Focus on Cellulose ethers

Ukunqunywa Kokuqukethwe Okubalulekile ku-Non-ionic Cellulose Ether nge-Gas Chromatography

I-Non-ionic Cellulose Ether nge-Gas Chromatography

Okuqukethwe kwama-substituents ku-non-ionic cellulose ether kwanqunywa i-chromatography yegesi, futhi imiphumela yaqhathaniswa ne-titration yamakhemikhali ngokudla isikhathi, ukusebenza, ukunemba, ukuphindaphinda, izindleko, njll., futhi izinga lokushisa lekholomu kwaxoxwa ngalo. Umthelela wezimo ze-chromatographic njengobude bekholomu kumthelela wokuhlukanisa. Imiphumela ibonisa ukuthi i-gas chromatography iyindlela yokuhlaziya okufanele idume.
Amagama angukhiye: i-non-ionic cellulose ether; i-chromatography yegesi; okuqukethwe esikhundleni

I-nonionic cellulose ethers ihlanganisa i-methylcellulose (MC), i-hydroxypropylmethylcellulose (HPMC), i-hydroxyethylcellulose (HEC), njll. Lezi zinto zisetshenziswa kakhulu kwezokwelapha, ukudla, i-petroleum, njll. ionic cellulose ether materials, kuyadingeka ukunquma okuqukethwe kwama-substituents ngokunembile futhi ngokushesha. Njengamanje, abakhiqizi abaningi basekhaya basebenzisa indlela yendabuko yokuhlaziya amakhemikhali ukuze ihlaziye, edinga abasebenzi abaningi futhi enzima ukuqinisekisa ukunemba nokuphindaphinda. Ngenxa yalesi sizathu, leli phepha lihlola indlela yokunquma okuqukethwe kwama-non-ionic cellulose ether substituents nge-gas chromatography, lihlaziya izici ezithinta imiphumela yokuhlolwa, futhi lithola imiphumela emihle.

1. Isivivinyo
1.1 Ithuluzi
I-GC-7800 gas chromatograph, ekhiqizwa yi-Beijing Purui Analytical Instrument Co., Ltd.
1.2 Ama-reagents
I-Hydroxypropyl methylcellulose (HPMC), i-hydroxyethylcellulose (HEC), eyenziwe ekhaya; i-methyl iodide, i-ethyl iodide, i-isopropane iodide, i-hydroiodic acid (57%), i-toluene, i-adipic acid, i-o-di Toluene yayisezingeni lokuhlaziya.
1.3 Ukunqunywa kwe-chromatography yegesi
1.3.1 Izimo ze-chromatography yegesi
Ikholomu yensimbi engagqwali ((SE-30, 3% Chmmosorb, WAW DMCS); izinga lokushisa legumbi lokuhwamuka ngu-200°C; umtshina: TCD, 200°C; izinga lokushisa lekholomu 100°C; igesi yenkampani yenethiwekhi: H2, 40 mL/min.
1.3.2 Ukulungiswa kwesixazululo esijwayelekile
(1) Ukulungiswa kwesixazululo esijwayelekile sangaphakathi: Thatha cishe u-6.25g we-toluene bese ufaka eflaskini yevolumu engu-250mL, nciphisa uphawu nge-o-xylene, xukuza kahle bese ubeka eceleni.
(2) Ukulungiswa kwesixazululo esijwayelekile: amasampuli ahlukene anezixazululo ezihambisanayo ezijwayelekile, futhi amasampula e-HPMC athathwa njengesibonelo lapha. Ebhodleleni elifanele, engeza inani elithile le-adipic acid, u-2 mL we-hydroiodic acid nesixazululo esijwayelekile sangaphakathi, bese ukala ngokunembile ibhodlela. Engeza inani elifanele le-iodoisopropane, yikale, bese ubala inani le-iodoisopropane elengeziwe. Engeza i-methyl iodide futhi, ukale ngokulinganayo, ubale inani elengeza i-methyl iodide. Dlidliza ngokugcwele, yiyeke ime ukuze i-stratification, futhi ikugcine kude nokukhanya ukuze isetshenziswe kamuva.
1.3.3 Ukulungiswa kwesixazululo sesampula
Kala ngokunembile u-0.065 g wesampula eyomile ye-HPMC ku-reactor enodonga oluwugqinsi ongu-5 mL, engeza isisindo esilinganayo se-adipic acid, u-2 mL wesisombululo esijwayelekile sangaphakathi ne-hydroiodic acid, vala ngokushesha ibhodlela lokusabela, futhi ukale ngokunembile. Shake, bese ushisa ku-150 ° C imizuzu engu-60, unyakazisa kahle phakathi nesikhathi. Cool futhi ukale. Uma ukuncipha kwesisindo ngaphambi nangemva kokusabela kungaphezu kuka-10 mg, isisombululo sesampula asivumelekile futhi isisombululo sidinga ukulungiswa kabusha. Ngemuva kokuthi isisombululo sesampula sivunyelwe ukumela ukuhlukaniswa, dweba ngokucophelela u-2 μL wesisombululo sesigaba sezinto eziphilayo, usijove ku-chromatograph yegesi, bese urekhoda i-spectrum. Amanye amasampuli e-non-ionic cellulose ether aphathwe ngendlela efanayo ne-HPMC.
1.3.4 Umgomo wokulinganisa
Uma sithatha i-HPMC njengesibonelo, i-cellulose alkyl hydroxyalkyl ether exutshwe ne-hydroiodic acid ukuze iphule wonke amabhondi e-ether e-methoxyl ne-hydroxypropoxyl futhi ikhiqize iodoalkane ehambisanayo .
Ngaphansi kwezimo eziphakeme zokushisa nezingangeni komoya, nge-adipic acid njenge-catalyst, i-HPMC isabela nge-hydroiodic acid, futhi i-methoxyl ne-hydroxypropoxyl iguqulwa ibe i-methyl iodide ne-isopropane iodide. Ukusebenzisa i-o-xylene njengento emuncayo nencibilikayo, indima ye-catalyst ne-absorbent ukukhuthaza ukusabela okuphelele kwe-hydrolysis. I-toluene ikhethwa njengesixazululo esijwayelekile sangaphakathi, kanti i-methyl iodide ne-isopropane iodide kusetshenziswa njengesixazululo esijwayelekile. Ngokuya ngezindawo eziphakeme kakhulu zezinga langaphakathi nesixazululo esijwayelekile, okuqukethwe kwe-methoxyl ne-hydroxypropoxyl kusampula kungabalwa.

2. Imiphumela kanye nengxoxo
Ikholomu ye-chromatographic esetshenziswe kulokhu kuhlolwa ayiyona indawo epholile. Ngokwephuzu lokubilisa lengxenye ngayinye, i-oda eliphakeme yi-methyl iodide, isopropane iodide, toluene ne-o-xylene.
2.1 Ukuqhathanisa phakathi kwe-gas chromatography kanye ne-chemical titration
Ukunqunywa kokuqukethwe kwe-methoxyl ne-hydroxypropoxyl ye-HPMC nge-titration yamakhemikhali sekuvuthiwe, futhi okwamanje kunezindlela ezimbili ezivame ukusetshenziswa: indlela ye-Pharmacopoeia kanye nendlela ethuthukisiwe. Kodwa-ke, zombili lezi zindlela ezimbili zamakhemikhali zidinga ukulungiswa kwenani elikhulu lezixazululo, ukusebenza kuyinkimbinkimbi, kudla isikhathi, futhi kuthinteka kakhulu yizici zangaphandle. Uma kuqhathaniswa, i-gas chromatography ilula kakhulu, kulula ukuyifunda nokuyiqonda.
Imiphumela yokuqukethwe kwe-methoxyl (w1) nokuqukethwe kwe-hydroxypropoxyl (w2) ku-HPMC inqunywe i-chromatography yegesi kanye ne-chemical titration ngokulandelanayo. Kungabonakala ukuthi imiphumela yalezi zindlela ezimbili isondelene kakhulu, okubonisa ukuthi zombili izindlela zingaqinisekisa ukunemba kwemiphumela.
Ukuqhathanisa i-titration yamakhemikhali kanye ne-chromatography yegesi mayelana nokusetshenziswa kwesikhathi, ukusebenza kalula, ukuphindaphinda kanye nezindleko, imiphumela ibonisa ukuthi inzuzo enkulu ye-chromatography yesigaba iwukuba lula, ukushesha nokusebenza kahle okuphezulu. Asikho isidingo sokulungiselela inani elikhulu lama-reagents nezixazululo, futhi kuthatha imizuzu engaphezu kweshumi kuphela ukukala isampula, futhi isikhathi sangempela esilondoloziwe sizoba sikhulu kunezibalo. Ngendlela yekhemikhali ye-titration, iphutha lomuntu ekwahluleleni indawo yokugcina ye-titration likhulu, kuyilapho imiphumela yokuhlolwa kwe-gas chromatography ithintwa kancane izici zomuntu. Ngaphezu kwalokho, i-gas chromatography iyindlela yokuhlukanisa ehlukanisa imikhiqizo yokusabela futhi ilinganisele. Uma ikwazi ukusebenzisana namanye amathuluzi okulinganisa, afana ne-GC/MS, GC/FTIR, njll., ingasetshenziswa ukukhomba amasampula ayinkimbinkimbi angaziwa (amafayibha ashintshiwe) Imikhiqizo ye-Plain ether) inenzuzo kakhulu, engenakuqhathaniswa ne-chemical titration. . Ngaphezu kwalokho, ukukhiqizwa kabusha kwemiphumela ye-chromatography yegesi kungcono kunaleyo ye-chemical titration.
Ububi be-chromatography yegesi ukuthi izindleko ziphezulu. Izindleko ezisuka ekusungulweni kwesiteshi se-chromatography yegesi ukuya ekunakekelweni kwethuluzi kanye nokukhethwa kwekholomu ye-chromatographic ziphezulu kunaleyo yendlela yekhemikhali ye-titration. Ukucushwa kwethuluzi elihlukile nezimo zokuhlola kuzophinde kuthinte imiphumela, njengohlobo Lomtshina, ikholomu ye-chromatographic nokukhetha kwesigaba esimile, njll.
2.2 Umthelela wezimo ze-chromatography yegesi emiphumeleni yokunquma
Ngokuhlolwa kwe-gas chromatography, ukhiye uwukuthola izimo ezifanele ze-chromatographic ukuze uthole imiphumela enembe kakhulu. Kulesi sivivinyo, i-hydroxyethylcellulose (HEC) ne-hydroxypropylmethylcellulose (HPMC) zisetshenziswe njengezinto zokusetshenziswa, futhi nomthelela wezici ezimbili, izinga lokushisa lekholomu nobude bekholomu, kwafundwa.
Lapho izinga lokuhlukanisa R ≥ 1.5, libizwa ngokuthi ukuhlukana okuphelele. Ngokwezinhlinzeko ze- "Chinese Pharmacopoeia", u-R kufanele abe mkhulu kuno-1.5. Kuhlanganiswe nezinga lokushisa lekholomu emazingeni okushisa amathathu, ukulungiswa kwengxenye ngayinye kukhulu kuno-1.5, okuhlangabezana nezidingo eziyisisekelo zokuhlukaniswa, okungu-R90°C>R100°C>R110°C. Uma kucatshangelwa isici somsila, isici somsila r>1 siyisiqongo somsila, u-r<1 uyisiqongo sangaphambili, futhi u-r oseduze ngu-1, ukusebenza kangcono kwekholomu yechromatographic. Nge-toluene ne-ethyl iodide, R90°C>R100°C>R110°C; I-o-xylene iyisincibilikisi esinephuzu eliphezulu lokubila, u-R90°C
Umthelela wobude bekholomu emiphumeleni yokuhlola ubonisa ukuthi ngaphansi kwezimo ezifanayo, ubude bekholomu ye-chromatographic kuphela obushintshwayo. Uma kuqhathaniswa nekholomu egcwele engu-3m ​​no-2m, imiphumela yokuhlaziya nokucaca kwekholomu engu-3m ​​kungcono, futhi uma ikholomu iyinde, kuba ngcono ukusebenza kahle kwekholomu. Lapho inani liphezulu, umphumela uthembeke kakhulu.

3. Isiphetho
I-Hydroiodic acid isetshenziselwa ukucekela phansi ibhondi ye-ether ye-non-ionic cellulose ether ukuze kukhiqizwe i-iodide ye-molecule encane, ehlukaniswa i-chromatography yegesi futhi ibalwe ngendlela yangaphakathi evamile ukuze kutholwe okuqukethwe kokuthatha indawo. Ngaphezu kwe-hydroxypropyl methylcellulose, ama-cellulose ethers alungele le ndlela ahlanganisa i-hydroxyethyl cellulose, i-hydroxyethyl methyl cellulose, ne-methyl cellulose, futhi indlela yokwelashwa yesampula iyafana.
Uma kuqhathaniswa nendlela yokulinganisa yamakhemikhali evamile, ukuhlaziywa kwe-gas chromatography kokuqukethwe okuyingxenye ye-non-ionic cellulose ether kunezinzuzo eziningi. Isimiso silula futhi kulula ukusiqonda, ukusebenza kulula, futhi asikho isidingo sokulungiselela inani elikhulu lemithi nama-reagents, okusindisa kakhulu isikhathi sokuhlaziya. Imiphumela etholwe ngale ndlela ihambisana naleyo etholwe nge-chemical titration.
Lapho uhlaziya okuqukethwe okuyingxenye nge-gas chromatography, kubaluleke kakhulu ukukhetha izimo ezifanele nezifanele zechromatographic. Ngokuvamile, ukunciphisa izinga lokushisa kwekholomu noma ukukhulisa ubude bekholomu kungathuthukisa ngokuphumelelayo ukulungiswa, kodwa kufanele kuthathwe ukunakekelwa ukuze kuvinjwe izingxenye ukuthi zingafinyeleli kukholamu ngenxa yokushisa kwekholomu ephansi kakhulu.
Njengamanje, abakhiqizi abaningi basekhaya basasebenzisa i-chemical titration ukuze banqume okuqukethwe kwezinye izinto. Kodwa-ke, uma kucatshangelwa izinzuzo nezingozi zezingxenye ezihlukahlukene, i-gas chromatography iyindlela yokuhlola elula nesheshayo okufanele ithuthukiswe ngokombono wezitayela zentuthuko.


Isikhathi sokuthumela: Feb-15-2023
Ingxoxo ye-WhatsApp Online!