JOURNAL OF SCIENCE OF HNUE Natural Sci.. 2013, Vol. 58, No. 3, pp. 42-49 Thi.s paper is available online at http;//stdb.hnue.edu.i
PHAN T I C H , DANH GIA H A M L U O N G C H I VA ASEN T R O N G M O T SO LOAI RAU T R 6 N G 6 HUYEN BO T R A C H , T I N H QUANG BINH
Nguydn Dtic Vucfng^ Nguyfin Dinh Luyen^, Bach Ngoc Chi'nh^
' TrUdng Dai hpc Qudng Binh. '^TrUilng Dai hpc Supham Hue, Truimg Dai hpc Hue, '^Trudng THPT Chuyen Qudng Binh
Tom lat. Bai bao phan tieh, danh gia ham liidng Pb va As trong 32 mau rau {16 mflu rau eai va 16 mftu rau mudng) d xii Dong Trach, huyen Bo Trach, tinh Quang Binh. Kcl qua cho thky phUdng phap quang phd hSp thu nguyen tii khong ngon luTa 16 graphite (GF-AAS) xac dinh Pb va As co gidi ban phat hien (LOD), gidi han dinh liTdng (LOQ) thap, do diing va dp lap lai tdt. Ham lifdng trung binb ciia Pb va As trong rau mudng cao hdn trong rau cai. Ham lUdng Pb va As dildc danh gia va so sanh vdi tieu chuan Viet Nam theo thdi gian va vi trf lay mau.
TU khda: Danh gia, ham lUdng, Pb, As. rau mudng, rau eai, phiTdng phap quang phd hkp thu nguyen tii" khong ngpn liTa.
1. Mol dau
Viet Nam chiu anb hifdng ciia khi hau nhiet ddi gid mua nen dUdc thien nhien iTu dai, thuan ldi cho nhidu loai thifc vat phat trien, trong do co cac loai rau. Rau la ngudn cung cap cac Ioai vitamin phong phii, re tidn vi thd khong the thidu trong moi bfla an hang ngay cua ngiTbi dan. Rau co tac dung lam cho boat dong sinh li cua cd the tidn hanh dUdc binh thabng, didu hoa. Neu thieu rau se lam cho cd the phat trien khong binh thdbng va phat sinh nhicu benh tat. Hdn the nfla, rau la nguon cung cap cac axit hiiu cd, cac hdp chat thdm, chat xd, cac chSi vi lUdng va cung cap nang Iddng cho cd the [ 1,2].
Hien nay nhu cau tieu thu rau xanh ngay cang tang, vi Idi nhuan nen nhidu ngifcJi trdng rau da sii dung cac hoa chat bao ve thdc vat, phan bon hoa hpc va sii dung nddc 6 nhiem dc tifdi rau. Didu nay, da lam cho mpt sd dpc td nhd diT lUdng thudc bao ve thdc vat, mpt sd kim loai nang co dpc tinh cao (Pb, As, C d . . . ) ti'ch luy vao trong rau anh hddng dgn chat lfldng rau sach, gay hau qua nghiem trpng cho sflc khoe ngfldi sfl dung [3-5].
Ngay nhan bai: 15/4/2013. Ngay nhan dang: 2/6/2013.
Tac gia lien lac: Nguy&n Diic Vuong. dia chi e-mail: [email protected]
Pbdn tl'ch, ddnh gid hdm lupng chi vd asen trong mot sd loai rau...
Phfldng phap quang phd hap thu nguyen tfl (AAS) la mpt trong nhflng phfldng phap phan tich co nhidu flu diem, dfldc sfl dung phd bien de phan tich Ifldng vdt cac kim Ioai d cac ddi tfldng khac nhau [6].
Xuat phat tfl nhflng van dd tren, trong bai bao nay chung toi trinh bay kdt qua phan tich, danh gia ham lfldng Pb va As trong mpt sd loai rau trdng 6 Bo Trach, ndi cung cap ngudn rau sach chfnh cho thanh phd Dong Hdi, tinh Quang Binh.
2. Noi dung nghien cihi 2.1. Phan thtfc nghiem
* Thiet bi vd hda chdt
May quang pho hap thu nguyen tfl nhan hieu AA 6800 Shimazu (Nhat Ban) ciing vdi he ghep ndi thiet bi tfl dpng bdm mau (ASC-6I00) vao 16 GFA-EX7. can phan tich, may chung eat nfldc hai ldn va cac dung eu khae.
Cac dung dich chuan goc Pb va As 1000 ppm eua hang Merck ehuyen dung cho phfldng phap AAS.
* Ldy mdu nUdc, xiC li vd bdo quan mdu
Sd dd lay m l u d xa Ddng Trach, huyen Bd Trach dfldc trinh bay tren Hinh I, mlu dfldc lay 4 ddt: ddt 1 (25/2/2012), ddt 2 (5/4/2012), ddt 3 (15/5/2012), ddt 4 (6/7/2012).
Mdi ddt lay 8 mhx d 4 vi tri khac nhau, gdm 4 mlu rau cai va 4 mau rau mudng; quy each lay mau, xfl li va bao quan mau theo tai lieu [7, 8].
Hinh 1. Sd do ldy mdu rau trdng 3 huyen Bo Trach, tinh Qudng Binh Cdc mdu duoc ki hieu Cij. M^, trong do: i ^ 1 -f n {thii U( dot idy mdu). j ^ 1 ^ m (vi tri lay mdu)
43
Nguydn Du'c Vifdng, Nguydn Dinh Luyen va Bach Ngpc Chi'nh 2.2. Ket qua va thao luan
2.2.1. Xay dtfng dtfcfng chuan, khao .sat gidi han phat hicn, gidi han dinh ItfcTng Phfldng phap difdng chuan dfldc dflng dc xac dinh ham Ifldng Pb va As, ket qua xiiy dflng dflcJng chua'n difdc ihc hicn iicn Hinh 2, vdi Pb phfldng trinh co dang: A = 0. OKiNC i 0.0359 (vdi he sd tfldng quan /? - 0,9'J91), vdi As phfldng trinh co dang .1 0,01350 I 0,01 ly (vdi H -- 0,9995), trong do r' la ndng dp (ppb). Ndng dp cua Pb cung nhfl As eo sfl tudng quan tuydn linh tdt trong khoang 2 : 15 ppb. Gidi ban phat hien (LOD), gidi han dinh Ifldng (LOQ) cua phep do GF-AAS trong phep xac dinh Pb va As da dfldc xac dinh. LOD xac dinh Pb lii 0,16 ppb va As la 0,18 ppb; LOQ xac dinh Pb va As lan Ifldt lii 0,54 ppb vii 0,59 ppb.
C(ppb) •
(d) (b)
Hinh 2. Dudng chudn xdc dinh Pb (a) va As (b) 2,2,2, Danh gia do lap lai va do dung cua phep do
Do lap lai cua phuong phap dUdc xac dinh Ihong qua do lech chuan tUdng d6i (RSD). Tien hanh phan tfch 6 mlu rau cai (thuoc mau Tji) va 6 mlu rau mu6ng (thuoc mail M;„), roi them chuan Me (Pb 10 ppb va As 10 ppb doi v6i 6 m.iu Cu; Pb 20 ppb va As 20 ppb doi vdi 6 mlu il/,,,) vao 12 mau do, dem phan tich lai duoc kat qua ghi dcac Bang 1 va 2.
Theo Horwitz, khi phan tich nhflng nong do c6 ppb, sai so trong npi bo phong thi nghicm nho hOn 1/2 RSD dfloc tinh theo cong thflc: RSD (%) = 2"' »"s'^' (C: nong do chat phan tich) la dat yeu cau.
D6i vdi phep phan tich Pb: R S D „ „ „ ^, 2(' » ''ISM 'o ") = 25 > 0,88.2 ppb.
D6i vdi phep phan tich As: RSD„„„„, :.- 2" ' " ' e * ' •»"'') = 26 > 0,98.2 ppb.
Nhu vay phuong phap GF-AAS dat dflpe dp lap lai tot khi phan tich Pb, As trong rau muong va rau cai.
Dp dung cua phuong phap duoc danh gia thong qua dp thu hoi. KSt qua phfldng 44
Phdn tich. ddnh gid hdm luong chi vd asen tivnif mot so loai rau...
phap xiic dinh ham Iflpng Pb va As theo phitOng phap them chuan, dp thu hdi lln Ifldt dat til 98,2 ; 101,1% va 97,5 -: 99,9%. Nhfl vay, phflOng phap GI--AAS dat dflpe dp dung tot.
Bang l.JKeUpiajcdc dinh do lap lai khi phan lich Pb Irong cdc mdu ran
Kl hicu mau C i ^ i CM--, C3, ,.
r , i 1 C l -.-, C l „
M . i - 1 MM--!
M-M -3 MM-i Mn--.
'".»-„
Ham la(tngPb (/i.g/kg rau lUifi) Lan 1
24,49 24,6.1 24,7.'i 24,50 24.3.1 24,-"i4 48,68 50.0."i 48.75 49.90 49.26 .t9,()()
Lan 2 24.77 24.43 24.61 24.73 24.40 24.26 48.52 50.28 49,01 49,78 49.46 49,14
Lan 3 24.70 24,42 24.78 24.33 24.38 48.86 50,07 49,18 49,64 49,37 49,23
Ham It/rfng Pb (rung binh: X .1 e(,,.,n,n52) (//.g/kg rau tfldi)
24,65 l-0,.35 24,42 1 0..54 24.71 1 0,22 24.58 1 0.30 24.35 1 0.10 24,40 1 0.35 48.68 1 0,42 50,13 1 0.33 48.98 1 0.55 49.77 1 0.50 49,36 1 0.25 49.12 i0..30
R.SD (%) 0,58 0.88 0,36 0,50 0,16 0.57 0.35 0,27 0,44 0.25 0.20 0.24
Bang
Kl hieu mau C31 -1 Cn-•^
C,n-^
Cil -4 C l - 5 C i - ( i /1/31-1 J1/31--2 MM-:S MM- 1 MM -.-, J l ' j i -0
2. Ket gud xdc dinh dp lap lai khi phdn lich As trong cdc mdu rau Ham \Uftag As
(//g/kg rau tiroi) Lan 1
20.31 20.44 20.44 20.48 20.68 20.62 42,83 42,94 42,87 42,45 42,71 42.92
Lan 2 20,63 20,24 20.35 20,42 20,85 20.31 42.30 42.76 43,10 42.19 42,91 42,66
Lan 3 20.51 20.13 20,24 20,62 20.71 20.25 42,44 42.96 42,.54 42,22 42,46 42.58
Ham Iirrfng A.S trung binh: X ± ?(,,-,o,95.2) (//g/kg rau tfl((i)
20,48 ± 0,40 20,27 i 0,38 20,34 -i 0,25 20.51 i 0.25 20.74 J. 0.23 20.39 1 0.50 42,52 4: 0,69 42,89 1- 0,27 42,83 :t 0,70 42.29 i- 0.35 42,69 ± 0,55 42,72 1- 0,45
RSD (%) 0,79 0.78 0.50 0.50 0,44 0.98 0,65 0.25 0,66 0,33 0,52 0.42 2.2.3. Xac dinh h a m lufdng P b va As trong r a u
Ket qua phan tich bam lifdng Pb va As trong rau 6 xa D6ng Trach huyen Bo Trach sau 4 ddt vdi 32 mau difdc trinh bay d Bang 3.
Nguyen Dflc Vitdng, Nguygn Dinh Luyen va Bach Ngoc Chinh
M a u
Mn My,.
Ma
" Mu M21 M-22
Mz,
A/2.1 A/31 A/:i2 MM A/34 A/4, A/42 A/43 A',1
Bdng,?. Kel qua xdc dinh hdm luifni.
Kau m u o n g H a m lining P b
(//g/kg lirai) 29,21 1 0,38 50.92 1 0.62 18.71 i 0,66 28.12 1 0,60 26,96 .1 0,27 .36,29 t o , 12 15.87 1 (),16 26.27 1 0.21 29.57 1 0.47 43,01 1 0.17 17,.13 J . 0,32 29.29 1. 0,20 30,01 ± 0 , 2 8 40,86 ± 0,56 17,81 ± - 0 . 4 4 27.52 J; 0.54
H a m IflOng A s (//g/kg tifrti) J 26,19 ± 0 , 2 1 14,57 ± 0 . 2 1 5.46 -J 0.06 15,37-1-0.07 18,53 ± 0 . 2 4 13,44 ± 0 , 2 5 7,91 ± 0 , 1 6 13.74 1- 0,24 22.95 -1 0,30 13.74 1 0.19 7.96 1 0.18 18.09 ± 0 . 1 4 25,16 ± 0 , 2 5 15,57 ± 0 , 3 2 6,65 ± 0 , 1 6 14.79 ± 0 , 1 7
Pb vd As trong rau d xd Ddng Trach
M a u
Cu Cu Ca Cn On C-n C-n C-ii CM C.a
C,
C l C l C 2 C , 3 Cu
Kau cai H a m liriing P b
(/Ig/kg Iflili) 14.06 :L 0,24 9.10 j 0 , 1 9 7,58.1 0.43 19,96 ± 0 , 1 2 13,22 ± 0 , 2 6 10,04 ± 0 , 1 3 8.80 ± 0 , 1 7 17.62 ± 0 , 1 4 14,64 ± 0 . 2 3 10.45 ± 0 , 1 9 9.22 ± 0 . 1 7 19.06 ± 0 . 2 0 13.87 ± 0 , 2 3 9.24 ± 0 . 1 7 7,68 ± 0,20 16,89 ± 0,22
H a m Ifltfng As
(//g/kg tuai) 7,89 ±0,08 J 7,74 ±0,09 1
5,61 ± 0 , 1 4 ; 5,69 ± ft 19 9,76 ± 0 , 1 3 9,29 ± 0 , 1 5 6.92 ± 0 , 1 0 7,62 ± 0 , 1 9 10,78 ± 0 , 2 1 8,74 ± 0,20 6.68 ± 0 , 1 6 7,62 ± 0 , 1 8 10.46 ± 0 , 1 3 7.25 ± 0 , 1 1 5.89 ± 0 , 1 2 8.97 ± 0 , 1 1
2.2.4. Danh gia ham lifdng Pb va As trong rau
Bdng 4. KSt qud phan tick ANOVA 2 chieu cita sit biin dpng hdm lifpng Pb, As trong raa cdi
M c
P b
As
N g u o n phu'<fng s a i
Gifla Ciic vi tri {S\) Gifla cac ddi (5'^^)
Sai so thi nghicm
Phifdng sai tong Giua cac vi tri (S'j^)
Giua Ciic ddi (S'f^) Sai s o thi nghiem
(S?-„)
Phuong sai tdng l o n g binh phirifng
249.27 4.35 6,02 259,64
25,06 7,89 6,34 39,30
B a c til do (/)' 3 3 9 15 3 3 9 15
P h u o n g sai 83,09
1.45 0,67 17,31 8,35 2,63 0,70 2,62
Ptinit
l-'l = 124.24 1=2 = 2.17
F , = 11,85 P 2 = 3,73
'lilhuyel O' 0 , 0 , 5 , / i = 3 , / 2 = 9 ) 1
3,86 ii 3,86 !
'
3,86 3,86
^TK ^" phuong sai md id sai sd cua lydn thdn phtrong phdp xdc dinh hdm lupng Pb^
46
Phdn tich. ddnh gid hdm lupng ehi vd a.sen trong mpt .w loai rau...
De danh gia ham liTdng Pb vii As trong rau cai theo vi tri vii thdi gian \ky mau, chiing toi ap dung phifdng phap thong ke phan tich phddng sai 2 yeu to (ANOVA 2 chieu) [9], ket qua difdc ghi 5 Bang 4.
Bang 4 cho thay khi xac dinh Pb va As eo Fy ian Iddt la 124,24; 11,85 dlw ldn hdn
^ifihuyei (3,86) tifdng ling vdi mdc y nghia p ~ 0,05. NhiT vay, cac vi tri lay mau trong moi ddt khac nhau co ham li:fdng Pb va As trong rau cai d viing khao sat khac nhau co y nghia ve mat thong ke vdi p < 0, 05. Hay noi each khac, cac vi tri lay mSu co anh hiidng dSn kdt qua phan tich ham lUdng. NgiTdc lai, gia tri F-^ d6u nho hdn Fuimyi nen ham lifdng Pb va As trdng rau cai giiia cac ddt lay mSu trong moi vi tri khong khac nhau co y nghia ve mat thong ke vdi p > 0.05. Viec danh gia ham liTdng Pb va As trong rau mu6ng cung cho ket qua tifdng tu.
2.2.5. So sanh ham lufdng Pb, As trung binh trong rau muong va rau cai K6t qua so sanh ham lUdng Pb va As trung binh trong rau mu6ng va rau cai diTdc ghi d Bang 5. Ket qua d Bang 5 cho thSy ham lu'dng Pb va As trung binh trong rau muong cao hdn so vdi rau cai.
Bang S. Cdc dai lifdng thong ke thu diipc khi ddnh gid hdm lUpng Pb vd As trong rau Nhom khao
sat Rau muong (n = 16) Rau cai (n = 16)
Cac dai Iuong thong ke TB,
Pb As Pb As
'g/kg 29.24 15.01 12.62 7,93
mm -:- max.
/ig/kg njfdi 17,33 ± 50.92 5.46 + 26,19 7,68 -:- 19,96 5.61 ~ 10,78
Phudng sai(S2) 7,42 4.23 0.67 0,70
Do lech chuan (S) (/igAg)
2.72 2.06 0,82 0.84
RSD
(%)
9.30 13.72 6,50 10,59 De khang dinh cho nhan xet tren, ti§n hanh danh gia so sanh dp lap Iai cua ham llidng Pb trong 2 loai rau qua chuan F (Fischer):
FTr„h = 4 = l l , 0 7 > F ( (j)-0,0.5;/2=15,/l-lS) = 2,86
(5^ va S.f la phfldng sai cua Pb trong rau mu6ng (S^ - 7,42 /j.g/kg) va trong rau cai (S| = 0,67 /ig/kg); CO bac tu do tflong flng la /i = /7i - 1 = 15 va /j = n2 - 1 = 15, n-i va 02 la so mau eua rau muong va rau cai).
Nhfl vay, dp lap Iai ciia ham Iflong Pb trong 2 loai rau la khac nhau co y nghia v6 mat th6ng ke v6i mflc y nghia 7; < 0,05.
- Tfnh dp lech chuan chung cua 2 loai rau:
__(m-l)Si±(n2-l)S^ - 4 05 =* S . = 2 01,ig/k»
- Tinh gia tri cfla chuan t (fl day (Sj) va [S^] khae nhau):
„ ITB4-TB2I ^
47
Nguydn Dflc Vfldng, NguySn Dinh Luy6n va Bach Ngoc Chi'nh
(7'H, = 29,24 /jg/kg; T f l j = 12,52 /;,g/kg; n, = 16 vii -ni = 16)
Vi (n,,,, = 23.37 > /(,„ii,n,r.;/,-i„) - 2,10 nen ham Iflpng Pb trung binh trong rau muong va rau cai la khac nhau co y nghia ve mat thdng kc vdi mflc y nghia p < 0, (15. Kh qua cho thay hiim Iflpng I'b trung binh trong rau muong cao hOn so vdi rau cai.
Vi (r,,,!, - 12. 75 > /(,,.-n,/n;/,2i| = 2. 09 nen ham lupng As trung binh trong rau muSng va rau ciii la khac nhau co y nghia vc mat th6ng kc vdi mflc y nghia p < 0,05. Ket qua cho thay hiim Ifldng As trung binh trong rau muong cao hrtn so vfli rau cai.
2.2,6, So sanh hiini lurtng l>h, As t r u n g binh trong r a u vili ticu c h u a n cho phep vc ve sinh an tuan thiTc p h a m
K6t qua so sanh ham Iflpng Pb va As trung binh trong rau muong va rau cai dupc ghi fl Hang 6 cho thfiy hiim Iflpng Pb va As trong cac mau rau da khiio s.-it dcu thSp hOn nhidu gidi han cho phep theo lieu chuan Vict Nam. Vi the eo the khang dinh ngflfli dan y(;n tam siin xu5t vii sfl dung cac loai rau cai vii rau muflng trong fl ndi dSy.
Bdng 6. Kk qua so sdnh hdm tuong I'h vd As Irnng rau vdi lieu chuan Viet Nam Nhiim khao
sat Kau muong Kau ciii
TB. //g/kg Pb As Pb As
29.24 15,01 12.62 7,93
mm + max.
//g/kg Ifldi 17.33 :• 50,9 5,46 ±26,19
7.68 ± 19,9 5,61 ± 10,78
Do lech chuiin (S) (/igftg)
2.72 2.06 0,82 0.84
RSD
9.30 13.72 6.50 10,59
TCcho phcp(//E/kg
rau tuoi)
<500
<200
<500
<200 Ticu ehuan cho phep vh an toiin thflc pha'm eua ticu ehuan Vict Nam (TCVN, 1995) d6i vdi Pb lii < 500 /ig/kg rau tflPi;(rCVN, 1998) doi vdi As l.i < 200 /ig/kg rau tflfli.
3. Ket Iuan
Chung t()i da tien hanh khiio sat gidi ban phiit hicn (LOD) va gifli ban dinh Ifldng (LOQ), dp dung, dp liip lai cua ciic phep xac dinh hiim Iflpng Pb va As bang phflPng phap GI'-AAS trong cac mSu rau. Ket qua cho thSy, phep xac dinh co LOD va LOQ nho, do dung va dp lap lai tflt.
Dii ap dung phflOng phap quang pho hap thu nguyen tfl khong ngpn lfla dung 16 graphit vao vice xac dinh hiim Iflpng Pb va As trong 32 mau rau d xii Dong Trach, Quang Trach, Quang liinh. Ham Iflpng kim loai trung binh (/ig/kg tfldi) trong rau xac dinh dilOc la: 12,62 /ig/kg den 29,26 /;,g/kg ddi vdi Pb; 7,93/ig/kg den 15,OI/i,g/kg doi vfli As.
Ticn hanh danh gia hiim Iflpng Pb, As trong rau theo thang va vi tri. KSt qua cho thay ham lupng kim loai trong rau muflng va rau cai fl cac thfli gian lay mSu khae nhau la nhfl nhau cd y nghia v6 mat thong ke vfli // > 0,05; con theo vi tri khac nhau cd ham Iflpng khac nhau co y nghia ve mat thong kc vfli ;) < 0,05,
Ham Iflpng Pb va As trung binh trong rau mudng cao hdn trong rau cai va ham
Phdn tfch. ddnh gid hdm lupng chi vd a.sen trong mdt sd loai rau...
lu'dng Pb trung binb trong rau cao hdn so vdi As. So vdi eac tieu chuan Viet Nam thi ham Iddng cac kim loai nay deu thap hdn. Difiu nay cho thay viec tieu thu san pha'm rau vung khao sat la dam bao an toan.
TAI LIEU THAM KHAO
[I] D6 Van Ai, Mai Trong Nhuan, Nguyin Khac Vinh, 2000. Mdtsd ddc diem phdn ho asen trong tu nhien vd vdn de d nhiim a.sen irong mdi trudng d Viet Nam. Kl yfiu Hoi nghi quoc te ve 6 nhiem asen: Hicn trang, tac dong den sdc khoe cong dong va cae giai phap phong ngiia. Ha Npi, tr. 21 -32.
[2] Nguyfin Thi Ngoc An, Dddng Thi Bich Hue, 2007. Hien trang 6 nhiem kim loai ndng trong raa xanh d ngoai d Thdnh phd Ho Chf Minh. Tap chi Phat trien Khoa hoc va Congnghe, 10(01). tr. 41 - 4 6 .
(31 Trinh Thi Thanh, 2003. Ddc hpc mdi truiing vd .sue khde con ngUdi. Nxb Dai hoc Qu6c gia Ha Noi.
[4] Le Huy Ba, 2001. Ddc hpe mdi truimg. Nxb Dai hoc Quoc gia TPHCM.
[5] Dang Kim Cbi, 1999. Hda hpc mdi truimg Nxb Khoa hoc va Ki thuat, Ha Noi.
[6] Pham Luan, 1987. Phuong phdp pbdn tfch pho nguyen tu. Nxb Quoc gia Ha Noi.
[7] Cue An toan ve sinh thifc pham, 2009. Bd Y Te, Hudng ddn ldy mdu kii'm nghiem phuc vu hdu kie'm. Cong van 1181/ATTP-TCKN, ngay 29 thang 07 nam 2009, Ha Npi.
18] Pham Luan, 1999. Gido trinh hudng ddn vi nhung vdn de co sd cda cdc ky thual xd ly mdu phdn tfch (phdn 1). Dai hpc Khoa hpc TU nhien, Dai hoc Qu6c gia Ha Npi.
[9] Doerffel, 1983. Thdng ke trong hda hpc pbdn tfch. Nxb Dai hpc va Trung hpc ehuyen nghiep. Ha Npi.
ABSTRACT
An analysis and evaluation of levels of lead and arsenic in some vegetables in Bo Trach District, Quang Binh Province The contents of Pb and As found in 32 samples of vegetables {16 samples of water morning glory (rau muong) and 16 samples of cdlza (rau cai)) in Ddng Trach Cdmmune, Bd Trach District. Quang Binh Province was analyzed and estimated. The results show that the GF-AAS method for detemining Pb and As has a low limit of detection (LOD), a low limit of quality (LOQ), good accuracy and repetonce. The contents df Pb and As found in water mdrnmg glory (rau muong) were higher than in colza (rau cai). The contents of these metals were estimated versus time and sample taking sites. The data were compared with Vietnamese standards.
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