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T^p d u Khoahpc DHQGHN, Khoa hpcTynJuIn va C 6ngngh|, T§p 30, So 1 (2014) 51 57 Xac dinh hkn luong As(III) trong nuac ngam tai xa Van Phuc, Thanh Tii, Ha Npi bang phu0ng phap dien di mao quan stl dimg[.]
T^p d u Khoahpc DHQGHN, Khoa hpcT ynJuIn va C 6ngngh|, T§p 30, So (2014) 51-57 Xac dinh hkn luong As(III) nuac ngam tai xa Van Phuc, Thanh Tii, Ha Npi bang phu0 ng phap dien di mao quan stl dimg detecta do dan dien khong ti6p xuc Nguyen Kim Diem Mai ' , Pham Thi Thanh Thiiy', Duong H5ng Anh^ 'Truong Dai Hqc S u Phgm Tp.Ho ChiMinh ^Trung tarn Nghiin cuu Cong nghe Mdi truang va Phdr trien Bin vO'ng, Truong Dai hoc Khoa hoc Tu nhien, DHQGHN 334 Nguyen Trai, Hd Ngi, Viet Nam Nhan ngSiy 05 th^ng ] nim 2013 Chinh siia 19 thang 12 nam 2013; chSp nhin dSng 30 tfaang 12 nam 2013 Tom tat Bai bao trinh bay ket qua sit dung phucmg phap di?n di mao quan phan ti'ch rieng hkm luOTig As(lII) nude ngJun tai xa Van Phuc, Thanh Tri Ha Noi Cac ket qua phan tfch cho thSy lugmg As(lll) dao dpng khoang tu nho hon 5pg/L toi gSn 400 pg/L KSt qua ddnh gii muc d6 tuemg quan ciia hai phucmg phdp CE - C^D vi AAS cho thay phuong phdp nghiSn ciru c6 tuomg quan rat tot v6i phucmg phap AAS vdi h^ so tuong quan = 0,99 khoaog gia tri % sai so giOa hai phucmg phap la 0,6 - 7,0% Dieu chOng minh rang phSn ti'ch As(III) bing phucmg phap di|n di mao quw cho cic ket qua c6 dp tin cay cao Tit khoa: Dien di mao quan As(lll), nude ngam Md' dau Ngay nay, tai nbieu vung nong then Viet Nam, ngudi dan vln dang sii dung nude ngam nhu ngu6n nude chfnh phuc vu cho cac muc dich sinh boat va san xuat Tuy nhien, nhiSu nghidn cuu cho thay c6 hien tugng nhilm asen tai mot s6 khu vuc ca a mien Bac cung nhu mien Nam Viet Nam Trong theo quy chuan QCVN 09:2008/BTNMT, gidi han cho phep ciia asen nude ngam 50pg/L thl theo danh gia cua UNICEF tir 2001 - 2004 d Ha Nam cd tdi 50,2% tdng s6 7024 mau nude ■Tde gia liSn h i DT: 84-912380373 E-maiJ hoanggiangaO@ginjil com giSng khoan ducrc khao sdt cd nong dp asen Idn hem 50 ng/L [1], C6n d tinh Dong T h ^ 260 m lu nude ngam khao sal cd 22% so mau cd nong dp asen vuert q u i 50 pg/L [2] Do d ndng thSp nhung viec pheri nhilm asen mot thdi gian dai cung s8 gay ede tac ddng xdu din sire khoe nhu: gay Id loet da, tac dong din hd hd hap, tim mach, he tieu hda, v i phat tiiln t h ^ ung thu gan, than, phdi, btog quang, Trong mdi trudng tu nhidn, asen thudng ton t^i d bdn trang thai oxi hda la -HI, 0, HI va V, d§c biet uong mdi trudng thiiy quyin, asen xuat hien chii ylu a hm dang la asenit (HI) va asenat (V) Trang thdi oxi hda, dang ton tai cua asen se N.K.D Mat va nnk ITgp chi Khoa hoc DHQGHN, Khoa hoc Tie nhiSn va Cong nghe, TSp 30, So (2014) 51-57 quyet dmh doc tinh, sir hnh dong kha nang van chuyen cua no moi truong Doc linh ciia asen doi vcri sinh vat giam dan theo thii tu : asin -> asenlt asenat hop chat asen hiiu CO Nhir vay, moi tiudng nirdc, cac hop chat asen hoa tri c6 d w tmh cao hon cac d ^ g asen hoa cri Do vay, viec xSy dung phucmg phap xac dinh riSng re ham lirgng timg d ^ g ton tai ciia asen dac biet Ih As(III) ludn la mot bai toSn doi voi cdc nha khoa hoc de d&ih gia nii ro sue khoe Hien nay, cac phirong phap thuong diing d6 xac dinh ham Iirong asen la phuong phdp quang hap thy nguy6n tCr (AAS) va plasma cam ung gh6p noi khoi (ICP-MS), nhien cac phucmg phip chi x&c djnh h ^ luepng asen tong mlu, neu muon xac djnh rieng re cac hop ph§n can ket hop voi mot phucmg phap tach trucrc Sir dung phuong phdp VonAmpe hba tan vdi difn eye dia quay v ^ g c6 the ddnh gia rieng rS, d6ng thoi hhm lugng As(in) \ k As(V) [3]; bang phuong phap c6 the xac djnh AsCE) b khoang nong vai chuc ng/L, nhiSn, lai k6m nh^iy d6i voi As(V) As(V) kdm boat dong ve m it dien hda Phuong phap dien di mao qutui viing la voi nguyen tSc phan tdeh ede chat dua tren su khac vS linh dpng dien di, dSc biet c6 loi viec phan tich ede ion mang difn Theo ede nghien cuu [4-6], cho thay phucmg phap dien di mao quan phti hop cho viec phan tich cac dang asen khac Tuy nhien, nhuyc diem Ion nhat ciia phuong phap la gibi han phai hien c6n cao (khoang mg/L) Nhbm nghien cuu cua chiing toi da phat trien quy tiinh phan tich As (V) va As (HT) m lu nubc bang phucmg phap difn di mao quan sir dung detector dp din khbng tidp xiic kieu tu difn (C‘'D) [7] Tuy nhien nghiSn cuu As(HI) phai phan tich gian tiep qua As(V) vi phSn tich true d ip A s(E ) gibi han dinh lupng Id 73|ig/L khbng du nhay de phan tich cac mau mbi truong so sanh vbi gibi hyn cho phdp ciia As nubc ngam la 50pg/L Vi vay, chung tbi da tiep tuc nghien cuu va hoan thien quy trinh phan tich true tiep tieu phan As(III) tren thiet bi CE-C'D vbi muc tibu tang db nhay, giam gibi han phdt hien Bai bio se trinh bay k it qua su dung quy trinh CE-C'D mbi phat trien de phSn tich hdm lupng As (in) cic mau nubc ngam ISy tai xa Van Phuc, Thanh Tri, Ha Npi vbi phucmg phdp doi chung Id AAS Tbyc nghifm 2.1 Hoa chdt, thiet bi Cac hoa chit su dung qua trinh phan tich deu Id loai tinh khiet phan tich Cdc hoa chat dung d l pha dung dich chuao va dem dupe mua tu hang Fluka, Thuy SI bao gbm: natri meta, 2-(N- morpholin)etansunphouic axit (MES), L-arginine, hexadexyltnmetyl amonibromua (CTAB) Ngodi ra, qud trinh xu li m lu su dung mbt sb hba chit: 1,10-Phenathrolin (Trung Qubc), axit nitric (Merck, Due) Tat ca cac dung dich chuan vd dem deu dupe chuan bi nubc deion Cac thi nghiem dupe tiln hdnh tren he thilt bi dien di mao quan tu ch i ddt tai phbng thi nghiem vbi bp ngubn cao the thuong pham (CZE 20(X)R, Spellman, Pulborough, UK) He thilt bi su dung bb detecto C“D thuong pham ciia eDAQ (EA120) D6ng dien sinh te bdo se dupe chuyen gia tri hieu dien the; cac gid tri sau db s5 dupe khuech dai, ipe nhieu b tan sb thap vd cubi cung dupe chuyen tbi bb ghi va he thong xCt ly dQ lifu ecorder (eDAQ, Denistone East, NSW, Australia) N K D M va rink ITap chi Khoa hoc D NQ C H N , Khoa hoc Tic nhien va Cong nghe, Tap 30, S o l (2014) 51-57 Cpi mao quan diing qua trinh phSn tich Uk cot silica voi dirong kinh 50pm va ducng kmh ngoM Ik 375pm (Polymicro Technologies, Phoenix, AZ, USA) c6 tong chieu dki 60cm va chieu dai hi?u dyng la 52cm D6i voi mao quan moi, dku tiSn duoc nra bang dung dich NaOH IM 20 phdt, sau d6 rCra lai bang niroc deion 15 phut, vk cu6i cung Ik bom dung dich dem qua mao quan khoang 60 phut m roc sir dung de dam bao chat boat dqng bS mat CTAB du^c phu deu tren be m§t mao quan Sau m6i Ian phan tich, mao quan dutpc nia lad bang dung djch dem phdt 2.2 Lay mdu va tien x u ly mau Mau nuac ngara diroc Iky tai xa Van Phuc, Tlianh Tri, Hk Noi Cac mau nuac ngam dugc lay len dieu kien khong c6 oxi va dugc Igc nhanh qua mang xenlulo acetat co kfcb thuac 0,45 pm Doi vdi ckc mau phan tich As (lH) bang phuong phap AAS; de tach rikng As(III) va As(V), mku nuoc ngam se dugc rua qua cot nhom silicat [8] Khi do, As(V) se bi giu lai tren cgt tkch va As(III) di khoi cot Cuoi cung, ckc mau nuac chi chiia As(III) dugc axit hoa toi pH < 2, bao quan a nhiet dg 4°C cho den phkn ti'ch Voi phuong phap dien di mao quan, mku nude ngam sau Igc se dugc them 1,10Phenanthrolin de phuc vdi skt tranh hien tugng As bi hap phu len be mat ciia kkt tiia sat Sau dd, mku nude se dugc rua qua cot chua nhua trao doi cation loai axit manh-WoIfatit KPS de loai bo phan bicacbonat nude Dk tranh su oxi hda As(lII) As(V) phai tien hanh sue nita suot qua trinh xu If m lu Cuoi cung, cac m lu dugc cho vko Ig km, chiia day mku vk dugc bao quan d nhigt dg 4“C cho den phan tich 2.3 Quy trinh phan rich Hlnh Gian phkn b6 cac dang ton tai eda As theo pH -E h [9] Gian phan bo ckc dang ton tai cua As theo pH cho thay thugc vko pH va the oxi hda khii mk asen ton tai d cac dang khke nhu: HjAsOj, H2As03‘, HAsOj’", AsOj^', H3ASO4, HiAsO*', HA s04^', vk AsOa^’ De phan tich As(in) bang phuong phkp dien di mao quan ta phai chuyen As(III) m lu ve dang mang dien H^AsOj' Anion H2As03‘ tdn tai moi trudng cd pH=9-12 Nhu vky, quy trinh phan tich phai chu y hai diem sau: - Dung djch dem dugc lua chgn 1km pha dgng quk trinh tach dien di phai cd pH khoang -12 Tuy nhikn ydi phuong phap dien di mao quan viec thuc hien d pH cao ( > 9) se gky nhiku khd khan anh hudng manh cua dong EOF [10] vay qua quk trinh khao skt dung dich dem dugc lua chgn cd thknh phan bao gom 12mM MES - 21mM Arg - 30pM CTAB (pH = 8,9) - Doi vdi m lu phan tich, de 1km tang dg nhay cua phuong phkp thi phai chuyen ckc hgp chkt As(ni) mau ve dang mang difn H2ASO3' ckng nhieu cang tot Do dd, giai phkp 54 NXD Mai va imk /Tap chi K/ioa hoc DHQCm Wioa hoc Tif iihi?n va Cong nghe Tap 30, Sff (2014) 51-57 dugc de xuat la tSng gia tri pH ciia mlu nude phan ti'ch bang each them 2mM Arginia vk mau se c6 pH = 9,6 Viec bom m lu dugc thue hien blng phuong phap dien dong hgc vdi thS bom 6kV va thdi gian bom mau la 60s Hieu dien the taeh dugc su dyng qua irinh phin tdeh la 20kV, Dudi cac difiu kien toi uu, doi vdi chat chuin, phuong phap c6 gidi han phdt hien As(III) la 5ixg/L; gidi han djnh lugng la 17)ig/I,; khoang nong tuyen tinh lir 20 den 150pg/L; he s6 tuemg quan tuySn ti'nh R'=0,997, va lap lai RSD=1- 7% ( n ^ ) [10] Loc qua mang xenlulo acetat Phuong P h u o n g p h ap AA S CE-CD I Suckbinito _I L oai As(V*) b m g cot nh o m -alicai T jophucvdi 1,10-PhaianihroIin A xit b o a m ill bang ax h HNO} Dung Tiong lo kin, bao quan b 4'C ^ Sue nito i i Loai Bicacbonat bing nbya trao ddl cation B ao (Tuan b 4°C i Phan rich Trong p hong th in g l u m , Xac ^n h ham luong As(III) bang phuong phap them chuan Hinh Quy ttinh phan tich tryc tiep As(lII) bang phuong phip CE-C^D vl so sanh bang AAS Ket qua va thao lu^n 3.] Anh huemg cua ede anion n (7 ban Tin hieu ciia cac anion nen thudng xuat hien khoang tir 150 dSn 250s va l i pic duemg, As(III) cho pic am d 350s; do, vS CO ban, ede anion nen khong anh hudng den sir xuat hien ciia pic As(IIl) tren dien di dd Tuy nhien, ede anion c6 ki'ch thude be vd dien tich Idn nen dp dung phuong phdp bom m lu bdng dien dong hoc, chiing se canh tranh vdo mao quan trude, lam hm che luong anion H^AsOj' bom vdo mao quan va do lam cho tin hieu pic As(III) b| giam chidu cao pic so vdi khong c6 anion mau Nhu vay, doi vdi cac mau cd cung hdm lugng As(IH) nhung c6 lugng anion khde se cho tin hieu As(III) c6 chieu cao vd dien rich khac Vi vay, phai cd bien phdp de khac phuc anh hudng ciia cac anion di trdnh xay sai sd qua trinh Doi vdi moi ion Cl', NOj', SOj"', P04^', hdm lugng ciia chiing m lu 1cm hon 5mg/L thi dien tich va chieu cao pic A s(in) bi sai khde 30% so vdi m lu khong cd ede anion nen De khac phuc anh hudng cua chiing den v i|c xdc djnh nong dg ciia As(III) mau th |t thi phai su dung phuong phdp them chuan de loai anh hudng cua nen mau Tuy nhifin, doi vdi nhung m lu khong phdt hien dugc As(III) N.K.D Mai va nnk /T ^ c h i fOmt lipc DHQGHN, Klua hoc Ttr nhien va Cong nghe, Tap 30, S o l (2014) Sl-57 nhimg him Iirgng anion m lu rit cao ho|ic mau As{ni) c6 nong vuot qua khoang tuydn tfnh thi phai pha loang mlu S.2 K it quaphan tfch cdc mdu mr&c ngdm Dja diem lay mau dugc l^a chon la 15 gieng khoan t?i xa Van Phiic, Thanh Tri, H i Noi, dSy l i ncri dien hinh c6 hi?n tugng As dao dong tuong doi m ^ giua cic dja dilm Cling xa Ham lircmg As (IE) cac mau niy dSu dugc ph2n ti'ch bing phircmg phap CE-C’D theo cSc diSu kien toi mi da khao sat va so sinh bSng phircmg phip AAS vdi k k qua cu thS dugc trinh b iy Hinh v i Bang I Hinh la VI du v l dien di phin ti'ch mgt mlu that Cac dai lugng thong kS tuong ling la Sy/,=6,989; SE.=6,344; SEi,=0,02108 Rieng vdi he so a= -8,914, d l so sanh a vdi gia tri chung toi da dung chuan thdng ke Fisher [11] NSu xem a«0 thi phuong trinh y=a+bx dugc viSt y=b’x G il trj phuong sai ciia hai phuong trinh tuong ung la S-y=49,91vl S’> ,0 Khi P=0,95 va fj=8, fi=9 thi F„nh= S’V S>l,71a wik /Tap chi KJioa hoc DHQGHN, Khoa hoc Tu nhien va Cong nghc, Tap 30, S o l (2014) 51-57 L d ic a m o ti Cac tic gia tran cam cm Quy Phat trien Khoa hoc v i C6ng nghe quoc gia (de ma s6 104.07-210.21) v l Truong Dai hgc Su Ph?m Tp.HCM (dS tju ma s6 CS.2013.19.19) da tai trg cho nghi^n cuu n&y Cdc t4c gia tran cam on su gidp ciia cdc dong nghiep tiii Tning tSm CETASD qud trinh thirc hi?n nghi€n cuu n^y Tm lieu tham khao [1] [2] [3] [4] Berg M- et al Arsenic Contamination of Groundwater and EJrinking Water in Vietnam; A Human Health Threat Environmental Science & Technology 35(13)(2001)2621-2626 Nguyen Van Lap, T.T.K O., Arsenic containmination on groundwater in Dong Thap province and adjacent areas Mekong river delta South Vietnam, National Workshop on Arsenic Contamination in Groundwater in Red River Plain Ha Noi (November 23, 2006) 5458 Le Ty Thanh, N.B.H.A., Xay dyng qui trinh phan ti'ch As(III) v l As(V) bang phuong phap Von-Ampe h6a tan su dhng dipn eye dJa quay vang tu lao Tap chf phan tfch H6a, L^ va Sinh hpc 10(2005) 30-35, Chen, „ J -M, Lin and R Naidu, Separation of arsenic species by capillary electrophoresis with sample-stacking techniques Analytical and Bioanalytical Chemistry 375(5) (2003) 679684 [5j Schlegel, D., J Matnisch, and R Wennrich, Speciation analysis of arsenic and selenium compounds by capillary electrophoresis Fresenius' Journal of Analytical Chemistry 354(5-6) (1996) 535-539 [6] Zhang, P,, et al., Determination of arsemc species by capiUary zone electrt^horesis with large-volume field-amplified stacldng injection, Hectrophoresis 22(16) (2001) 3567-3572 [7] Nguyen, H.T.A, et al Study of the determination of inorganic arsenic species by CE with capacitively coupled contactless conductivity detection Electrophoresis 28(19) (2007) 3500-3506 [8] Dousova B , et a l , Sorption of AsV on aluminosihcates treated with Fell nanoparticles Journal of Colloid and Interface Science 302(2) (2006) 424-431, [9] C A J.Appelo, Postma D., Geochemistry, groundwater and pollution, A.A Balkema Puplishers, Leiden (2005) [10] Nguyen Kim Diem Mai, Nghign ciiu quy trinh phan ti'ch niu phan asen III niroc ngam bang phuong phap diln di mao quan sii dung detector dq din khSng tiep xuc, Truong Dai hoc Khoa hoc Tu nhien - Dai hpc Quoc Gia Ha Noi, Luan van thac sy, (2013) [11] Ta Thi Thao, Giao trinh Th6ng ke Hda PhSn tfch, Tnrcmg Dai hoc Khoa hpc Ty nluen Ha Noi, (2010) Determination of As(III) in Groundwater in Van Phuc, Thanh Tri, Hanoi by CapiUary Electrophoresis Combined With Capacitively Coupled Contactless Conductivity Detector Nguyen Kim Dilm Pham Thi Thanh Thiiy^, Duong Hong Anh^ 'H o Chi Mmh City University o f Pedagogy 'Research Centre fo r Environmental Technology and Sustainable Development, VNU Univeristy o f Science, 334 Nguyen Trat, Hanoi, Vietnam Abstract: In this paper, analysis of As(III) in groundwater samples selected from Van Phuc vilagge, Thanh Tri, Ha Noi using capillary electrophoresis method is presented As(III) concentrations were found to range from 5pg/L to 400 pg/L Results obtained by capillary electrophoresis method shown good correlation with those determined by AAS method with the correlation coefficient R" of 0,99 decision of the proposed method was very good (errors range 0,6 —7,0%) The proposed capiUary electrophoresis method was proven to be highly reliable and practicably appliable Keysvords' Capillary electrophoresis, AsdH), groundwater ... AsOj^'', H3ASO4, HiAsO*'', HA s04^'', vk AsOa^’ De phan tich As( in) bang phuong phkp dien di mao quan ta phai chuyen As( III) m lu ve dang mang dien H^AsOj'' Anion H 2As0 3‘ tdn tai moi trudng cd pH=9-12... eda As theo pH -E h [9] Gian phan bo ckc dang ton tai cua As theo pH cho thay thugc vko pH va the oxi hda khii mk asen ton tai d cac dang khke nhu: HjAsOj, H 2As0 3‘, HAsOj’", AsOj^'', H3ASO4, HiAsO*'',... tich As (V) va As (HT) m lu nubc bang phucmg phap difn di mao quan sir dung detector dp din khbng tidp xiic kieu tu difn (C‘''D) [7] Tuy nhien nghiSn cuu As( HI) phai phan tich gian tiep qua As( V)