng . Vdi pbUdng pbap kieb boat ndtron
,
Vasen da cbo biet
•
bam ludng asen trong mot it toe eon sot lai cua Napoleong
Idn
bdn trong
toe ngUdi
binh thudng 13
Ian .
Tu do dan den
mot each bieu
kbae
ve nguyen nban lam cbo vi cUu boang de
•
kia chet mot each dot ngot .
Huon
phan tieb bing pbUdng pbap kieb boat ndtron ,
can
CO
nbung tbiet bi rat pbUc tap , dit tien .
Ngoii

ra ,
nbung cong trinb pbong ,
ebong
nhiem xa cung kha ton kem .
Bdi vay
,
cbi nbung ed sd dau nganh cua nba nUdc mdi xay
di^ng
dude pbUdng pbap nay .
NgUdi ta biet rat nbieu nen cue pho asen
/17,^0
]
.Tuy
nbien , do do
Idn
cua dong tu dien va phan ung dien cue cua
asen kbong tbuan
ngbich
, pbUdng pbap cUc pho
c6
dien kbong
the xac dinb nguyen to nay d nong do dUdi
lO'-^mol/l
. Nam
1981 , Le LUdng ( Vien boa hoc cong ngbiep , Tong cue boa
chat ) da dung cUc pho song vuong xac dinh asen
;
do nbay
chUa vUdt qua
1.10"-^

mol/1 . Sd di nhu: vay vi may cUc pbo
song vuong
OH-104 chi
nbay doi vdi cac nguyen to eo pban
Ung dien cUc tbuan ngbich
.
Cac may cUe pbo tast , cue pbo
xung cbo do nbay xac dinb cao bdn , song do
ebUa
eo thiet
bi nay nen
cbUa
tbu nghiem
dUdc
.
Nam
1983
,
Le
v^n
Bi-oh
( luan an tot ngbiep
dei
I'.oc
Tong hdp Ha noi
)
da xac dinb du:de asen thap den
1.10"
mol/1 dUa vao song xue tac bidro trong nen
LiCl

0,llu
-s-
Fe (III)
5,8.1C~\ol/l
( pH
=
3,2 ) . Bo nbay
nl-y
cbUa
tboa man yeu eau thUe te .
•
PbUdng_£ba£_di|n lioa_boa_tan
Vdi cac may cUc pho
c^
dien , ta eo the tbUe bien
d\i6c,
• • .
pbUdng pbap dien boa boa tan . Co the xem day la mot bien
the cua phudng pbap cUe pho . Bdi v|y , pbUdng pbap nay
10
eon dude goi la pbUdng pbap cue pbo eo lam giau , cue pbo
n^Ude
( Inverse Polarogrspby ) hay von-ampe
n^\i6c
( Inverse
Voltammetry ) . Tbeo Koch
0.
G.
7 44 7
, pbUdng pbap dien

boa boa tan
c6
the xac dinb nhieu nguyen to d nong do thap
den 1
ng/ml
. NbU vay , ve
m§t
do nbay , pbUdng pbap nay so
sanb
dUde
vdi pbUdng pbap kieb boat ndtron va bdn ban cac
pbUdng pbap kbae da trinb bay d tren . Nhieu tac gia nUdc
ngoai da dung pbUdng pbap dien hoa boa tan ngbien cUu van
de xac dinb asen . Ho da dat
d-\l6Q,
mot sd ket qua dang
kbieb le
,
song cung eon nhieu van de pbai ban crude kbi ap
dung vao boan canb cu the nUdc ta bien nay .
Trong nbung nam ebong My
cu:u
nUde , vdi
nhUng
bai bao
le te trong cac tap cbi tbieu so , ehung toi biet the gidi
bit dau phat
trien
phudng pbap pban tieb dien boa mdi nay.
Bdi vay , dau

nSm
1973
i
i^gsy
sau kbi hiep dinb Pari ky
ket
,
tu gia ndi sd tan
trS
ve Ha noi , ehung toi da lam
nbung viec can tbiet de xay dUng pbUdng pbap nay . Bai bao
dau tien trong nude tbuoc linh vuc nay
viet
ve viec xac
dinb bae trong cbi tinb kbiet
/^
62
7
•
^"^1 may ^'^^
P^o
OH-
102 va dien cue Pt tu ebe ,
Tr^n
Huu Hoan va
con^^
sU da
. • a
'
a

•—'
.
xac dinb dude bam
lUdng
Ag thap den
n.lO"^
o
ma kbong qua
eac giai doan taeb
boSe
lam giau . Gong trinh nay da dUdc
pbuc vu viec ngbien euu nang cao chat ludng
acqai
chi va
viec tinh ebe chi bing phudng pbap nong ehay vung . Trai
qua
nam
thing , phUdng pbap pban tich dien boa boa tan da
dudc xay dung
"s
va pbat trien d mot so cd sd nbu : Bo mon
pban tich cua Kboa boa Trudng dai hoc
T^ng
hdp Ha noi ,
Phong phan tieb cua Vien boa Vien kboa hoc Viet nam
,Pbong
pban tich cua Vien boa boc cong ngbiep Tong
cue
boa chat .
11

o
0 o
Tu nbung dieu trinb bay tren , ta thay , cae phudng
pbap quang , bao gom :
trSe
quang , quang pho hap tbu
nt^njen
tu , quang pbo pbat xa nguyen tU deu kbong du do nbay de
xac dinh asen d
lUdng
nbo bdn 100 ng
hoSe
0,1 ppm . Luon sU
dung dude cac phudng pbap do pbai lay ludng mau
Idn
va qua
giai doan lam giau rat pbUc tap
.
Hdn nua , van de cung cap
, nbap tbiet bi vat tU can tbiet cbo mot so pbUdng pbap von
dUde
Ua
ebuong
tren the gidi ( nbu quang pho bap tbu nguyen
tu )
gap
kbo
khan,khien
cbo ehung kbo ap dung rong rai d
nude ta . Phudng pbap kieb boat ndtron dat do nbay

ly
tudng
,
CO
the tboa man dude moi yeu eau thUc te ve viec xac dinh
asen . Song ehung toi kbong du trinb do va tbiet bi de
tbue
hien phudng pbap nay . Va lai , luan an eo mue dieb tim
mot pbUdng pbap xac dinb asen du nbay va de dang pbo cap den
cac cd sd de mong dap ung
d\i(ic
rxhieu yeu eau da dang trong
n\X6c
. Trong cac phUdng pbap con lai thi pbUdng pbap dien
boa boa tan eo by vong hdn ca . Chung toi ebon phudng pbap
nay vi ngoai nbung
uu
diem cua no da
ke
tren , trude bet
cbung toi
CO
phudng tien vi da tich
luy
dude it nhieu kinh
ngbiem
•
Muon ngbien euu tot ,
trUde
tien ta can biet cac thong

tin da eo ve tinb chat dien boa cua asen vi tinh binh xac
dinb asen tren the gidi bing phudng pbap da ebon .
>fH
0
;so
'J*
'«tfr ^;K^>a:3»"-"-
12
2.1/
Tinb chat dien hoa cua asen
Tinb chat dien boa cd ban cua asen ( tren dien cUc giot
tbuy ngan ) da trinh bay trong cac tai lieu
/
17,20,34,45
7-
NbUng
thong tin nay eo the soi sang pban nao ed ebe cua cae
pbUdng pbap dien boa boa tan xac dinb asen va giup ta dinb
budng
ngbien cUu tiep theo
.
/
2.1.1 - Asen boa tri V
NgUdi ta tbay vai song nbo cua asen (V) trong
HCl
6M
boae
8M vi mot song kbU kep trong HCl 11,5
M
, cbieu cao

cua no giam theo nong do axit va mat ban trong HCl 9
^
/48
7-
Nbung , nhin cbung , asen (V) kbong bi khu tren dien cue
gi,t
tbuy ngan
/ 17,^5
7 •
Trong tu nbien , asen c6 the ton tai d dang boa tri (V),
do do muon xac dinb no pbai cbuyen ve boa tri (III) nhd phan
Ung boa hoc .
2.1.2
-
Asen boa tri III
• Tinh chat dien boa cua asen (III) ,
trfen
dien eUc giot
tbuy ngan , trong moi trudng HCl da
d\l(5c
ngbien cUu ky nbat
va cung tbu
d\X6c
nbieu thong tin mau
tbuati
nbat . TRong moi
trudng nay , asen ton tai d nbieu dang kbae nbau . Theo
Arnold
f3^
7

GO
tac gia cbo
rang ,
trong HCl
,
asen (III)
CO
the ton tai d cae dang sau :
AsCl^
,
As(OH)Gl-, ,As(0H) Cl,
As(OH)^^
,
H^AsO^
, kbong c6 anion phUc eloroasen . Trong
HCl 12 M , dang Uu tien
li
AsGl
, trong HCl 9
K.
li
AsCl,.
va
3
va
"o
As(0H)Cl2
, con trong HCl 5M ,
c6
tat ca 3 dang ke tren .

c6
tac gia lai cbo ring , trong HCl
4M
c6 cac anion pbuc
cloro
vi du
AsCl^
. Tai lieu sac ky trao
dgi
ion
/
20
7
cbo tbay
13
trong HCl tU 0 den 12 mol/1 he so pban bo cua asen tren ea-
tionit
Dowex-50
be bdn 1 . Bieu do congbia la , asen neu ton
tfi
d dang ion dUdng dien tbi cung
cbi
vdi ty le rat nbo .
Tren anionit
Bov/ex-1
, he so pban bo cua asen be bdn 1 kbi
nong
c?o Eei
be bdn 4mol/l , vi
Idn

bdn 10 khi nong do HCl
Idn
hdn 8 mol/1 . Bieu do
c6
nghia la
,
khi nong do HCl
Idn
hdn
4 mol/1 , trong dung dicb eo anion pbuc eloroasen va ty le
pbuc anion cbiem Uu the kbi nong do HCl
Idn
hdn 8 mol/1 . Ket
hdp bai tii lieu sic ky trao doi ion tren , ta suy ra ring ,
trong dung dicbHGl tu 0 den 4 mol/1 , asen ton tai cbu yeu
3
dang hdp chat trung tinb
.Tim
bieu dang ton tai cua asen
trong dung dieb HCl eo
Idi
cbo viec thao luan ket qua ngbien
eUu sau nay .
Tbeo Kriukova T. A.
/
17 7
,
i^ot;
so tac gia thay ,
tron^

moi trudng HCl , asen (III) cbo 4 song cue pbo , dang vi the
cua ehung tbay doi tbeo nong do axit
.Song
tbu nbat Ung vdi
sU tao thinb asen nguyen to ( elemental arsenic )
,
song tbu
bai va tbu ba Ung vdi sU khu cua
H^AsO^,
va
AsjO-
,
con song
tbu tu Ung vdi sU khu cua asen nguyen to den
ASH-
. Vi
sii
phue
tap cua pb6 nen eac tac gia nay cbo ring moi trudng HCl
kbong tbieb hdp cbo mue dieb pban tieb .
Koltboff I.
h.
7
^3
7 cbo biet , mot so tac gia kbae
thay , Trong HCl
IM
chUa 0,01 % gelatin , asen (III) cbo mot
song pbuc tap bit dau
t'u"

-0,4 V ( sv. SCE ) va dong
g^idi
ban
dUdng nbu dat
d\t6c
d -0,8 V den -0,9 V ung vdi sU khu du 6
electron thanb asin (
ASH^
) . Tuy nbien ho
ban
kboan la ,sau
dong gidi ban do eon eo mot song
kbae.nen
ngbi ngd ehinh
~-ia
tbuyet cua minb
14
Tbeo
Milner
G.'V.C.
/
48
7 i
Kaxirkova cbo rang , trong
HCl
BI
, asen(III) cbi cbo 2 song
3
vung -0,3 va -0,6 V ( sv.
SCE ) , song

thU
nbat kbong dinb
lUdng
va eo the ung vdi sU t
tao tbinb asen nguyen to eon song tbu bai Ung vdi sU khu asen
nguyen to tdi asin , cbieu cao song niy ty
levdi
nong do asen
trong dung dieb . Cung theo
IVIilner
G.V;/.C.
,
ileites
thay asen
(III) ebo bai song trong dung dieb HCl . Song tbU nbat eo
E-,
yp »
-
0,428
V ( sv. SCE ) , cbieu cao cua no ty le vdi nong
do asen trong khoang
1,8.10"^
-
9*10
mol/1 . Kbi nong do asen
tang , cbieu cao song nay kbong bien doi nUa . Tac gia do giai
tbieb la , asen nguyen to
d\L6o
sinb ra da tao thanb mang ( film)
vi bi hap

phu
tren be mat dien cue giot
tbuy'
ngan . Song thU
bai
chi
bieu bien tot kbi nong do asen (III) tang den
5«10"''^
'
. Khi nong do asen cao bdn , song nay eo cue dai kep ky
di . Khi dung xanbmetylen de ebong cUc dai ,
Leites
tbay
ring^
bing so dong kbuecb tan (
i^-
C"
.m"^*^.
t"
""^^^
) cua song tbu
bai gap doi bing so nay cua song thU
ribat
. Ngbien cUu sau sic
hdn , tac gia niy cbo ring , trong HCl
lii.
, asen bi khu thanb
bai
bude
, moi

bude
tbu 3 electron . Neu
nbunn
ket luan ed
ban cua
Meites
phu bdp thUc te , tbi ta
c6
the xac dinh asen
bing pbUdng pbap dien boa boa tan dUa vao sU dien pban lam
giau no d dang boa tri (0) .
Qua trinb khu asen (III) tren dien cue giot tbuy ngan
rat pbuc tap . Nbieu cd ebe c6 ging giai tbich qua trinh niy
da dudc neu ra . Boi vdi song tbu nbat , cd ebe sau day
c6
le
tbich
Yi^-g
bdn
cs,
f
':>^
/ :
'
As(OH)J ^
Gl"
-^
e
-SilMk^
•As(0H)Gl

^
OH"
As(OH)Cl ^
e
_cham_^
^^ ^^^ ^ ^^^ ^ ^^^
As (I)
^
e .
^^^^>
As
15
Tbeo cd ebe nay , ion
CI
trong
Idp
kep boat dong nbu
mot eau noi giUa dien cue lam viec va ion asen (III) . Loai
cd ebe
eau
iori kieu nay thudng
gap
trong eac phan ung oxi
boa kbu
-
Song thU bai
chUa
giai tbieb
d\i(5c
tboa dang

.
Cd
che
tren ngoii viec ehung to qua trinb khu tren dien eUc giot
tbuy ngan cua asen rat
phiie
tap , con noi len ring qua trinh
do khong tbuan nghich . NbU the , phudng pbap eUc
pbS
song
vuong xac dinh asen ( xem mac 2.0 ) kbong tbich hdp . Luon
dung phudng pbap nay , pbai tim dUdc nen sao sho asen phan
Ung dien
o^c
du tbuan ngbich .
Su kbu asen (III) trong cae moi trudng kbae cung dudc
ngbien cUu
f 17,^5,^8 7
. Trong
H^SO^
0,5
Ivi
chUa o,01
^i
ge-
'latin
, asen cbo bai song . Cbieu cao song thU nbat ty le
vdi nong do asen (III)
.
Cac song nay xuat hien d the am

bdn trong moi trUdng HCl vdi the
nu?a
song
Ian ludt
la -0,7
V vi -1,0 V ( sv. SCE ) .
IsTbu
vay , muon lam giau asen
trong moi trudng
HpSO^
pbai dien pban d the am hdn trong
moi trudng
HGl
, do do nbieu kim loai bi dien pban theo nen
do
ebon
loc se kem hdn . Trong
HNO^
IM
, asen cung cbo bai
song vdi the
ntfa
song tudng tu trong
H
,S0_^
. Trong moi tr
trUdng rudu
-f
axit
sunfurie

, asen cung cbo eac song ro
vdi the
HL^a
song
Ian
ludt la -0,6 V , -0,88 V va -1,15
V
.
Asen (III) kbong bi khu trong moi trUdng kiem , trung tinb
boSe
kiem tatrat . Trong moi trUdng kiem manh , asen (III)
cung bi oxi boa den asen (V)
.
Nbu vay , ta tbay moi trudng
kiem va trung tinb
-kbong Idi
cbo phudng pbap xac dinb dUa
vao
each
lam giau asen S dang boa tri
(C).
.
Su kbu asen (III) trong dung dieb
KI
cung dude xem xet
r
'5^ 7
'
Trong KI 0,1
M

ehUa chat ebong cue dai , asen cbo
16
bai song ro kbi nong do cua no thap
h(5n 8.10"
mol/1 . Trong
KI 0,1
M
(
pHaa
2,0
" ^,4
) , cbieu cao song ty le vdi nong
do asen (III) cbo den
I.IO"'^
mol/1 . Neu nong do asen
Idn
bdn , quan be tren kbong eon nUa . Cbieu cao song dat gia
tri gidi ban kbi nong do asen vudt qua
4.10"'^mo
1/1
.Nbd
tinb toan ly tbuyet , ngUdi ta tbay , d day eo bien tudng
bap phu ding nbiet -
Trong eac moi trUdng eo chat tao pbUc manh nbu pirogalol
, axit oxalic , axit tatric , EBTA
-t
KCN
v.v.
, the
nife.

song cua asen dicb ve
phia
am boae mat
bSn
. Bdi vay , eac
moi trudng ay cung kbong tbieb bdp vdi phudng pbap dien
boa boa tan xac dinb asen .
Tu nbung dieu da trinb bay , ta rut ra may nban xet
nbu sau :
1 )
MSI
trudng HCl eo le la moi trudng tbieb hdp hdn ca
cbo viec xac dinh asen bing phudng pbip dien boa boa tan .
2 ) Trong dung dicb KI , asen
c6
bap phu ding nbiet .
3 ) Muon xac dinb asen (V) , pbai kbu no den boa tri (III)
bing eac pban Ung boa hoc tbieb bdp .
17
2.2
/ Cac pbUdng pbap dien boa boa tan xac dinb asen
Tbeo eac thong tin ve tinh chat dien boa cua asen da
trinb bay d mue
tr-ude
, ta thay ring , cae phudng pbap dien
boa boa tan xac dinh asen deu dUa tren kha nang dien pban
lam giau asen d dang As (0) . Nbung tai lieu xac dinh asen
da
eng
bo d nudc ngoai eo the chia lam bai nbom nhu sau :

2.2.1 -
PHUdng_£ba£_dien_hoa_boa_tan_anot
Cac pbUdng pbap dien hoa boa tan anot deu dua tren kha
nang oxi boa dien hoa As (0) da tao
tbqnb
trong giai doan
lam giau den As(III)
Cic moi trudng
HGIO^
7
^2 7
,
H^SO^
£
5^
7 ,
K^SO^
^
HNO^
£
IS J CO
the dung lam moi trudng dien pban . Tuy nbien,
HGl 1
Iv!
la moi trudng dudc sU dung nbieu hdn ca
/"
11,12,13,
21,32,42,54 7 .
Bo nbay xac
d^inh

phu tbuoc nbieu vao loai dien cue lam
viec
d-i/dc
sU dung
,
Vdi dien cUe Pt , dung moi
trudnfe
HCl
Uvl
, Truebina
L.P.
/
32
7 c6
the xac dinh dude nong do asen
thap den
2.10'^^
mol/1 , eon
Gustaf,;
P.
£^2
7
da dat tdi
do nbay 2.10
^
mol/1 . Bien cue vang
dxt6o
sU dung nbieu nbat
/ 11,12,13,21,42,46,54 7 va cung dat do nbay cao nbat
/

12,
13,42,46 7
• Ching
ban , kbi dung dien cue vang , trong moi
trudng HGl
lii^
, Kaplin
A.A. /
12
7
dat dudc do nbay
6.10"^
mol/1 , con Gustaf
F.
^
42
7
cong bo pbat hien dUdc 0,02
ng/ml , tuc
"3.10*"^^
mol/1 . Kaplin
n.k.
thay Cu cin trd sU
xac dinb Asen rat nhieu ngay ca kbi £
On(11) 7
: £
ks{lll) 7
Idn
bdn 1:2. Trong eac doi tUdng tu nbien va ky tbuat
\-\16n^

Cu thudng
Idn
bdn ludng As . Nbu vay , neu dung dien
cue vang pbai ket bdp vdi mot qua trinb
tach
tbich hdp
l,H_Ml^^
18
Kbi dung dien cue Pt va Au , Gustaf
E.
/
42
7
i^ban
thay cbung
de bap phu oxi , gay trd ngai ebo sU xac dinb . Ngoai ra , e
cac dien cUc nay c6 do ben cd hoc kem nen kbo sU dung . Bien
cue graphit kbong nbay / 11, 32
/
-
Cbing
ban , vdi dien cue
do , khao sat d moi trUdng
HGIM
vi
H^SO^
0,5
M
, Trushina L.
P.

7"
32
7
kbong the xac dinh asen 3 nong do be bdn 1.10" mol/1 .
Tuy nbien , neu van dung dien cUc graphit mi cbo asen cung
dudc
lim
giau vdi dong trong giai doan dien pban tbi trong giai
doan boa tan ngUdi ta tbu dude tin bieu pban tich c6 cUdng do
manh bdn ro ret
/ 11,16,^3
7 • Roizenblat E.
M.
£
2.7
7
^|^
tbay , ngay ca
lUdng
vet Cu (II) trong nude cat cung lam tang
dong dinb boa tan anot cua asen -
Fnieu
tac gia cbo ring £ 16,
23,27 7 kbi Ou
va As cung bi dien pban 3 dang boa tri ( 0 ) ,
tren be mat dien cue da tao thanb hdp chat gian kim loai bae
• aa .
•-•- —'
aa
bai Cu-As eo boat tinh dien boa manh . Khi dung dien eUc gra-

phit ket hdp vdi be bae bai Cu-As , Krapivkina T. A. £
16 7
va Neiman E. Ya.
7 25
7
c6
the xac dinh asen d nong do
10"
-
10"-^
mil/l
.
Thong tbUdng , pbUdng
pbap'xung
vi pban boa tan nbay bdn
pbUdng pbap von-ampe boa tan khoang 100
Ian
. Tuy nbien , doi
vdi asen , pbUdng pbap xung vi pban boa tan kbong the hien uu
viet ve mat do nbay so vdi phudng pbap kia
7"
^2
7" •
Be tang do ebon loc , doi kbi ngUdi ta eon su dung ky
tbuat doi
itfoi
trUdng . Muon lam viec nay , dau tien nguyen to
can xac dinh
dxL6Q,
lim giau 3 moi trudng tbich hdp , sau do dudc

boa tan d mot moi trudng
cb9n
lo^
kbae - Vdi ky tbuat nay ,
Toropova V. P. £
31
7 da xac dinb asen trong hon hdp vdi 10
Ian
Cu(II)
,
100
lin
Bi(III) , Sb(III) , Sn(II)
ya
Pb(II) .
T^e
gii
nay sU dung moi trudng dien phan la HCl
5-8
M
, moi trudng
boa tan li KOH
IM
vi dien cUe tbuy ngan tinh . Tuy
njrjien
, do
19
nbay cua phudng pbap kbong dat tdi 1.10 mol/1 .
Kbi doc cae tai lieu pban tieb asen bing cac pbUdng pbap
dien boa hoi tan anot , ta eo mot so suy ngbi xung

quanh
van
de dung dien cue
so'
sanb va do nbay rat cao mi nbieu tac gia
da cong bo . Tran HUu Hoan
/
63,64
7
da nban thay cae dien cue
ealomen va bae elorua loai tbUdng mai
c6
the dUa vao dung dieb
do mot ludng vet Hg(II) boae Ag(I) - Trong cae moi trudng axit
vo cd , tin bieu boa tan anot cua tbuy ngan , bae , asen gan
nbu trung nbau nen de gay
nbami Ian
.
Ii.ac
dau , ngudi ta dinb
kha nbieu giay mo ta viec xac dinh seen asen , song kbong eo
mot cbu tbich nio ve viec dung dien eUc so
sar±i .
NbU tren da
neu , Gustaf
F.
cong bo phat bien dudc As 0,02 ng/ml , song
cbi dUa ra
pb6
von-ampe boa tan cua dung dicb 1

(ug/ml
, tUc
50.000
Ian Idn
bdn .
Mae
dau vay , tin bieu nay cung cbi li mot
dinb kbong dep , tu , cbieu rong nua dinh do
dUde
tdi
-140
mV .
2.2.2
-
5iJl?^5S_Eiii2_Sil^
^22_-^2§_5§2-_2552!^
Cac phudng pbap dien boa boa tan catot dUa tren kha nang
khu dien boa As(0) thanb asin (
AsH^
)
Nam 1980 , Brainina Kb. Z.
/
4,29 / dung dien eUc mang tbuy
ngan tren graphit xac dinh
d\i6c
nong do asen thap den
1.10"^mol/l
bing pbUdng pbap von-ampe boa tan catot . Tac gia nay sU dung
dung dicb nen nbu sau : HCl 1,5
M ^

2 M
-s-
KI 0,4 M
-s-
Esi^O^).^
3,5
.10"
- 5
95-10"
M . Phudng pbap nay eo do
ebon
loc tot ,
nbieu nguyen to , trong do eo cac kim loai kiem , kiem tbo
•,
^'e
(II) , Co , SO" , Cl~
Ya
PO^"
kbong can tr3 . Tuy nbien ,
Cu(Ii;
can trd
;
ngay ca khi nong do Gu(II) gap 10
Ian
As(III) , tin
bieu pban tich cung bien mat . Tac gia
c6
dUa ra vai Ung dung
tbUe te , nbung
kfeong

cbu y den kha nang mat asen
lue
xu ly mau
20
bing hon bdp
HpSO^
•!•
HF
/
29 7
-
Theo Bolezal
^.£77 »
nbd sU dung dong vi
As^
, tu
lau
, ngudi ta biet eo den 45
%
asen bi mat khi dung hon hdp axit do .
Belova T. Ya.
/" 2 7 sU
dung be bae ba
I-Gu-As
dau tien
vao nam 1975 •
lac
gia niy dung
dien
cUc tbuy ngan tinb xac d

dinb asen trong nen HCl 3M
-s-
KI 0,015
M ^
CuSO^
5.10"^
M ,
3 nbiet do 80
-
180
^
C . Neu tinb den do ben cua KI vi tbuy
ngan kim loai trong moi trUdng axit manb , nbiet do cao , ta
tbay pbUdng pbap niy rat kbo
thUe
hien
.
Vdi phudng pbap von-
ampe boa tan catot dong xoay cbieu ,
h9
xac
dinli
dudc asen d
vung nong do 1.10
'
mol/1 . Phan ung xac dinb asen nay
d\i6Q,
gia tbiet li theo cd che xue tac
.
2.3 / Cac van de ngbien eUu trong luan an nay

Tu phan tong quan tren , ta rut ra dUdc
nhSng
nban xet
tong quat nhU sau :
1) Ngudi ta
CO
ging tang do nbay bing each dung cae dien cue
che tao
tii
kim loai qui nbu Au , Pt boae su dung cae bdp chat
gian kim loai Cu-As kbi dung dien cue graphit , tbuy ngan tinb
2) Moi trudng dien pban thudng dung la HCl
HI
( boa tan anot )
boae
HCl 1

3 M ( boa tan catot )
. Co
le HGl li chat dien ly
tbieb bdp nbat cbo viec xac dinh asen bing cac phudng pbap
dien boa boa tan . Nban xet nay phu bdp vdi dieu da rut ra tu
tinb chat dien boa cua asen
,
neu 3 mue 2-1
. 'a
3) Trong cae doi tudng tu nbien va ky tbuat ,
feem
ludng vet
Cu tbUdng

Idn
bdn ludng vet As . Cae dien cue lam bing kim 1
loai qui cbo do nbay cao song bi Cu gay tr3 ngai . Bdi vay ,
trong sU dung tbue te pbai qua mot giai doan taeh pbuc tap .
Kbi dung he Cu-As , ngudi ta pbai them mot ludng muoi Gu(II)
vao dung dieb do , do do tren tbue te , Gu (II) trong mau