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

_1191644092.unknown

_1191644119.unknown

_1191644298.unknown

_1191575013.unknown

_1191575057.unknown

_1191576964.unknown

_1191575050.unknown

_1191414199.unknown

_1191414037.unknown

_1191413179.unknown

_1191413468.unknown

_1191413749.unknown

_1191413418.unknown

_1191409836.unknown

_1191412959.unknown

_1191409652.unknown

_1161962040.unknown