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XAC NH GLUXIT (HYDRAT CACBON)
Bo co Ha hc Thc phm Phng php xc nh ng kh-ng tng
PHNG PHAP XAC NH
NG KH NG TONGA.CAC PHNG PHAP XAC NH TONG QUAT
. I. Phng phap Bertrand Phng phap nay da tren c s trong moi trng kiem ( glucose, fructose, maltose) co the de dang kh ong (II) oxid thanh ong (I) oxid co mau o gach, qua o tnh c lng ng kh
nh lng ng kh thng dung thuoc th Fehling 1 va 2 .Khi tron hon hp nay ta co phan ng :
CuSO4 + 2NaOH Cu(OH)2 + Na2SO4
Cac phan ng tiep theo nh sau:
Cu2O + Fe2(SO 4)3 + H2SO 4
2CuSO4 + 2FeSO4 + H2O
10FeSO4 + 2KMnO4 + 8H2SO4 5Fe2(SO4)3 + 2MnSO4 + K2SO 4 + 8H2O
T lng KMnSO4 tieu ton t o ta tnh c Cu(I) va tnh c lng Cu. Do o tnh c lng ng a dung
Vi du bang tm ham lng glucoza bang phng phap BERTRAND
BANG TM LNG GLUCOZA
Glucoza
(mg)KMnO40,1N(ml)Glucoza
(mg)KMnO40,1N(ml)Glucoza
(mg)KMnO40,1N(ml)Glucoza
(mg)KMnO40,1N(ml)
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
333,24
3,55
3,87
4,17
4,49
4,80
5,12
5,43
5,73
6,05
6,36
6,67
6,96
7,27
7,57
7,84
8,14
8,45
8,74
9,03
9,33
9,63
9,94
10,1034
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
5610,4
10,7
11,0
11,3
11,6
11,9
12,2
12,5
12,7
13,0
13,3
13,6
13,9
14,1
14,4
14,7
15,0
15,2
15,5
15,8
16,1
16,4
16,657
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
8016,9
17,2
17,4
17,7
18,0
18,2
18,5
18,8
19,0
19,3
19,5
19,8
20,1
20,2
20,5
20,8
21,1
21,3
21,6
21,8
22,1
22,4
22,6
22,981
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
10023,2
23,4
23,7
23,9
24,1
24,3
24,6
24,8
25,1
25,3
25,6
25,9
26,1
26,3
26,6
26,8
27,0
27,3
27,5
27,8
II.Phng Phap Luff-Schoorl Trong moi trng OH nhe, glucose b kh trong thuoc th Lupso cho ket tua Cu2O, dung e nh lng glucose
CuSO4 + 4NaCO3 + 2HOOC- CH2 C CH2- COOH
O- Cu O
C COONa NaOOC C
(A)
CH2OH (CHOH)4 CHO + 2A + 2H2O Cu2O + CH2OH (CHOH)4 COOH
COOH
+ 4NaOOC CH2 C CH2 COONa
OH
Cu2O + I2 + 4HCl 2CuCl2 + 2HI + H2O
I2 + Na2S2O3
Na2S4O6 + 2NaI
(Natrithiosulfat)
T lng Natrithiosulfat dung e chuan o lng Iod d ,ta co the xac nh c lng ng ban au.
Vi du :bang tm lng glucoza theo LUFF-SCHOORL
BANG E TM LNG GLUCOZA THEO LUFF-SCHOORLNatri thiosunfat 0,1NGlucozaNatri thiosunfat 0,1NGlucoza
mlmgHieu somlmgHieu so
1
2
3
4
5
6
7
8
9
10
11
122,4
4,8
7,2
9,7
12,2
14,7
17,2
19,8
22,4
25,0
27,6
30,32,4
2,4
2,5
2,5
2,5
2,5
2,6
2,6
2,6
2,6
2,713
14
15
16
17
18
19
20
21
22
2333,0
35,7
38,5
41,3
44,2
47,1
50,0
53,0
56,0
59,1
62,22,7
2,8
2,8
2,9
2,9
2,9
3,0
3,1
3,1
3,1
III. Phng phap dung ng ke
Da tren s phan cc anh sang cua saccharose va dung ng ke o nang suat quang phan cc cua sacchorose
Dung cu : ng ke ,nhiet ke .Bnh nh mc 100ml ,can phan tch
Can 2,6 g ng kh cho vao coc nc cat, cho vao bnh nh mc, cho dung dch vao ng ke. oc ch so ham lng Saccharose tren ng ke.
Trong 1 ong nghiem, hut 1ml dung dch saccharose va 1ml thuoc th Fehling (pha 4 ml thuoc th Fehling). un soi cach thuy trong 3 phut, khong co hoac co t tram o hien ra.
IV. Phng phap nh lng ng kh bang 3,5-dinitrosalycylic acid
Co mot vai tac nhan c dung e nh lng ng nh ac tnh cua ng. 3,5-initrosalicylic acid (DNS) co mau vang trong dung dch kiem se b kh thanh 3-amino-5-nitrosalicylic co mau o cam
V.nh lng ng kh theo Schaffer-Hartmann:
Neu ta pha tron mot dung dch nhng ion ong nh th ta co mot can bang hoa hoc theo nh luat tac dung khoi lng :
Cu++ + 4I 2Cu+ +2I- + I2
Neu co mot chat nao o nhan mat tat ca ion Cu++ can bang hoan toan dch chuyen ve pha trai ,trong dung dch bay gi ch co cac chat hoa hoc oxalo-cuivric va nhng ion I ch khong con mot iod t do nao na. Bay gi neu ta them vao dung dch mot lng tha KIO3 va acid hoa dung dch, IO3 - gap ion I- phong thch mot lng tha ion la A . Neu ta kh mot phan hp chat oxalo Cu2+ thanh Cu+
2Cu++ + 2OH- 2Cu+ + H2O + O
_CHO + O
_COOH
va acid hoa sau
5KI + KIO3 + 3H2SO4 3I2 + 3H2O + 3K2SO4
Ion Cu+ se hp vi mot lng I- cho CuI . Do o khi acid hoa ch mot phan I- con lai tac dung vi KIO3 e phong thch mot lng iod a. V vay hieu so ( A a) tng ng vi lng ng da vao phan ng tren.
VI. Phng phap mau tren pho quang ke
Ferricyanur
2K3Fe(CN)6 + KOH 2K4Fe(CN)4 + H2O + O
CH2OH - (CHOH)4 CHO + O HOOC (CHOH)4 - COOH
Cac loai ng kh co kha nang kh Ferricyanur ( Fe3+) thanh ferrocyanur ,ion nay se co mau xanh am ( xanh prusse). Nh vay ta co the dung phng phap nay e nh lng ng .
Thuoc th A: 1,33g Na 2CO3 + 162,5mg KCN + 250 ml nc cat
Thuoc th B : 375 mg K3Fe(CN)6 + 250 ml nc cat
Thuoc th C : 375 mg Fe{(NH4(SO4)2} + 250g sodium lauryl sulfat + 250ml H2SO4 0,005N
Dung dch mau 0,02 mg/ml can 0,01 g hoa tan trong 500ml nc cat
Cho 1ml A + 1ml B un soi cach thuy, lam lanh, cho 5ml ddC. e yen trong 15 phut roi oc o hap thu 690 nm.
VII. Phng phap o mau
Neu roi mot dong sang (cng o I0) vao mot cuvet ng dung dch th mot phan nho cua no (cng o Ir) b phan xa t mat cuvet, mot phan khac (cng o Ia) b dung dch hap thu, phan con lai (cng o It) i qua cuvet. Gia cac ai lng nay co he thc sau:
I0 = Ia + Ir + It
(1)
Trong thc te, v oi vi mot loai phan tch ta ch s dung mot cuvet, nen cng o dong sang phan xa la khong oi, no lai khong ln nen co the bo qua. Do o phng trnh tren co the n gian thanh:
I0 = Ia + It
(2)
Bang cach o trc tiep ta co the xac nh c cng o dong sang roi vao (Io) va dong sang i qua dung dch th nghiem (It). ai lng Ia co the tm c theo hieu so cac ai lng Io va It, ch khong o trc tiep c no.
Da tren nhieu thc nghiem, P. Bougueur roi I. Lambert a thiet lap nh luat phat bieu nh sau: Nhng lp chat hu c chieu day ong nhat, trong nhng ieu kien khac nh nhau, luon luon hap phu mot t le nh nhau cua dong sang roi vao nhng lp chat o.
nh luat nay c bieu dien bi phng trnh:
(3)
Trong o:
It Cng o dong sang sau khi qua dung dch
Io Cng o dong sang roi vao
e C so logarit t nhien
L Chieu day cua lp
K He so hap phu
Neu oi sang c so logarit thap phan ta c phng trnh co dang:
(4)
Trong phng trnh nay, he so K goi la he so tat. T nh luat nay ta suy ra:
1. T so gia cng o dong sang sau khi xuyen qua lp dung dch vi cng o dong sang roi vao, khong phu thuoc vao cng o tuyet oi cua dong sang roi vao.
2. Neu chieu day lp dung dch tang theo cap so cong th cng o dong sang sau khi xuyen qua lp o giam theo cap so nhan.
e hieu ro y ngha va tr so cua he so K, ta gia thiet rang cng o dong sang sau khi qua lp dung dch giam i 10 lan, tc la:
Theo phng trnh (4) th
10 KL = 10 1 = 10 va KL=1
(5)
Do o:
Nh vay, khi he so tat co tr so bang ai lng nghch ao cua chieu day lp dung dch (thng o bang cm) th co kha nang lam cng o dong sang i qua no yeu i 10 lan.
He so K ch phu thuoc vao ban chat chat tan va bc song anh sang roi vao. Do o nh luat Bougueur_Lambert ch ung cho tia n sac, tc la cho anh sang co bc song xac nh.
Khi nghien cu s hap thu anh sang bi dung dch, Beer a xac nh rang he so tat k t le vi nong o cua chat hap thu, tc la:
K=L
(6)
ay: C- Nong o chat tan
- He so khong phu thuoc nong o.
nh luat Beer tng t nh luat Bougueur_Lambert
inh luat Bougueur_Lambert khao sat s thay oi o hap phu anh sang dung dch co nong o khong oi, khi thay oi chieu day lp hap phu. Con nh luat Bia khao sat s thay oi o hap phu anh sang bi dung dnh co chieu day khong oi, khi thay oi nong o.
Ket hp cac cong thc (4) va (6) ta c phng trnh cua nh luat c ban cua phng phap o mau: nh luat Bougueur_Lambert -Beer:
(7)
Neu nong o C c bieu dien bang phan t gam/lt, con chieu day lp L bang cm th goi la he so tat phan t, o la he so phu thuoc vao bc song cua anh sang roi vao, ban chat chat tan, nhiet o dung dch.
Bang cach bien oi phng trnh (7) ta co the rut ra y ngha cua mot ai lng thng gap trong phng phap o mau.
Ty so gia cng o dong sang sau khi qua dung dch (It) vi cng o dong sang roi vao dung dch (Io) goi la o truyen qua, ky hieu bang:
ai lng T ng vi chieu day lp dung dch bang 1cm goi la he so truyen qua.
Log cua ai lng nghch ao vi o truyen qua goi la o tat, ky hieu E (extinction) hay mat o quang,ky hieu D (optical dencity).
T cong thc nay ta suy ra rang mat o quang D ty le thuan vi nong o chat tan trong dung dch.
VIII.Phng Phap Sac Ky Giay
1.Nguyen ly c ban cua phng phap :
Co nhieu phng phap sac ky nhng trong ky thuat che bien thc pham, phng phap sac ky giay c dung nhieu nhat.
2.Giay sac ky : la loai giay co kha nang gi tren be mat mot lng nc ln. Trong kh quyen bao hoa hi nc, giay tham c 22% nc, theo trong lng giay. Giay sac ky la loai giay ac biet lam t loai bong cao cap, co ham lng xenluloza rat cao (>99%).
Tr so Rf:
Tr so Rf cua mot chat la ch so gia quang ng i c cua chat o tren quang ng i cua dung moi (di ong) tren giay.
Gia tr so Rf va he so phan bo () lien he vi nhau theo phng trnh :
Trong o :
A- o am giay
P- Khoi lng giay
Can c vao tr so Rf (trong cung mot he dung moi, cung mot nhiet o) ta co the biet c th t sap xep cua cac chat can phan chia tren giay, ngha la co the nh tnh c cac chat (cac gia tr Rf cua cac chat thng c cong bo trong cac sach).
Tuy nhien, trong thc te, nhat la ieu kien nc ta (kh hau, thiet b, v.v) gia tr Rf cua chat can phan chia thng khong gi c co nh, nen cach tot nhat e nhan biet tng chat (nh tnh) la cho chat tieu chuan va chat can phan chia chay song song tren cung mot giay sac ky.
Muon tu sac ky bao hoa hi dung moi th tu phai kn va trong tu nen at mot so coc cha dung moi, trong moi coc co ng mot vai tam giay sac ky.
Trong lng phan t : noi chung tr so Rf tang theo chieu tang cua trong lng phan t cac chat can phan chia.
Dung moi : thng dung ru nhieu cacbon (butylic, amylic) lam dung moi chay sac ky cac chat. Neu tang ham lng nc trong he dung moi th Rf cung tang. ac biet, neu them axit hoac baz vao he dung moi, se lam thay oi o phan ly cua chat tan, anh hng en s tch ien cua nhom chc phan cc cua chat tan, do o lam thay oi ro ret tr so Rf, tham ch co khi lam thay oi ca th t sap xep cua cac vet chat tan tren sac pho.
3.Dung moi :
Kha nang phan chia cac chat phu thuoc chu yeu va he so phan bo cua chat tan gia hai tng di ong va bat ong. Do o viec la chon dung moi co y ngha quan trong hang au. Can c e chon dung moi di ong :
Can phai chon dung moi di ong nao ma trong dung moi o cac chat b phan chia co o tan be va co nh. Neu chat b phan chia co o tan ln th no se di chuyen song song vi dung moi. Neu co o tan be trong dung moi di ong th chat can phan chia se nam ngay tai vet cham.
e phan chia tot cac chat th he so phan bo cua chung phai ln hn 1 (), ngha la o tan cua chung trong dung moi bat ong phai ln hn dung moi di ong.
Ngoai ra con phai biet o tan cua cac chat can phan chia trong hon hp cua chung khac nhau the nao trong dung moi. Trng hp khong khac nhau th khong the phan chia c.
oi vi cac chat tan trong nc th dung dung moi hu c hoac hon hp dung moi hu c nc e lam dung moi di ong. Ngc lai, oi vi cac chat tan c trong dung moi hu c ma khong tan trong nc, th dung dung dch nc bao hoa dung moi hu c lam dung moi di ong. Trong trng hp au, dung moi bat ong la nc; trng hp sau la cac dung moi phan cc hoac t phan cc.
4.Cac phng phap chay sac ky Phng phap mot chieu : ngi ta cho dung moi di ong chay t au tren cua giay xuong hoac t au di cua giay len. Cho dung moi di ong t di len ch co ket qua tot khi cac chat can phai chia co Rf khac nhau ro ret. V dung moi luc nay ngoai viec chu tac dung cua lc mao dan hut len, con b trong lc keo xuong.
Cho dung moi di ong t tren xuong thng c dung e tach hon hp cac chat co Rf gan nhau. u iem cua phng phap nay la : nh sc hut cua trong lc lam dung moi chay xuong nhanh hn, giup cho cac chat de tach khoi nhau hn. Tuy nhien, phng phap tren xuong oi hoi thao tac phc tap hn, nen e tach hon hp t chat va cac chat co Rf khac nhau ro ret, ngi ta hay dung phng phap di len.
Phng phap hai chieu : u iem cua phng phap nay la tach c hon hp cac chat co Rf rat gan nhau ma trong phng phap mot chieu khong the tach ra c. Trong phng phap nay, ngi ta cho hai dung moi chay theo hai chieu giay vuong goc vi nhau.
Ngoai ra con phng phap sac ky tron, cho dung moi chay t tam giay at nam ngang toa ra cac pha, song kha nang tach cung khong tot lam, nen phng phap nay cung t pho bien.
5. Cac thuoc hien mau sac ky :
Giay sac ky sau khi c nho cac chat can phan chia, e kho va cho vao tu chay sac ky th sau mot thi gian nhat nh, dung moi chay tren giay en mot oan nhat nh, lay giay ra khoi tu va e kho va phun cac thuoc hien mau e hien vet cac chat can phan chia tren sac pho.
Noi chung, cac thuoc hien mau sac ky la cac chat hoa hoc, co phan ng tao thanh hp chat mau vi chat can phan chia (trong nhng ieu kien phan ng nhat nh : nong o thuoc hien, nong o cac chat can phan chia, nhiet o, v.v) Co hai loai thuoc hien mau sac ky :
Thuoc hien chung : la loai thuoc hien co phan ng vi nhieu chat trong cung hon hp chat can phan chia.
Thuoc hien ac biet : la thuoc hien ch co phan ng ac hieu vi mot chat trong hon hp chat can phan chia.
6.Sac ky nh lng :
nh lng la khau cuoi cung, tiep sau khau nh tnh (tach cac chat can phan chia tren giay sac ky). Thng tien hanh nh lng nh sau :
Sau khi sac pho c hien mau bang thuoc hien thch hp, dung but ch khoanh nhng vong tron dien tch bang nhau quanh vet mau chat can xac nh va chat chuan (cham tren cung mot giay sac ky va cung mot ieu kien chay sac ky) ong thi khoanh mot hoac hai vong tren khoang giay trang (khong co vet mau) e lam mau trang. Sau o cat nhng khoanh tron ra khoi giay va cho vao ong so mau, cho dung moi thch hp e thoi mau. e mot thi gian cho mau thoi ra het, roi em o mau tren may so mau vi knh loc va cuvet thch hp.
B.CAC PHNG PHAP XAC NH CAC LOAI NG
I.Phng phap nh tnh
1. Cac phep th hoa hocHydro carbonPhep thieu kienKet qua
ng kh
Glucose
Fructose
Maltose
LactoseDung dch BenedictNghien mau mo vi mot chut nc, loc cho 2 cm3 dch chiet vao ong nghiem, them 2 cm3 dung dch Benedict, un nong ti 950C trong 2 phut oi mau hoac cho ket tua mau o gach
Dung dch Fehling 1 va 2Cho 1 cm3 dung dch Feling 1 va 1cm3 dung dch Fehling 2 vao 2cm3 dung dch chiet mo, en 920C trong 2 phut oi mau hoac cho ket tua mau o gach
ng khong kh
Saccharose (ng ma)Dung dch BenedictTh nh vi ng kh se khong cho phan ng. un nong 2 cm3 dung dch chiet mo ti vi 1 cm3 dung dch HCl loang e thuy phan ng ma thanh cac ng n , trung hoa bang NaOH, lam phep th nh oi vi ng kh oi mau hoac cho ket tua mau o gach
Tinh botIot trong dung dch KINho len mau mo lam nat vi nhiet o trong phongMau xanh en
GlycogenIot trong dung dch KINho len mau mo lam nat vi nhiet o trong phongMau o tm
CelluloseDung dch SchultzCho lat cat mo cho vao dung dch va a len knh quang hoc e xem Mau tm
LigninDung dch phlorluxin acid hoaCho lat cat mo cho vao dung dch va a len knh quang hoc e xem Mau sang o
2. Cac phep th bang Enzym
Glucose : xac nh bang Enzym hexokinase theo cac phan ng sau
D-glucose + ATP
ADP + glucose-6-phosphat + NADP+
ADP + glucose-6-phosphat + NADP+
gluconate-6-phosphat + NADPH +H+ Fructose : enzym hexokinase cung tacong len fructose . Xac nh fructose sau khi a xac nh glucose
D-glucose + ATP ADP + Fructose -6-phosphat
ADP + Fructose -6-phosphatGlucose-6-phosphat
Galactose : D-galactosenic acid + NADH + H+ D-galactose + NAD+
Mannose : xac nh mannose t do theo phng trnh phan ng sau
D-mannose + ATP ADP + Mannose-6-phosphat
Mannose-6-phosphat Fructose-6-phosphat
Saccharose : Saccharose thng khong co trong te bao ong vat, xac nh saccharose theo phng trnh phan ng sau ay:
Sacchrose + H2O D-glucose + D-fructose
Maltose
Maltose + H2O 2 D-glucose
Lactose thng co trong sa
Lactose + H2O D-galactose + D-glucose
Rafinose co trong cu cai ng
Rafinose + H2O D-galactose + Saccharose
Tinh bot : co nhieu trong thc vat va trong mot so vi sinh vat
Tinh bot + (n 1) H2O n-D-glucose
3. Phan ng vi amin thm
Nhieu amin thm se ong ac lai vi aldose va cetose trong acid acetic tinh khiet e hnh thanh cac san pham mau ma he so hap thu cua nhng chat nay c dung e nh tnh cho mot glucid hoac mot nhom glucid
S dung nhng amin thm hoac o lng hap thu nhng bc song xoay chieu xen ke e cho ra mot o rieng biet cho moi loai ng.
Glucose, mantose, glactose phan ng vi toluidine tao ra cac san pham co mau xanh vi cung he so cc ai hap thu 630nm trong khi o fructose khong hap thu bc song nay . Disaccharide phan ng nhng cap o khac nhau va pentose cho san pham mau ma phan t co he so hap thu trong khoang 480-630nm
Cac amin thm c s dung bao gom p-aminosalicylic acid, p-aminobezoic, diphenylamin, p-aminophenol .P-aninophenol hoat ong nhom ketose c dung e nh lng fructose
4. Phan ng vi acid manh va phenol
Khi un mot acid manh vi pentose va hexose b ehydrat hoa tao thanh dan xuat furfural va hyroxyfurfural . Nhom andehyde cua nhon nay se ngng tu vi hon hp phenolic tao thanh san pham co mau lam c s cho viec nh tnh glucid.
(Phan ng mau cua chat ng
Phan ng mau tong quat (phan ng Molish)
Tat ca cac chat ng eu cho mau tm oi vi dung dch Naphthol trong H2SO4 am ac. o trong ong nghiem 1ml dung dch ng 1% va 2 giot dung dch Naphthol 15% trong ru. Lac eu, nghieng ong va cho H2SO4 am ac t t theo thanh ong. Co s tao thanh mot lp mau tm hien ra mat ngan cach gia hai chat long. Neu thay the bang anthrone tao thanh san pham co mau xanh.
( Phan ng kh cua ng
Tnh kh oxygen cua cetose va aldose Phan ng vi thuoc th Fehling
Thuoc kh nay la dung dch CuSO4 vi dung dch soude am ac va tartrat kep natrium va kalium. Tac dung cua soude am ac len CuSO4 cho hydroxyd ong( CuO , H2O) tan trong dung dch nh s hien dien cua tartrat .
2(CuO , H2O)
Cu2O + 2H2O + O
Trong mot ong nghiem o 1ml thuoc th Fehling va 1ml dung dch glucose . un soi cach thuy trong 5 phut co tram hien o gach Cu2O nh s kh ong nh thanh ong nhat bi glucose
Phan ng vi acid piric
2ml piric + 1 giot kiem ac +1 ml glucose cho mau vang
Phan ng vi thuoc th phenyl hydrozin
Trong moi trng acid acetic, chat ng tac dung vi phenyl hydrozin cho ta mot hp chat goi la osazon c bieu tnh dang tinh the, quang tnh va dung iem cua chung.
Thuoc th phenyl hydrazine
Can 1g Chlohyrate Phenyl hydrazine va 3g CH3-COONa them 1ml CH3COOH am ac va 5 ml nc cat. un nhe lac eu e hoa tan.
Phan ng vi thuoc th phenyl hydrazin
Trong ong th ng 1ml thuoc th phenyl hydrazin ta them 1ml trong nhng dung dch sau ay : glucose, fructose , galactose , lactose , maltose, arabinose va xylose
un soi cach thuy trong 30 phut e nguoi t t ta c mot tinh the mau vang
II.Phan tch nh lng
Da vao cac phng phap a trnh bay trong phan A,ta co the nh lng cac loai ng
( Mot vai cach xac nh cac loai ng cu the
(Phan tch ng ma :
Thanh phan ng ma Lng ( min- max)(g)
Saccharose
71- 81,5
ng kh
0,1- 0,5
X ba
8- 13
Nc
80- 88
(Xac nh Saccharose :
Phng phap ch th xanh methylen
Phan ng ng kh cung tng t nh phng phap Bertrand ch khac la Cu2O tao nen c hoa tan bang ferrocyanur kali, cuoi cung ch th xanh methylen chuyen thanh khong mau
Dung dch Fehling A : 35 g CuSO4 .5H2O + 0.05 g xanh methylen + nc cat thanh 100ml dung dch
Fehling B: 117g kali tatrat + 9,4 g kali ferrocyanur K4(Fe(CN)6) + 26,4 g NaOH + nc cat tao thanh 100ml dung dch
Can 10g Saccharose cho vao bnh nh mc 200ml, cho them 100g nc cat va 1ml dung dch HCl ac. em un trong noi cach thuy 700C trong 30 phut, e nguoi cho them nc cat e c dung dch ng 5%
Can 10g ng kh cho vao bnh non 250 ml, cho 10 ml nc cat, 5 ml dung Fehling A va 5 ml dung dch Fehling B, em un soi, nho nhanh dung dch glucose tieu chuan vao, mau xanh dung dch se chuyen thanh khong mau.
X =
G: Lng ng knh em phan tch
VO : the tch glucose chuan 0,1 g mau chuan
V1: the tch glucose chuan 0,1 g mau ng
(ng cat, ng phen, ng bot :
(Xac nh ham lng ng kh
Thanh phan : cho 2g ng vao bnh non 250ml, them 100 ml nc cat, nho vai giot phenolphtalein 10%, trung hoa dung dch bang NaOH 20% + 20 50 ml dd Pb(CH3COONa)2
Lay 25 ml dung dch lam mau th cho vao bnh non, cho them 25 ml dd F.A + 25 ml dd F.B, tiep tuc nh lng ng bang mot trong cac cach tren .
(Xac nh ham lng Saccharose: theo phng phap Bertrand
X= (A B) . 0,95
A: lng glucose sau thuy phan.
B: lng ng kh xac nh c tren.
Mau sac
Mui
V
Hnh thc ng cat
Vang nhat, vang nau.ng bnhthng
Ngot, khong chua, khong ang
Tinh the eu, ri, kho.
ng phen
Nau ti, nau sam
Thm mui ng
Ngot, khong chua, khong ang
Khoi ch nhat, sac canh ng bot
Vang nhat, vang nau
Thm mui ng
Ngot, khong chua, khong ang
Hat nho, ti
Phan tch Glucose t san pham giau tinh bot : Xac nh ham lng glucose, maltose, dextrin, tinh bot trong san pham :
a) Phng phap Bertrand cai tien :
(Xac nh glucose:
Dung thuoc th oxi hoa rieng glucose :
CuSO4 + 4NaCH3COO Na2SO4 + Na2 [Cu(CH3COO)4]
CH2OH (CHOH)4 CHO + 2Na2 [Cu(CH3COO)4] + 2H2O
Cu2O + 4CH3COOH + CH2OH (CHOH)4 COOH
T lng Cu2O ta tnh c lng ng kh
BANG TM LNG GLUCOZAGlucoza
(mg)
0,1N(ml)Glucoza
(mg)
0,1N(ml)Glucoza
(mg)
0,1N(ml)Glucoza
(mg)
0,1N(ml)
10
11
12
13
14
15
16
17
18
19
202,34
2,69
3,06
3,42
3,78
4,14
4,49
4,85
5,22
5,49
5,5721
22
23
24
25
26
27
28
29
30
316,28
6,62
6,96
7,29
7,63
7,97
8,16
8,67
9,00
9,28
9,5632
33
34
35
36
37
38
39
40
41
429,83
10,11
10,40
10,68
10,96
11,23
11,51
11,80
12,04
12,43
12,51
43
44
45
46
47
48
49
5012,76
12,84
13,24
13,48
13,73
13,96
14,20
14,44
(Xac nh Maltose :Maltose c xac nh theo phng phap dung hieu so bang cach dung thuoc th oxyhoa ca Maltose lan glucoza roi suy ra Maltose
BANG TM MANTOZA THEO GLUCOZA
Glucoza
(mg)
0,1N(ml)Glucoza
(mg)
0,1N(ml)Glucoza
(mg)
0,1N(ml)Glucoza
(mg)
0,1N(ml)
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
1,52
1,68
1,81
2,00
2,16
2,32
2,48
2,63
2,79
2,95
3,14
3,27
3,43
3,59
3,75
3,90
4,07
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
4,28
4,29
4,54
4,70
4,87
5,04
5,18
5,34
5,52
5,66
5,12
5,96
6,16
6,30
6,46
6,62
6,7844
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
6,93
7,09
7,25
7,41
7,57
7,73
7,89
8,05
8,21
8,37
8,53
8,68
8,84
9,00
9,16
9,32
9,48
61
62
63
64
65
66
67
68
69
70
71
72
73
74
759,64
9,80
9,96
10,11
10,28
10,41
10,64
10,75
10,91
11,08
11,20
11,38
11,55
11,71
11,87
(Xac nh Dextrin : Dextrin b ket tua hoan toan trong con, con glucose, maltose tan trong con. (Xac nh tinh bot : Trong glucoza thanh pham, tinh bot chu yeu dang hoa tan, nen phai xac nh bang cach cho glucoza thanh pham thuy phan toan bo, xac nh tong lng glucoza roi tr i lng glucoza t do, mantoza, dextrin a xac nh tren, se biet c glucoza do tinh bot thuy phan ra, sau o tnh ra tinh bot.
b) Phng phap dung Iod :
(Xac nh Glucose :
Nh phng phap Bertand cai tien nhng lng Cu2O c hoa tan bang iod, dung natrithiosulfat chuan o lng iod d vi ch th tinh bot hoa tan.
BNG TM LNG GLUCOZA 0,1N
(ml)Glucoza
(mg) 0,1N
(ml)Glucoza
(mg) 0,1N
(ml)Glucoza
(mg) 0,1N
(ml)Glucoza
(mg)
7,0
7,1
7,2
7,3
7,4
7,5
7,6
7,7
7,8
7,9
8,0
8,1
8,2
8,3
8,4
8,5
8,6
8,7
8,8
8,9
19,07
19,28
19,44
19,69
19,89
20,10
20,32
20,53
20,76
20,97
21,21
21,43
21,66
21,90
21,13
22,41
22,62
22,87
23,11
23,37
9,0
9,1
9,2
9,3
9,4
9,5
9,6
9,7
9,8
9,9
10,0
10,1
10,2
10,3
10,4
10,5
10,6
10,7
10,8
10,9
23,64
23,89
24,16
24,23
24,70
24,97
25,25
25,54
25,83
26,12
26,42
26,72
27,02
27,32
27,64
27,95
28,27
28,60
28,92
29,2611,0
11,1
11,2
11,3
11,4
11,5
11,6
11,7
11,8
11,9
12,0
12,1
12,2
12,3
12,4
12,5
12,6
12,7
12,8
12,9
29,60
29,95
30,28
30,64
31,00
31,36
31,72
32,09
32,47
32,86
33,24
33,63
33,92
34,36
34,80
35,25
35,67
36,10
36,53
36,96
13,0
13,1
13,2
13,3
13,4
13,5
13,6
13,7
13,8
13,9
14,0
14,1
14,2
14,3
14,4
14,5
14,6
14,7
14,8
14,9
15,037,41
37,87
38,30
38,77
39,23
39,62
40,19
40,67
41,16
41,67
42,17
42,68
43,21
43,73
44,27
44,81
45,36
45,91
46,48
47,05
47,62
(Xac nh maltose:
Iod trong dung dch kiem cung oxy hoa maltose . Xac nh tong lng Maltose + Glucose lng Glucose, ta co the tnh c lng maltose :
CH2OH (CHOH)4 CHO + I2 + 3NaOH CH2OH (CHOH)4 COONa
+ 2NaI + 2H2O
BNG TM S ml 0,1N NG VI GLUCOZA.
(KHI XAC NH MANTOZA)Glucoza
(mg) 0,1N
(ml)Glucoza
(mg) 0,1N
(ml)Glucoza
(mg) 0,1N
(ml)Glucoza
(mg) 0,1N
(ml)
19,07
19,28
19,44
19,69
19,89
20,10
20,32
20,53
20,76
20,97
21,21
21,43
21,66
21,90
22,13
22,41
22,62
22,87
23,11
23,37
2,12
2,14
2,16
2,19
2,21
2,23
2,26
2,28
2,31
2,33
2,36
2,38
2,41
2,43
2,46
2,49
2,51
2,54
2,57
2,60
23,64
23,89
24,16
24,43
24,70
24,97
25,25
25,83
26,12
26,42
26,72
27,32
27,64
27,95
28,27
28,60
28,92
29,26
29,60
29,95
2,63
2,65
2,66
2,71
2,74
2,75
2,80
2,87
2,90
2,94
2,97
3,04
3,07
3,11
3,14
3,17
3,21
3,25
3,29
3,3330,28
30,64
31,00
31,36
31,72
32,09
32,47
32,86
33,24
33,63
33,92
34,36
34,84
35,25
35,67
36,10
36,53
36,96
37,41
37,87
3,36
3,40
3,44
3,48
3,52
3,57
3,61
3,65
3,69
3,74
3,78
3,82
3,87
3,92
3,96
4,01
4,06
4,11
4,16
4,21
38,30
38,77
39,62
40,19
40,67
41,16
41,67
42,17
42,68
43,21
43,73
44,27
44,81
45,36
45,91
46,48
47,05
47,624,26
4,31
4,40
4,47
4,52
4,57
4,63
4,69
4,74
4,80
4,86
4,92
4,98
5,04
5,10
5,15
5,23
5,29
Sac k giay :
Da vao tnh chat glucose, maltose, dextrin de tan trong nc va tach ra tren sac ky giay khi chung c keo bang he dung moi thch hp.
Can 10 g glucose ( mau phan tch ) cho vao bnh nh mc 100ml cho nc cat den vach nh mc. Nho len sac k giay FN3 ba cham moi cham 0.01 ml dd bnh cha cach nhau 3cm, 3 mau cham cha glucose va mau maltose, 3 mau cha dextrin
at mau giay vao bnh chay sac k vi he dung moi A(hoacB) cho en khi dung moi chay c 25cm th dng lai, em say kho, phun thuoc hien, em cat vet ng dextrin mau nau sam, lay em so mau chua 3ml CH3COOH ac e thoi mau t 1 2 gi em so mau tren may. Theo mat o quang hoc o c maltose, glucose, dextrin tieu chuan, ta xac nh c lng glucose, maltose, dextrin trong mau.
Dd A : n- butanol,CH3COOH, nc(4:1:5).
Dd B : n-butanol, acetol, nc(2:7:1).
Thuoc hien anilin 0,9ml, acid cua tatrat 1,7g hoa tan trong 50 ml C2H6COOH
Qua: lam ket tua pro trc, loc ba, em un cach thuy roi nh lng nh tren.
Pro + Pb(CH3COO)2 Pro ket tua
K2Cr2O4 + Ca2+ CaCr2O4 + 2K
Na2HPO4 + Pb(CH3COO)2 Pb(CH3)2 + CH3COONa
Tinh bot :
a) Thuy phan tinh bot thanh glucose .nh lng ng kh roi suy ra lng tinh bot .(Nh a neu tren)
Phng phap Mecke: thuy phan tinh bot
Tinh bot
Dextrin + Glucose + Maltose
b) Phng phap chuan o iod: bnh 1 :1/5 ml nc cat ; bnh 2: 2/5 ml dung dch thuy phan .Cho 10ml iod vao moi bnh roi cho 15ml NaOH cho en khi mat mau iod . Cho acid sulfuaric vao e hoa tan ong(I) oxid . Iod tach ra c chuan o bang natrithiosulfat cho en khi dung dch co mau vang .Them lng tinh bot vao en khi mat mau xanh
X=(V1 V2 ).0,009.0,9.V.100/V3g
X ham lng tinh bot
V1 ml natrithiosunfat bnh kiem tra
V2 ml natrithiosunfat bnh th nghiem
V3 ml dung dch thuy phan a phan tch
V ml dung dch thuy phan a
g so lng nguyen lieu em phan tch
c)Da vao kha nang lam quay mat phang phan cc anh sang
(Phng phap Luff Schoorl
Hoa chat : HCl 1,124% , Molydat amoni 2,5 % ,
Phan cc ke
Lay 5g mau tinh bot cho vao coc 100ml cho them 50 ml HCl 1,124 % vao .em un soi cach thuy, lam lanh xuong khoang 200C cho them 5 ml Molydat amoni, cho them nc cat vao, em loc ba. Dung dch tro thu c cho vao phan cc ke, o goc quay :
C =
( :ch so oc c tren may phan cc ke
[ (]D20 goc quay rieng cua tinh bot
l :chieu dai ong phan cc
Goc quay rieng cua mot so chat nh sau;
Khoai tay194,50
Gao185,90
Ngo184,60
Lua m 182,70
an mach 181,50
San 1880 d) Phng phap tach tinh bot va say :
Hoa chat : Bnh ng dd C6H6 (co voi hut chan khong , pheu buchner ,giay loc, becher, bnh nh mc
Coi chay s, con 100,70o,99o, ether, HCl 20% .
Cach tien hanh :
Nguyen lieu giau tinh bot nh gao , khoai lang , khoai tay, can 1-2 mau, nghien nhuyen, cho mot t ether, khoay eu, chuyen vao becher, them 20 ml dd HCl 20%, khoay cho tan het tinh bot, nh mc thanh 100 ml dd bang nc cat .
Hut 50 ml dd loc cho vao cho vao becher cha 110 ml con 99o khoay, e yen trong 10-15 phut trong tu lanh cho tinh bot ket tua
Chuan b mot mieng giay loc a say kho, loc tinh bot, ra bang 20 ml con 70o va 99o en khi het phanh ng HCl ( th bang AgNO3)
Say giay loc 130oC, ta thu c tinh bot kho
X =
Lay 100 ml dung dch thu c sau thuy phan em loc cho vao bnh cha dung tch 250 ml , cho them 6ml dd HCl 30% em un cach thuy trong 2 gi , lam lanh cho them 3- 4 giot methylen da cam , dung NaOH trung hoa HCl d en khi dung dch oi mau , cho them nc cat vao .Lay mot t dung dch em nh lng glucose bang mot trong cac phng phap tren .
X =
C :Khoi lng tinh bot tng ng vi 20ml dd ng dung trong th nghiem
a: lng glucose trong 20 ml dung dch th nghiem
b : lng glucose trong 20 ml dung dch mau
Cho 2ml dung dch vao bnh tam giac 250ml ,cho 100ml dd HCl 2% un cach thuy trong 2 gi ,e nguoi , nho them 4 5 giot methylen da cam ,trung hoa HCl d bang NaOH ti khi oi mau 300C. Cho dung dch vao bnh nh mc 250ml ,cho them nc cat den mc vach , em loc , xac nh lng glucose trong dung dch ,ta co the tnh c tinh bot trong nguyen lieu
TB =
a : lng glucose co trong 20 ml dung dch ferrocyanur kali
b : lng glucose trong 20ml dung dch ng loang tieu hao khi nh phan
m : khoi lng tinh bot em thuy phan
Cellulose
Cellulose x ba con lai sau khi thuy phan tinh bot ,lignin va cac sac to khac, cac tap chat b thuy phan bi kiem + acid. Sau khi loc, say, en nung cellulose thanh tro, t ham lng tro tnh ham lng cellulose trong mau th.
Can 25g nguyen lieu a c nghien mn cho vao bnh cha 50ml nc cat, them 10ml HCl am ac. em un soi dd den khi tinh bot b thuy phan hoan toan
Pentozan
La thanh phan cua chat ban x (Hemicellulose) cua te bao thc vat
(C5H8O4)n + nH2O
nC5H10O 5
un nguyen lieu cha cha pentozan trong dung dch HCl 12% :
Pentozan
Pentose furfurol
Trong dung dch, Glucose cung b phan huy tao thanh oxymethyl- furfurol ,tuy nhien ay la mot chat khong ben nen ta co nh lng Pentozan :
CH CH
Br C CBr
+ 2Br2
CH
CH
BrC CBr
O CHO
O CHO
KBrO3 + 5KBr + 6HCl 3Br2 + 6KCl + 3H2O
Br2 + 2KI +
2KBr + I2
COOH
CH2 - COONa
CH2 - COONa
CH2 - COONa
CH2 - COONa
hexokinase
G-6-phosphat dehydrogenase
G
(VO V1)0.1
Glucose phospho isomerase
Galactose dehyrogenase
Hexokinase
Phosphomannose isomerase
D-fructosidase
(-glucosidase
(-galactosidase
(-galactosidase
Amyloseglucosidase
bm
a . 150 . 100
C
(10a b) * 0,9
(10a b) . 0,9
Mm
M - Mtb
[ (]D20 l .5
100 ( . 100
Amilase
SVTH: HC04TP1 Trng HBK TPHCM Trang - 1 -
_1191413850.unknown
_1191644001.unknown
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_1191644119.unknown
_1191644298.unknown
_1191575013.unknown
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_1191575050.unknown
_1191414199.unknown
_1191414037.unknown
_1191413179.unknown
_1191413468.unknown
_1191413749.unknown
_1191413418.unknown
_1191409836.unknown
_1191412959.unknown
_1191409652.unknown
_1161962040.unknown