Tsom ntsoov rau Cellulose ethers

Kev soj ntsuam thiab kuaj ntawm Hydroxypropyl Methylcellulose

1. Kev txheeb xyuas tus qauv ntawm hydroxypropyl methylcellulose

(1) Siv 1.0g ntawm cov qauv, kub 100mL dej (80 ~ 90 ℃), do tsis tu ncua, thiab txias hauv ib da dej dej khov kom txog thaum nws dhau los ua kua nplaum; Muab 2mL ntawm cov kua rau hauv lub raj kuaj, thiab maj mam ntxiv 1mL ntawm 0.035% anthrone sulfuric acid raws li lub raj phab ntsa tov thiab tawm rau 5 feeb. Ib lub nplhaib ntsuab tshwm ntawm qhov sib txuas ntawm ob lub kua.

 

(2) Siv cov kua qaub uas tsim nyog siv rau kev txheeb xyuas hauv (I) saum toj no thiab muab tso rau ntawm lub khob iav. Raws li cov dej evaporates, ib daim ntaub ntawv ductile.

 

2. Kev npaj ntawm hydroxypropyl methylcellulose tsom xam txheej txheem kev daws teeb meem

(1) Sodium thiosulfate standard tov (0.1mol/L, siv tau: 1 hli)

Kev npaj: Boil txog 1500mL dej distilled, txias thiab tso tseg. Qhov hnyav 25g sodium thiosulfate (nws qhov hnyav molecular yog 248.17, sim ua kom raug li 24.817g thaum hnyav) lossis 16g anhydrous sodium thiosulfate, yaj hauv 200mL ntawm cov dej txias saum toj no, dilute rau 1L, muab tso rau hauv lub raj mis xim av, thiab muab tso rau hauv qhov chaw tsaus, lim thiab tso tseg tom qab ob lub lis piam.

 

Calibration: Nyhav 0.15g ntawm siv poov tshuaj dichromate thiab ci kom qhov hnyav tas li, raug rau 0.0002g. Ntxiv 2g poov tshuaj iodide thiab 20mL sulfuric acid (1 + 9), co zoo, thiab tso rau hauv qhov tsaus ntuj rau 10 feeb. Ntxiv 150mL dej thiab 3ml 0.5% starch qhia tov, thiab titrate nrog 0.1mol / L sodium thiosulfate tov. Cov tshuaj hloov ntawm xiav mus rau xiav. Hloov qaim ntsuab ntawm qhov kawg taw tes. Tsis muaj poov tshuaj chromate tau ntxiv rau hauv qhov kev sim dawb. Cov txheej txheem calibration yog rov ua 2 mus rau 3 zaug thiab qhov nruab nrab tus nqi raug coj mus.

 

Cov molar concentration C (mol / L) ntawm sodium thiosulfate txheem tov yog xam raws li cov qauv hauv qab no:

 

Hauv cov mis, M yog qhov loj ntawm potassium dichromate; V1 yog qhov ntim ntawm sodium thiosulfate noj, mL; V2 yog qhov ntim ntawm sodium thiosulfate noj nyob rau hauv qhov kev sim dawb paug, mL; 49.03 yog dichromium sib npaug rau 1 mol ntawm sodium thiosulfate. Qhov loj ntawm potassium acid, g.

 

Tom qab calibration, ntxiv me me ntawm Na2CO3 los tiv thaiv microbial decomposition.

 

(2) NaOH txheem tov (0.1mol/L, validity lub sij hawm: 1 hli)

Kev npaj: hnyav txog 4.0g ntawm NaOH ntshiab rau kev tshuaj ntsuam rau hauv lub beaker, ntxiv 100mL ntawm distilled dej kom yaj, ces hloov mus rau 1L volumetric hwj, ntxiv dej distilled rau lub cim, thiab tawm rau 7-10 hnub kom txog thaum calibration.

 

Calibration: Qhov chaw 0.6 ~ 0.8g ntawm ntshiab poov tshuaj hydrogen phthalate (muab rau 0.0001g) qhuav ntawm 120 ° C rau hauv 250mL Erlenmeyer hwj, ntxiv 75mL ntawm distilled dej kom yaj, thiab ces ntxiv 2 ~ 3 tee ntawm 1% phenolphthalein qhia. Titrate nrog titrant. Do cov tshuaj sodium hydroxide npaj rau saum toj no kom txog thaum nws liab me ntsis, thiab xim tsis ploj hauv 30 vib nas this raws li qhov kawg taw tes. Sau qhov ntim ntawm sodium hydroxide. Cov txheej txheem calibration yog rov ua 2 mus rau 3 zaug thiab qhov nruab nrab tus nqi raug coj mus. Thiab ua ib qho kev sim dawb.

 

Qhov concentration ntawm sodium hydroxide tov yog xam raws li hauv qab no:

 

Hauv cov mis, C yog qhov concentration ntawm sodium hydroxide tov, mol / L; M sawv cev rau qhov loj ntawm potassium hydrogen phthalate, G; V1 - qhov ntim ntawm sodium hydroxide noj, mL; V2 sawv cev rau sodium hydroxide noj hauv qhov kev sim dawb paug Volume, mL; 204.2 yog cov molar loj ntawm poov tshuaj hydrogen phthalate, g / mol.

 

(3) Dilute sulfuric acid (1 + 9) (lub sij hawm siv tau: 1 hli)

Thaum stirring, ua tib zoo ntxiv 100 mL ntawm concentrated sulfuric acid rau 900 mL ntawm distilled dej thiab ntxiv maj mam thaum stirring.

 

(4) Dilute sulfuric acid (1 + 16.5) (lub sijhawm siv tau: 2 lub hlis)

Thaum stirring, ua tib zoo ntxiv 100 mL ntawm concentrated sulfuric acid rau 1650 mL ntawm distilled dej thiab maj mam ntxiv. Do thaum koj mus.

 

(5) Starch qhia (1%, validity lub sij hawm: 30 hnub)

Qhov hnyav 1.0g ntawm cov hmoov txhuv nplej siab, ntxiv 10mL dej, do thiab ncuav rau hauv 100mL ntawm boiling dej, boil rau 2 feeb, cia sawv ntsug, thiab coj tus supernatant rau tom qab siv.

 

(6) Starch qhia

Noj 5 mL ntawm npaj 1% starch qhia tov thiab dilute nws nrog dej mus rau 10 mL kom tau 0.5% starch qhia.

 

(7) 30% chromium trioxide tov (lub sijhawm siv tau: 1 hli)

Qhov hnyav 60g ntawm chromium trioxide thiab yaj hauv 140mL ntawm cov dej tsis muaj organic.

 

(8) Potassium acetate tov (100g / L, siv tau rau 2 lub hlis)

Dissolve 10 g ntawm anhydrous potassium acetate granules nyob rau hauv 100 mL ntawm ib tug daws ntawm 90 mL ntawm glacial acetic acid thiab 10 mL ntawm acetic anhydride.

 

(9) 25% sodium acetate tov (220g / L, validity lub sij hawm: 2 lub hlis)

Dissolve 220g anhydrous sodium acetate hauv dej thiab dilute rau 1000mL.

 

(10) Hydrochloric acid (1: 1, lub sijhawm siv tau: 2 lub hlis)

Sib tov cov concentrated hydrochloric acid thiab dej hauv qhov sib piv ntawm 1: 1.

 

(11) Acetate buffer (pH = 3.5, lub sijhawm siv tau: 2 lub hlis)

Dissolve 60mL ntawm acetic acid nyob rau hauv 500mL dej, ces ntxiv 100mL ntawm ammonium hydroxide thiab dilute mus rau 1000mL.

 

(12) Lead nitrate npaj tov

Dissolve 159.8 mg lead nitrate hauv 100 mL dej uas muaj 1 mL nitric acid (density 1.42 g / cm3), dilute rau 1000 mL dej, thiab sib tov zoo. Zoo tsau. Cov tshuaj yuav tsum tau npaj thiab khaws cia rau hauv cov iav tsis muaj hlau lead.

 

(13) Lead standard solution (lub sij hawm siv tau: 2 lub hlis)

Ua kom raug ntsuas 10mL ntawm txhuas nitrate npaj tov thiab ntxiv dej rau dilute rau 100mL.

 

(14) 2% hydroxylamine hydrochloride tov (lub sijhawm siv tau: 1 lub hlis)

Dissolve 2g ntawm hydroxylamine hydrochloride hauv 98mL dej.

 

(15) Ammonia (5mol / L, siv tau rau 2 lub hlis)

Dissolve 175.25g ammonia dej thiab dilute rau 1000mL.

 

(16) Mixed kua ( siv tau: 2 lub hlis)

Sib tov 100mL ntawm glycerol, 75mL ntawm NaOH tov (1mol / L) thiab 25mL dej.

 

(17) Thioacetamide tov (4%, siv tau rau 2 lub hlis)

Dissolve 4g ntawm thioacetamide hauv 96g dej.

 

(18) Phenanthroline (0.1%, lub sijhawm siv tau: 1 hli)

Dissolve 0.1g ntawm phenanthroline hauv 100mL dej.

 

(19) Acid stannous chloride (lub sij hawm siv tau: 1 hli)

Dissolve 20g ntawm stannous chloride nyob rau hauv 50mL ntawm concentrated hydrochloric acid.

 

(20) Potassium hydrogen phthalate standard buffer tov (pH 4.0, validity lub sij hawm: 2 lub hlis)

Ua kom raug hnyav 10.12g ntawm potassium hydrogen phthalate (KHC8H4O4) thiab qhuav ntawm (115 ± 5) ℃ rau 2 mus rau 3 teev. Dilute rau 1000ml nrog dej.

 

(21) Phosphate standard buffer solution (pH 6.8, validity lub sij hawm: 2 lub hlis)

Ua kom raug hnyav 3.533g anhydrous disodium hydrogen phosphate thiab 3.387g potassium dihydrogen phosphate qhuav ntawm (115 ± 5) ° C rau 2 ~ 3 teev, thiab dilute rau 1000mL nrog dej.

 

3. Kev txiav txim siab ntawm hydroxypropylmethylcellulose pawg cov ntsiab lus

(1) Kev txiav txim siab ntawm cov ntsiab lus methoxyl

Kev txiav txim siab ntawm pawg methoxy cov ntsiab lus yog nyob ntawm qhov kev sim uas muaj methoxy pawg. Hydroiodic acid decomposes thaum cua sov los tsim volatile methyl iodide (boiling point 42.5 ° C). Methyl iodide yog distilled nrog nitrogen nyob rau hauv tus kheej-reactive tov. Tom qab ntxuav kom tshem tawm cov khoom cuam tshuam (HI, I2 thiab H2S), methyl iodide vapor yog absorbed los ntawm acetic acid tov ntawm potassium acetate uas muaj Br2 los ua IBr, uas yog ces oxidized rau iodic acid. Tom qab distillation, cov ntsiab lus ntawm receptor yog pauv mus rau lub raj mis iodine thiab diluted nrog dej. Tom qab ntxiv formic acid kom tshem tawm ntau tshaj Br2, KI thiab H2SO4 ntxiv. Cov ntsiab lus methoxyl tuaj yeem xam los ntawm titrating 12 nrog Na2S2O3 tov. Qhov sib npaug ntawm cov tshuaj tiv thaiv tuaj yeem qhia tau raws li hauv qab no.

 

Cov cuab yeej ntsuas cov ntsiab lus methoxyl yog qhia hauv daim duab 7-6.

 

Hauv 7-6(a), A yog 50mL round-bottomed flask txuas nrog lub catheter. Nws muaj ib tug ncaj cua condensation raj E vertically ntsia ntawm lub raj mis, txog 25cm ntev thiab 9mm puab txoj kab uas hla. Sab saum toj kawg ntawm lub raj yog khoov rau hauv lub khob capillary raj nrog ib txoj kab uas hla ntawm 2 hli thiab lub qhov hluav taws xob tig mus rau hauv qab. Daim duab 7-6(b) qhia txog cov cuab yeej txhim kho. Daim duab 1 qhia txog cov tshuaj tiv thaiv lub raj mis, uas yog 50mL round-bottomed flask, nrog lub raj nitrogen ntawm sab laug. 2 yog ntsug condenser raj; 3 yog lub tshuab ntxhua khaub ncaws, muaj cov kua ntxhua khaub ncaws; 4 yog lub raj nqus dej. Qhov sib txawv loj tshaj plaws ntawm cov cuab yeej no thiab Pharmacopoeia txoj kev yog tias ob lub absorbers ntawm Pharmacopoeia txoj kev tau muab tso rau hauv ib qho, uas tuaj yeem txo qhov poob ntawm cov kua dej zaum kawg. Tsis tas li ntawd, cov kua ntxhua hauv lub tshuab ntxhua khaub ncaws kuj txawv ntawm cov tshuaj pharmacopoeia. Nws yog dej distilled, thaum lub cuab yeej txhim kho yog kev sib xyaw ntawm cadmium sulfate tov thiab sodium thiosulfate tov, uas yooj yim rau nqus impurities hauv cov roj distilled.

 

Instrument pipette: 5mL (5 pieces), 10mL (1 daim); Qhov hnyav: 50 ml; Iodine ntim lub raj mis: 250mL; Kev ntsuas ntsuas.

 

Reagent phenol (vim nws yog ib qho khoom, nws yuav yaj ua ntej noj); carbon dioxide los yog nitrogen; hydroiodic acid (45%); analytical qib; poov tshuaj acetate tov (100g / L); bromine: qib ntsuas; formic acid: analytical qib; 25% Sodium acetate daws (220g / L); KI: analytical qib; dilute sulfuric acid (1 + 9); sodium thiosulfate txheem tov (0.1mol / L); phenolphthalein qhia; 1% ethanol kua; starch qhia: 0.5% Starch aqueous tov; dilute sulfuric acid (1 + 16.5); 30% chromium trioxide tov; organic-dawb dej: ntxiv 10mL ntawm dilute sulfuric acid (1 + 16.5) rau 100mL dej, kub rau boiling, thiab ntxiv 0.1ml ntawm 0.02mol / L permanganic acid Potassium titer, boil rau 10 feeb, yuav tsum nyob twj ywm liab; 0.02mol/L sodium hydroxide titrant: Calibrate 0.1mol/L sodium hydroxide titrant raws li Suav Pharmacopoeia Appendix method, thiab raug dilute rau 0.02mol nrog boiled thiab txias distilled dej / L.

 

Ntxiv li 10mL ntawm cov kua ntxhua rau hauv lub tshuab ntxhua khaub ncaws, ntxiv 31mL ntawm cov kua nqus dej uas tau npaj tshiab rau hauv lub raj nqus dej, teeb tsa lub ntsuas, hnyav li 0.05g ntawm cov qauv qhuav uas tau qhuav kom qhov hnyav tas li ntawm 105 ° C (raug rau 0.0001. g), ntxiv cov tshuaj tiv thaiv ntawm ℃ Hauv lub raj mis, ntxiv 5 mL ntawm hydroiodide. Ceev nrooj txuas cov tshuaj tiv thaiv lub raj mis mus rau qhov rov qab condenser (moisten qhov chaw sib tsoo nrog hydriodic acid), thiab tso nitrogen rau hauv lub tank ntawm tus nqi ntawm 1 mus rau 2 npuas ib ob.


Post lub sij hawm: Feb-01-2024
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