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Tap chf KHOA HOC DHSP TP HCM So 30 ndm 2011 XAC DINH LifeU CHlfeU TRONG CUA P-32 CHO NHAN VIEN BLTC XA B A N G PHAN TICH NlTOfC TIEU vA DO NHAP NHAY LONG N G U Y S N V A N HONG', PHAM H O N G THAI" T6M TAT Mdu nudc tiiu cua dSi tugng bj nhiim xg P-32 dugc thu gdp, xu ly hda hgc rdi hogt dg beta trin he nhdp nhdy Idng ALOKA-LSC-6100 Sau dd, diing chuang trinh chuyin dung MONDAl 3.0 sS tinh dugc liiu hieu dung Kit qud nghiin ciru dugrc dp dung xdc dinh liiu cho nhdn vien birc xg d Vien Nehien ciru hgt nhdn Ngodi phuang phdp ndy ciing dugc so sdnh vdi phuang phdp bdng Sngjim GM vd kit qud cho thdy nd cho dg nhgy vd dg chinh xdc cao han ddi tugng bf nhiim xg P-32 & mure hogt dg thdp Tir khda: xdc dinh lilu chieu trong, nhap nhdy I6ng, lilu hi?u dyng (lieu todn than) ABSTRACT Determining internal dosimetry ofP'32for radiation workers by analysis of the human urine and liquid scintillation counting Urine samples from the subjects internally contaminated with P-32 are collected, chemically processed, and measured beta activity by the liquid scintillation counting system of ALOKA-LSC-6100 Then, effective doses are calculated by using the specialized software ofMONDAL3.0 The results are applied in dosimetry for the radiation workers in the Nuclear Research Institute Besides, this method is also compared with that of using GM counter, and the result is shown it gives sensitivity and accuracy better in the case of subjects contaminated at low activity level Keywords: internal radiation dosimetry, liquid scintillation counting, effective dose (dose for whole-body) Mfrdau Dinh lieu chilu doi voi cdc dong vj ph6ng x^ phdt beta bdng phuong phdp nhdp nhdy 16ng dd dugrc nghien cuu vd dp dvmg biln tai nhilu phong thi nghiem tren the gioi [4, 5] T^i Vift Nam, phuong phdp ndy khd moi me nhung da dugrc ap dyng 6r mgt^sd co so nghien cuu linh vuc moi tiorong, tiuiy vdn ddng vi CO mgt so tinh chat uu vift cua phuong phdp ndy nhu dg nhay xdc dinh tdt, chinh xdc ciia phuong phdp cao Vi vdy, nlu sir dyng phuong phdp ndy dl xdc dinh P-32 nuoc tieu nguoi phyc vy cho viec xdc dinh lilu chilu ti-ong se co y nghia thilt thuc hon vi mo rgng dugrc khd ndng xdc djnh lieu chilu ti-ong muc boat tiidp [3, " TS, Vi$n Nghifen ci>u Hgt nhdn Dd Lgt ThS, Vi$n Nghi6n cCi-u Hgt nhSn Dd Lgt 68 mF Tap chf KHOA HOC DHSP TPHCM Nguyin Vdn Hiing vd tgk 8] Xdc dinh lilu chilu d6i \6\ P-32 cho nhdn vien buc x^ dya tren phep phdn tich nuoc tieu nguoi vd tren hf nhdp nhdy long dugrc nghien cuu dp dyng ldn ddu tien tai Vif n Nghien cuu hat nhdn (Dd L^t) D I loai trir nhiing dnh hu6ng bdi 1-131 hay nhOtig ddng vf ph6ng xa khdc hifn difn nuoc tilu ddn din sai so xdc dinh P-32, vi vdy cdn thilt phdi tdch P-32 khoi cdc ddng vi gdy nhieu nhu 1-131 (d Vifn,ti-ongcdc dgrt Ld phdn ung hat nhdn boat ddng thi thudng san xudt ddng thdi P-32 vd 1-131 dl cung cdp cho cdc bfnh vifn nudc) Ben canh dd, vifc tdch vd ldm gidu P-32 nudc tieu cdn gdp phan ldm tdng nhay va dg chinh xdc ciia phuong phdp ddi vdi P-32 Phuong phdp ndy cd tinh din tdch hda hgc vd ldm gidu ddng vi cho kit qud tot hon (mdu nudc tilu dugrc trgn dung dich chdt nhap nhdy nen ldm tdng hifu sudt phdt quang tin hifu tdi detector nhap nhdy Do dd hifu suat ghi cao, dat din 98%) so vdi phuong phdp su dyng hf hoat beta tdng cdng dimg ong dim GM dang dp dyng tai Vifn (phuong phdp Cling phdi tdch hda hgc P-32 mdu nudc tilu, sau d6 boat tren hf beta tdng cdng dung dng dim chua GM nhung hifu suit ghi nhd, chi dat 20%) Hon nua, nhdn phdng xa P-32 dugrc ldm gidu len 10 lan, tuc Id khd nang phdt hifn P-32 tdt hon 10 lan so vdi luc chua tdch hda hgc Thyc nghiem 2.1 Th u gdp vd ch uan bi mdu nu&c tiiu Mau nudc tilu ciia cdc ddi tugrng khdng bi nhilm xa (P-32, 1-131, hay cdc dong vi phdng xa khdc tu qud trinh sdn xudt chat phdng xa hay xa tri bdng ddng vi phdng xa, ) dugrc thu gdp vdo cdc binh nhua sach loai 0,5 lit Sau dd cho them vdo ml Focmandehit (Formol) dl bdo qudn trdnh bi bdc miii hdi sau mdt thdi gian luu mdu DO kilm tra tren hf phd kl gamma phdng thdp dl xdc dinh hifn trang "phdng xa" cua mlu Sau mdu dugc cho them mgt lugrng ddng vi phdng xa P-32 vd 1-131 bilt trudc hoat DO boat tren phd tren kl gamma phdng thap HPGe Canberra [2] dl xdc dinh sd dim tai dinh ndng lugrng 364,5 keV ciia 1-131 vd kit qud dugrc trinh bdy tren hinh -1 "5 ô ằ - 364.5 ã 400 300 200 • • 100 • • J,^ ^ 140O 1800 1800 2000 Ning lij-?ng (E/2) ITmh Phd gamma cua mdu nu&c tiiu cd chira P-32 vd 1-131 tru&c tdch hda P-32 69 Tap chf KHOA HOC DHSP TP HCM So 30 ndm 2011 2.2 Tdch hda P-32 mdu ntf&c tliu 2.2.1 Nguyen ly Vifc tdch hda P-32 mlu nudc tilu dya tren nguyen ly sau [2,4,6]: • Khi cd m^t ion Mg^* vd ion NH^ dung djch ammoniac, ion POl' tao nen kit tiia mdu trdng NH4MgP04, khdng tan dung djch ammoniac nhung tan axit: NH;+Mg'* + POl- = NH^MgPO, i • Khi cd mdt mu6i molipdat (NH4)2Mo04 dung dich HNO3, ion POl' tao nen kit tiia amoni photpho molipdat (NH4h [Pmoi204o] cd mdu vdng khdng tan axit nitric nhung tan kilm vd dung djch amoniac: ^NHl-^PO]- + \2MoOl- •¥24H' =iNH,),[PMo^^OJ + \2H^O i 2.2.2 Quy trinh Viec tdch P-32ti-ongmau nudc tilu dugrc thyc hifn theo quy trinh sau [2, 4, 6]: 1- Lay 50 ml nudc tilu vao binh trdn 250 ml ThSm gam KMn04 vd ml H2SO4 (khoi lugrngriengd = 1,84 g/cm^) dun tren bip cdch catti-ong2-4 gid 2- Them dung djch O-xalic acid cho din liic dung dich mau mdt mdu, loc bd kit tiia (nlu cd) Them ml dung djch chat mang P (15,3 mg P0"''4) 3- Them dung dich NH3 (d) cho din luc dung dich mau cd mdi trudng kilm 4- Them ml thu6c tiiu Mg^"", khuiy phiit, ly tdm hdn hgrp tdch tiianh hai phdn: Tiia mdu trdng vd dung dich 5- Hda tantiiabdng ml dung dich HNO3 3M (a) 6- Dun can phin dung dich vd chuyin vl mdi trudmg kilm bdng NH3, cho tilp ml dung dich chit mang photpho vd lap lai budc Lly tiia, bd dung djch Hda tan tiia bdng ml dung djch HNO3 (b) Trgn hai phan (a) vd (b) vdi 7- Them vdi gigt Aerosol O.T vd ldm Im dung djch bdng nudc ndng Them tu tir 30 ml dung dich thu6c thii molybdate, kholy khodng phiit, ly tam, bd phdn nudc ndi Rua kit tiia hai ldn bdng ml dung djch NH4NO3 0,5 M 8- Hda tan kit tiia bdng ml dung dich NH4OH (d = 0,88 g/cm^) 9- Chuyin todn bg dung dich mlu vdo cuvet chuyen dyng, boat P-32 tren hf nhip nhdy Idng ALOKA-LSC-6100 trongtiidigian 20 phiit/mlu 10- Tinh toan va hifu chinh boat P-32 2.3 Xdc dinh d^ sgch phdng xa sau tdch hda Sau thuc hifn quy trinh tdch hda P-32, mlu dugrc tren phd kl gamma ti-ong cung dilu kifn: hinh hgc mlu, thdi gian do, khodng each giiia mlu va ddu dd cua hf do, gidng nhu trudc thuc hifn tdch hda P-32 dh xdc dinh sach phdng xa ciia mlu 70 Tap chf KHOA HOC DHSP TPHCM Nguyin Vdn Hiing vd tgk sau tdch (hinh 2) Kit qud cho thiy sau tdch hda P-32 thi khdng cdn thiy I131 Dilu chung td quy trinh tach hda ddi vdi P-32 la tin cay, da loai bd dugc ddng vi khdng quan tdm Id I-131 2" 500 I ^ 400 300 200 - 100 wmm 20 220 420 620 820 1020 1220 1420 1620 1820 NSng 11/909 (E/2) Hinh Phd gamma cua mau nu&c tiiu sau tdch hda P-32 2.4 Xde dinh hiiu suat tdch P-32 Vifc tinh hifu suit tdch hda dua vao cdng thuc sau [5]: H(%)=—.100 (1) 4) Trong dd A la boat xdc dinh dugc sau tdch hda va A© Id boat ban ddu them vdo nudc tieu Mlu nudc tilu da bilt boat P-32 nhu d myc Ap dyng quy trinh tdch hda d muc dh tdch P-32, sau dd mlu dugc tren hf nhip nhdy Idng Ap dyng phuang phdp ngoai suy hifu suit ghi diing mlu chuin C-14 dang dung dich ciia Nhdt Bdn (di kem theo hf ALOKA-LSC-6100; khdng cd dung dich chudn P-32 nen dung dung dich chuin C-14 de ngoai suy hifu suit ghi) dh xdc dinh boat ciia P-32 [2, 3, 8] Tien hdnh quy trinh xac dinh hifu suit ghi ldn tren mlu nudc tieu khdc Tir dd tinh duoc hieu suit tdch hda trung binh ddi vdi P-32 mlu nudc tilu Id (90 ± 3)% [2] 2.5, Xdc dinh gi&i han phdt hi^n Gidi ban phdt hien LOD (Limit Of Detection) ciia nhdn phdng xa quan tam d muc tin cdy 95% dugc tinh theo cdng thiic sau [1,2]: LOD = 2,71 +4,65 V ^ (2) Trong do: LOD la gidi ban phat hien ciia hf do, B la sudt dem phdng, va t la thdi gian 71 S6 30 ndm 2011 Tap chf KHOA HOC DHSP TP HCM Hoat phdng xa cyc tieu cd thi dugc MDA (Minimum Detectable Activity) dugc tinh theo cdng thuc sau [1, 2]: LOD (3) MDA = H Trong dd: MDA la ho^t dg phdng xa thdp nhlt dugc (Bq) vd H Id hifu sudt ghi ciia hf Thu gdp mlu nudc tilu sach "phdng xa" vd chudn bi mlu th\rc hifn nhu d muc nhung khdng them P-32, 1-131 vdo mlu, thyc hifn vifc tach hda P-32 nhu quy trinh d myc Mlu sau tdch hda, dugc hda tan bdng ml NH4OH Do cdc mlu tren hf nhip nhay Idng thdi gian 20 phiit/mlu sd xdc dinh dugc LOD == 0,117 Bq Hifu chinh cdc qud trinh hda hgc nhu ldm gidu dong vi P-32, hifu suit tdch hda, thi tich mlu xdc djnh dugc MDA ~ 69,5 pCi/lit Tu dd xdc djnh dugc boat dg phdng xa ciia P-32 tham nhdp vdo co thi qua dudng hit thd (sau mgt ngdy) tiieo phuomg phdp nhip nhdy Idng vd phuong phdp tren hf GM vd cho kit qud tuong ung Id 74 Bq va 440 Bq Ap dyng chuong trinh ddnh gid lilu chilu chuyen dyng MONDAL 3.0 [2, 7] se tinh dugc lilu hifu dyng (lilu todn thdn) theo hai phuong phdp tuong ung la 0,08nSvvdO,5|iSv[l,2] 2.6 Dfnh liiu chiiu cho mpt so doi tugrng tham gia sdn xudt P-32 2.6.1 Chudn bi vd hogt dg mdu Mlu nudc tilu ciia cac doi tugng tham gia sdn xult ddng vj P-32 dugc thu gdp sau mdt ngdy (sau ngdy tiln hanh sdn xult P-32) vdi thi tich tu 100 din 200 ml Xir ly so bd vd tiln hdnh tdch hda P-32 nhu quy trinh myc Sau dd mlu dugc boat beta ciia P-32 bdng hai phuong phdp sau: - Phuong phap nhip nhdy long: thdi gian 20 phiit/mlu, tinh boat P-32 bdng phep ngoai suy hifu suit dimg mlu chuin dung djch C-14 [3, 8] F F - Phucmg phdp diing dng dem GM [2, 5] Kit qud xdc djnh boat P-32 (Bq/ngdy) vd lugng xdm nhdp (Intake - ky hifu la I) theo dudng hit thd dugc neu bdng [2, 6, 8] Bdng Kit xdc dfnh hogt dp P-32 mdu nu&c tiiu cda doi tugrng dgrt sdn xuat theo hai phuorng phdp (Ky hi^u: ong dim GM "GM*', nhdp nhdy Idng "LSC'\ khdng xdc dfnh "NA*') TT Ngay san xuat P-32 Ngay mau Doi tugng Hoat dg P-32 mau nudc tilu (Bq/ngay) va gia trj I (Bq) cua doi tugng Dgt Lo phan umg hoat dgng 28/6-2/7/2010 I(Bq) Hoat dg P-32 (Bq/ngay) 72 4/7/2010 7/7/2010 TBinh GM LSC GM LSC 149,2 ±15,2 161,5 ±11,7 3,1E-H)3 3,3E-K)3 Nguyin Vdn Hiing vd tgk Tap chi KHOA HOC DHSP TPHCM Dgt Lo phan ung hoat dgng 19-23/7/2010 Ho^t dg P-32 (Bq/ngay) I(Bq) GM LSC GM LSC 25/7/2010 27/7/2010 T.Binh 125,8 ±10,4 140,2 ±9,7 2,6E+03 2,9E+03 25/7/2010 27/7/2010 P.Thg 70,4 ±8,1 74,1±6,8 l,4E+03 1,5E-H)3 Dgt Ld phan Omg hoat dgng 9-13/8/2010 Ho^t dg P-32 (Bq/ngay) 15/8/2010 17/8/2010 P.Thg I(Bq) GM LSC GM LSC 60,5 ± 7,2 55,6 ±5,4 l,2E+03 1,1E-K)3 E)gt L5 phan iimg ho?t dgng 6-11/9/2010 Hoat dg P-32 (Bq/ngay) 14/9/2010 16/9/2010 P.Thg I(Bq) GM LSC GM LSC 210,4 ±17,2 203,7 ±12,7 4,3E+03 4,2E-K)3 E)gt Lo phan ung hoat dgng 4-8/10/2010 I(Bq) Hoat P-32 (Bq/ngay) GM LSC GM LSC 11/10/2010 14/10/2010 T.Binh 35,6 ± 6,3 32,1 ±4,1 7,2E-K)2 6,6E-K)2 11/10/2010 14/10/2010 P.Thg 47,3 ±6,5 52,5 ± 8,4 9,7E+02 l,lE+03 E)gt Lo phan umg hoat dgng 8-12/11/2010 Hoat P-32 (Bq/ngay) 1(13q) GM LSC GM LSC 14/11/2010 17/11/2010 T.Binh 179,8 ±17,2 186,5 ± 14,3 3,7E+03 3,8E-K)3 11/11/2010 17/11/2010 P.Thg 193,7 ±17,9 210,5 ± 16,9 4,0E+03 4,3E+03 Dgt Lo phan ung hoat dgng 3-7/01/2011 I(Bq) Hoat dg P-32 (Bq/ngay) GM LSC GM LSC 10 9/01/2011 12/01/2010 T.Binh NA 34,2 ±5,2 NA 7,0E4{)2 11 9/01/2011 12/01/2010 P.Thg NA 30,9 ±4,7 NA 6,4E+02 Dgt Lo phan ung ho?it dgng 17-21 / 01 /2011 I(Bq) Hoat dg P-32 (Bq/ngay) GM LSC GM LSC 12 23/01/2011 26/01/2011 TBinh NA 25,8 ±4,2 NA 5,3E+02 13 23/01/2011 26/01/2011 P.Thg NA 28,7 ±5,4 NA 5,9E-H)2 73 Sd 30 ndm 2011 Tap chf KHOA HOC DHSP TP HCM 14 15 Dgt Ld phan ung hoat dgng 14-18/02/2011 I(Bq) Ho^tdg P-32 (Bq/ngay) LSC GM LSC GM _j 76,4 ±9,3 l,3E+03 l,6E+03 65,3 ± 8,5 20/02/2011 23/02/2011 T.Binh 4,7E+02 NA 22,6 ±4,1 NA 20/02/2011 23/02/2011 P.Thg 2.6.2 Ddnh gid liiu chiiu trongr^.' doi v&l P-32 Tu gid trj boat P-32 xdc djnh dugc (Bq/ngdy), tinh thdi dilm nhan phdng xa thdm nhdp vdo co thi theo dudng hd hip Id I ngdy (thdi dilm tu liic sdn xult P-32 din llic lly mdu nudc tilu), su dyng phdn mIm MONDAL 3.0 se tinh dugc lugng boat d^ thdm nhdp theo dudng hit thd (bdng 1) vd lilu hifu dyng gdy hit phdi P-32 Kit qud tinh lieu tdng cgng ddi vdi 15 ldn thu gdp mlu ciia ddi tugng dugc rieu bdng 2, dd ky hifu D (^Sv) la lilu hifu dyng (theo cdc dgt thu gdp mdu) cua tung ddi tugng bj nhilm P-32 Tir bdng thiy rdng, kit qud n h ^ dugc lilu hieu dyng (Id lilu tich luy mgt lugng P-32 xdm nhdp vdo co thi dang tiic thdi, da dugc chuong trinh MONDAL 3.0 xii ly vd tinh todn, cd tinh tdi ylu td phan vdt ly vd dao thdi sinh hgc [1]) cd gid trj ndm ddi tuong ung Id 0,79 - 4,80 nSv theo phuong phdp dung dng dim GM vd 0,51 - 4,80 jiSv theo phuomg phdp nhip nhdy Idng Bdng Kit qud tinh liiu hi^u dung D (pSv) ddng chuang trinh MONDAL 3.0 theo hai phuorng phdp (GM vd LSC) 74 TT Ngdy sdn xult P-32 Ngdy mdu Ddi tugng 10 11 12 13 14 15 4/7/2010 25/7/2010 25/7/2010 15/8/2010 14/9/2010 11/10/2010 11/10/2010 14/11/2010 11/10/2010 9/01/2011 9/01/2011 23/01/2010 23/01/2010 20/02/2011 20/02/2011 7/7/2010 27/7/2010 27/7/2010 17/8/2010 16/9/2010 14/10/2010 14/10/2010 17/11/2010 17/11/2010 12/01/2010 12/01/2010 26/01/2011 26/01/2011 23/02/2011 23/02/2011 T.Binh T.Binh P.Tho P.Tho P.Thg T.Binh P.Tho T.Binh P.Thg T.Binh P.Tho T.Binh P.Tho T.Binh P.Tho D (nSv) Phuong phdp GM 3,40 2,80 1,60 1,40 4,80 0,79 1,10 4,10 4,40 NA NA NA NA 1,50 NA Phuong phdp LSC 3,60 3,20 1,70 1,20 4,60 0,72 1,20 4,20 4,80 0,77 0,70 0,58 0,65 1,70 0,51 Nguyen Vdn Hung vd tgk Tap chi KHOA HOC DHSP TPHCM Tu cdc gid trj lilu hieu dyng xdc djnh dugc d bang cho thiy tit ca cdc gid trj rit thlp (nlu lly gid tri lilu trung binh mdt thdng nhdn vdi 12 thdng dh dugc lilu tdng cdng mgt ndm) so vdi lilu gidi han cho phep hdng ndm (20 mSv/ndm) [1, 2] Dilu chiing td cdc doi tugng cd bj nhilm xa tilp xiic vdi P-32 nhung vdn dam bdo vl mdt an toan biic xa 2.7 So sdnh kit qud dinh liiu Trong dilu kifn phuong phdp xii ly hda va lam gidu mlu nhu nhau, phuong phdp dung dng dim GM vd phuong phdp nhip nhdy Idng cho kit qud djnh lilu cd su sai khdc khdng qua 14% (hinh 3) Tai mgt sd dgt sdn xult cila thdng vd ndm 2011, cdc ddi tugng bj nhiim P-32 d miic thap thlp nen khdng xac djnh dugc lilu bdng phep dung dng dim GM, nhien cd thi phdt hifn dugc bdng phep nhip nhdy Idng Dieu ndy cho thiy, phuomg phdp nhip nhdy Idng cho nhay cao hon so vdi phucmg phdp diing dng dim GM ddi tugng bj nhilm xa P-32 d miic boat thlp Do thi so sanh lieu toan than 5 D Oo long beta Q Oo nh^p nhay Idng i i Ha 10 11 12 13 i 14 15 T7ii> ty theo phu'ong phap ^ , w r ITinh So sdnh liiu hieu dung ciia P-32 bdng phuong phdp dimg ong dim GM vd phuong phdp nhdp nhdy long Ket luan • Tir kit qua thuc nghifm tren thiy rdng phuong phap djnh lilu bdng phep nhip nhdy Idng cd nhay vd chinh xdc cao so vdi phuong phdp dung dng dem GM Vifc dp dyng kit qud nghien ciiu dh xdc dinh lilu cho hai ddi tugng (la nhdn vien biic xa) lam vifc true tilp tren day chuyin sdn xult P-32 d Vifn mdt sd dgt sdn xult P-32 cho thiy lilu tdng cgng trung binh theo nam la nhd hon lilu gidi ban cho phep Tii do, cd thi dp dyng quy trinh tren dh xdc djnh lilu chilu cho cdc nhdn vien biic xa cd tilp xiic vdi ngudn phdng xa hd P-32 d cdc co sd biic xa khdc ciing nhu cho cdc bfnh nhdn chin dodn vd dilu trj bdng P-32 d cac co sd y tl 75 Tap chi KHOA HOC DHSP TP HCM S6 30 ndm 2011 TAI L i f u THAM KHAO Nguyen Vdn Hiing (2003), Nghiin cicu dinh liiu chiiu trin ca s& phuang phdp todn thdn vdphdn tich nudc tieu ngu&i, Ludn an Tiln sT Vdt ly, Bg GD & DT Pham Himg Thdi, Nguyen Vdn Hiing vd cgng sy (2011), Nghien ciru dp dung quy trinh xdc dinh P-32 vd I-l31 nu&c tiiu bdng phuang phdp nhdp nhdy Idng phuc vu dinh liiu chiiu trong, Bdo cdo tdng kit de tdi d p Co sd ndm 2010, Vifn NLNTVN D.L Horrocks (1974), Application of liquid scintillation counting, Packard Instrument Co., Inc Japan IAEA (2000), Indirect methods for assessing intakes of radionuclides causing occupational exposure Safety reports series No 18, Vienna, Austria IAEA (1989), Measurement of radionuclides in food and environment Technical report series, No 295, Vienna, Austria NCRP (1987), Use of bioassay procedures for assessment of intenal radionuclide deposition Report No 87, Bethesda, MD, 20814, UK N Ishigure et al (2000), MONDAL 3.0, a personal computer program for monitoring to dose calculation, NIRS, Japan Y Kobayashi (1987), Liquid scintillation analysis, science and technology, Packard Instrument Co., Inc., Japan (Ngdy Tda so?n nh$n dirge bdi: 26-4-2011; ngdy ch4p nh$n dSng: 13-6-2011) 76 ... bj nhiim P- 32 d miic thap thlp nen khdng xac djnh dugc lilu bdng phep dung dng dim GM, nhien cd thi phdt hifn dugc bdng phep nhip nhdy Idng Dieu ndy cho thiy, phuomg phdp nhip nhdy Idng cho nhay... P- 32 bdng hai phuong phdp sau: - Phuong phap nhip nhdy long: thdi gian 20 phiit/mlu, tinh boat P- 32 bdng phep ngoai suy hifu suit dimg mlu chuin dung djch C-14 [3, 8] F F - Phucmg phdp diing dng... T.Binh P. Tho P. Tho P. Thg T.Binh P. Tho T.Binh P. Thg T.Binh P. Tho T.Binh P. Tho T.Binh P. Tho D (nSv) Phuong phdp GM 3,40 2,80 1,60 1,40 4,80 0,79 1,10 4,10 4,40 NA NA NA NA 1,50 NA Phuong phdp LSC
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