PHAN TCH VA KHAC PHUC
NHNG S CO THNG GAP
TRONG S DUNG THIET B
QUANG HOC
2.1.1. Cac thanh phan
2.1.1.1. en nguon
2.1.1.2. Bo phan tao anh sang n sac
2.1.1.3. Cuvett o va ngan cha cuvett
2.1.1.4. Detector
2.1.1.5. He thong quang hoc
2.1.2. May quang pho thong thng
2.1.3. May quang pho diode array
2.1. S khi v nguyn l hot ng ca h thng my o UV-Vis
2.1.4. Cau hnh
2.1.4.1. Kieu mot chum tia
2.1.4.2. Kieu hai chum tia
2.1.4.3. Kieu Split-beam
2.1.4.4. Kieu Dual-wavelength
2.2. Cc s c thng gp v cch khc phc
2.3. Hieu chuan van hanh
2.1. S o khoi va nguyen ly
hoat ong may quang pho t
ngoai kha kien UV-Vis
Double-beam UV-Vis. spectrophotometer
CAC THANH PHAN CHNH CUA MAY UV-Vis
en nguon (1)
Bo phan tao anh sang n sac (2)
Cong o va ngan cha cong o (3)
Detector (4)
He thong quang hoc (5)
EN NGUON (LAMP) (1)
AC IEM CUA NGUON SANG LY TNG
Cng o sang hau nh khong thay oi va
u manh moi bc song trong vung t
ngoai kha kien.
o nhieu thap
Can dung on ap e on nh cng o bc xa
cua en nguon
Cho cc ai bc xa hu ch trong vung
kha kien (t 656,0 en 656,2 nm) c
dung e kiem tra o ung cua bc song
may quang pho.
Nhieu gay han che en hieu nang cua
may.
Thi gian ban huy (cng o en giam
ch con phan na so vi gia tr luc mi lap
at) xap x 1.000 gi.
10
l Ranges of Common Sources
EN DUNG CHO VUNG KHA KIEN
en Tungsten
Si ot lam bang wolfram. Chat lieu lam bong bang thuy tinh. Nhiet o si ot hoat
ong la 2.870 K.
en Tungsten/Halogen
Co mot lng nho iod ben trong vo en bang thach anh cha si ot wolfram.
Nhiet o si ot hoat ong gan 3.500 K.
S phan bo nang lng phu thuoc vao
nhiet o. vung kha kien, nang lng
en thay oi theo ien the hoat ong. Do
vay can thiet dung on ap.
ac iem
Cho cng o sang at yeu cau s dung
tren mot phan vung t ngoai va toan bo
vung kha kien (t 340 en 900 hay 1.100
nm).
o nhieu rat thap, rat t troi ng nen.
Thi gian s dung khoang 10.000 gi.
SO SANH EN TUNGSTEN VA EN
TUNGSTEN/HALOGEN
Tuoi tho cua en tungsten/halogen cao hn gap oi so vi en
tungsten.
en Tungsten, tungsten b thang hoa di tac dung cua nhiet o cao lam si
ot b mon dan theo thi gian va b t
e lai vet en tren au bong en.
Ket qua la tuoi tho en b giam.
en Tungsten-Halogen, iod
phan ng vi hi tungsten b thang
hoa di tac dung cua nhiet o cao
tao thanh hp chat WI2.
Chat nay (WI2) ngng tu tren
si ot giai phong wolfram, nen
si ot khong b mon, gia tang tuoi
tho en.
EN XENON
Tao ra nhng bc xa co cng o ln bang cach cho dong ien iqua bau kh
xenon.
Cho pho lien tuc t 250 - 600 nm.
ac iem
Cho cng o sang at yeu cau
lien tuc trong vung UV-Vis.
Thng dung trong nhng ng dung
nh o t le tan xa hay quang
pho huynh quang can cng o cao.
BO PHAN TAO ANH SANG N SAC
(MONOCHROMATOR) (2)
Cac thanh phan quang hoc cua mot
bo phan tao anh sang n sac bao
gom: khe vao (1), knh chuan truc (2),
bo phan tan sac gom lang knh hay
cach t (3), mat phang hoi tu (4), khe
ra (5).
Tao ra anh sang vi cac bc song
khac nhau c tan sac nhng goc
khac nhau.
Bo phan nay dung e chon t
nguon sang mot anh sang n sac
co bc song mong muon i qua
mot khe ra thch hp.
Bo phan tan sac: co 2 loai thong
dung la lang knh va cach t.
PRISMS
20 6/29/2014
1 2 3
: angle of deviation
LANG KNH (PRISM)
ac iem
Tao ra anh sang nhieu mau sac nh
cau vong t anh sang mat tri.
Cau tao n gian va re tien nhng
cho goc tan xa khong tuyen tnh va
phu thuoc nhiet o.
Nhc iem cua lang knh
Pho cho bi lang knh khong tuyen tnh
ve bc song.
Lang knh hap thu mot phan nang lng
anh sang khi i qua no.
Goc tan xa phu thuoc nhiet o.
Phai tao ra c che quay lang knh tng
oi phc tap e co the kiem tra bc
song t thang o.
m = d sin
CACH T (GRATING)
S tan sac cua bc xa t ngoai kha kien co the c tao ra bang cach
hng mot chum tia a sac cho i
qua cach t dan truyen hoac ve pha
cach t phan xa (dung nhieu hn
trong thc te).
Cach t phan xa la mot ban thuy tinh
ma nhom. Tren be mat ma nhom nay
co nhng ranh song song va gan ke
nhau.
Phan b rach khong phan chieu anh sang, phan con lai ong vai tro mot
gng phang gom nhieu gng rieng
biet nhau.
Anh sang chieu ti phan ma nhom
khong b rach nay se b phan xa tr lai
theo nhng goc khac nhau tuy thuoc vao
bc song cua chung.
Cac tia phan xa se giao thoa vi nhau
tao nen van nhieu xa co bc song khac
nhau.
Khi quay cach t, ta thu c khe ra cac van co bc song khac
nhau.
Cach t phan xa anh sang nhng
bac khac nhau nen phai dung knh
loc e ch cho anh sang cua bac
anh sang phan xa mong muon en
au do.
CACH T LOM (CONCAVE GRATINGS)
c tao thanh tren be mat lom
Cho phep thiet ke mot bo tao anh sang
n sac ma khong can bo phan chuan
truc phu tr, gng hoi tu v be mat
lom co the phan tan roi tap trung
bc xa khe ra.
Loai nay co u iem la gia re, s giam
thieu cac be mat quang hoc lam gia
tang mc nang lng cua bo tao anh
sang n sac cha cach t lom.
HOLOGRAPHIC GRATINGS Ky thuat quang hoc tao cach t tren
be mat thuy tinh phang hay lom bang
tia laser.
Ky thuat nay cho phep tao cac ranh
ong eu ve kch thc va hnh dang.
Cach t loai nay cho cac pho khong
co anh sang lac va nhieu (ghost).
Tao thanh bang cach chieu 2 chum tia laser giong nhau t 1 goc thch hp
len mot be mat thuy tinh co tam chat
can quang.
Van giao thoa tao thanh t 2 chum tia
tren tang nhay chat can quang lam cho
no tan ra e lai mot cau truc co khac
vach
Sau o phan con lai c ma nhom
hoac nhng chat phan xa khac e tao
thanh cach t phan xa
U IEM CUA CACH T SO VI LANG KNH
Cho o phan giai tot hn
Cho s tan sac tuyen tnh
o rong cua giai pho la hang tnh
C che chon bc song n gian hn
CONG O VA NGAN CHA CONG O
(CELL & CELL HOLDER) (3)
CONG O
c lam bang chat lieu sao cho
anh sang trong vung o phai truyen
qua (trong thc te cac loai cong o co
o truyen toi a la khoang 90% moi
bc song trong vung UV-Vis)
Trong vung t ngoai (di 350 nm)
dung dung coc lam bang thach anh
hay silica (silic dioxid) nong chay.
Trong vung kha kien dung dung
cong lam bang thuy tinh silicat
hoac bang chat deo (nha acrilic).
Quang lo cong o thong thng
nhat la 1 cm.
Ngoai ra con co cac cong o co
quang lo t 0,1 en 10 cm dung cho
cac nong o thch hp ma khong
can pha loang tiep theo.
KIEU CONG O TIEU CHUAN
Pho bien nhat la loai cong o hnh khoi ch nhat. Quang lo coc o thong
thng nhat la 1 cm.
Ngoai ra con co cac cong o co quang lo t 0,1 en 10 cm e dung
cho cac nong o thch hp ma khong
can pha loang tiep theo.
Neu the tch mau co gii han th dung cong o co ca so.
MOT SO KIEU CONG O AC BIET
Microcell
La loai cong o co ca so rat nho
(co mat cat 2 x 2,5 mm). Ch can
lng mau xap x 60 l e o.
Ultra-microcell
La loai dung cu o mi thiet ke e
o the tch mau c microlit (2-5l) bao gom mot bo phan tiep hp va
mot ong mao quan bang silica
nong chay quang lo ngan dung
mot lan.
Cho trc tiep mau o vao ong mao quan, sau o cai vao bo phan
tiep hp. Quang lo giam cho phep
o cac mau co nong o cao ma
khong can pha loang. Ap dung e
o nong o va o tinh khiet cua
AND va nong o protein.
Coc o kieu dong chay lien tuc
Dung trong trng hp t ong
hoa nh trong may quang pho
ghep noi vi may o o hoa tan.
NGAN CHA CONG O (CELL HOLDER)
Ngan cha cong o e o o uc
(Turbidity Cell Holder)
Ngan cha cong o c dch chuyen
ra xa detector so vi v tr bnh thng
va mot khe at gia mau va detector.
Khe nay ch cho phep anh sang lo i
qua mau ma khong cho anh sang tan
xa en en detector.
Micro-Auto 12 Cell Holder
La loai ngan cha cong o dung
trong sinh hoa e phan tch ong hoc
enzym. Bao gom cac ngan cha cong
o co the tch toi thieu 100 l va bo
phan ieu hoa nhiet o bang dong
nc hoac kieu Peltier.
Water circulated Cell Holder
La loai ngan cha cong o duy tr
c nhiet o bang mot dong nc
luan chuyen lay t may ieu nhiet
(Thermostat). Dung trong phan tch
enzym.
Micro-Auto 6 Tm
Cell Holder
La loai ngan cha coc o dung trong
sinh hoa e xac nh tm
(thermal melting
point) cua AND. Bao gom mot bo phan
kiem soat nhiet o kieu Peltier, quat lam
nguoi ngan cha coc o bang khong kh,
bo phan lam sach hi ngng tu tren
thanh coc o dung kh nitrogen, hai ien
cc hieu nang cao Peltier, bo phan o
nhiet o bang cam bien nhiet.
DETECTOR (4)
La cac ong thuy tinh hoac silica c tao
chan khong vi cathod la kim loai kiem,
anod tch ien dng.
Khi anh sang chieu ti cathod, cac
electron c tach ra va i ti anod lam
cho the tang len t le vi cng o anh
sang.
o nhay pho cua cac te bao xac nh
bang chat lieu cathod, vi antimon/cesium
t 190 600 nm, vo oxid cesium/bac t 600 1000 nm.
Detector ong nhan quang
(Photomultiplier)
Nguyen tac hoat ong gan giong te bao
quang nhng co them bo khuech ai ben trong
lam cho loai nay co o nhay ln hn tren thang
pho rong hn.
Anh sang gay ra s bc xa photon t
photocathod, giong nh trong te bao quang
nhng anod c sap xep thanh day dynod co
the tang len khong ngng.
43 2- Photomultiplier tube (PMT)
Detector silicon diod (Silicon diode)
Co hieu nang cho toan bo thang o
rong, vng chac, o tho cao hn ong
nhan quang va khong tieu hao nhieu
ien nang.
Chuoi diod la mot tap hp cac detector
photodiod rieng biet xep at ke nhau
tren tinh the silicon tuyen tnh trong ma
tran tao nen.
Moi diod co mot tu ien va c noi
vi dong au ra bang mot cai ngat.
SiSi
SiSi
SiSi
SiSi
Al
p-type = mobile positive
charge resides in Si
crystal (+ hole rich)
SiSi
SiSi
SiSi
SiSi
P
n-type = mobile negative charge resides in Si crystal (e- rich)
3- Photodiode
3- Photodiode array
au tien tu ien c tch mot gia tr ien nhat nh.
Khi photon tham nhap vao silicon,
nhng phan mang ien tch t do tao
thanh e xa tu ien.
Tu ien lai c tch ien nhng
chu ky ac trng cho chu ky o oi vi
moi chu ky quet.
Lng ien can e nap cho tu ien t le vi so pho ton c phat hien bi moi
diod hay noi cach khac t le vi cng o
sang.
Pho hap thu thu c bang cach o
lng s thay oi cng o sang tren
toan khoang bc song. Thong thng
detector chuoi photodiod cha 1024
detector photodiod rieng biet.
HE THONG QUANG HOC
(OPTICAL SYSTEM) (5)
S dung cac thau knh hay gng lom e tap trung anh sang. Neu dung
loai knh thong thng co the b sai lac
ve mau sac.
Knh tieu sac ket hp nhieu loai knh
vi ch so khuc xa khac nhau khong
gay ra hien tng sai lac ve mau sac
nhng gia thanh cao.
Gng lom re hn knh tieu sac va cung khong b sai lac ve mau sac
nhng be mat nhom de b an mon lam
giam hieu nang.
Tren moi be mat quang hoc ke ca
giao dien gia cac thanh phan cua knh
tieu sac, 5 10 % anh sang the hien qua s hap thu hay phan chieu.
Mot may quang pho ly tng phai
thiet ke vi be mat quang hoc toi thieu.
MAY QUANG PHO THONG THNG
Anh sang a sac t en nguon tap trung khe vao cua bo tao anh sang
n sac cho truyen qua mot cach chon
loc mot day anh sang hep.
Day anh sang nay i qua mau, lo ra
va en detector.
o hap thu cua mau la hieu gia
cng o anh sang ti detector cua
mau trang va mau th.
May loai nay thch hp e o o hap thu mot bc song tren pho
nhng khong thch hp lam khi o
nhng chat khac nhau nhng bc
song khac nhau hoac khi lay pho
cua mot chat.
e lam c ieu nay, bo tao anh
sang n sac phai xoay mot cach c
hoc gay ra sai so do o tai lap. Qua
trnh thu nhan d lieu can co thi
gian.
CAU HNH
Kieu mot chum tia
Co the la loai may quang pho
thong thng hoac may quang pho
day diode.
He thong quang hoc n gian nen
co o nhay cao va gia thanh ha.
May quang pho oi chng do Vien tieu chuan va ky thuat quoc
gia Hoa ky va phong th nghiem
vat ly quoc gia Anh quoc s
dung la loai may mot chum tia.
May quang pho day diode ac
biet thch hp cho cau hnh mot
chum tia v thu c pho rat
nhanh va khoang thi gian o
gia mau trang va mau th b
giam en mc toi thieu.
Kieu hai chum tia
Chum tia i t en nguon ti bo tao anh sang n sac c tach ra
thanh hai chum tia n sac bang
nhau do mot bo chan sang t ong
xoay vai giay mot phut (chopper),
mot chieu ti mau o, mot chieu ti
mau oi chieu
Diagram of a double-beam UV-Vis.
spectrophotometer
Kieu split-beam
Giong vi loai may 2 chum tia nhng dung bo tach chum tia (beam splitter)
thay v chopper e cho anh sang i
qua mau trang va mau th ong thi
e en 2 detector rieng biet giong
nhau.
Vi cau hnh nay, mau trang va mau
th c o ong thi. He thong
quang hoc cung n gian hn may 2
chum tia thc thu.
Nhc iem la hai detector co the
khong hoan toan ong nhat nhau.
Diagram of a spilitter-beam UV-Vis. spectrophotometer
Kieu dual-wavelength
Cau hnh nay cho phep o 2 bc song ong thi nh khi nghien cu 2
phan ng xay ra ong thi ben trong
mau.
Bo tao anh sang n sac cha 2 bo
phan tan sac.
May loai nay at hn may quang
pho thong dung va c dan thay the
bang may quang pho diode array co
the ghi pho ong thi nhieu bc
song khac nhau.
MAY QUANG PHO DIODE ARRAY
Anh sang a sac t en nguon i qua mau roi tap trung khe vao
cua bo tao anh sang a sac sau o
b tan sac tren day diode, moi
diode o mot day hep cua ca pho.
Kch thc cua diode va khe vao
cua bo tao anh sang a sac co lien
he en o rong day cua anh sang
phat hien.
61 6/29/2014
3- Photodiode array
Moi diode thc hien chc nang nh mot khe ra cua bo tao anh sang n
sac.
e giam thieu phan ng quang hoa,
may co ca chap e chan anh sang
t en nguon cho ti tien hanh o
mau.
May loai nay cho phep thu nhan d
lieu rat nhanh, o tai lap bc song
rat tot va o tin cay rat cao.
u iem
Ghi pho nhanh
Dung e nghien cu ong hoc
nh tnh va nh lng cac thanh
phan tach ra t cot sac ky
Nhc iem
Nang suat phan giai kem (1-2nm)
Gia thanh cao
2.2. CAC S CO THNG GAP
VA BIEN PHAP KHAC PHUC
EN KHONG CHAY KHI M NUT
POWER
Nguyen nhan
1a. Day nguon khong
noi vi may
1b. No cau ch nut
power
1c. Chay en nguon
1d. Mach ien b hong
1e. The nguon thap
Khac phuc
1a. Kiem tra day
nguon
1b. Thay cau ch nut
power
1c. Thay en
1d. Goi chuyen vien
bao tr
1e. Dung on ap
GIA TR O HAP THU CAO BAT THNG
VA KHONG TR VE 0 KHI NHAN PHM
AUTO ZERO
Nguyen nhan
Mot trong 2 hoac
ca 2 en nguon b
chay hoac khong
m
Khac phuc
M en len. Thay en
O HAP THU DAO ONG MANH
Nguyen nhan
3a. Chum tia oi
chieu b chan
3b. en tat hoac
b chay
Khac phuc
3a. Kiem trang
i cua chum tia
3b. Kiem tra nut bat
en va tnh trang
en
O PHANG NG NEN NAM NGOAI
GII HAN CHO PHEP
Nguyen nhan
Chum tia i qua
mau b chan mot
phan
Khac phuc
Don sach vung
chum tia i qua
mau va tien hanh
hieu chnh ng
nen
BC SONG HIEU CHNH NAM NGOAI
GII HAN CHO PHEP
Nguyen nhan
H hong ve c
hay ve ien
Khac phuc
Goi chuyen vien
bao tr
NHIEU NG NEN LN BAT THNG
Nguyen nhan
6a. o nhay detector kem
6b. Mot trong nhng bo phan quang hoc sau ay b
h hong:
Bo phan chuyen oi
nguon sang
Khe sang
Knh loc
Khac phuc
6a. Goi chuyen
vien bao tr
6b. Goi chuyen
vien bao tr
NHIEU NG NEN LN BAT THNG
Nguyen nhan
6c. en nguon a
het han s dung
6d. ien the cung
cap cho thiet b
thap hn quy nh
6e. Nhieu co nguon
goc ngoai lai
Khac phuc
6c. Thay en nguon
6d. S dung on ap
6e. at thiet b xa
cac trng ien t
hoac cac nguon
gay rung lac
NHIEU NG NEN LN BAT THNG
Nguyen nhan
6f. Thiet b khong
noi at
6g. o rong khe
sang nho
Khac phuc
6f. Noi at cho
thiet b
6g. Tang gia tr o
rong khe sang
O LECH D LIEU LN
KHONG CHAP NHAN C
Nguyen nhan
7a. en nguon b
yeu
7b. ng i cua
chum tia b anh
hng do dau van
tay hay bui
7c. Cong o hay ca so b ban
Khac phuc
7a. Thay en nguon
7b. Ra cong o
hay/va ca so
7c. Ra cong o hay/va ca so
MAY KHONG OC C TAT CA CAC
NH THEO QUY NH
Th du: Rifampicin co 4 cc ai hap thu
237, 254, 334 va 475nm. May khong ghi c
nh 237nm
Nguyen nhan
at o rong khe
sang (slit width)
khong phu hp
Khac phuc
Giam o rong khe
sang
O HAP THU DAO ONG MANH
Nguyen nhan
Dung cong o
thuy tinh e o
mau bc song
t ngoai
Khac phuc
Thay bang cong
o thach anh
O HAP THU GIAM DAN
Nguyen nhan
Dung moi b boc
hi
Bot kh hien
dien tren thanh
cong o khi cho
dung dch vao
Khac phuc
Dung cong o
co nap ay
Lam ay cong
bang pipet
O HAP THU THAY OI ANG KE
GIA CAC LAN O
Nguyen nhan
Dung cac cong o co o thau
quang khac nhau
Khong nh hang cong o
Khac phuc
Dung mot cong o e o cac mau
S dung cong vi cung mot mat
quay ve pha anh
sang
NH HAP THU B LECH VE PHA
BC SONG NGAN
Nguyen nhan
Hien tng
Tracking
(Tracking error)
do quet pho toc
o qua nhanh oi
vi may hai chum
tia
Khac phuc
Giam toc o
quet pho
Ghi pho chuan
trong cung ieu
kien
NH HAP THU B THAY OI SO VI
GIA TR QUY NH
Nguyen nhan
Dung moi s dung
khong chuyen
dung cho quang
pho
Dung moi co lan
nc
Khac phuc
Dung loai dung
moi thch hp
2.3 Hieu chuan va van
hanh may quang pho UV-
Vis
Hieu chuan
Xac nh o on nh, o ung, o chnh xac cua may. Kiem tra tnh trang hoat
ong cua may
Phat hien nhng khiem khuyet cua thiet b
Cung cap cac d lieu cho ngi bao tr e xac nh nhng hong hoc cua thiet b
nham ho tr trong sa cha
NOI DUNG
Kiem tra o phang ng nen (check of
baseline flatness)
Tren toan thang bc song, o thang giang (Fluctuation) cua
ng nen so vi khong kh phai
nam trong khoang qui nh cua
bang thong so ky thuat.
Th du
- May Hitachi U3210 co o thang giang
trong khoang 0,001Abs
- May Hitachi U2010 co o thang giang
trong khoang 0,002 Abs (200-950nm)
- May Hitachi U3000 co o thang giang
trong khoang 0,001Abs
- May Ultrospec III co o thang giang trong
khoang 0,002 Abs
Cong o (cells or cuves)
Thng dung cac cong o tieu chuan
Cac cong o phai am bao cac yeu cau sau:
Phan be mat hng chum tia va cho
chum tia i qua phai that phang, nhan
va song song vi nhau.
Hai ban anh sang ti vi anh sang i
qua phai song song vi nhau.
Quang lo trong cong o phai am bao gia
tr danh nh
Cong o thng c lam bang:
Thach anh (Quartz) cho vung o t
ngoai va kha kien
Thuy tinh cho vung o kha kien
Yeu cau cac cong o phai cho o hap
thu hay o thau quang luon luon bang
nhau khi cha cung mot dung moi hay
cung mot dung dch o trong cong. Cac
cong o co be day 10 mm co dung sai cho
phep ve o dai quang trnh la 0,005 cm
hay 0,05/10 = 0,005 = 5o/oo
Kiem tra bc song (control of wavelengths)
May phai am bao o ung cua bc
song (wavelength accuracy) theo ch tieu
ky thuat cua may do nha san xuat e ra
va phu hp vi yeu cau k thut ( 1nm t
200 - 400nm; 3nm t 400 - 700nm).
oi vi may quang pho UV-Vis the he
mi, en D2 c s dung nh la mot
nguon sang tao mot vach sang bc
song 656,1 nm e kiem tra o ung cua
bc song (656,4 - 655,8 nm).
oi vi ngi hieu chuan may th s dung
knh chuan holmium oxide hay dung dch
holmium perchlorat e kiem tra o ung cua
bc song.
Trong trng hp may o iem va khong
co chc nang quet pho, tien hanh o o hap
thu tai cac iem xung quanh cac cc ai e
kiem tra.
Kiem tra o hap thu (control of absorbances )
Kiem tra o hap thu cho biet o ung cua
may (Photometric Accuracy).
May phai cho cac thong so ap ng vi cac
thong so ky thuat e ra cho moi may va yeu
cau k thut.
Vi may at c o ung theo qui nh cho
phep co the thc hien phep o tuyet oi.
Dung dung dch kali dicromat. Gii han hap
thu la 0, 01 AU
Ghi pho cua dung dch toluen (TT) trong
hexan (TT) 0,02 % (tt/tt). Gia tr toi thieu cua
ty so gia o hap thu cc ai 269 nm va o
hap thu cc tieu 266 nm phai ln hn 1,5
Ghi chu: Theo BP 2005, ch tieu nay khong bat buoc.
o phan giai cho phan tch nh tnh (resolution)
ao ham bac hai (second derivative)
Vi may cho phep thc hien cac bien
oi t pho thong thng sang pho ao
ham bac mot, bac hai hay bac cao hn
phai kiem tra moi tng quan gia ao
ham bac hai va nong o cua chat can
khao sat. Moi tng quan nay phai tuyen
tnh.
May phai lay c ao ham bac hai theo
ung qui nh.
Gii han anh sang lac (limit of stray light)
Anh sang lac (stray light) la nguon goc gay
sai so chnh cho may nen c qui nh rat
chat che khi hieu chuan may.
Yeu cau khi o la tia chieu ti mau o phai
that s n sac.
Khi chum tia chieu ti bo tao anh sang n
sac e tao thanh cac tia n sac, co cac quang
sai nen dan en viec tao ra cac tia la i kem
vi tia n sac chieu ti mau do s cha hoan
hao cua s tan sac
Mau khong hap thu cac tia nay
Tiep theo cac tia nay lai chieu en detector,
lam giam o hap thu cua nh can khao sat nhat
la khi o vung gan 200 nm va dung dch co o
hap thu cao.
Anh sang lac cung gay ra s sai lech am cho
nh luat Lambert Beer khi o thang o co o
hap thu cao.
Anh sang lac cung tao ra khi buong o (sample
compartment) khong kn.
Yeu cau may phai cho gii han cua anh sang
lac trong pham vi cho phep.
Van hanh
May quang pho UV-Vis
o iem (nh lng)
Quet pho(nh tnh)
o ong hoc
o iem (nh lng)
Bat may, si am (warming up).
Chon bc song can o.
Cho chum sang i qua mau trang.
Hieu chnh cong o.
at mau vao khoang o.
oc gia tr o hap thu.
Cac iem can lu y
Lam ve sinh cong trc khi o.
Khong dung cong b nt hoac xc.
S dung cung mot cong cho chum
tia oi chieu.
Hng cung mot mat cua cong ve
pha anh sang.
Chat long trong cong ng mau th
va mau oi chieu eu phai khong co
bot kh va tieu phan.
Cac iem can lu y
Lau cong can than bang giay tham
mem hoac vai khong x.
Khong x tay vao be mat trong
suot cua cong o.
Dung moi s dung khong c co
o hap thu anh sang trong vung
bc song can o.
Cong mau th phai c ra t
nhat 3 lan bang dung dch mau th
trc khi o.
Cac iem can lu y
Kiem tra cong e am bao s khac
biet ve o hap thu khong phai do
cong b ban.
Khong o o hap thu khi co bot kh.
Khong s dung cloroform bc song di 245 nm.
Dung moi s dung phai lay t cung
mot chai.
Neu dung moi la nc, nen dung nc
mi cat.
Cac iem can lu y
Nen bao quan dung moi hu c
trong chai thuy tinh mau, khong
ng trong chai nha.
Oxy trong dung dch lam tang o
hap thu neu dung moi la con
bc song di 230 nm.
Cac hp chat cacbonat hap thu
manh bc song di 240 nm.
Can o nhanh va ay nap cong o.
Quet pho (nh tnh)
Tien hanh giong nh o iem.
bc song di 230 nm, o hap
thu nen di 0,7.
Nen quet pho UV t 370 nm en
bc song ngan nhat van cho ket
qua ung.
Can at ung o rong khe sang
e co o phan giai can thiet.
o ong hoc
Khao sat o ben cua mau va van toc cac phan ng thuy phan chat
nen do enzym xuc tac.
Tien hanh bc song xac nh.
Ghi lai s thay oi o hap thu theo thi gian.
EN DUNG CHO VUNG T NGOAI
en Deuterium
Deuterium b kch thch ien ap suat thap tao ra pho phat xa lien tuc trong
vung t ngoai
Bong en lam bang thach anh v thuy tinh hap thu manh anh sang vung
bc song di 350 nm
Cho cng o sang at yeu cau s dung lien tuc trong vung t ngoai (t
200 en 340 nm)