Ukuzinza kwe-methylene blue: ukukhanya, i-pH, izincibilikisi nokonakala

Isixazululo esijwayelekile se-methylene blue esihlanjululiwe sifundeka njengo-0.842 ku-664 nm ngoMsombuluko. NgoLwesihlanu lona lelo bhodlela lifundeka njengo-0.791, futhi akekho oshintshe ukugxila kwaso. Umbuzo wokuqala uthi ingabe udayi ulahlekile. Umbuzo wesibili, onzima kakhulu, uthi kusho ukuthini ukuthi "ulahlekile".

Ukuzinza kwe-methylene blue akuyona imfanelo eyodwa. Kuyizinqubo eziningana zonke ezinciphisa ukumuncwa kokukhanya kubude begagasi obufanayo. Ukuncishiswa okubuyiseleka emuva, ukushintsha kokuhlangana kwama-molecule, nokuwohloka okungabuyiseleki emuva kubukeka kufana lapho kufundwa ubude begagasi obubodwa. Leli khasi liyazihlukanisa ukuze ukuhlolwa kuhunyushwe ngendlela efanele.

Okugxilwe kukho lapha ukuzinza kokwakhiwa kwesixazululo nokuhlolwa. Ngokugcinwa kwamabhodlela, ukuphathwa kwamabhodlela avuliwe nemibuzo yokuphelelwa yisikhathi, bheka isiqondiso sabathengi sesikhathi sokugcinwa. Alukho usuku lokuphelelwa yisikhathi olunikezwa lapha, ngoba isikhathi isixazululo esihlala ngaso kufanele siqinisekiswe ngokugxila, isitsha nesimo sokugcinwa esithile.

Qala ngokuchaza into okukhulunywa ngayo

I-methylene blue eyomile ne-methylene blue encibilikisiwe ziziphatha ngokuhlukile. Irekhodi le-PubChem le-methylene blue lichaza usawoti we-chloride, onesisindo sefomula esicishe sibe ngu-319.9 g/mol ohlotsheni olungenamanzi, onamakristalu aluhlaza okotshani ngokumnyama nezixazululo eziluhlaza okwesibhakabhaka ngokujulile emanzini nasotshwaleni. Imithombo yomlando eqoqiwe ichaza i-trihydrate njengezinzile emoyeni, kanti amaphepha okuphepha amanje ayalela ukuba igcinwe esitsheni esivalwe ngokuqinile, endaweni eyomile, epholile, engenisa umoya futhi evikelwe ekukhanyeni.

Lokho kwenza into eqinile ibe namandla okuhlala ingashintshile uma igcinwe ngezimo ezijwayelekile zaselabhorethri. Lokhu akusho okufanayo ngezixazululo. Umbhalo wamanje wokubuka kuqala we-USP uthi izixazululo eziqukethe i-methylene blue kufanele zilungiswe zisanda kwenziwa ngaphambi kokuhlaziywa, ukupakishwa kugcinwe kuvalwe kahle, kuvikelwe ekukhanyeni futhi kugcinwe ngaphansi kuka-30 C. Lowo myalelo uyindlela yokuqapha ekuhlaziyweni, hhayi ubufakazi bokuthi zonke izixazululo ziyafiphala ezinsukwini ezimbalwa. Usho ukuthi ukuzinza kwesixazululo se-methylene blue kufanele kuboniswe, kungacatshangwa nje. Ukubuka kuqala kwe-monograph ye-USP ye-methylene blue kuchaza isisekelo sokuhlolwa kobuningi esisetshenziswa kuleso sinqumo.

Ukukhanya: ukulahleka okuyinhloko okungagwenywa

I-methylene blue imunca ukukhanya ebangeni elikhishwa ukukhanya okujwayelekile. I-monomer imunca ngamandla eduze kuka-658 kuya ku-665 nm, inendawo eyengeziwe yokumunca ye-dimer eduze kuka-605 kuya ku-610 nm namabhendi e-ultraviolet eduze kuka-292 nm nangaphansi. Ngakho ukukhanya okubomvu kwetafula lomsebenzi kuhambisana ngqo nebanga lokumunca likadayi. Ukukhanya kwe-fluorescent, ama-LED amhlophe ne-UV-A nakho kungaqeda umbala wezixazululo ezihlanjululiwe ezimweni zokuhlolwa. Awukho umbala owodwa wokukhanya ophephile; kukhona kuphela ukunciphisa ukuchayeka.

Ikhemistri ebangelwa ukukhanya iqala ngesimo se-triplet. Ukukhanya okumunciwe kudlulisela udayi esimweni esivusiwe, bese i-triplet evelayo ingadlulisela amandla noma ama-electron ku-oksijeni encibilikisiwe. I-monomer ehlanjululiwe yenza ukwakheka kwe-singlet oxygen ngendlela ephumelelayo, futhi kubikwe izivuno ze-quantum eziseduze kuka-0.5 emanzini. Umthombo ojwayelekile walolu hlelo ucwaningo lwe-triplet ye-methylene blue ne-singlet oxygen.

I-singlet oxygen akufanele ibizwe ngokuthi iyimbangela eyodwa yawo wonke amabhodlela afiphele. Izixazululo ezichayekiswe emisebeni ziqukethe izinhlobo ze-leuco ezincishisiwe kanye nodayi abasuswe amaqembu e-methyl, futhi ababhali bocwaningo lokuchayekisa i-methylene blue ekukhanyeni okubonakalayo basho ngokusobala ukuthi indlela lezi zinqubo ezihlukaniseka ngayo ayikanqunywa. Ukuncishiswa okubangelwa ukukhanya nokubuyiseleka emuva, ukususwa kwamaqembu e-methyl ku-N nge-oxidation, ezinye izinqubo zamakhemikhali ezinhlobo ze-oksijeni ezisebenzayo, nokuqhekeka okulandelayo kungenzeka ngesikhathi esisodwa.

Kolunye ucwaningo lwezinto, udayi ongu-10 mg/L emanzini ku-20 C walahlekelwa cishe ngamaphesenti angu-37 okumuncwa kokukhanya ngemva kwemizuzu engu-120 ngaphansi kokukhanya okubonakalayo kwaselabhorethri, nangamaphesenti angu-53 ngaphansi kokukhanya kwelanga, kuyilapho isampula yokulawula ebumnyameni ingakhombisanga ukulahleka okutholakalayo ngisho naku-80 C. Lezo zinombolo zivela ocwaningweni lwezinga lokushisa nokukhanyiswa kwe-methylene blue emanzini futhi zichaza kuphela leyo mishini yokuhlola. Zibonisa ukuthi ukukhanya kunomthelela omkhulu, hhayi isikhathi sokulahleka kwengxenye yenani kwelinye ibhodlela.

I-oksijeni idlala izindima ezimbili, yingakho "ukuchayeka emoyeni" kungacacile. I-oksijeni ivumela ukwakheka kwezinhlobo ze-oksijeni ezisebenzayo ezivela kudayi ovusiwe, kodwa iphinde yenze i-oxidation ye-leucomethylene blue engenambala iyibuyisele esimweni esiluhlaza okwesibhakabhaka. Ngakho umoya ungaqeda umbala wesixazululo esisodwa futhi ubuyisele umbala kwesinye. Umehluko phakathi kokwakheka kwe-leuco nokubhujiswa uchazwa kabanzi kukhemistri ye-redox ye-methylene blue ne-leucomethylene blue.

Ukuhlangana kwama-molecule kushintsha ukuzwela ekukhanyeni kwe-molecule ngayinye. Ama-H-dimer abhekene ngobuso abuyela ngokushesha esimweni esingavusiwe futhi akhiqiza i-triplet ne-singlet oxygen okuncane kakhulu kune-monomer, njengoba kukalwe ocwaningweni lwezici ze-dimer ye-methylene blue lapho ichayekiswe ekukhanyeni.

I-pH: ukuzinza phakathi nendawo, ushintsho lwamakhemikhali emaphethelweni

Ebangeni elisuka ku-asidi liye esimweni esingathathi hlangothi, i-cation eluhlaza okwesibhakabhaka esesimweni se-oxidation imelana kangcono nezinqubo zamakhemikhali ze-alkali ezenzeka ngokuzenzakalelayo kunalapho i-pH iphezulu. Isifinyezo esiqoqwe ku-PubChem sokuthi le nto igcina yenzeka kanjani emvelweni asilindeli ukuthi i-hydrolysis ibe nomthelela omkhulu cishe ku-pH 5 kuya ku-9, kodwa lokho kuwukulinganisela kwemvelo, hhayi ukuqinisekiswa kwemikhiqizo yezemithi.

Ucwaningo lwakudala lwathola ukuthi udayi ohlanjululiwe eduze kuka-25 C wawuzinzile kakhulu ngaphansi kwe-pH ecishe ibe ngu-9.5, ukususwa kwamaqembu e-alkyl kuqala cishe ku-pH 9.5 kuya ku-9.8, noshintsho olusheshayo ku-pH 12 phakathi kwezinsuku. Umphumela uvela ocwaningweni lwangaphambilini lokuzinza kwe-methylene blue esixazululweni se-alkali futhi kufanele ufundwe njengobufakazi bendlela inqubo esebenza ngayo, hhayi njengombandela wokucaciswa komkhiqizo.

I-alkali enamandla ingaphinde ishintshe indlela yekhemistri. Ku-0.1 M we-alkali emanzini, umkhiqizo oyinhloko owahlukaniswa kwakuyi-Bernthsen methylene violet, umkhiqizo we-hydrolysis ye-alkali, njengoba wahlonzwa ocwaningweni lokonakala kodayi be-phenothiazine ku-alkali. Lokho kuwukubola kwamakhemikhali, hhayi ukushintsha kombala kwenkomba ye-pH.

Ukuncishiswa kukhiqiza i-leucomethylene blue, ecishe ingabi nambala futhi ebuyiselwa kalula esimweni se-oxidation ngumoya, ngokushesha lapho i-pH iphezulu nangokunensa ku-asidi. Ukuncika ku-oksijeni kwachazwa ocwaningweni lokuncishiswa kwe-methylene blue okubangelwa ukukhanya nokubuyiselwa kwayo esimweni se-oxidation. Ngakho ukulahleka kombala oluhlaza okwesibhakabhaka kufakazela kuphela ukuthi inani lezinhlobo ezisesimweni se-oxidation lehlile, hhayi ukuthi lokhu kubangelwe ukuncishiswa, ukuhlangana kwama-molecule noma ukubhujiswa.

Izincibilikisi nokuhlangana kwama-molecule: ububanzi bokumunca bungashintsha ngaphandle kokulahleka

Amanzi ancibilikisa usawoti we-chloride kalula. I-PubChem iqoqa inani elicishe libe ngu-43.6 g/L emanzini ku-25 C kanye nezincazelo ezingezona ezamanani zokuncibilika ku-ethanol naku-chloroform, kuyilapho ulimi lwezincwadi zemithi lusebenzisa amagama anjengokuncibilika kancane noma ngokulinganiselwe ezintweni ezicacisiwe. Uhlobo lwe-hydrate, ukuhlanzeka, amandla ama-ion namagama asetshenziswayo kuchaza ingxenye yalokhu kwehluka. Umhlahlandlela wokuncibilika kwe-methylene blue nokulungiswa kwesixazululo uchaza indlela yokubika isisekelo sento elinganisiwe esihambisana nenani.

Ukukhetha isincibilikisi kushintsha izinhlobo zamakhemikhali ezikhona, hhayi ukuncibilika kuphela. Ezingxubeni zamanzi ne-methanol, ukuhlaziywa kwe-spectrum kuhlukanisa i-monomer, i-dimer ne-trimer emanzini kanye ne-monomer eku-methanol, njengoba kuboniswe ocwaningweni lokuhlangana kwama-molecule e-methylene blue ezincibilikisini ezixutshiwe. Utshwala abuqedi ukuhlangana kwama-molecule: ama-dimer namaqoqo amakhulu ayaqhubeka nokuba khona ku-methanol, ethanol, propanol nase-butanol, ngokusho kocwaningo lokuhlangana kwama-molecule okuncike esincibilikisini.

Emsebenzini wangempela, isincibilikisi, amandla ama-ion, izinga lokushisa nokugxila kungashintsha indawo yesiqongo nekhono lokumunca ngaphandle kokubhujiswa kukadayi. Gcina isampula nesixazululo esijwayelekile ohlelweni olufanayo lwezincibilikisi futhi uqinisekise ubudlelwano bomugqa oqondile. Incazelo ye-IUPAC yomthetho ka-Beer-Lambert ichaza izimo ezidingekayo ukuze ukumuncwa kokukhanya kuhambisane nokugxila.

Ukufiphala okubuyiseleka emuva kuqhathaniswa nokonakala okungabuyiseleki emuva

Ukususwa okuqhubekayo kwamaqembu e-methyl ku-N kukhiqiza i-Azure B bese kuba izinhlobo ze-Azure ezinamaqembu e-methyl ambalwa ne-thionine. Ukufaka umoya ebhodleleni akusibuyiseli emuva leso sinyathelo, futhi ukuhlukana kwezindlela kwangempela kuyehluka, ngakho akufanele kudwetshwe njengeketango elilodwa eliqinile. Inethiwekhi iboniswe ocwaningweni lwemikhiqizo yokususwa kwamaqembu e-methyl ku-methylene blue.

I-leucomethylene blue yona ingakolunye uhlangothi. Iwuhlobo oluncishiswe ngama-electron amabili, cishe olungenambala, futhi i-oksijeni noma esinye isenzeli se-oxidation singabuyisela udayi oluhlaza okwesibhakabhaka. Ukulawulwa ezincwadini zemithi kubonisa uhlangothi olungabuyiseleki emuva: i-monograph yamanje ye-USP ilawula i-Azure B njengokungcola okucacisiwe, okuhambisana nokususwa kwamaqembu e-methyl okuyindlela yokwakheka kokungcola okufanele iqashwe.

I-oxidation elandelayo ikhiqiza imikhiqizo evuleke izindandatho neyehlukaniswe yaba izingcezu. Lokho kuwukubhujiswa. Ilabhorethri ayidingi ukuhlonza zonke izingcezu. Idinga ukugwema ukubiza konke ukwehla kokumuncwa kokukhanya ngegama elifanayo.

Ithebula lobufakazi bokuzinza ngokwesimo

Leli yithebula eliyinhloko elisetshenziswa njengomthombo kuleli khasi. Umugqa ngamunye uchaza isimo, ukuziphatha okusekelwe ubufakazi obuqine kakhulu, nesilawuli esivimbela isiphetho esingalungile.

Izilawuli zomsebenzi wokulinganisa ubuningi

Lungisa izixazululo ezijwayelekile zokuhlaziya zisanda kwenziwa futhi ugcine isikhathi sokuchayeka sifushane. Qondanisa izinga lokushisa, i-pH, isincibilikisi, amandla ama-ion nebanga lokugxila phakathi kwezixazululo ezijwayelekile namasampula. Faka isampula yokulawula ebumnyameni lapho kufundwa ukonakala, kanye nesampula yokulawula echayekiswe ekukhanyeni engenaso isikhuthazi sokusabela ekuhlolweni kwekhemistri ebangelwa ukukhanya. Lapho i-spectrum ibalulekile, rekhoda yonke i-spectrum yokukhanya okubonakalayo kunobude begagasi obubodwa, ngoba odayi abasuswe amaqembu e-methyl namaqoqo bamunca emabangeni asondelene kodwa angafani ncamashi. Ama-spectrum ancike ekugxileni asekela leso seluleko abhalwe ocwaningweni lokuhlaziywa kwe-spectrum ngokugxila nokuhlangana kwama-molecule.

Ungaguquli noma yimuphi umphumela kuleli khasi ube yisikhathi sokugcinwa. Isikhathi esiqinisekisiwe sihambisana nokwakhiwa kwesixazululo, isitsha, ukugxila, isikhala somoya esingenhla, ukulawulwa kwamagciwane nesimo sokugcinwa okuchaziwe. Lokho kuqinisekiswa kusingathwa isiqondiso sabathengi sesikhathi sokugcinwa, esisekelwa yileli khasi kodwa elingasithathi indawo.