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NUUNG CIIU
VIET TAT
TT
1
2
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17
Tieng Viet
Do
lech cluidu
Dp/ii^
hoc
xuc
tac
Bien
i^io'i
tin cay
Ccic rdi

loan
thieu
hut idt
Gic/i
han dinh
hi'ang
Gio'i
han
phdt hien
Hoi dong
kiem
scat cac rdi
loan
thieii
hut idt
Ilocnion Tj
Idt
i>dn
protein
Khocing
tin cay
Kich gidp td
Phcin
ticJi
ddng chdy
Phd/i ffch
kich
Jioat
no'tron
QuT

nhi dong Lien hiep qudc
To chu'c Y te'The gioi
Thu'ngJiiem
mien
dich
phong
xci
Thyroxin
Tieng
Anh
Standard Deviation
Catalytic kinetic
Confidence Limits
Iodine Deficiency Disorders
Determination limit
Detection limit
International Council for
the
Control of
Iodine Deficiency Disorders
Triiodothyronine
Protein Bound Iodine
Confidence Interval
Thyroid Stimulating Hormone
Flow Injection Analysis
Neutron Activation Analysis
United Nations Children
'sFund
World Health Organization
Radio Immuno Assay

Tetraiodothyronine
Vict
tilt
SD
DHXT
CL
CRLTHI
GHDL
GHPH
ICCIDD
Tj
PBI
CI
TSII
FIA
NAA
UNICEF
WHO
RIA
r,
DANH
MUC
CAC
HINH
STT
1
2
3
4
5

6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
Ten hinli
Hinh LI. Gidn do bien ddi
ndng luang plidn li'ng
trong tien trinh
phdn
ifng
Hinh i 2. Do
tin
xdc dinh nong do chat
xiic
tac theo
plni'ong

phdp tga
Hinh L3. Do
tin
xdc dinh nong do chat
xiic
tdc theo phu'o'ng phdp
CO
dinh thdi gian
Hinh L4. Do
tlii
xdc dinh nong do chat xuc tdc theo phu'o'ng phdp
CO
dinh tin hieu do
A^
Hinh L5. So' do bieu dien thuc nghiem tim dieu kien tdi
u'u
theo
phu'o'ng
phdp du'dng doc nhd't
Llinh
3.L Do
tin
bieu dien do hap thu cua dung dich Ce(IV) theo
ndng
do
Llinh 3.2. Gid tri chudn Student
ciia
cdc he so hoi c/uy
Llinh 3.3.
Sitphu

thuoc cua tdc do phdn
li'ng
theo nhiet do (L >
15
ng/ml)
Hinh 3.4.
Sii'phu
thuoc cua tdc do phdn
li'ng
theo nhiet do (L < 15
ng/ml)
Hinh 3.5.
Suplui
thuoc cua tdc do phdn
ii'ng
theo thdi gian
Hinh 3.6.
Suphu
thuoc cua tdc do phdn
ung
vdo nong
dp
chdt xuc
tdc
(pinto'ng
phdp dn dinh thdi gian)
Hinh 3.7.
Sit
phu thuoc cua tdc do phdn
itng

vdo ndng dp chdt xuc
tdc
(phu'o'ng
phdp tga)
Hinh 3.8.
Plid
hap thu dung dich clopromazin sau khi hi oxi hoa
hang
I-I2O2
Hinh 3.9. Gid tri chudn Student cua cdc he
sdhoi
quy
Hinh
3.10.
Do
tlii
chudn bieu dien
sit
phu thuoc ndng dp idt vdo tga
Hinh
3.1
L Gid tri chudn Student
ciia
cdc he
sdhoi
quy
Hinh 3.12. So' do bieu dien qui trinh phdn
ticli litc/ng
vet idt trong
nitdc

tieu
llinh 3.13.
Sit
phu thuoc
ciia
tdc dp phdn
I'tng
theo ndng dp chdt
xuc tdc
Hinh 3.14. So' do bieu diin qui trinh phdn tich
lu'p'ng
vet idt trong
su'a vd
toe ngitdi
Hinh 3.15.
Sa
do bieu dien qui trinh phdn tich
lu'p'ng
vet idt trong
hiiyet
thanh
Llinh
3.16.
So'do
qui
trifih
phdn tich
litpng
vet idt trong
nu'dc

sinh hoa!
Llinh 4.L Do
tin
bieu dien
ham lu'p'ng
idt-nien trung vi cua hai
nliom
phu
nn'imang
thai vd ddi
chu'ng)
phdn
bdtheo viing
sinh thdi
Hitih
4.2. Ham
lu'p'ng
idt
nieu (nliom cliii
citu:
A vd
nlidni
chu'ng:
B) vd idt trong su'a me
dcdc viing
sinh thdi cdc
nliau
Trang
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93
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107
116
118
DANH MUC CAC BANG
STT
1
2
3
4
5
6
7

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19
20 j
21
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27
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29
30
Ten bang
BciiiM
1.1.
Mot
sotinli chdt li
hoc cua idt
Bang 1.2. Nhu can idt hang ngdy theo

tiidi
Bdng L3. Phdn
loai mi'tc
dp thieu hut idt
dita
vdo nong dp idt nieu
Bang 1.4. Dieu kien thi nghiem cua cdc yen to'dnh
hitdng
Bdng
1.5.
Gid tri cdnh tay don d vd tham sd
(p
trong ma trdn
tlutc
nghiem bdc hai tdm xoay
Bdng
1.6.
Quy hoach hod thuc nghiem theo phu'o'ng phdp du'dng
ddc
nhd't
Bdng
1.7.
Nhu'ng cong trinh nghien
citu
xdc dinh
lu'png
vet idt bdng
phito-ng
phdp DHXT
klwng sit

dung he
[Ce'^-As^^f tit 1985'2()()()
Bdng
3.1.
Cdc
mi'tc
gid tri vd khodng bien thieu cua cdc yen td
Bdng 3.2. Ma trdn tlutc nghiem vd ket qua
Bdng 3.3. Anh hitdng dinh
lu'p'ng
cua cdc yen
tdden
hdm muc tieu
Bdng 3.4. Cdc gid tri ddc
tritng
cua
phu'o'ng
sai thi nghiem
Bdng 3.5. Gid tri cdc he
sdhoi
quy trong
phu'o'ng
trinh hoi quy
Bdng 3.6. Anh hitdng dinh
lu'p'ng
cua cdc he sd hoi quy sau khi da
loai bo cdc he sd klwng co y
ngliTa
Bdng 3.7. Cdc gid tri cua phdn tich phu'o'ng sai
Bdng 3.8. He sd hoi quy sau khi loai bo cdc yen td anh hitdng

klwng ddng ke
Bdng 3.9. Ket qua sai
klidc
giu'a li
thiiyet
vd tlutc nghiem
Bdng 3.10. Quy
hoqch
hod tlutc nghiem theo pinto'ng phdp du'dng
ddc nhd't
Bdng
3.11.
Ket qua khdo sdt anh hitdng cua mot
sdchdt
gay can
Bdng
3.12.
Ket qua xdc dinh ndng do idt trong mdu gid
Bdng 3.13. Ket qua xdc dinh hdm
lu'p'ng
idt trong
nude
mdy thdnh
phd I
Iiie
Bdng
3.14.
Ma trdn tlutc nghiem bdc hai tdm xoay 4 yen td
Bdng 3.15. Khodng bien thien vd cdc
mi'tc

thi nghiem
Bdng 3.16. Anh hitdng dinh litpng cua cdc yen
ttJ'de'n
hdm muc tieu
Bdng 3.17. Phdn tich phu'o'ng sai cdc he
sdhoi
quy
Bdng
3.18.Cdc
he
sdhoi
quy trong
phu'o'ng
trinh hoi quy
Bang 3.19. Anh
hitong
dinh
lu'p'ng
cua cdc
yen
to sau khi loai bo
cdc he
sdkhong
c6 y
ngliTa
Bdng 3.20. Cdc gid tri phdn tich
plntang
sai
Bdng
3.21.

Cdc he
sdhdi
quy trong
phu'o'ng
trinh hoi quy
Bdng 3.22. Dieu kien tdi
itu ciia
phdn
ting
chi thi [Clopromazin-
H,0.j
Bdni^
3.23. Gioi han
diih hiiVng ci'ia nipt
so chat gay can
Trang
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36
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74
IV
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43

44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
Bdng
3.24. Ket qua khdo sdt
sicdiing
EDTA
deche
Fe^*
va
Fe^*
Bdng 3.25. Ket
qiid
khdo sdt khodng
tuye'n tinli

Bdng 3.26. Ket
qiid
xdc dinh
ham lu'p'ng
iot trong
niio'c
sinh hoat
bdng phu'o'ng phdp trdc quang DHXT he
[Clopromazin-H2O2I vd
lie ice-" As^y
Bdng 3.27. Cdc
mii'c
thi nghiem
Bdng 3.28. Ma trdn thuc nghiem vd ket
qud
tin nghiem
Bang 3.29. Anh
hu'ong
dinh litpng cua cdc yen to den hdm muc tieu
Bdng 3.30. Ket qud phdn tich
phu'o'ng
sai
Bdng 3.31. Cdc he
sdhoi
quy trong
phu'o'ng
trinh hoi quy
Bdng 3.32. Anh hitdng dinh litpng cua cdc he sdhoi quy co y
nglua
Bdng 3.33. Cdc gid tri

ciia
phdn tich pinto'ng sai
Bdng 3.34. Cdc he
sdhoi
quy da hieu
chinli
Bdng 3.35. Dieu kien tdi
u'u
de phdn huy mdu
nude
tieu
Bdng 3.36. Ket qud do dp phong xa tru'dc vd sau khi phdn huy mdu
bdng
(NHdiSjO,
Bdng 3.37. Ket qud khdo sdt
klid
ndng tieu
khit
SCN' bdng
(NHdS20,
Bdng 3.38. Ket qud khdo sdt khd ndng tieu
khitF'
bdng
(NLI^SjO^^
Bdng 3.39. Ket qud khdo sdt khd ndng tieu
khit
axit ascorbic bdng
(NHdS^O,
Bdng 3.40. Ket qud khdo sdt khd ndng tieu
kliii

protein bdng
(NHJS20,
Bang 3.41. Ket qud khdo sdt dp lap
Igi
npi nghiem
Bdng 3.42. Ket qud khdo sdt dp lap Igi lien nghiem
Bdng 3.43. Ket qud khdo sdt dp thu hoi
Bdng 3.44. Ket qud xdc dinh nong dp iot trong 22 mdu nu'dc
tieii
being
hai
kT
thuat
phdn Inly
mdu:
axit cloric
vd
amonipesunfat
Bdng
3.45.
Hdm lu'p'ng iot-nieu
ciia
phu
nit
khong mang thai vd
khong CO
con < 5 tuoi
dThi(a
Thien Hue
Bdng 3.46. Ket qud khdo sdt dp lap

led
trong mdu sua vd
toe ngu'di
Bdng 3.47. Ket qud khdo sdt dp thu hoi khi them
1'^'
vdo mdu
nghien
cii'u
Bdng 3.48. Dp thu hoi khi them
KIOj
vdo mdu nghien
cii'u
Bdng 3.49. Ket qud phdn tich hdm
lu'p'ng
iot trong mdu
toe
chudn
Bdng 3.50. Ket qud xdc dinh hdm
lii'png
iot trong
toe
theo hai
phu'o'ng
phdp: phdn tich kich hoat no'tron vd dong hpc
xiic
tdc
Bdng
3.51.
Ket qud xdc dinh hdm
lu'p'ng

iot trong sua me
Bdng 3.52. Ket qud xdc dinh
hdm lu'p'ng
iot trong
toe
Bdng 3.53. Ket qud khdo sdt dp hoi
pliuc
(iot trong huyet thanh)
Bdng 3.54. Ket qud xdc dinh hdm
liipng
iot trong mdu huyet thanh
chudn
Ai,jp
75
75
79
81
82
83
83
84
85
85
85
86
87
88
88
88
89

90
90
91
92
94
97
98
98
100
101
101
101
105
105
62
63
64
65
66
67
68
69
70
71
72
73
74
Bdng 3.55. Ket qud xdc dinh FBI trong huyet thanh bdng
pinto'ng phdp
DHXF

(1) vd xdc dinh tdng
Tj
vd
T^
trong huyet
thanh
phu'o'ng
phdp
RIA^**^
(2)
Bdng 3.56. Ket qud xdc
duih
ham
litang
PBI vd tdng nong dp
L trong mot sd mdu huyet thanh cudn rdn tre
so'
sinh
Bdng 3.57. Ket qua khdo sdt dp lap
led
Bdng 4.1. Hdm litpng idt-nien cua hpc sinh tieu hoc
df
cdc xa
vd
phit&ng
thuoc
tinh Thita
Thien Hue
Bdng 4.2. Ket qud xdc dinh hdm
lu'p'ng

iot-nieu
(/ugl'/di)
dphu
nil'
mang thai vd nliom phu
ml
ddi chu'ng
Bdng 4.3. Hdm
lu'p'ng
iot-nieu phdn
bdtheo
thai ki
Bdng 4.4. Hdm
lu'p'ng
idt trong su'a me
Bdng 4.5. Hdm
lu'p'ng
idt-nieu
(/ugL/dl)
cua cdc bd me dang
cho con
bii
(nliom A) vd nliom chu'ng
(nlwm
B)
Bdng 4.6. Hdm
lu'p'ng
idt trong mot
so'loai
sua hop vd su'a bpt

d'Thita
Thien Hue
Bdng 4.7. Ket qud xdc dinh hdm litpng PBI vd idt vd co' (L)
trong huyet thanh
dcudng
rdn tre
so'sinh
tai
thita
Thien Hue
Bdng 4.8. Ket qud xdc dinh hdm litpng idt-nieu d mdu ngdu
nhien vd mdu 24 gid
Bdng 4.9.
LIdm lu'p'ng
idt trong tdc
Bdng 4.10. Ket qud xdc dinh hdm lu'p'ng idt trong nu'dc sinh
hoat d cdc vung sinh thdi
106
107
108
112
115
\\6
117
118
119
120
122
123
124

5V
\>^
MUC LUC
Trang
DAT VAN
DE
i
Chuong
1.
TONG
QUAN 4
1.1. Gioi thieu
phuang
phap dong hoc
xiic
tac 4
1.1.1. Nguyen tac 4
1.1.2.
Cac
phuang
phap xac dinh nong do chat
xiic
tac bang
phuang
phap dong hoc 5
1.1.2.1. Phuang phap do toe do ban
&lu
5
1.1.2.2.
Phuang phap

a'n
dinh lh5i gian 6
1.1.2.3. Phuang phap
codinh tin
hieu do
(Ao)
6
1.1.3.
NhQiig
yeu to
anli huong
chu ycu den phuang phap phan
tich
DHXT 7
1.1.3.1. Anh huang ciia nhiet do den
toe
do phan
ling
7
1.1.3.2.
Anil
huang cua hang so dien
moi
dung dichden
toe
do phan ung 7
1.1.3.3. Anh huang cua
luc
ion trong dung dich
den toe do

phan ung 8
1.1.3.4.
Do nhay
CLia
phuang phap phan
tich
DHXT 9
1.2. Nhung diem can chu y khi phan tich
lugng
vet 12
1.3. Cac dac trung
h'
hoa sinh cua iot 13
1.3.1. Dai cuang ve
idt
13
1.3.2.
Nhu
Cctu
va vai
tio
iot
Iroiig
sinh
li
nguai 15
1.3.3. Hap thu va chuyen hoa iot 16
1.3.4.
Subaitiet
iot 17

1.3.5.
Nguy ca thieu va
thija
iot 17
1.3.5.1. Nguy
ca
thieu idt 17
1.3.5.2.
Cac rdi loan thieu hut idt tren the giai 18
1.3.5.3. Nguy
cathiia
idt 18
1.3.6.
Nhung chi thi sinh hoc
thuang
duac
su"
dung de danh gia dinh
duong
idt 6 ngudi 18
1.3.6.1.
Idt
trong mau 18
1.3.6.2.
Idt trong tdc va mong 19
1.3.6.3. Idt trong
nude
lieu va sua me 19
1.3.7.
Phan

loai va danh gia muc do
tliieu
dii idt dua vao
idl-nieu
19
1.4. Mot sd
phuoiig
phap phan huy
niSu
nghiem de phan
ticli luoiig
vet idt 20
1.4.1. Phuang phap
udt
20
1.4.2.
Phuang phap kho 21
1.4.3. Phuang phap
thiiy
nhiet phan 21
1.4.4.
Cac phuang
phap
khac 21
1.5. Tdng quan cac phuang phap xac dinh
luang
vet idt 22
1.5.1. Cac phuang phap xac dinh
lugng
vet idt 22

1.5.1.1. Phuang phap phan
tich
quang
phd
22
15.1.2.
Phuang phap
s^c
ki
23
1.5.1.3. Phuang phap dien ho 24
1.5.1.4.
Phuang
phap
phan
tich kich
hoat natron 25
1.5.1.5.
Phuang phap
miSn
dich phong xa 27
1.5.1.6.
Cac Phuang
phap
khac 28
1.5.2.
Phuang phap xac dinh idt dua vao cac phan ii'ng xuc tac 28
1.5.2.1. Phuang phap phan
tich
DHXT dong chay 28

1.5.2.2.
Phuang phap DHXT khong
sir
dung phan
ling chi
thj
[Ce(lV>As(III)]
29
1.6. Phuong phap ke hoach hoa thuc nghiem 29
1.7.
Tinli
llinh nghien cuu xac dinh ham
lugng
idt trong :
nude
tieu, sua,
toe,
huyet thanh nguoi va nuoc sinh hoat 34
1.7.1. Idt trong nude tieu 35
1.7.2.
Idt trong sua 37
1.7.3. Idt trong huyet thanh 38
1.7.4.
Idt trong tdc 38
1.7.5.
Idt trong
nude
sinh hoat 39
1.8. Ket luan phan
fong

quan 39
Chuong 2. NQI
DUNG VA
PHUONG
PHAP NGHIKN
CUU.
41
2.1.
Ngi dung nghien
ciiu
41
2.1.1.
Khao sat cac dieu kien de xac
djnh
lugng vet idt
bang phuang phap trdc quang DHXT, phan ling
chi
thi [Ce(IV)-A s(III)]
va
[clorpromazin-H202]
41
2.1.2. Nghien cuu dieu
ki6n
phan hiiy
mSu 66 xAy
dung qui trinh phan
lich
de
Xiic
dinh lugng vet idt trong

nude
tieu, sua, tdc, huyet thanh ngudi
va
nude
sinh hoat 41
2.1.3.
Xac
dinli
mdi tuang quan
ciia
ham lugng idt trong cac ddi tugng:
nude
lieu,sua me, tdc, huyet thanh d cudng rdn tre sa sinh,
nude sinli
hoat 42
2.2.
Vat
hcu
va phuang phap nghien
ciiu
42
2.2.1.Thietbi
42
2.2.2. Dung cu va hoa chat 43
2.2.3.
Phuang phap nghien
ciiu
45
2.2.3.1.
Lay

miu
45
2.2.3.2. Nghien
ciiu
ap dung mo hinh toan hoc de qui hoach hoa thuc
nghiem
nh^m thn
dieu kien
thi
nghiem tdi uu
ciia
cac yeu td anh hudng
den phiin ling chi thi [Ce(IV)-As(III)]va
[clopromazin-H202]
va dieu kien
de phan
hiiy mSu nude
tieu 47
2.2.3.3.
Phuang phap xac dinh idt 47
2.2.3.4. Phuang phap danh gia do tin cay
ciia
qui trinh phan
tich
47
2.2.3.5.
XLI'
ir
sd
heu

phan
tich bang
phuang phap thdng ke 48
Chuong
3.
KET QUA VA THAO LUAN 49
3.1.
Phuong phap trac quang DHXT xac dinh lugng vet idt, dung phan
ling
chi
thi
[Ce(IV)-As(III)]
49
3.1.1.
Casdciia
phuang phap 49
3.1.2. Khao sat cac dieu kien thuc nghiem 51
3.1.2.1.
Chon budc sdng de do do
hap
thu
ciia
dung dich Ce(IV) 51
3.1.2.2. Khoang tuye'n
tinh
cua ndng do Ce(IV) 51
T^
3.1.2.3.
Tim
dieu kien tdi uu cua nong do dau cac

tcxc
nhan tham gia
phcin li'ng chi thi [Ce(IV)-As(III)] theo phuang phap dudng ddc nhat 52
3.1.1.4. Anh hudng ciia cac yeu
tdkhac
59
3.1.2.5. Xac dinh ndng do idt trong
mSu
thuc tc 64
3.1.3.
Ket
luan 64
3.2.
Phuong phap trdc quang DHXT xac dinh lugng vet idt,
dijng
phan
ling
chi thi
[clopromazin-HjOa]
65
3.2.1.
Ban chat phuang phap 66
3.2.2. Khao sat
nhQng didu
kien thuc nghiem 68
3.2.2.1.
Phd hap thu
ciia
CPH sau khi oxi hoa 68
3.2.2.2.

Tim di6u
kien tdi uu ciia cac tac
nhan
tham gia phan
ling chi
thi
r[CPH-
H2O2]
theo phuang phap dao ham rieng 68
3.2.2.3.
Anh hudng ciia nhung yeu
id
khac 74
3.2.2.4. Phuang
tiinh
dudng
chuan,
khoang tuye'n
tinh
va GHPH 76
3.2.2.5.
Xac dinh ham lugng idt tren
mau
thuc te 77
•
Ket
luan 80
3.3.
Xay dung qui trinh phan tich lugng vet idt trong
nude

tieu, sua, tdc
huyet thanh ngudi va
nude
sinh hoat 80
3.3.1.
xay
dung qui trinh phan
tich
lugng vet idt trong
nude
tieu 80
3.3.
i.l.
Phan huy mau nude tieu bang amoni pesunfat 80
• Su dung phuang phap dao ham rieng nham tim dieu kien tdi uu de
plu'in
hiiy mau nude
lieu bang
ki
thuat amoni pesunfat
81
3.3.1.2. Qui trinh phan
ifch
lugng vet idt trong nude lieu 90
3.3.1.3.
Danh gia do tin cay cua qui trinh phan
tich
90
3.3.1.4. Xac dinh ham lugng idt tren
mSu

thuc te 94
3.3.2.
xay
dung qui trinh phan
tich
lugng vet idt trong sua va tdc ngudi 95
3.3.2.1.
Danh gia do tin cay ciia qui
liinh
phan
tich
trong sua va tdc 97
3.3.2.2. Ket qua phan
tich
tren
mau
thuc te 100
3.3.3.
xay
dung qui trinh phan
tich
lugng vet idt trong huyet thanh 102
3.3.3.1.
Dcinh
gia do tin cay ciia qui trinh phan
lich
lugng
vcl
idt trong
huyet thanh 104

3.3.3.2. Xac
dinli
hiun
lugng idt d
diuig
PBI va long ham lugng
I"
trong
mSu
tluieic.
106
3.3.4.
xay
dung qui
tiinh
phan
lich
lugng vet trong nude sinh hoat 107
Chuong
4. MOI TUONG QUAN CUA HAM
LUONG
IOT TRONG
CAC
DOI
TUONG:
NVOC
TIEU,
SITA,
TOC,
HUYET THANH

VA
NU'CC
SINH HOAT
111
4.1.
Ham lugng idt-nieu trong cac ddi tugng nhay cam
111
4.1.1.
Hoc sinh tieu hoc (8-12
tudi)
dcac
viing sinh thai khac nhau
111
4.1.2. Ham lugng idt-nieu ciia phu
nirmang
thai
dcac vCmg
sinh
ihai
114
4.2.
Mdi tuong quan giua ham lugng idt-neu va idt trong sua me
117
4.3.Ham
lugng idt trong huyet thanh
dcudng
rdn tre
sasinh 120
4.4. Ham lugng idt trong nude tieu va trong tdc cua ngudi trudng thanh 122
4.5. Ham lugng idt trong

nude
sinh hoat 123
KET LUAN 126
TAI LIEU THAM KHAO
PHU LUC (Gdm 37 bang sd lieu tho, trinh bay cac
kdt
qua phan
tfch
ham lugng
idt trong 2079
miiu
sinh hgc lay tii' ca the ngudi va moi trudng)
/s'.
DAT VAN
Dfi
Trong nhieu nam qua d
nude
la, cung nhu cac nude khac
lien
the
gidi,
ngudi la da va dang quan
lam
nhieu den va'n de dinh duang idt trong ca the ngudi
va idt trong moi trudng. Dinh duang idt la van de loan cau. Mac du
idl
cd trong ca
the vdi mot lugng khong
Idn
(khoang 15mg); nhung no

lai
dugc xem la mot
Irong
nhimg
nguyen td vi lugng tdi can
Ihidt
cho su phat
tri^n
ciia ca the ngudi. Ngudi la
ndi:
"idt
\l\
nguyen td can thiet cho phat
tiien tri
tue"
[22],
Co"
the con ngudi thieu hay
thiia
idt
ddu gay
ra nhieu tac hai va thudng gpi
la "cac rdi loan thieu hut idt" (Iodine Deficiency Disorders:
IDD).
Cac rdi loan
thieu
hill
idl (CRLTHI) gay ra can benh xa hoi, anh hudng den
siic
khde cong

ddng va su phat trien xa hoi tren loan the gidi
[14],
[17].
Danh gia
tinh
trang dinh dudng idt trong ca the, ngudi la su dung nhung
chi
lieu sinh hgc nhu ham lugng idl trong huyet thanh, idt trong sua, va dac
biel la
idl trong nude tieu (con ggi la idt-nieu)
[133],
De xac dinh lugng vet idt trong cac
dich sinh hgc, ngudi la thudng
sii"
dung nhQng phuang phap phan
tich
cong cu
nhu:
srlc
ki
khi
(GC),
sdc ki
long hieu suat cao
(HPLC),
kich
hoat
nalion,
do the
dung dien cue chgn

Igc
ion,
trac
quang dong hgc
xiic Uic
(DHXT)
[44], [57], [77],
[79],
[92] Trong
dd,
phuang phap trdc quang DHXT dang dugc nhieu phong
Ihi
nghiem tren the gidi
sii'
dung, do cd nhieu uu diem nhu: phan
lich
nhanh,
do lap
lai cao, gioi han phat hien (GHPH)
thap,
thiet bi
re
Tuy vay, cd nhieu ycu
id
anh hudng den dong hgc phan ung nhu; chat can trd
ciia
n6n,
nhiet do va thdi gian
phan ung Vi the can phai nghien
ciiu

khau phan
hiiy mSu
de xay dung qui trinh
phan
tich
va tdi uu hda cac dieu kien
thi nghiem Cac
van de nay cho den nay
vfm
chua dugc cac tac gia cong bd thdng nhat [65], [92],
[121], [131], [142].
Tu nam
1995,
Thii
ludng Chinh phii
nude la da ban hanh nghi dinh ve vice
"Van
dong loan dan an mudi
Iron
idt" de phong chdng CRLTHI [9]. Danh gia
hieu qua
ciia
Chuang trinh nay, Benh vien Ngi
liel
Ha Ngi, cung nhu cac nude
•^'^.
N:^^
tren the gidi, dang
sii'
dung chi tieu idt trong

nude
lieu d
liia
tudi: 8-12 va xem do
la thong sd dai dien de danh gia tinh trang dinh dudng idt d cong ddng [4], [39].
Tuy nhien, ham lugng idl trong sua me, trong huyet thanh cudng rdn
Ire
sa sinh
cung la nhung
chi
tieu sinh hgc
giiip
giam sat hieu qua
ciia
chuang trinh can
Ihicp
idt.
Ben canh idt-nieu d
liia
tuoi 8-12, thi ham lugng idt-nieu d nhung ddi lugng
khac nhu: phu nu mang thai, cac ba me dang cho con
bii,
la nhung ddi lugng cung
cap
true liep
idt cho thai nhi va
tie
sa sinh, vi the de phong
ngiia
nhung hau qua

ciia
CRLTHI cd the xay ra ddi vdi tre sa sinh, can theo doi idt-nieu d nhung ddi
tugng nay.
Mai
khac, mot sd tac gia cho rang idt trong ca the cung dugc bai liel qua
tdc.
Nhu
ihc,
idl trong tdc cd mdi tuang quan
w6i
idt-nieu hay khong? Cd the su
dung idt trong tdc lam cha't
chi
thi de theo doi tinh trang dinh duang idt d ngudi
dugc khong?
Nhu vay, de giai quyet
nhiing
van de tren day,
Irudc
lien can nghien
ciiu
khau phan hiiy
mSu
de xay dung qui trinh phan
tich
xac dinh lugng vet idl trong
Ccic
ddi tugng sinh hgc, tiep den la danh gia tuong quan giua ham lugng idl trong
cac mau sinh hoc, cung nhu tuang quan
giij'a

ham lugng idt trong ca the ngudi dan
sdng d
Ccic viing
sinh thai khac nhau. Mdi tuang quan
ciia
ham lugng idt vdi cac
yeu td tren day cd y
nghia
rat
Idn,
se
giiip
cac nha quan
li
y te cd nhung dinh
hudng dung cho
vice bd
sung idt trong
lu'ng
giai
doan.
The nhung, cho den nay d
nude
la chua cd Uic gia nao de cap den nhung van de tren day mot
cacii lie
thdng.
Xual
phat
lu
nhu'ng van de tren, trong luan an nay

chiing
toi nghien
ciiu
ap
dung phan
ling
DHXT xac
dinh
lugng vet idt trong cac ddi tugng sinh hgc va moi
trudng,
nhiim
lam sang td mot sd qui
luat
tuang quan tren. De thuc hien dugc muc
dich
dd, luan an can thuc hien nhung nhiem vu sau:
1.
Nghien
ciiu
ap dung mo hinh loan hgc de qui hoach hda thuc nghiem
nham
lim
cac dieu kien
Ihi
nghiem tdi uu thuc hien phan ling DHXT
sii'
dung he
[Ce(IV)]-As(III)] va
[clopromazin-H202]
de xac dinh lugng vet idl.

2.
Nghien
ciiu
khau phan hiiy
mAu
de
xay
dung quy trinh phan tfch lugng
vet idt trong
nude
lieu, sua, tdc, huyet
Ihanh,
va
nude
sinh
hoal.
3.
Xac dinh mdi tuang quan ciia ham lugng idt-nieu d hgc sinh tieu hgc, ba
me mang
Ihai,
ba me cho con
bii
dang sdng d cac
viing
sinh thai khac nhau va
tuong quan
ciia
idt-nieu vdi idl trong sua ciia cac ba me dang sdng d mien
niii,
ddng bang va ven bien.

4.
Xac dinh idt trong tdc va khang dinh idt trong tdc cd the
dQng
lam chat
chi thi de danh gia tinh trang dinh dudng idt trong ca the ngudi dugc khong?
5.
Xiic dinh mdi tuang quan giua ham lugng idt d dang PBI trong huyet
thanh d cudng rdn
Ire
sa sinh vdi trgng lugng cua
tie.
Cac
kel
qua thu dugc se gdp phan danh gia hieu qua
ciia
chuang trinh
phong chdng CRLTHI d tinh Thiia Thien Hue.
Chuongl
T6NG
QUAN
1.1.
Gl6l TlllfiU
PHUONG PHAP PHAN TICH DONG HOC XUC TAC
1.1.1. Nguyen tdc [37], [51], [91], [139]
Ca sd
ciia
phuang phap phan
tich
dong hgc
xiic

lac (DHXT)
la
xac dinh
ndng do chat
xiic
lac dua vao Uic dung
ciia
chat
xiic
lac
Icn
phan
liiig chi
thj. Vi
tdc do
ciia
phan
ling
chi thi
ly le
vdi ndng do cha't
xiic
tac, do dd bang each do tdc
do phan
ling chi
thi cd the suy ra ndng do cha't
xiic
tac.
Vdi dieu kien phan ling gia bac 1, phuang trinh bieu
diln

tdc do phan
ling
cd dang:
d[A]
V =
dt
=
k[A][C]
+ kJA] (1.1)
Trong do: k : Hang sd tdc
d6
phan ii'ng
xiic
tac
k, : Hang sd tdc do phan
ling
khong
xiic
tac
C : Ndng do chat
xiic
tac
A : Chat
chi
thi
Trong phan
ling xiic
tac, chat
xiic
tac dong vai tro tao thanh

phiic
chat trung gian (hoac
phiic
hoat hoa) lam giam nang lugng boat hoa
ciia
phan ling
[21],
do dd tdc do phan
ling
tang
len.
Su bien ddi nang lugng
trong lien trinh phan
ling
dugc bieu
didn
theo sa dd
b
hinh
1.1.
Toa do phan
ling
Hinh
I.L
Gian dd bien doi nang lugng phan
ling
trong lien trinh phan
ling
(Trong do A va
B

la hai chat phan ii'ng; K la chat
xiic
tac)
1.1.2. Cac phuong phap xac dinh ndng do chat
xiic
tac bang phuang
pliap
dong hgc [37], [51], [82], [91], [139]
Di xac dinh ndng do cha't
xiic
lac, ngudi la six dung hai phuang phap vi
phan va
lich
phan, trong dd phuang phap vi phan thuc hien dan gian han, do dd
hi^n
nay da sd cac cong trinh nghien
ciiu
ve phan
tich
DHXT, ngudi la thudng
diing
phuang phap vi phan. Khi
sii"
dung phuang phap nay, ngudi la do cac dai
lugng hda ly nhu do hap thu,
chi6u
cao pic
ciia
ddng dien phan, chieu cao sdng
cue

phd
la
ham ciia ndng dd chat
xiic
tac. Neu tat ca cac tac nhan tham gia phan
ling
xiic
uic deu cd dinh
Ihi
ndng
d6
cha't
xiic
tac se chi phu thuoc vao ndng do
cha't chi
ihi.
Su phu
thu5c
nay
chi
gidi han trong
m6l
khoang ndng
d6
nao do.
Sir
dung phuong phap vi phan de xac djnh ndng
d6
cha't
xiic

tac, ngudi la thudng
diing ba phuang phap sau.
1.1.2.1. Phuong phap tdc do ban dau
(cun
ggi la phuang phap tga)
Tdc do phan ling dugc do theo thdi gian phan
ling
C3
A
c,
tga'
tgtti
tgttz
tgai
Q) tgao
t
C,
C2
c,
c
Llinh 1.2. Dd thi xac dinh ndng do chat
xiic
tac theo phuang phap tga.
Qua trinh thuc hien phuang phap nay nhu sau: ngudi la do ndng do chat
chi
thi thong qua
tin
hieu phan ling theo thdi gian,
ling
vdi cac ndng do chat

xiic
tac
khac nhau,
xay
dung cac dudng dong hgc, sau dd xac dinh tga
ciia
cac dudng
bieu
didn,
va dung dd thi bieu
di6n
su phu thuoc tga vao ndng do chat
xiic
tac
(hinli
1.2).
Dd
tlii
nay dugc xem
nliudd tlii
chuan de xac
dinli
ndng do chat
xiic
lac.
Xcic
dinh ndng do chat xac tac bang phuang phap nay can phai lien hanh nhieu
thi
nghiem,
vi the cd do

chinh
xac cao. U'u diem
ciia
phuang phap nay la han
chc
dugc
anh hudng cua nhiet do, tuy nhien chi ap dung dugc ddi vdi nhung phan
ling
dan gian,
klii
cd su phu thuoc tuye'n
tinli
giua tdc do
plian ling
vdi ndng do chat
xiic
tac.
1.1.2.2. Phuang phap an dinh thoi gian
Phuang phap nay dua vao viec do tdc do phan ung
chi
thj
ling
vai nhung
ndng do chat xuc tac khac nhau khi cd dinh thdi gian
I;
nghla
la lai mot thdi diem
nao dd
ciia
phan ling, ngudi la do (do hap thu,

chidu
cao pic, )
ciia siin
pham tao
thanh ciia cac gia tri ndng do chat
xiic
tac khac nhau va bieu
diSn
su phu thuoc
ciia
(do hap thu, chieu cao pic, ) theo ndng do chat
xiic
tac.
Phuang phap nay dan gian va cd do lap lai cao, nen thudng dugc six dung
khi phan tfch hang
loat mSu
nghiem.
Hinh 1.3. Dd
tlii
xac dinh ndng do chat
xiic
lac theo phuang phap an dinh thdi gian
1.1.2.3. Phuang phap cd djnh tm hieu do (Ay)
Phuang phap nay dua vao nguyen tac: do thdi gian
(I) ling
vdi do hap thu
d Ccic ndng do chat
xiic
tac khac nhau
(C^j

) dat den gia tri
A(,
nao dd va dung
dudng bieu dien su phu thuoc
1/t
-
C^^.
i/t'
l/t3
1/t
1/t.
i
A
A
I
f)
ti
l2
t3
.c.
^Q
^c
kh
t^
Hinh
1.4.
Do thi xac
diiili
nong do chai
xiic

tac
theo
phuong phap cd dinh
tin hieu
do (A,,)
1.1.3. Nhung ycu
tdanh
hudng chu ycu den phuang phap phan
lich DIIXT
1.1.3.1. Anh hudng cua nhiet do den tdc do phan ting [21], [51], [82], [139]
Nhiet do phan ling la mot trong nhung yeu td anh hudng manh nhat den tdc
d6
phcin ling. Theo
thuy^'t
va cham, khi tang
nhi6t
d6,
su chuyen dong nhiet cua
cac phan
lu
trong binh phan
ling
tang do dd lam tang sd va cham cd hieu qua
(nhung va chain cd nang lugng vugt qua hang rao the nang de xay ra phan
ling),
vi
the tdc do phan ling tang. Cd the bieu
didn
su phu thuoc nay theo phuang trinh
Arenius nhu sau:

d(lnk)
dT
RT-
-E/RT
hay
K^Ae-'^'"'
(1.2)
:z^InK =
lnA-—
Hoac logK
= logA
(1.3)
RT
•
2,303RT
Trong dd
K :
hfing
sd tdc do phan ling.
T : nhiet do tuyet ddi
E : nang lugng hoat hda
R : hang sd
khf
A : hang sd
(thiia
sd tan sd)
Phuang trinh (1.3) chiing td hang sd tdc do gia tang theo nhiet do. Thong
thudng khi nhiet do tang
10"C
thi tdc do phan

ling
tang iix 2-3
Ian.
Phuang
irinh
(1.3) cung thudng dugc
diing
de
tinh
nang lugng hoat hda, neu hang sd tdc do
dugc do
nhi^u
Ian.
1.1.3.2. Anh huong
ciia h£ing sddien
moi dung
djch
den tdc do phan
ling
[85]
Vi
phan ling
xiic
tac ddng the xay ra trong dung dich, do dd, dung moi
ddng vai trd quan trgng ddi vdi cac phan
ling
xay ra theo ca che ion; nghla la tdc
do phan
ling
xay ra trong dung dich phu thuoc mot phan vao hang sd dien moi

(dielectric constant) ciia dung dich.
Gia
sii"
phan ling giua hai cha't A va B xay ra theo phuang trinh:
A + B
—>
AB*
(dang phiic hoat hda)
Nd'u
ggi k,-
lii
hang sd tuang tac giua cac ion trong dung dich,
e
la hang sd dien
moi,
theo Kirchhoff
giiia
k^
va
e
cd mdi quan he nhu sau:
Ink,
=lnkn-*-
e
2KT
1-
1^
M-
8KT
1 +

£^
N (1.4)
Trong dd:
M
=
{z,+z,y Zl
Z
^
va
N = ^
'AB'
A
'B
'A
'B
"AB
k„:
hang sd tdc do cua phan ii'ng xay ra trong moi trudng cd hang sd dien
moi
v6
han
I-IA
'
I^B
>
M-AB*-
momen
ludng cue ciia A, B, AB*
ZA
,

ZB
: dien
lich
ciia A va B
^A '
HJ
'
I'AB*-
ban kinh
ion
ciia
A, B, AB*
T : nhiet do tuyet ddi
K
: hang sd
Bollzman.
e : dien tfch cua proton
(l,602xlO"'^C)
Phuang trinh (1.4) cho thay, neu A va B la cac ion trai dau
(Z^-Zg
< 0), thi
khi
e
giiim, tdc do phan
ling
se tang len va ngugc lai, neu A va B la ion
ciing
dau
(ZA-ZB
> 0), thi khi

8
giam, tdc do phan
ling
se giam. Dua vao
tinh
chat nay, la cd
the khong che phan
liiig
nen, neu ca
die
phan
ling n6n
va phan
ling xiic
xay ra
khac nhau d giai doan quyet dinh tdc do phan
ling.
1.1.3.3. Anh
hudiig
cua luc ion trong dung djch den tdc do phan ling [85],
[139]
Trudng hgp trong dung dich cd hai chat A va B phan ling vdi nhau theo
phuang trinh:
A + B
->
AB^
(phuc
hoat hda)
Vdi su cd mat ciia
nhCing

mudi hay nhung nguyen
id
khac se anh hudng
den
can
bang tao phiic ciia phuang trinh tren.Va ngudi la thudng ggi anh hudng
nay la hieu ii'ng mudi. De giai
thich
anh hudng nay trong dung dich, ngudi la
sii"
dung phuang trinh :
logk
=
logko
+
ZAZBVM
+(bA
+
bs
+
b*)p
(1.5)
Trong dd k : hang sd tdc
66
phan
ling
xiiy ra trong dung djch cd
anii
hudng
ciia

Ccic mudi hay cac nguyen td khac.
k(,
: hang sd tdc do phan
ling
khi khong cd tac dung
ciia
cac loai
mudi hay
nguyen id
ngoai lai
ZA,
ZQ
: dien
tich
ciia A va B
[X
:lucion(ia =
iX*^i^'
^
bA,
bs,
b*
: hang sd kinh
nghi6m
ciia A, B, va phiic hoat hda
AB**
Phuong
llinh
(1.5) chiing
id

rang: vdi su cd mat
ciia
mudi ngoai lai cd the
dan den mot su gia tang tdc do phan
liiig
hda hgc ( neu dien
tich
ciia A va B gidng
nhau) hoac ngugc
lai,
tdc do phan ling se giam (neu dien
tich
ciia A va b trai dau)
1.1.3.4. Do nhay
ciia
phuang phap phan
tich
DHXT
[139]
Khi
sii"
dung cac phuong
i^hap
hda ly de xac dinh ndng do chat phan
tich,
do nhay
ciia
phuang phap dugc dinh nghla la gia tri
cue
tieu ciia li sd

P/e
:
Trong dd
P
Qnin= -
(1.6)
s
Cniin :
do nhay ciia phuang phap phan
tich
P :
tin
hieu do.
£
: hang sd
ti
le.
Phuang trinh
(1.6)
cho thay
C^^^
phu thuoc vao P va
£.
Trong phuang phap
phan tfch DHXT, bang each theo ddi tdc do
pluin ling
chi
Ihi,
ta cd the suy ra ndng
do chat

xiic
Uic. Neu
idc
do phiin ling
xiic
Uic dugc
tinh
ILT
phuang trinh:
^
= Xn,Cl=N,Cl
(1.7)
dt
Trong dd
X
: ndng do san pham tao thanh tai thdi diem t
X
: hang sd tdc do phan ling
KQ
:
lich
ndng do
ta't
ca cac cha't con lai
CK
:
ndng do cha't
xiic
tac
10

Tu(1.7),tacd:
C°^=~~
—
dt
xTic
Nhu the vdi mot lugng
cue
tieu ciia ndng do chat
xiic
tac cd the xem
^
^^x_^_A>^
(1.8)
AtxTic
AtN,
dday
:
NK
=
X-T^C
Trong dd
AtN^
biSu diSn
sd chu trinh ma mot phan
tir xiic
uic tham gia
trong khoang thdi gian At;
AlA^
con dugc ggi la he sd khuyech dai. Vi mdi chu
trinh

ciia
phan
lilig
se tao ra mot san pham phan
ling,
do vay neu sd chu trinh cang
Idn thi
san pham phiin ling cang tang
ngliTa
la do nhay phiin
ling
tang cao.
Phuang trinh (1.8) cung cho thay, do nhay
ciia
phan
ling xiic
Uic sc gia tang
CLing
\'6\
su gia
Uuig
cua
khoiing
thdi gian phan ling At.
Mat khcic,
iCi'
phuang trinh (1.3) thay rang khi tang nhiet do phan
ling
thi do
nhay

ciia
phuang phap xac dinh tang theo.
Tu
nhOng di6u
vua trinh bay d tren, va qua phuang trinh (1.8), cd the ndi
rang do nhay
ciia
phuang phap phan tfch DHXT la rat cao.
Neu
sii"
dung phuang phap trac quang de do tdc do phan
ling xiic
tac
(phuang phap
irac
quang DHXT); thi do nhay
ciia
phep xac djnh phu thuoc vao
khii nang do cudng do mau
ciia
chat hap thu (A) va he sd hap thu
moi
phan tu
ciia
/\
cha'l
dd
(e),
nghla la phu thuoc vao ti sd —. Ddi vdi phuang phap trac quang, cd
e

the Xiic dinh ndng do cha't
edn
phan
tich
cd
lO'^mol/L,
va neu thdi gian phan
ling
la
10
phiil;
ndng do chat phan
ling
bang 1
mol/L,
va he sd
xiic
lac bang
10^
thi do
nhay
ciia
phep xac dinh nhu sau:
Kmin
^Q_^_^o*
= 10 mol/L, nghla la trong 1ml cd the tim thay
10'
moi
hay
60.000

phan
tii"
cha't
xiic
tac
Neu trong lugng phan
tii'
ciia
cau
tii edn
phan
tich
la 100, thi do nhay ciia
phuang phcip la :
CKm.n=10"''g/nil
hay
IQ-'Vg/ml
11
Nhu vay, bang each
sii'
dung phuang phap
tide
quang DHXT, cd
Ihe
xac
dinh ndng do chat phan
tich
ca ng/ml ma khong can phai lam giau.
Tuy nhien, trong qua trinh thuc hien phuang phap phan tfch DHXT, cd
mgl

sd yeu
id
han
che
do nhay ciia phuang phap phan tfch, trong dd quan trgng nhat
la
su
iham
gia cua phan ling khong
xiic
tac (plum ling
nen).
Nhu da trinh bay d tren, ddi vdi phan
ling xiic
tac, tdc do phan
ling
do dugc
(v) thudng bao gdm tdc do chung ciia phiin
ling
cd
xiic
lac
(vjva
phan
ling
khong
xiic
Uic
(V(,);
V =

V;,
+
V(,
(1.9)
dx
dt
Vdi
K
: hang sd phan
ling
khong
xiic
lac.
va :
V(,
=
K.Tic
.
Tu(1.9),
tacd
:
Vk
= V -
v,,.
Khi su khcic bict giua v -
v„
la
Idn
so vdi v,„ trudng hgp nay sai sd
ciia

phep
xac dinh luang ddi nhd, nhung khi
sir
khac biel nay giam se
gay
sai sd
Ian,
do su
bien ddi
ciia
V(,;
va ngudi ta bieu
Ihi
su khac biet ciia v -
V(,
bang he sd a, vdi :
v^
>
aV().
(1-11)
Neu tdc do phan ling
xiic
tac
Idn
han rat nhieu so vdi phan
liiig
khong
xiic
tac,
thi:

C,,
= -^ .Tu-phuang
trinh (1.8) va (1.11), ta duac:
Q = -^^^^.^ =
^^^-^.a^
(1.12)
Kei hgp phuang trinh
(1.2)
va (1.12), do nhay ciia phuang phap xac dinh sc
K
phu thuoc vao li sd — , va duac
bi6u
diSn theo phuang trinh:
X
- =
e'
f^^
(1.13)
X
Trong dd
E(,
va
EK
la
nang lugng hoat hda cua phan
ling
nen va phan ling
xiic
tcic.
12

Phuong trinh (1.13)
chi
ra rang mudn cd do nhay
cue
dai, can phai su dung
loai phcin ung chi thi cd su khac biel cue dai giua hang sd tdc do ciia phan
ling xiic
lac va phan
ling
nen (nghla la
E„
va
E}^
khac biel cue dai). Neu su khac biel nay la
Idn,
thi
li
sd K/x Irong phuang trinh
(1.12)
cd the bd qua va
liic
dd cd
ihe
sii"
dung
phuang
tiinh (1.8)
de
linh
do nhay.

Do nhay
ciia
phan
ling xiic
tac cang cao khi nen 6n dinh(tuc la giam he sd
a Irong phuang trinh
(1.11)).
Sau day la nhung
nguyen
nhan quan trgng
gay
su
bieii ddi
ciia nen :
- Su dao dong nhiet do ciia binh phan ung
- Su khcic nhau ve thanh phan
ciia
dung dich nen va dung dich sii dung de
ve dudng cong chuan (dac biel la: pH, thanh phan mudi, luc ion, va cac tap cha'l
lii"
hda chat va
nvioc
cat),
- Su khac nhau ve be mat binh
pluin
ling,
su cd mat ciia chat hap phu, bui
va hai hda chat trong phong
Ihi
nghiem

1.2. NHUNG DIEM CAN CHU Y
Kill
PHAN
TICH LUONG VE I
IOT
•^ Su nhilm
ban va mat
chaft
phan tich [6], [43], [52], [65], [82], [133]
Trong qua trinh phan tfch lugng vet idt, can phai quan tarn
deii
mot sd yeu
td se cinh hudng manh den kel qua phan tfch, trong dd quan trgng nhat la: moi
trudng khong khf ciia phdng
thi
nghiem, do tinh khiet
ciia
hda cha't va nude cat, do
sach
ciia
dung cu
thiiy
tinh,
tinh
on dinh
ciia
thiet bi do Ra't khd de loai
Iru
nhung
yeu

id
neu tren, vi the, cac kel qua phan tfch lugng vet idt tren
cting
mot ddi tugng
cd khi dao dong kha
Idn,
tiiy thuge
vao ky thuat phan tfch ciia
liing
phdng
ihf
nghiem
cung nhu tay
nglie
thao Uic
ciia kl
thuat vien phan tfch.
Mai
khac, su
nhiSm
ban hoac mat chat phan tfch cung cd the xay ra trong
qua trinh lay
mfiu
va chuan bi
mau
de phan tfch; chang han nhu khi phan
hiiy mfiu
bang phuong phap udt
(hdn
hgp axit manh) hoac phuang phap kho (tro hda d nhiet

do cao) cd the lam mat hoac
nhi6m
ban chat phan tfch. De han che tdi da
vice
gay
sai lech kel qua phan
tich
can phai luan thii mot sd dieu kien can thiet sau:
Tiiudng
xuyen kiem tra he thdng phan tfch (nude cat, hda
cliat,
dung cu va
13
Ihiel
bi do, quy trinh chuan bi
mJu,
moi trudng khong khf phdng thf
nghiem).
Ngoai ra, hang ngay can phai lien hanh
Ihf
nghiem tren
mSu
trang, de hieu chinh
ket qua phan tfch (ket qua phan tfch bang ket qua do d mau phan tfch
ivix
ket qua
do tren
mAu
trilng).
1.3. CAC DAC TRUNG

LY-HOA-SINH
CUA IOT
1.3.1. Dai cu'ong ve idt [3],
[19],
[22], [26], [30], [40],
[119], [137], [146],
[147]
Idt la nguyen
id
thuoc nhdm
VIIA
trong bang phan hang luan hoan
Mendeleev. Nam 1812, B. Courlois
Ian
dau lien
phai
hien ra idt, khi ong ta dot
rong bien say kho lay tro de san xual diem lieu va tinh cd tim thay idl trong rong
bien. Nam I8I5 J.L. Gay-Lussac va Humphry Davy da nghien
ciiu Ifnh
chat hda
hgc cua idt va xac dinh idt la mot nguyen
id
hda hgc mdi.
Idl ran cd ap suat hai rat
Idn
nen d
nhiCl
do thudng idl bay hai va khi dun
ndng nhanh no

Ihang
hoa ma khong ndng chay. Hai idt cd mau tfm
sfun,
(vi
liie
dugc
dai
ten la idt
(lir
chQ:
Hy lap
lODES
cd nghla la tfm]), va hda
rfin
khi dugc
lam
lanh.
Trong cac dung mdi khong phan
cue (vi
du
CS2,
CCI4)
idt tan va cho dung
dich mau
ifm;
ddi vdi cac dung moi hiiu ca ma phan tir
chiia
oxi (nhu rugu, etc va
axelon) idl tan va cho dung dich mau nau. Trong dung dich mau tfm, idl d dang
phan

lii'
I2
gidng nhu trong trang thai hai, con trong dung dich mau nau, idl tao
nen vdi dung moi nhung sonval khong ben. Dua vao nhung dac diem nay, ngudi ta
da
sii'
dung phuang phap chiet trac quang de xac dinh idt
Idt cd the tan nhieu trong
nude
cd
cliiia
iodua
niid
tao nen phan
ling
ket hgp:
I2
+ r
=
I.,-
Dung dich
chiia
ion
I^
cd mau
nau
va cd
Ifnh
chat ciia mot hdn hgp phan
tir

I2
va ion 1*
Idl tao thanh hgp cha't mau xanh vdi hd tinh bgt, trong dd nguyen
tii"
idl
dugc sap xep trong cac ranh
cCia
polisacarit amilaza. Giua idt va hd tinh bgt khong
cd phan ling hda hgc xay ra ; khi dun ndng mau xanh bien mat, day la
Ifnh
chat
dac biel de' nhan biel idt.
14
Trong thien nhien chi xual hien mot ddng vj ben
'^^I.
Ddng vi phdng xa
nguy hiem nha't
la '^^I
cd thdi gian ban ra
1,57.10^
nam (dugc tao ra trong moi
trudng do qua trinh
thtr
vu khf hat nhan). Hien nay ngudi ta da dieu che dugc tren
22 ddng vi phdng xa. nhan tao, trong dd, hai ddng vi phdng xa
'"*'!
(thdi gian ban
hiiy 8 ngay) va
'^'^I
(thdi gian ban hiiy 60 ngay), dugc

ling
dung rong rai trong y hgc.
Mot sd
Ifnh
chat
If
hgc
ciia
idl dugc neu d bang
1.1
Bdng 1.1. Mot so
Ifnh
cha't
li
hgc ciia idt
Trgng
lugng
nguyen
tii-
126,93
Nhiet
d6
ndng
chay
"C
113,6
Nhift
do soi
*'C
184,5

Nang
lugng lien
kel X-X
kJImol
150
Do
dai
lien
kel/4
2,67
Nang lugng
hidrat hda
AHb.
tlhnol
297
The dien
cup
chuan
E\V
0,54
Vdi cau hinh dien
tii"
[Kr]4d'"4s^5p^,
idt cd the
idn
lai d 6
miic
oxi hda khac
nhau; -1, +1, +3, +5, +6, +7; trong dd hgp cha't
lO'^

va
IO4
ben vung han ca.
Trang thai hda tri
bdn
vung
nhal
ciia idl la I(VII),
chfing
han nhu mudi pciodat la
chat cd
Ifnh
oxi manh, cac phan ling oxi hda thudng xay ra manh liel va nhanh
chdng
ntn
hay dugc
ling
dung trong phan
tich
Trong moi trudng baza hoac axit ra't manh, idt ton lai d dang
10'^
; con
trong moi
Irudng
axil idt ton lai d dang I",
T
day la nhung dang
kcm
ben
ciia

idt.
Vi the, trong khi
lua
chgn phuang phap de xac dinh idt trong dung dich can phai
luu
y
deii
dac diem nay.
Cac the oxi
hda-khii'
lieu chuan ciia cac cap oxi
hda-khii"
ciia
cac
nguyen
td
trong phan nhdm VII A nhu sau:
F° =
0,54V
<F° =
1,07V
<F° =
1,36V
<F° =
2 87V
Do the oxi
hda-khii'
lieu chuan ciia idt nhd, nen idt
viia
cd

tinh
oxi hda lai
vLia
cd
Ifnh
khii'
Khii nang oxi hda-khii' ciia idl dugc trinh bay tdm tat trong sa 66 the dien
cue
cua cac hgp chat cua idt trong moi Irudng axit va moi trudng baza
15
4-0,7 +1,14 +1,45 +0,53
H5IOQ
—
IO3
—
HIO
—
I2
—
I
(moi trudng axit)
K20
+
0,7 +0,14 +0.45 +0.53
H3lOg
— IO3 —
10
—
I2 —
I (moi trudng baza)

+0,29
Tfnh oxi hda ciia idt the hien khi nd tac dung vdi chat
khii*
manh, vf du:
I2
+
Na2S203 =
21"
+
Na2S406
Phcin ling nay thudng dung trong phuang phap chuan do oxi hda-khii
Tfnh
khii"
ciia idt the hien khi nd tac dung vdi mot chat oxi hda manh, vf du:
CI2
+ 2KI = 2KC1 +
I2
Mgl dac diem quan trgng
cQa
nguyen
id
idt la nd cd kha nang
xiic
Uic cho
nhi6u
phan ling hda hgc [30]; dua vao dac diem nay cd the dinh lugng idt bang
phuang phap dong hgc
xiic
tac, va den nay ngudi ta da tim dugc rat nhieu he phan
ling dugc

xiic
tac bdi idt [51]. Tuy nhien khi
sir
dung phuang phap dong hgc
xiic
tac de xac dinh idt trong cac ddi tugng sinh hgc va moi irudng, can phai luu y
6cn
nhung
di6m
sau: Trong cac ddi tugng sinh hgc va moi trudng idt thudng
idn
lai d
trang thai hda tri -1,
+1 la
nhung dang kem ben, nen ra't
di
bi mat idl trong qua
trinh bao quan va che hda
mau
phan tfch; vi the, de loai
trii"
nhuge
diem nay, khi
chgn
kl
thuat phan hiiy
mSu,
can phai
sii'
dung cac tac nhan oxi hda manh de

chuyen idl
deii
trang thai hda tri +5 (dang rat ben ciia idt) va sau dd lai dua idl vd
dang
r
bang nhung tac nhan khir
ihfch
ling.
1.3.2. Nhu cau va vai trd idt trong sinh ly ngudi [38], [40],
[133],
[137]
Idl
\h
mot trong nhiing nguyen td vi lugng tdi quan trgng cho ca the ngudi.
Ca the ngudi trudng thanh chiia khoang
15
- 20 mg idt, trong dd khoang 70-80%
dugc du
Iru"
d tuyen giap. Ngoai tuye'n giap la ca quan thu nhan lugng
Idn
idt, mot
sd td
chiic
khac ciing thu nhan idt nhu tuyen
vii,
mang dem (chorion),
luycn
nude
bgt, da day, budng

triing,
tinh hoan,
lach,
tuyen thugng
than vdi
mot lugng nhd.
Idl la nguyen td ca ban de long hgp hooc-mon giap (Thyroxin-T4 va
Triiodothyronine
-T3),
cac hooc-mon giap nay ddng vai trd quan trgng
ciia
su