Tsp chi Khoa hgc DHQGHN, Khoa hpc Ty nhien va Cong nghe Tap 29, So 4 (2013) 29 35 hoa quy tnnh phan tfch dong thdi cac anion v6 ca trong man nude moi trudng sir dung he didn di mao quan van hanh bang[.]
Trang 1hoa quy tnnh phan tfch dong thdi cac anion v6 ca trong man nude moi trudng sir dung he didn di mao quan van hanh bang tay ket hop vdi detecto do dan khong tiep xuc Nguyen Bich N g o c\ Nguyin Kim Diem Mai^'^.
Duong Hong Anh‘, Pham Hung Viet'’*
' Trung tarn Nghiiit cihi Cong ngh? Moi tnicmg va Phdt triin Ben viing,
Tntcmg Dgi hQc Khoa hge Tu nhien, DHQGHN, 334 Nguyen Trai, Hd Ngi, Viet Nam
^Tntdng Dgi hpc Su Pham Tp.Ho Chf Minh
N h |n n g ly 05 thing l i n5m 2013 Chinh sua n g iy 19 thing 11 nSm 2013; ch ip nhan d in gn gay 16 thing 12 nim 2013
Tom tSt: Quy trinh phan ti'ch dong thdi ca phot phat va cic anion co ban khic trong nude nhir clonia nitrat, nitrit va sunphat trong nude su dyng he dipn di mao ^uan van hanh bing tay kit hop
hS d^m 50 mM Tris/50 mM MOPS d pH 7,7, mao quan PEEK va ip the -15kV Gidi han phit hi|n
tot Ket qua phin tfch mot so miu thpc cho thay tuong quan cao giOa phuong phip dien di mao quan da phat trien va phuong phip doi chung bing sic k;^ ion
Tir kh6a: Dien di mao quan, cam bien d$ din khong tiep xUc anion v6 co
1 fig t v in d l
Vdi d |c tinh phan tich cac chat tan dua CrSn
di£n tfch, ngay tit rat som, thu& dien di
(Capillary electrophoresis - CE) d a duoc nghien
cihi de umg dyng trong phan tfch cac ion v6 ca
Ban dau, nguai ta chti y lu sir dung detector
quang, den cuoi nhirng nam 1990, detector do
do d in khdng tiep xuc (C^D) ra doi da md rong
kha nang ip dung CE cho phan tfch c ic anion
vJi cation v6 co trong moi truemg nuac [1] Cac
■ T ic gia lien bS DT: 84-913572589
E-mail: phamhungviet@hus edu.vn
nghiSn cihi ciia Kuban [2], Mai Thanh Due [3]
da dua ra quy trinh phin tfch dong thdi cic anion co ban nhir CP, NO2', NOj', S04'', F Tuy nhiln, cac nghien curu niy d iu chira de cip toi viec dinh luong phot phIt, mot chi tieu quan trong trong cac quy chuan k j ihuSt Viet Nam ve
08:2008/BTNMT) va nude thai (QCVN 14:2008/BTNMT QCVN 24:2008/BTNMT (JCVN 28:2008/BTNMT),
Muc lieu cua nghien cuu nay la dua ra dugre quy trinh phan tfch dong thdi cac anion cloma, nitnt, nitrat, sunphat va phdt phat tren he thiet
Trang 2bi dien di mao quan tir che lao sir dung detector
do do dan khSng tilp xuc, gidp dira ra mot giai
phdp phan tfch don gian, chi phi thap va hieu
qua cao cho cdc tram quan tide chat lugng mrdc
hien nay
2 Phuung phap nghien cihi
2.1 Vgi lieu
Todn bq hoa chat duqc sii dung deu thuoc
loai tinh khiit phSn lich mua tu Merck
(Darmstadt, Germany) hoSc Fluka (Buchs,
Switzerland) Dung dich goc 100 mmol/L cua
cac anion v6 ca duoc pha tir muoi natri ran
tuong ling, rieng NOi' duoc pha lai tir dung
djeh goc 1000 ppm (Merck) Cac dung djeh goc
ndy sau duqc sir dung de pha m lu chuan Dung
dich dem duqc pha trong ngay, sieu Im loai bo
bot khi trude khi sir dung Tat ca dem, mau
chuan va m lu gia deu duqc pha trong nuoc
deion
2.2 KyihugTdo
H f thiet bi dien di mao quan duqc su dung
trong nghign cuu la he thiet bj tu lap d |t voi su
dung bq phat nguon cao the EMCO (t6i da ±15
kV) v i detecto dq din khong tiep xiic tu che t?o
noi voi bq ghi Pico ADC-16 D ira cue noi dat
duqc d |t a dau bom mau Detecto duqc dat o
gin diu dien cue cao the Diin the lich su dung
la -15 kV Nghiin cuu duqc thuc hien tren hai
loai mao quan l i mao quan silica v i mao quan
PEEK (poly(etheretherketone)) dSu c6 dudng
ki'nh trong 50 pm chieu d ii 60 cm va chieu dai
hiqu dung la 53cm Mao quan silica duqc xu 1^
voi NaOH IM trong 10 phiic va nude deion 10
phut Con mao quan PEEK khong phai xu ly
Mau duqc bom theo nguyen tic xiphong o dq
cao chinh lech 16 cm trong 20 giay,
Qua trinh tdi m i h6a duqc thuc hira theo phuong phap toi uu lin luqt timg ySu td: pH (thinh phin dem), ndng do dem va lua chqn mao quan C ic thong s6 duqc su dung de so sanh ket qua cua cac difiu kien la diqn ti'ch pic, thdi gian luu v i dq phan giai giua cic pic Sau khi tdi uu, phuong ph ip phan tich duqc dinh g ii thdng qua gidi han phat hifn - LOD (S/N = 3), hi§u su it thu hdi va dq lap lai Phuong phap cung duqc i p dung de phan tich cac mau nude mdi trudng lay tir cac gieng nude ngim tai xa Van Phuc, H i Ddng, H i Nqi va so sinh k it qua phan ti'ch thu duqc b in g phuong phip sic ky ion
3 K it qua thao luan
3.1 Phdl trien quy trinh a) Lua chon dim c6 p H phit hap
Trong nghiSn cuu niy, bon h? dem d pH khic nhau duqc su dung de khao s it anh hudng len su phan tich cua cic anion li: be dem histidine (12 mM) duqc dieu chinh pH bing axit axetic (His/Ace) den pH 4,0; he ddm MOPS - axit 3-(N-morpholino)propanesulfonic
va Histidine (MOPS/His) d ty le I /l vdi pH 5,8;
he dem MES-axit 2-(7^-morpholino) ethanesulfonic
va Histidine (MES/His) duqc pha d ty le I /l c6
pH 6,5; va he dqm Tris - Tris(hydroxymethyl) aminomethane v i MOPS (Tris/MOPS) cung d
ty le 1/1 vdi pH 7,7 D6i vdi cic he dem c6 pH
> 4, CTAB (hexadecyltrimethylamraonium bromide) duqc them v io d l diiu chinh ddng EOF Cac ion Cl', SO*^', NOs', NO:' duqc chuin bj d ndng dq 100 |lM rieng ion HPO^"' duqc chuan bj d ndng dq 250 |iM C ic dien di
do duqc trinh biy trong hinh 1
Trong dieu kien thf nghiem, chi c6 hai h? dem His/Ace v i Tris/MOPS cho phin tich tot
Trang 3giixa c ic pic Tuy nhiSn, dem Tris/MOPS c<5
phSn im viet hem do chieu cao pic ciia HPO*"'
t6t hem (65,78 mV) so vdi ciia dem His/Ace IS
(-38,42 mV), Hem the nua, d$ phan giai ciia cac
pic khi sij dung dem His/Ace k6m hem khi su
dung d?m Tris/MOPS Khfing chi v$y, dem Tris/MOPS c6 kha nang dirge tiep tuc toi iru do c6 the dieu chinh linh boat thoi gian lini vS do phan giai nh6r vao viec thay doi van t6c dong EOF
Hinh 1 Dien di do tdu phSn tach cac anion Cl', , N03‘, NOj', HP04^' sit dyng cac h? dem c6 pH khde nhau
b) Anh hit&ng cua nong do dim
Yeu to thu hai dirge khao sat la nong do cac
thSnh phan trong d ^ Hlnh 2 la dien di do cua
cac anion khi thay doi nong do Tris va MOPS
trong dem nhimg vin giu ti 1| 1/1 de khong lam
thay doi pH Co the thSy, khi tang n6ng do d?m, van toe ciia anion tang hay thoi gian liru giam Khong chi the, khi tSng nong do dgm, chan pic thu hgp lai gidp cho do phSn giai giO'a ede pic t6t hon nhu 6 Bang 1
Hinh 2 DiSn di do phSn tich d6ng thdi cac anion co ban cr cac nong d$ dSm khSc nhau (Tris/MOPS70: 70 mM Tris, 70 mM MOPS, 3 pM CTAB; Tns/MOPS50:50 mM Tris 50 mM MOPS, 3 pM CTAB; Tns/MOPS30
Trang 4B ^ g 1 Dq phan giai giiracacpic voi cdc ndngdp demTris/MOPS khac nhau
Cr - NOi’ NO:' ■ NO:' NO:' - S04^ SOj^' - HPO4
Tuy nhien, nong do dem c ^ g cao do din
ciia dung dich cm g Idn d in den ha chieu cao
ciia pic vli c5ng chieu cao nhiSu nen do hieu ling
nhi?t Jun, Tir thijc nghiem cho ihly, nong do 50
mM Tris, 50 mM MOPS 14 nong do phu hop
cho viec phan tach dong thoi c4c anion, dam
bao ca ve do phan giai gi&a c4c pic v4 chieu cao
pic so voi chieu cao nhilu nen
- J li
c) Logi mao quan
Trong cac nghien cihi tren he CE-C^D vdi mao quan silica d pH >4, CTAB - chit dilu chinh dong EOF - thirdng dupe them vao trong dung dich dem Dem Tris/MOPS50 dirqc khao sit a cac n6ng do CTAB khde nhau tir 0-5 pM (Hinh 3.)
NOj-*^
c r l /
J
rr5«OPS»CTAB$
1iS.TrfOPS60CT»B3
LiL
50 T r "S '' M ^ mm CtZ T n ^ S O CTAB5 50 mM Tns, 50 mM MOPS, 5pM CTAB; Tris/MOPS50 mqPEEK: 50 mM Tris 50 mM MOPS
su dung mao quan PEEK)
Khi khOng cho CTAB hay n6ng do CTAB
qua nho, v|in toe dong EOF Ion diy ion HP04-'
ve phfa nguqc lai, do do pic ciia phot phat chi
xuSt hien khi n6ng d6 EOF dii Ion Viec tang
nong dq CTAB lam giam van tdc EOF cOng
dan dfin chan pic hep lau, chieu cao pic tang nhurng d6ng thdi cung J4m giam do ph§n giai giGa c4c pic Ket qua th\rc nghifm cho thay khi tang nong do CTAB d6 phSn giai giua hai pic NOj’ - NOj- giam tir 2 (0 CTAB) xu6ng
Trang 51,47 (5 pM CTAB) M |t khac, nhilu nen tra
nen ro r |t hon khi giam van toe EOF bang viec
tang nong CTAB Nhir v |y , trong dieu kien
cua nghign curu n^y khi sii dung mao quan
silica, dem Tris/MOPS 50 CTAB 3 cho ket qua
tot nhat trong viec phan tdeh dong thoi cac
anion
B8n canh mao quan silica truyen thong,
mao quan tir vat lieu polime nhu mao quan
PEEK ducrc coi Ik mot lira chon mcri trong CE
D o khong c6 lop silanol tren bS mat, ben dong
dien thim kh6ng xuSt hien khi sir dung mao
quan P EEK Ket qua so sanh v i ^ sur dung hai
mao quan durge the hi?n trong Hinh 3 V i« sir
dung mao quan PEEK con cho ket qua chiSu
cao pic tot hon, hinh anh duong nen phang hon
so veri viec su dung mao quan silica Dong thoi,
do khong chiu tac dong ciia EOF nSn do l |p lai
cua dioi gian Iiru khi d6 cung tot hon
Veri kha nang phan tach tot, cho tut hieu pic
cao ro rang so vdd nhilu nen, thoi gian phkn
rich on dinh, dem 50 mM Tns va 50 mM MOPS sir dung mao quan PEEK dirge lua chon
Ik dieu kien toi iru cho qua trtnh phan tich dong thoi ckc anion trong m lu nuoc moi tnrbng
3.2 Ddnh gid quy tnnh phan tich
Dd dung cua phuong phap dugc kiem chiing bang vifc ti'nh tokn hidu suit thu hoi khi phkn (ich mau gia chira nam ion b nong do 100 )jM Phuong phap cho ket qua thu hdi tuong doi tot ved ca nam anion trong khoang tir 95- 112% (Bang 2.) Do lech chukn tuong doi ciia dien ti'ch pic doi vbi m lu chiia ca nkm anion o nong do 50 |J.M, 100 |iM vk 200 jlM dugc su
(n=7) cho ket qua trong khoang tir 4-10% Ket qua gioi b?n phkt hi^n cung nhu khoang duong chuan thu dugc tir nghien cuu nky da chung minh kha nang ap dung ciia phuong phkp trong danh gia chat lugng nubc theo ckc Quy chuan
Ky thuat Qude gia
Bang 2 Khoang dubng chuan, gioi ban phan tfeh vk d$ Ikp lai trong phan tich dong thdi ckc anion
sir dung he CE van hknh bing tay va detector C^D
iou
duong chuan
(liM) Duong chukn
Hi?u suit thu hoi RSDl (%) (n«7
50 pM)
RSD2 (%)
(n=7,
100 gM)
RSD3 (%) (n=7
200 uMl (pM) (mg/L)
Nong do luih theo N
Nong d$ tfnh theo P
Ddng then phuong phap nky cung da thknh
cong trong vifc ha gioi han phat hien ciia PO*^
15 jiM (465 ppb P04^‘-P) xuong thip hon cac
DghiSn cuu phan tich phot phSt tren he dien di mao quan tm be day [4]
Trang 63.3 Ap dung phdn tick mdu thgt
Thfligian lAi(s)
Hinh 4 GiM dd di?n di phin tfch mau that trSn h$ CE-C^D
Quy trinh phan u'ch sau khi hoan thien duoc
sii dung de phan tich m lu nude moi trudng
Mau nude ng4m dugc lay a cac giSng khai th&;
nude ngam trong khu vuc lang Van PhtSc,
D6ng, Ha N6i v i dugc danh ma s6 tir GWVPl
ddn GWVPIO Dien di dd ciia mau GWP4 dugc the hien trong Hinh 4 vtl ket qua do dugc bang
CE v& ket qua so sSnh tren IC dugc thS hidn trong Bang 3
B ^ g 3 Ket qua phan tfch it moi tniong trSn h§ CE-C‘‘D va ket qua so smh ciia IC
(pM) (liM) lech(%) (pM) (pM) lech(%) (pM) (pM) Ipch(%) (pM) (pM) lech
(%)
n.d.: khong phai hien
* Nong d$ chap hon gidi ban dinh Itrong ci I phuemg phap
Ket qua thu dugc tir hai phuemg phip cd do
sai lech trong khoang tu 4,5-17% ddi vdi ion
Cr Cd mgt so m lu phdt hien t b ^ h phIn S04^‘,
NO?', NOj' Tuy nhien, s6 m lu nude mdi
trudng cd chira ba ion nay khong cao nen s6
lugng kSt qua thu dugc chua du dg d^nh gid
hieu qua ciia phuemg phap KSt qua phan tfch
c r thu dugc tir dien di mao quan c6 tuong quan cao vdi ket qua thu dugc tir phuemg phdp ddi
quy trinh vdi chi phf th lp dugc dua ra trong nghiSn cuu nay cd the duoc sii dung thay thS cho phuemg phdp IC trong phan tfch ddng thdi c^c anion trong mau nude mdi tnremg Tuy
Trang 7nhiSn cdc nghien ciiu can dirac tiep tuc trien
khai de c6 the dugc gicri han phSt hien xuSng
v i tang dp lap lai cua phucmg phdp.
4 Ket luSn
Quy tilnh toi iru de c6 the phan tfch ddng
thoi cac chi tieu anion v6 ca trong nnoc (Cl',
N O i, NOj', S04^‘ va POa’’) sir dung mao quan
PEEK he dem a pH 7.7 dupe dua ra boi
nghien cuu n iy cho dp tin cay cao voi quy trinh
phan ti'ch don gian va chi phi thdp Cac di€u
CO so de p h it trien quy trinh phan tich cho cac
h f dien di mao quan tu dong giijp tang dp chinh
xdc cung nhu khoang nong dp phan tich
Nhom tac gia chan thkih cm su ho trp
Uli chfnh tCr Bp Cong thuong theo dfi t&i 03/HD-
DT.03.12/CNMT thupc an "Phat trien
nganh c6ng nghi^p m6i tnrdng Viet Nam d in nam 2015, tarn nhin den nam 2025"
TM lieu tbam khao []] Kub^in, P, and PC Hauser, Ten years of axial capacitively coupled contactless conductivity detection for CZE-a review, Electrc^horesis,
2009 30(1) p 176-188
[2] Kuban, P el al New fully portable instrument for the versatile determination of canons and anions by capillary electrophoresis with contactless conductivity detection Electroanalysis, 2007.19(19-20) p 2059-2065 [3] Mai T.D and P C Hauser, Anion separations using a sequential injection analysis manifold and contactless conductivity detection Electroanalysis, 2011 32(21) p, 3000-3007 [4] Mai T D et al Portable Capillary Electrophoresis Instrument with ^tomated Injector and Contactless Conductivity Detection Analytical chemistry, 2013 85(4) p 2333-2339
Method Development for Simultaneous Analysis of Inorganic Anions in Environmental Aquatic Samples Based on a Manually Operated Capillary Electrophoresis System Using a
Contactless Conductivity Detector
Nguyen Bfch N gpcf Nguyin Kim D ilm Mai^'^
Duong Hong Anh‘, Phgm Hung Viet’
'Research Centre fo r Environmental Technology and Sustainable Development VNU University o f Science, 334 Nguyen Trai, Hanoi Vietnam
'Ho Chi Minh City University o f Pedagogy
A bstract: A method for simultaneous analysis of phosphate and other inorganic anions (chloride, nitrate, nitrite and sulfate) in environmental water samples using manual capillary electrophoresis system coupled contactless conductivity detector was optimized The buffer o f 50 mM Tris/50 mM MOPS at pH 7 7, -15kV and PEEK capillary using was chosen Limits of detection of five anions were relatively low from 5 to 15 ^iM, relative standard deviations were lower than 10% and recovenes were
CE method and those obtained by IC method
Keywords: capillary electrophoresis, contactless conductivity detector, inorganic anions.