Chung toi chQn phuong phap ctfc ph6 dd xac dinh GaC nguyen t6 chi, d6ng, kern b6i cac ly do sau :
- Ham lU<.Jng chung 6 trong cac ngu6n nudc song va nudc sinh hO'!-t thudng dao d¢ng khoang 104d~n 10-2mg!lit .
- D¢nh~ycua phuong phap ctfc ph6 co thdch~p nh~ndu<.Jc: d6i vdi chi d¢nh~y khoang 10-7gam; d6i vdi d6ng dQ nh~y khoang 0,5.10-7gam; d6i vdi kern d¢ nh~y khoang 108gam.
Qui trinh phon t[eh chung eua phuong phap ale pM:
I Mftu nudc I
X111y mftub~ngphuong phap tach va lam giau
I Mftu da x111y I
Dung dichn~n
I Ghi ctfc ph6 I
X111y s6li~u
K~tqua
1. Cach Iiiy m§u nUdc :
- Mftu nudcd~uVaG nha may: ChungWil~ymftu nudc tren dong songt~icae vi tri cach xa 6ng hut 10m, 6 d¢ sau 1m val~y3 mftu /vi tri.
- Mftu nudc d~ura nha may : D6i vdi nha may nudc Tan Son va Thap Cham, chUng toil~y t~icac nha dan cach xa nha may khoang 100m va l~y 3 mftu /nha may. D6i vditr~m born nudc Quang Son, chung toiI~y t~inha dan(g~n nh~t) cach xa nha may 500m val~y3 mftu.
Cac mftu nudc chung toil~y6 b6n thdi didm :Ngay 15/7/2001 va 05/8/2001 (d~i di~ncho muan~ng),ngay 15/9/2001 va 05/1 0/200 1(d~i di~ncho mua ml1a).
- BinhPEdtfng mftu nudc du<.Jc rl1as~ch b~ngHN03,trang nudc cfttnhl~u l~n va dd kho. Trudc khiI~y mftu, binh du<.Jc trangnhi~u I~n b~ng chinh mftu nudc nghien cttu, r6il~ym6i mftu3lit va cho VaG do3ml dung dichHN03d~cdd bao quan.
2.Xii'ly mftu:
2.1. D6i viii nguyen t6 chi:
M~udUQcI~y250m!. Dung dung dich NH40H dieu crunh pH= 7-8 b~ngmay do pH, them Iml dung djch 2% NaDDC.Khu~y 20 phut. Sau do cho vao 50 mg than ho~ttinh va ti~p tl.;lC khufty 20 phut mla. LQc bo pha long,I~y phar~n, TVa s~ch bfug nudcc~t, cho vao do 20ml 7M HCI, dun nhy vakhu~ytrong 10 phutd~giaih~p. LQc bo phar~n, l~ypha long, co kho ta dUQcm~udii xl! 11'.
2.2. D6i viii nguyen t6 dang:
M~udUQCI~y250m!. Dieu crunh pH=4,5-5,0b~ngdung dich NH40H (vim~u dii chtia HN03d~bao quan). Them vao 10mi dung dich 1% 8-0xiquinolin trong rtiQu etylic.Khu~y 20 phut. Sau do them vao 50mg thanho~ttinh vati~ptl.;lckhu~y20 phut nila. LQc bo pha long,I~yphar~ngiaih~p b~ng10mi dung djch HCId~cva HN03d~c vditll~3:1, dun nhy. LQc bo phar~n, I~ypha long, co kho ta dUQcm~udii xl! 11'. 2.3.D6i vOi nguyen t6 kem :
M~udUQcI~y 100m!. Dung dung djch NH40H dieu crunh pH= 8b~ngmay do pH, them Iml dung djch 2% NaDDC.Khu~y20 phut. Sau do cho 50mg thanho~ttinh vati~p tl.;lCkhu~y20 phut nila. LQc bo pha long, I~yphar~n, TVa s~ch b~ngnudc dt, cho vao do 20mliM HCI, dun nhy vakhu~y trong 10 phutd~giaih~p.LQc bo pha r16, I~ypha long, co kho ta dUQcm~udii xl! 11'.
3. GhiCltCpha :
Cho 15 ml dung dich nen (chQn IQc6ph~nkhao sat nen ghi ph6) vaom~udii xV 11'. Ghi ct!c ph6 tren may Processor 646 VAtrong dieuk;~n: t5c dQ giQt thuy ngan 20 - 30 giQt/phut; Sl.;lC lien tl.;lC khiNzd~du6i0z;thdi gian do 10 phut trong khoangth~
di~nct!cnh~tdinh : ..
- D5i vdi nguyen t5 chi : - 300 mYd~n- 600 mY. - D5i vdi nguyen t5 d6ng: -350 mVd~n- 650 mY. - D5i vdi nguyen t5 kern: -1200 mVd~n-1500 mY. 4. Xii'ly s6li~u:
Chung toi ap dl.;lng phuong phap dUdng chufin d~ tinh toan ham lUQng cac nguyen t5ttldi~ntich dinh thu dUQcb~ngcach :
-L~pdUdng chufin :Ti~nhanh do ct!c ph6 cho m~uchufin vdi ham luQng tang d~n : 5; 10; 15; 20; 30; 40; 50; 70; 100 III dung djch chufin co n6ng dQ 0,1 mg/ml Wong ting vdi ham IUQng 0,5; 1,0; 1,5; 2,0; 3,0; 4,0; 5,0; 7,0; 10,0 Ilg trong nen dii chQn. Ghidi~ntich dinhd~ l~pdUdng chufin.
- Phuong trinh dUdng chufin : Dt!a vao quit~cbinh phuong t5ithi~u. Y=aX+b X :Ilg,Y : S(nA)
a=n'LXjYj - 'LXj'LY j
- Tlidi~ntieh dlnh ella m6im~u(sau khi dungehu~nDixondi10;,li tru cae s6 do co dQI~ehth6 b;,lo) ap d\!ng dUdngehu~n tim ham IUl/ng m6im~u. Sau do tim gia tri ham IUQng trung binh va sai s6.
X±L'1X vdi n ~)X, _X)2 s= 1=1 n
5.Xacdjnhhi~u suftt tach:
Ti~nhanh thlfehi~n do elfe ph65m~u ehu~n kh6ng taeh va eo taeh trong eung di~u ki~nditinhhi~usuk "
* Digiam sai sa cua phdo'ng phap chung toiti~n hanh khao sat:
- Khao sat ehQnn~nghi elfe ph6 : Dlfa VaG nguyent~eehQnn~nla :
+Cation ellan~nphai eoth~ am honth~ khil ella ehat khil elfe va anion ellan~nphM eoth~duong honth~ khil ella ehftt khil elfe.
+TrI1dng hl/p eo hai ehftt khil elfe eo th~ ban song trung nhauho~e g~n nhau rna kha nang phan giM ella may kh6ng phanbi~tdUl/e, ngoai y tren, no eon eo tae d\!ng t;,lO phtle vdi ca hai ehftt khil elfe sao ehoth~ ban song eua ehung khae bi~tnhau tren song e\.fe ph6.
+N~nphM eo tae d\!ng duy tri pH trong qua trinh khil elfe ph6, no eo thi tham gia VaG qua trinh khil elfe nhu mQt ehftt trung gian.
- Khao sat anh hu6ng eua eae nguyen t6 can : Nguyen t6 can la nhilng nguyen t6 eoth~ban songn~mtrong khoang ghi e\.fe ph6 eua nguyen t6 dn xae djnh.Dikhao sat anh hu6ng eua no, ehung t6i t;,lO eae m~ugia b~ng eaeh Ifty 5/l1 dung djehehu~n 1mg!ml tling nguyen t6 dn xae dinh va I~nIUl/t eaeth~tieh 10; 20; 30; 40; 50; 60; 70; 80/l1 dung dieh 1mg!ml ella eae nguyen t6 can VaG mQt thi tieh nhftt dinh nude eft! hai I~nr6iti~nhanh phan tieh theo qui trinh da ehQn .