phuc trinh sinh hoa -cs
TRANSCRIPT
TRNG AI HC CN TH
B GIO DC V O TO
TRNG I HC CN TH
VIN NGHIN CU V PHT TRIN CNG NGH SINH HC
PHC TRNH: TT SINH HA
MSHP:CS115
CN B HNG DNSINH VIN THC HIN
Ths.V VN SONG TONNGUYN THNH LNG 3112488
NGUYN VI KHNH 3112473
MAI CH LINH 3112479
U MINH KHA 3112468
H KIU OANH 3112516
Cn Th, Thng 11/2012
GII THIU
- Sinh Ha hc l nn tng ca cc mn sinh hc thc nghim khc nh: Protein v enzim hc, Sinh l thc vt, Sinh l ng vt, Vi sinh hc, Di truyn hc, Sinh hc phn t, Cng ngh sinh hc, Cng ngh enzyme.
- Ni dung chng trnh:
1. Pha ha cht
2. Carbonhyrate: Xc nh hm lng x th
3. Lipid: Kho xc hm lng lipid(h thng soxleh)
4. Nit tng: nh lng m tng(Kjeldahl)
5. Ammoniac: nh lng hm lng NH3
6. Glucide: Kho st hm lng ng kh trong ht la(nguyn trng, ny mm) (pp Nelson,1944)
TNG QUAN
Ht u en
u en l loi cy phn h u mc hng nm, ton thn khng lng. L kp gm 3 l cht mc so le, l cht gia to v di hn l cht hai bn. Hoa mu tm nht.Ht u en:.c cha hm lng dinh dng rt cao nh: protein 24.4 %, lipit 17.7%, glucid 53.3 %, hm lng acid amin v cc acid bo cha no cn thit cho c th cng rt cao. Bn cnh , trong u en cn cha rt nhiu loi vitamin nh A, B1, B2, PP, Ccng nhiu khong cht nh Ca, P, Fe tt cho s pht trin no b ca thai nhi v gip tng cng nng lng.
Ht la
La:l mt trong nm loicy lng thcchnh ca th gii, cng ving,la m,snvkhoai tyThnh phn ha hc ca ht laThnh phn ht la ni chung bao gm glucid, protein, cellulose, lipid, vitamin, khong v c,cc enzyme v nc. S phn b cc cht dinh dng trong thnh phn ca ht khng ging nhau.Tinh bt:L thnh phn ch yu ca ht la, chim 90% lng cht kh ca htgo xay xt. Tinh bt tn ti di 2 dngl Amylose v Amylopectin c t l thay i tythuc voging la. Tinh bt quyt nh gi tr cm quan ca go. Hm lng amylose trong go quyt nh do ca cm. Nu thnh phn tinh bt trong go c 10-18% amylose th cm c xem l mm,do, t 25-30% th cm c xem l cng. Cc loi go Vit Nam c hm lng amylose thay i t18-45% amylose. Go np c thnh phn tinh bt ch yu l amylosepectin( xp x 100%), cm rtdo v t n.
ng:Tn ti dng ch yu l saccharose, ngoi ra cn c mt t ngglucose, fructose, rafinose. Trong ht la nymm tn ti ng maltose.Trong mm la c enzyme amylase.
S liu tham kho cho cc kt qu th nghim t Bi 2 n Bi 6
Thnh phnu enNc mmNc tng
Protein(%)24,4%
Lipit(%)17,7%
S Th(%)
Glucide(%)53,3%
m amoni (mgN/ml)10 - 3010 - 22
Ngun:
http://www.duoclieu.org/2011/12/au-en-hat-vigna-cylindrica.html
http://www.dinhduongbabau.vn/dinh-duong-ba-bau/dinh-duong-ba-bau-voi-che-dau-den.html
http://sgtt.vn/oldweb/cacsobaotruoc/382_37/p23_nuoctuong.htm; http://www.khafa.org.vn/?cmd=newspub&cmdid=newspub-detail&idnew=1351.
NI DUNG THC HNH
BI 1: CHUN B HA CHTMc tiu
Vn dng cc khi nim nng chun b cc dung dch ha cht dng cho cc bi thc tp t bi 2 n bi 6
Mt s khi nim nng
Nng phn
Nng phn trm trng lng trng lng (w/w)
S gam ca mt cht ha tan hon ton trong 100 gam dung dch.
i vi cht rn khng ngm nc ta tnh theo cng thc sau:
i vi cht tan ngm nc ngi ta phi tnh lun nc ngm trong phn t ca cht tan sau tnh trng lng tng cng (trng lng cht tan v trng lng nc ngm) theo cng thc sau:
i vi cht lng c nng ha tan ti a c tnh theo phn trm, th d H2SO4 ha tan ti a 96% v vy khi cn cht lng ny cn tnh s gam cht trong dung dch theo cng thc:
Cmdd = mct * Ci vi cht lng ta c th chuyn thnh th tch thun tin cho pha ch v c tnh theo cng thc sau:
Vi:
C: nng phn trm dung dch cn pha (%)
Cmdd: nng phn trm dung dch cn pha (%)
V: th tch cn ly (ml)
C: nng cht tan hin c (%)
d: t trng cht tan (g/ml)
mct: s gam cht tan cn s dng (g)
mdd: khi lng dung dch cn pha (g)
M: Phn t gam khng ngm nc (g/mol)
M: phn t gam c ngm nc (g/mol)
Nng phn trm trng lng th tch (w/v)
S gam ca mt cht ha tan trong 100 ml dung dch.
V d: pha 300 ml dung dch NaCl 15% (w/v) ta cn 45g NaCl sau cho dung mi t t vo (tng t mt ha tan) ri iu chnh cho 300 ml.
Nng phn trm th tch th tch (v/v)
S ml ca mt cht ha tan trong 100 ml dung dch.
Nng ca mt dung dch c p dng theo cng thc sau:
V1*C1 = V2*C1
Vi:
V1: th tch dung dch cn ly pha (ml)
V2: th tch dung dch cn pha (ml)
C1: nng dung dch cn ly pha (%)
C2: nng dung dch cn pha (%)
Nng mol
Nng mol (M) l s mol cht tan c trong 1 lt dung dch.
i vi cht tan l cht rn khng ngm nc, ta p dng cng thc:
mct = M*Mw*V
i vi cht tan l cht rn ngm nc, phn t gam cht tan phi bao gm trng lng phn t gam ca cc phn t nc ngm v p dng cng thc trn
i vi cht tan l cht lng tinh khit ta tin hnh cn v pha nh cht rn khng ngm nc.
Cht tan l cht lng c phn trm thp ta s dng cng thc sau y:
Vi:
mct: khi lng cht tan cn ly (g)
Mw: phn t gam (g)
V: th tch dung dch cn pha (l)
M: nng mol cn pha (M)
C: nng thc ca dung dch (%)
Nng ng lng gam
Nng ng lng gam (N) l s ng lng gam, ca mt cht c trong 1 lt dung dch hay s mili ng lng gam ca mt cht c trong mt ml dung dch.
Dng c - ha cht
Dng c
- Cn in t
ng ong cc loi
Micropipet
Bnh tam gic
Cc nha
Ha cht
Dng v pha ha cht theo bng sau:
BiHa cht, vt dng th nghimNng Tng th tch cn pha (ml)Tng lng ha cht (gam/ml/t)Din gii (ngn gn) phng php chun b
1Chun b chung
Ht ht m0,6kgSy 50 60oC trong 5 gi (tri mng trn khy inox)
Bnh ht m1 bnhBnh kh, sch
Np bnh thoa vaseline
2Carbonhydrate
H2SO45%(v/v)100ml5 mlCho 90ml nc ct vo cc thy tinh, dng pipet thy tinh ht 5ml H2SO4 vo cc khuy u, cho dung dch vo ng ong, thm nc n vch 100ml.
NaOH5%(v/v)100ml5 gamCho 90ml nc ct vo cc thy tinh, cho 5g NaOH vo cc khuy u, cho dung dch vo ng ong, thm nc n vch 100ml.
Cc ( m)
Giy lc mu
3Lipid
Diethyl ether2000 ml
Giy lc 15 x 15 cm2
Dy ch
4Nit tng
Se:K2SO4:CuSO41:100:1011,1gam
H2SO4 chun 0,1N0,1N1 lt1 lt
NaOH40% (w/v)500 ml200 gamLy 300 ml nc ct cho vo cc 500ml, t vo mt chu nc gim nhit . Cn 200 gam NaOH cho t t vo cc nc, khuy cho tan ht ri. Cho dung dch vo ng ong thm nc ct cho 500 ml.
Thuc th Acid boric1000 ml
Acid boric100g/10lt10gong 10ml Methanol vo cc 1 cho tip 6,6mg Methyl Red vo cc, khuy u.
ong 10ml Methanol cho vo cc 2 cho tip 9,9mg Bromoresol creen, khuy u.
cho 900ml vo cc 1lt cho 10g acid boric vo cc, khuy u. Cho tip ln lt dung dch cc 1,2 vo cc, khuy u. Cho hn hp dung dch vo ng ong. Thm nc cho 1lt
Methanol200ml/10lt20ml
Bromoresol creen99mg/10lt9,9mg
Methyl Red66mg/10lt6,6mg
5Ammoniac
H2SO4 chun 0,1N0,05 N1000 ml500 mlLy 400 ml nc ct vo cc 1000ml, ong 500ml H2SO4 0,1N, khuy u, sau cho dung dch vo ng ong v thm nc ct cho 1000ml
Thuc th Acid boric
Acid boric
Methyl Red
Bromoresol creen
Ethanol
6Glucid
Tinh bt tan1% (w/v)
A1100 ml
- K-Na-tartrate.4H2O15 gam/lt1,5 gamong 20ml nc ct. Cn 1,5 gam K-Na-tartrate.4H2O cho vo nc ct ri khuy cho tan ht
- Na2CO3 (khan)30 gam/lt3 gamong 15ml nc ct. Cn 3 gam Na2CO3 (khan) cho vo nc ct khuy cho tan ht
- NaHCO320 gam/lt2 gamong 30 ml nc ct cho vo cc thy tinh, cn 2 gam NaHCO3 cho vo nc ct ri em ung v khuy iu cho tan ht
- Na2SO4 (khan)180 gam/lt18 gamong 30 ml nc ct cho vo cc thy tinh, cn 18 gam Na2SO4 (khan) cho vo nc ct ri em ung v khuy cho tan ht.
Ly 4 phn trn li v iu chnh cho 100 ml
A250 ml
- CuSO4.5H2O5 g/250 ml1 gamong 20 ml nc ct, cn 1 gam CuSO4.5H2O ri khuy cho tan ht
- Na2SO4 khan45 g/250 ml9 gamong 25 ml nc ct, cn 9 gam Na2SO4 khan sau ung v khuy cho tan ht
Trn chung 2 phn li v iu chnh cho 50 ml
B150 ml
- (NH4)6Mo7O24.4H2O26,5 g/450 ml2,94 gamong 20 ml nc ct, cn 2,94 gam (NH4)6Mo7O24.4H2O cho vo nc ct v khuy cho tan iu.
- H2SO4 m c21 ml2,3 mlong 25 ml nc ct, ong 2,3 ml H2SO4 m c. Cho axit vo nc ri khuy cho u.
Trn chung 2 phn li v iu chnh cho 50 ml.
B2:
- Na2HAsO4.7H2O3 g/25 ml5 ml0,6 gamong 4 ml nc ct, cn 0,6 gam Na2HAsO4.7H2O cho vo nc ct v khuy cho tan. iu chnh cho 5 ml
B4:
- H2SO4 (24N)1,5 N100 ml75 mlong 20 ml nc ct, ong 75 ml H2SO4 (24N), trn li khuy cho u ri iu chnh cho 100 ml
Glucose100 mM20ml0,36gLy 15ml nc ct cho vo cc, cn 0,36g cho vo cc v khuy u. cho dung dch vo ng ong thm nc cho 20ml.
Bi 2: CARBONHYDRATE (NH LNG X TNG)
Mc Tiu
Kho st hm lng x th trong nguyn liu u en.
Nguyn tc Phng php nh lng x th (cellulose) da vo kh nng ha tan nhng hp cht khng phi cellulose (non cellulose) bng dung dch acid sulphuric v sodium hydroxide.
Phng Php
Chun b ht ht m, giy lc :
Sy ht ht m 60-700C trong khong 4-5 gi ; vo bnh ht m (sy trc 1 ngy).
- Sy giy lc (15 x 15cm2) 1050C n khi lng khng i
Xc nh m :
Sy cc 105oC
Cn 1gr bt u en
Sy mu 105oC (4-5h)
vo bnh ht m (15-20 pht)
Cn m(cc +mu)Cng thc tnh kt qu:
Hm lng m = (M1 - M2) x 100/M1
M1: khi lng bt mu
M2: khi lng bt mu sau khi sy
Xc nh hm lng tro:
Cc
Cn 1gr bt u en
Tro ha 600oC (1h)
vo bnh ht m (15-20 pht)
Cn m(cc + tro)Cng thc tnh kt qu:
Hm lng tro= mtro x100/mmuXc nh hm lng x:
Cn 1 gram mu (dng giy du) bng cn phn tch, chuyn mu vo cc phn tch x (ti my).
Thm vo mu phn tch 150 ml H2SO4 1,25N v 3- 5 git n-octanol. (chng to bt).
un si mu trong 30 pht
Ra mu vi nc nng 4 ln.
Thm vo mu 150 ml NaOH 1.25N + 3-5 git n-octanol (chng to bt).
un si mu trong 30 pht
-
Ra vi nc nng 4 ln.
Tin hnh lc qua giy lc ( sy n khi lng khng i v cn khi lng).
em mu sy 600C trong ngy, sau cn khi lng mu phn tch v trnh by kt qu.
Cng thc tnh kt qu:
Hm lng x = mx th x 100/mmuKt Qu Th Nghim V Tho Lun
1.m :
- Trc khi sy:M1 = mu en=1,0017 gram
- Sau khi sy :
mCc=19,7143 gram
mCc +u en = 20,6117 gram
M2 = mu en= gram
Hm lng m =
(Kt qu th nghim cho thy hm lng m trong u en 10,4123(%)
2.Tro ha:
- Trc khi tro ha:
mu en = 1,0052 gram
- Sau khi tro ha:
mcc=20,0968m(Cc + tro) =20,1526 gram
mTro= m(Cc + tro) mCc=20,1526 20,0968=0,0558 gram
- Hm lng tro=
(Kt qu cho thy hm lng tro chim t l khong 5,5511(%)
3.Hm lng x th:
Trc khi sy
mu en = 1,0369 gram
Sau khi sy:
mGiy lc = 1,743 gram mS th = (1,846 1,743) = 0,103 gram
mGiy + u en = 1,846 gram
- Hm lng x th=
(Kt qu cho thy hm lng x th chim t l khong 26,85% cao hn so vi s liu tham kho l 19%, sai lch 7,85%. Kt qu th nghim sai lch so vi s liu tham kho do thao tc tin hnh th nghim ca nhm cha c ng lm, hoc do thit b th nghim khng chnh xc, hoc do mu c nhiu tp cht. Ta thy hm lng x th trong Cm 26,85%(theo th nghim) cao hn trong bp 9,5%(theo ti liu thao kho).
Bi 3: LIPID
Mc tiu: Kho st hm lng lipid trong mu u en.
Nguyn tc
Lipd c nhiu trong tht, c, trng, sa, cc loi ng ccLipid khng tan trong nc, tan tt trong cc dung mi hu c nh diethyl ether .Da vo tnh cht ny ly trch lipit kho st hm lng.
Hm lng lipit c th c tnh bng cch cn trc tip lng du sau khi chng ct loi sch dung mi hoc tnh gin tip t khi lng b cn li. th nghim ny chng ta tnh theo cch gin tip.
Thit b, dng c, ha cht, mu:
Thit b, dng c: bp un, h thng soxhlet dng trch ly cht bo, giy lc, ch cun.
Ha chc: dimethylether.
Mu vt: u en
Phng php tin hnh
Xc nh khi lng khng i ca t giy lc(15x 15cm)
Cn 1gram mu(bng cn phn tch) vo giy lc.
Gp giy gi mu bng tng gi khong 3x5 cm2 v dng ch ct cht hai u ti giy.
Ln lc chun tng ti vo ng hnh tr ca h thng soxhlet.
Tin hnh ha tan cht bo bng mt lt dimethyl ether trong thi gian 12 gi bng h thng soxhlet.
Thu mu vo khay inox, v t khay vo t ht(30 pht).
Sy ti cha mu 105oc n trng lng khng di(5 gi)
Cng thc tnh kt qu: Hm lng cht bo = M2.100/M1(%)
+ M1: khi lng mu ban u(gram)
+ M2: khi lng lipid
Kt qu v tha lun Xc nh khi lng khng i ca t giy lc
Trc khi sy:
mgiy = 1,8468 gram
Sau khi sy:
mgiy =1,763 gram
Xc nh hm lng lipid c trong muTrc khi xc nh hm lng lipid:
mgiy (sau khi sy)=1,763 gram
M1= mu en =1,0067 gram
Sau ha tan lipid:
mgiy+mu=2,6823 gram
mmu = mgiy+mu - mgiy (sau khi sy) =2,6823 - 1,763 =0,9193 gam
Khi lng lipid:
M2= M1 - mmu = 1,0067 0,9193 = 0,0874 gram
Hm lng cht bo:
u en =
( Hm lng lipit trong u en theo kt qu th nghim l 8,682% l khng ph hp nh s liu tham kho khong 17,7%. Trong th nghim c sai do thi gian ra mu trong h thng Soxhlet l khong 24h.Bi 4: NH LNG PROTEIN TNG (Kjeldahl)Mc tiu: Xc nh hm lng protein bng cch xc nh hm lng Nit trong mu u en bng phng php Kjeldahl.
Khi qut-nguyn tc
1.Khi qutProtein c cu to t nhiu nguyn t C,H,O,N,S,Ptrong s cc nguyn t ny, Nit chim t l tng i cao (khong 15 17%) v tng i n nh trong thnh phn ca protein. V vy v nguyn tc, protein trong thc phm c nh lng bng cch st nh nit tng s v kt qu nhn vi 6,25 (xem nit tng s chim 16%).
Phng php ny c Kjeldahl pht trin nm 1883 v tr thnh phng php phn tch hiu qu hin nay v c nhng u im l hu nh c th phn tch i vi tt c cc loi mu, chi ph khng cao
2. Nguyn tc
Khi un mu vt c cha nit (m) trong H2SO4 m c vi s hin din ca cht xc tc thch hp th cht hu c b oxy ha;Nit c phng thch di dng NH3, sau (NH4)2SO4 c to thnh trong iu kin c H2SO4.
Di tc dng ca H2SO4 m c v c cht xc tc thch hp nhit cao, cc hp cht c cha nit b phn hy v b oxy ha n CO2 v H2O, cn gc amin chuyn thnh Aoniac v tip tc kt hp vi H2SO4 to thnh mui amoni sulfat tan trong dung dch. y l giai on cng ph m trong mu
2 NH3 + H2SO4 (NH4)2SO4
Trong qu trnh chng ct, (NH4)2SO4 tc dng vi NaOH d tha v gi phng NH3:(NH4)2SO4 + 2 NaOH Na2SO4 + H2O + 2 NH3
Amoniac sinh ra s c hp thu bng dung dch acid Boric c cha cht ch th to thnh tetraborat amon. Sau chun dung dch ny bng dung dch chun H2SO4 0,1N, NH3 c gii phng v xc nh c lng nit, theo cc phn ng sau:
NH4OH + 4 H3PO3 (NH4)2B4O7 + 7 H2O
(NH4)2B4O7 + H2SO4 + 5 H2O (NH4)2SO4 + 4 H3PO3Vt liu
- Tit b,dng c: t sy 105oC, l v c ha mu, my phn tch m bn t ng, ng phn tch m tng, nh ht m, cc ng mu xc nh trng lng khng i.
-Ha cht: Se:K2SO4:CuSO4 = 1:100:10, H2SO4, H2SO4 0,1N,NaOH 40%,Acid boric, methyl red, bromoresol green, ethanol, MgO
- Mu vt:u en .
Phng php tin hnh1.V c ha0,5g bt u en
5ml H2SO4
mung xc tc
4200C/1h30
ngui (sn phm v c ha)
2.Chun nit tng:T ng: s dng my chun nit.
Bng tay:
Sn phm v c ha
H2O (1)
50ml dung dch NaOH 40%
H2O (2)
Si (10 pht)
Thu Nit bng H3BO3 (30ml)
Chun bng H2SO4 0,1N
Kt qu v tha lun (t ng):
Hm lng Nit tng:
N = 3,84%
Protein tng trong u en = N x 6,25 = 3,84% x 6,25 = 24 %
(Hm lng protein tng trong u en theo kt qu th nghim l 24% lch khong 0.4% so vi ti liu tham kho l 24,4%. S trn lch ny c th do sai xt trong thao tc th nghim.
Bi 5: NH LNG AMMONIAC
Mc tiu: Xc nh hm lng Nit trong mu nc mm
Nguyn tc
Khi un mu vt c cha nit (m) trong H2SO4 m c vi s hin
din ca cht xc tc thch hp th cht hu c b oxy ha;Nit c phng thch di dng NH3, sau (NH4)2SO4 c to thnh trong iu kin c H2SO4.
Di tc dng ca H2SO4 m c v c cht xc tc thch hp nhit cao, cc hp cht c cha nit b phn hy v b oxy ha n CO2 v H2O, cn gc amin chuyn thnh Aoniac v tip tc kt hp vi H2SO4 to thnh mui amoni sulfat tan trong dung dch. y l giai on cng ph m trong mu
2 NH3 + H2SO4 (NH4)2SO4
Trong qu trnh chng ct, (NH4)2SO4 tc dng vi NaOH d tha v gi phng NH3:
(NH4)2SO4 + 2 NaOH Na2SO4 + H2O + 2 NH3
Amoniac sinh ra s c hp thu bng dung dch acid Boric c cha cht ch th to thnh tetraborat amon. Sau chun dung dch ny bng dung dch chun H2SO4 0,1N, NH3 c gii phng v xc nh c lng nit, theo cc phn ng sau:
NH4OH + 4 H3PO3 (NH4)2B4O7 + 7 H2O
(NH4)2B4O7 + H2SO4 + 5 H2O (NH4)2SO4 + 4 H3PO3Phng php tin hnh
0,5ml nc mm
60ml H2O ct
3g MgO
si 10 pht
Thu bng H3BO3
nh lng bng H2SO4 0,05N
Cng thc tnh kt qu:
N=0,0007 * (VH2SO4 -VH2SO4 i chng) * 1000/V N: Hm lng Nit tng (mgN/ml).
V: th tch nguyn liu em phn tch (ml)
VH2SO4: th tch H2SO4 0,05N chun cho mu (ml)
VH2SO4 i chng: th tch H2SO4 0.05N chun cho mu i chng (ml)
0,0007: s gram N tng ng vi 1ml H2SO4 0,05N
Kt qu v tho lun.VH2SO4 =2,5 ml
VH2SO4 i chng =0,05 ml
N=(0.0007 x (VH2SO4 - VH2SO4 i chng ) x 1000/V
= (0,0007 x (2,5 -0,05) x 1000)/0,5=3,43(mgN/ml)
( Hm lng m trong nc mm theo kt qu th nghim l 3,43(mgN/ml). T suy ra loi nc mm ny c hm lng m thp, so snh theo s liu tham kho.
Bi 6: DLUCIDE (PP NELSON)
Mc tiu: kho st hm lng ng kh hin din trong mu la (nguyn trng, ny mm).
Nguyn tcDa vo tnh kh ca cc nonosaccharide, nh lng glucose theo phn ng oxi ha kh. Glucose l cht kh, Cu2+ trong thuc th ng l cht oxi ha.Trong mi trng kim un nng glucose kh Cu2+ thnh Cu2O, sau Cu2O to ra s kh phc cht arsenomolybdate to thnh sn phm c mu xanh. Lng ng kh c trong dung dch s c xc nh gin tip qua lng phc to thnh bng cch o quang ph hp th.
CO32- + H2O ( HCO3- + OH-HCO3- + H2O ( H2CO3 + OH-RCHO + 2Cu2+ +2OH- ( RCOOH + Cu2O + H2O
Cu2O +H2SO4 ( Cu2SO4 + H2O
Cu+ + MoO42- ( Cu2+ + Molybdenum blue
Phng php:
Dng ng chun Glucose:
Pha dung dch ng chun: chun b 6 ng nghim, cho vo mi ng thnh phn cc cht theo bng sau:
ng123456
[Glucose](mM)00.20.40.60.81
Vglucose(ml)00.20.40.60.81
Vnc(ml)10.80.60.40.20
Dng ng chun: chun b dy 6 ng nghim ( nghim thc lp li 3 ln)
ng123456
[Glucose](mM)00.20.40.60.81
Vglucose(l)150150150150150150
Vthuc th ng(l)150150150150150150
Ly giy bc bt ming ng nghim, un cch thy10 pht, ngui nhit phng
Vthuc th Arseno- molybdate(l)150150150150150150
Vnc ct(ml)111111
20 trong ti. Ly tm nu c cn, o quang ph bc sng 520nm
Xc nh hm lng ng kh trong mu la (nguyn trng v ny mm):
Ha tan 5 gam mu vo 50 ml nc ct, khuy u trong 30 pht, vt ly dch ri lc bng giy lc ly dch trong tin hnh th nghim.
ong th tch dung dch trch sau khi lc.
Chun b dy 3 ng nghim, pha long dch trch theo bng sau:
ng123
pha long10 ln100 ln1000 ln
Vdch trch(l)200200(Ca ng 1 pha long)200(Ca ng 2 pha long)
Vnc ct(l)180018001800
Tin hnh xc nh hm lng ng kh trong mi mu la: chun b dy 3 ng nghim (nghim thc lp li 3 ln) cho vo mi ng thnh phn mi cht theo bng:
ng123
Vdch trch(l)150150150
Vthuc th ng(l)150150150
Ly giy bc bt ming ng nghim, un cch thy 10 pht, ngui nhit phng
Vthuc th Arseno- molybdate(l)150150150
Vnc ct(ml)111
20 pht trong ti. Ly tm nu c cn, o quang ph bc sng 520nm
Cng thc tnh kt qu:
Hm lng ng trong nguyn liu (mg/g)= X *n *V/ m
Trong :
V(ml): th tch dch chit gc
m (g): khi lng mu cn
n: h s pha long sao cho OD nm trong ng chun
X (mg/ml): nng glucose tnh c t phng trnh th ng chun.
Kt qu th nghim v tho lun:
Dng ng chun: kt qu sau khi o quang ph bc sng 520nm:
ng123456
[Glucose](mM)00.20.4 0.60.81
Ln 10.1240.2410.2280.3230.4890.620
Ln 20.1160.1930.2260.3380.4200.585
Ln 30.1280.2140.2290.3350.4710.642
Trung Bnh0.1230.2160.2270.3320.4600.616
Xc nh hm lng ng kh trong mu La: Kt qu sau khi o quang ph bc sng 520nm
Mu la nguyn trng
ng123
pha long10 ln100 ln1000 ln
Ln 10.2590.2310.134
Ln 20.2340.2270.113
Ln 30.2450.2120.135
Trung bnh0.2460.2230.127
Mu la mm
ng123
pha long10 ln100 ln1000 ln
Ln 11.0360.3310.147
Ln 21.0160.2270.121
Ln 30.8950.3290.128
Trung bnh0.980.2960.132
T phng trnh ng chun y=0.4717x+0.0931 ta tm c nng ng kh c trong mu la ti cc nng pha long trong bng sau:
Mu la nguyn trng
ng123
pha long10 ln100 ln1000 ln
OD trung bnh0.2460.2230.127
Nng ng kh (mM)0.3220.2750.072
(Nng ng kh trong mi ng khng t l vi nng pha long chng t th nghim c sai xt.
tnh hm lng ng trong mu la ta chn h s pha long n =10.
X = 0.322 (mM) = 0.322* 0.18(mg/ml) =0.05796 (mg/ml)
V=37 (ml)
m= 5gHm lng ng trong la = X *n *V/ m = 0.05796 *10*37/5 =4.289 (mg/g)
Mu la ny mm:
ng 123
pha long10 ln100 ln1000 ln
OD trung bnh0.980.2960.132
Nng ng kh (mM)1.880.430.082
( Nng ng kh trong mi ng khng t l vi nng pha long chng t th nghim c sai xt.
tnh hm lng ng trong mu la ta chn h s pha long n =100.
X = 0.43 (mM) = 0.43* 0.18(mg/ml) =0.0774 (mg/ml)
V=34 (ml)
m= 5gHm lng ng trong la ny mm = X *n *V/ m = 0.0774 *100 *34/5 =52.632 (mg/g)
Tho lun:
Hm lng ng kh trong la ny mm cao hn la nguyn trng do: Trong la nguyn trng ng tn ti ch yu dng saccharose- khng phi ng kh.Cha t ng kh nh gluocose, fructose. Trong la ny mm tn ti ng mantose-ng kh, nh hot ng xc tc ca enzyme amylase trong mm la thy phn to nn monosaccharide-ng kh.Do hm lng ng kh trong la ny mm cao.
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