Ubururu bwa methylene nk'ikimenyetso: icyo ihinduka ry'ibara ryerekana mu by'ukuri

Umutekinisiye ashyira ubururu bwa methylene mu gikombe cya laboratwari, agatunganya pH, maze agategereza ko ibara ryerekana urugero rw'aside. Nta gihinduka mu buryo busobanutse. Ahubwo yongeramo igitonyanga cy'umuti w'aside asikorubike, maze ubururu bukazimira. Azunguza icupa rya laboratwari mu mwuka, ubururu bukagaruka. Ni irangi rimwe, ariko rifite imyitwarire ibiri itandukanye cyane. Uru rujijo ni rwo ngingo yose y'iyi nyandiko: ubururu bwa methylene ni ikimenyetso cya redox gisubiza ku ihererekanywa rya elekitironi, si ikimenyetso cya pH gisubiza kuri porotoni. Iyo iri tandukaniro risobanutse, ibindi byose na byo birumvikana.

Itegeko ngiro rikubiye mu nteruro imwe. Ubururu bwerekana ko imiterere yanyuze muri okisidasiyo ihari. Kutagira ibara byerekana ko imiterere yanyuze muri redigisiyo, ubururu bwa leucomethylene, ihari. Ikintu cyose gihererekanya elekitironi gishobora guhindura iyo miterere. Aside na baze byonyine ntibishobora kubikora, nubwo pH ihindura volitaje iryo hinduka riberaho.

Imiterere ibiri itera ibara

Ubururu bwa methylene bwanyuze muri okisidasiyo ni kationi ya methylthioninium, sisitemu ya phenothiazinium ifite impeta eshatu ziri mu buso bumwe, itangwa nk'umunyu wa chloride, uwo PubChem yandikaho nka methylthioninium chloride. Mu mazi arimo uyu muti ku rugero ruto, monomeri inyunyuza urumuri hafi ya 664 nm, kandi uko kunyunyuzwa ni ko gutuma ijisho ribona ubururu. Imiterere ijyana na yo yanyuze muri redigisiyo, ubururu bwa leucomethylene, ifite igikanka kimwe, ariko azote yo mu mpeta yo hagati iba yongeweho porotoni kandi igice gitera ibara kiba cyahungabanye. Ni yo mpamvu isa n'itagira ibara, naho agace kayo gakomeye ko kunyunyuzamo urumuri kakaba mu mirasire ya ultraviolet (inyandiko ya PubChem ku miterere ya leuco).

Reyakisiyo rusange ihererekanya elekitironi ebyiri, ariko umubare wa porotoni uterwa na pH kuko imiterere yanyuze muri redigisiyo yakira porotoni mu buryo bwa aside. Isesengura rishingirwaho mu kwerekana ubutabire bwa redox ritanga potansiyeli isanzwe iri hafi ya +0.53 V kuri pH 0 na potansiyeli igenwa n'imimerere iri hafi ya +0.011 V kuri pH 7, bipimwe ugereranyije na elekiturode ya hidrojeni. Hagati y'izo ngingo, potansiyeli irahinduka uko pH ihinduka. Voltametri yo muri iki gihe, mu bushakashatsi ku myitwarire ya redox na potansiyeli z'amarangi, ibona hafi 29.5 mV kuri buri gice cya pH kuva hafi ya pH 4 kugeza kuri 10, bihuye n'uburyo bwa elekitironi ebyiri na porotoni imwe, na hafi 88.5 mV kuri buri gice cya pH munsi ya pH 4, bihuye n'uburyo bwa elekitironi ebyiri na porotoni eshatu. Bityo, potansiyeli yatangajwe idafite pH yayo nta cyo ivuze. Buri gihe baza igipimo cy'ihinduka na elekiturode fatizo byashingiweho muri uwo mubare, kuko indangagaciro zapimwe ugereranyije na elekiturode za feza zidashobora kugereranywa ako kanya n'izapimwe ku gipimo cya hidrojeni. Imiterere n'imiterere yihariye by'ishingiro ni byo bigena igice gitera ibara, kandi urupapuro rujyana n'uru rwerekeye gutegura uburyo bwo gusoma redox rusobanura uko izi miterere zombi zifasha mu guhitamo ibigize umuti.

Uwo mwanya wo hagati ku gipimo cya potansiyeli ni wo utuma iri rangi rigira akamaro. Kuri pH 7 riri mu bintu bikora okisidasiyo mu buryo bworoheje: rifite ubushobozi buhagije bwo kwakira elekitironi ku bizitanga neza nka ascorbate cyangwa NAD(P)H, ariko ntirizifata cyane ku buryo ritashobora kuzihererekanya kuri ogisijeni yashonze cyangwa ku bice birimo feri(III). Bityo rikomeza guhinduranya imiterere aho kuguma muri umwe. Redigisiyo ituma ibara rizimira. Umwuka wongera kurikoresha okisidasiyo. Inzira ni imwe mu byerekezo byombi.

Impamvu ibibazo bya pH bikomeza kugaruka

Hari amasoko atatu y'urujijo akunze kugaruka muri laboratwari no mu mashuri, kandi buri rimwe rifite igisobanuro gifatika kirikosora.

Iya mbere, pH ihindura potansiyeli, bigasa n'aho ari ugusubiza kuri pH. Iyo pH izamutse, izi miterere zombi ziroroherwa no kunyura muri redigisiyo ku gaciro kadahindutse gasomwa kuri elekiturode, bityo ikintu kimwe gitanga elekitironi kigatuma ibara ry'irangi rizimira vuba. Ariko nta ntambwe yo kongeraho porotoni yonyine itera ihinduka risobanutse riva ku bururu rikajya ku kutagira ibara mu rugero rusanzwe. Isuzuma ryimbitse ryo mu 2025 ku miterere yihariye y'ubururu bwa methylene rivuga ko agaciro ntarengwa ka 665 nm kaguma hafi kudahinduka kuva kuri pH 2 kugeza kuri 12, hakabaho gusa ihinduka rito mu kunyunyuzwa k'urumuri. Porotoni zitunganya volitaje. Elekitironi zihindura ibara.

Iya kabiri, icyiciro gihabwa iri rangi mu rutonde rw'ubumenyi kirayobya. Kuri ubu PubChem yinjiza uruhare rwatanzwe na ChEBI rwita iri rangi ikimenyetso cya aside na baze. Iryo zina ntirigomba gufatwa nk'ikimenyetso cy'uko ubururu bwa methylene bwitwara nka phenolphthalein cyangwa methyl red. Mu mirimo isanzwe ikorerwa mu mazi, si uko bwitwara.

Iya gatatu, uruvange rwa Tashiro rukoresha iryo zina. Ikimenyetso cya Tashiro ni uruvange rwa methyl red n'ubururu bwa methylene, aho methyl red itanga igisubizo cya aside na baze naho ubururu bwa methylene bugatanga ibara ry'ubururu ryo inyuma. Ibyo bihindura ihinduka riva ku mutuku rijya ku muhondo rikaba ihinduka ry'amabara avanze rigaragara neza kurushaho. Uruvange rwa Tashiro rugurishwa rutanga urugero rwa pH 4.4 kugeza kuri 6.2, naho uruvange rwasobanuwe rwa ITW Reagents rugaragaza umutuku wijimye werekeza ku ibara rya violet kuri pH 4.4 kugeza ku cyatsi kuri pH 5.8. Nta na rumwe muri izo ntera ari intera y'ihinduka ry'ubururu bwa methylene ubwabwo. Iri rangi ni irifasha kugaragaza ihinduka, si ryo riripima.

Hari imimerere idasanzwe ikwiye kwitonderwa. Hafi ya pH 13, imimerere ifite baze nyinshi ishobora kubyara ibinyabutabire byo mu bwoko bwa methylene-violet, bifite ibara kuva ku mutuku kugeza kuri roze, binyuze muri hidrolize idashobora gusubizwa inyuma. Iyo roze ni ukwangirika, si iherezo rigaragazwa n'ikimenyetso. Yifate nk'ikimenyetso cyo kujugunya umuti, si icyo gusoma.

Aho bukora nk'ikimenyetso cya redox

Imikoreshereze ya kera ni titirasiyo ya Lane-Eynon y'isukari zifite ubushobozi bwa redigisiyo. Umuti ushyushye wa Fehling urimo baze ukorerwa titirasiyo hongerwamo isukari, naho ubururu bwa methylene bukongerwamo hafi y'iherezo; ubururu busigaye burazimira iyo ubushobozi bw'isukari bwo gukora redigisiyo burenze ubukenewe kuri cuivre(II). Uburyo bwa AOAC bwa Lane-Eynon bukomeza kubiza uruvange kugira ngo umwuka w'amazi usohoka ugabanye okisidasiyo yakongera guterwa n'umwuka, ubusanzwe hakoreshejwe ibitonyanga bike by'umuti w'irangi. Ihinduka ry'ibara ryerekana ko nta cuivre ishobora gukorerwa redigisiyo isigaye. Ibyo ni amakuru ya redox ku biri mu icupa, si amakuru ya pH.

Uburyo bwa kera bwo gupima hakoreshejwe titirasiyo bwakoreshaga iyi mitekerereze n'ahandi. Irangi rivanze ku rugero ruto ryashoboraga gusimbura amidoni muri titirasiyo zimwe zikoresha iyode, aho alukolo yatumaga amidoni idakwiriye gukoreshwa, ku rugero rw'imikoreshereze rwa hafi 0.05 g kuri liter. Icyakora, irangi rirengeje urugero rishobora gukora uruvange rw'ikinyabutabire cya iyode n'irangi, nk'uko Sinnatt yabigaragaje mu 1912. Ibitabo bikusanya uburyo bwa laboratwari na byo bishyira iri rangi mu bikoreshwa muri titanometri na iyodometri. Uburyo bwa Gal bwo gupima aside asikorubike bwo mu 1936 bwakoreraga irangi redigisiyo hakoreshejwe ibyakuwemo vitamine C, hanyuma irangi risigaye rigapimwa hakoreshejwe titirasiyo isubira inyuma na titanium trichloride. Ubu ubwo buryo ni ubwo mu mateka kurusha uko bukoreshwa buri gihe, ariko bwerekana ihame: ikintu gitanga elekitironi gihindura ubururu kikabugira ubudafite ibara, kandi kubura k'ubururu ni ryo herezo.

Uburyo bwo gupima ogisijeni yashonze bukoresha izi miterere zombi mu cyerekezo kinyuranye. Bumwe mu buryo bwatangajwe bubanza gukorera irangi redigisiyo hakoreshejwe glucose muri ethanol ivanze n'amazi irimo baze, hanyuma ogisijeni yashonze igakoresha okisidasiyo imiterere ya leuco idafite ibara, ikayisubiza ku bururu hafi ako kanya. Bupima hafi ya 600 nm kugeza kuri hafi 13 micrograms kuri milliliter, nk'uko byasobanuwe na Okumura na Hashitani. Ntukitiranye ibi na titirasiyo ya kera ya Winkler yo gupima ogisijeni yashonze, ikoresha amidoni ku iherezo; amabwiriza ngenderwaho ya NOAA ya Winkler ateganya amidoni iri hafi ya 1 percent. Uburyo bwo gupima ogisijeni bukoresha ubururu bwa methylene ni itsinda ryihariye, rifite icyerekezo cy'ihinduka ry'ibara kinyuranye.

Icupa ry'ubururu rikoreshwa mu ishuri na ryo ni izi miterere zombi ku rugero ruto: glucose mu muti urimo baze ikorera irangi ry'ubururu redigisiyo, ikarihindura imiterere idafite ibara iyo ridakozweho, naho kurizunguza bigashongesha ogisijeni irikoresha okisidasiyo ikarisubiza ku bururu. Uburyo bwose n'ibigenzurwa muri iryo gerageza biri mu iyerekanwa ry'icupa ry'ubururu, naho imyanya y'uduce two kunyunyuzamo urumuri n'ihinduka ryayo riterwa no kwishyira hamwe kwa molekile biri ku rupapuro rw'ibipimo by'urumuri n'ingaruka z'ingano y'ibishonze. Iyi nyandiko igumana gusa uburyo reyakisiyo ikora, kuko amabwiriza y'igerageza n'ibipimo by'urumuri buri kimwe gikeneye imimerere yacyo.

Imbonerahamwe y'imiterere y'ibara: imiterere, ibiyitera n'imbibi

Iyi mbonerahamwe ni isoko y'ibanze yifashishwa muri iyi nyandiko. Soma umurongo wose mbere yo kwizera iherezo iryo ari ryo ryose.

Ibibazo bituma iherezo ridasobanuka

Umwuka ni wo ubanza gukekwa igihe cyose iherezo rigenda rihinduka. Imiterere ya leuco yongera kunyura muri okisidasiyo byoroshye, cyane cyane muri sisitemu zirimo baze, bityo titirasiyo yari igeze ku kutagira ibara ishobora kongera kuba ubururu iyo irekewe aho cyangwa izungujwe cyane. Kumira umwuka aho kugumana imiterere ari ngombwa, shyira ukuzunguza ku buryo bumwe, kandi usome ku gihe cyagenwe.

Urumuri ni rwo rwa kabiri rukekwa. Iri rangi rigira uruhare muri reyakisiyo ziterwa n'urumuri, kandi kurimurikira hari ibitanga elekitironi bishobora kuzimya ibara ryaryo binyuze mu nzira zirimo ibinyabutabire byatakaje amatsinda ya methyl. Bika imiti y'irangi ikoreshwa mu isesengura ahatagera urumuri, kandi ntusome iherezo munsi y'amatara akomeye yo ku meza ya laboratwari.

Ingano y'ibishonze ni iya gatatu. Kationi yanyuze muri okisidasiyo yishyira hamwe ikora dimeri n'amatsinda manini, hamwe n'agace ko kunyunyuzamo urumuri kimukiye hafi ya 610 kugeza kuri 615 nm. Bityo umuti urimo irangi ryinshi ushobora kugaragara nk'utagifite impinga isanzwe, kandi utanduye. Ongera amazi kugeza mu mimerere yiganjemo monomeri mbere yo gusuzuma ibipimo by'urumuri cyangwa iherezo.

Hari ibindi bintu bibiri biyobya bucece bikwiye kuvugwa, kuko bigira ingaruka cyane cyane ku mirimo ikoresha ingano nto y'ibishonze. Iri rangi rifatira ku buso aho ikirahure gihurira n'amazi ku rugero rushobora gupimwa, ibyo bikayobya imiti fatizo irimo irangi rito n'ibipimo by'umuvuduko wa reyakisiyo; ibikoresho cyangwa cuvettes bya polimeri ni byo bikemura iki kibazo aho ubunyangamugayo bw'ibipimo ari ngombwa. Nanone, irangi rigurishwa rishobora kuba ririmo umwanda wo mu muryango wa thiazine, harimo Azure B, wavanywemo ku buryo bweruye mu bushakashatsi bwa kera bwo gutunganya irangi. Bityo, imirimo y'isesengura igomba kugaragaza urwego rw'ubuziranenge aho kwibwira ko buri cupa ryanditseho ubururu bwa methylene ririmo ibinyabutabire bimwe neza neza. Ku bushake, ibisobanuro birambuye by'ihinduka ry'ibipimo by'urumuri riterwa no kwishyira hamwe kwa molekile byagumishijwe ku rupapuro rw'ibipimo by'urumuri.

Urutonde rugufi rwo kugenzura ku meza ya laboratwari

Koresha umuti utuma pH iguma hamwe, kandi wandike pH iruhande rwa buri potansiyeli na buri herezo. Gena imimerere ya ogisijeni: kubiza hamwe n'igikingira cy'umwuka w'amazi mu mirimo yo mu bwoko bwa Lane-Eynon, naho ahandi ukoreshe igikingira cya gaze idakora reyakisiyo cyangwa igihe cyagenwe. Koresha irangi ku rugero ruto bihagije kugira ngo ubone monomeri, rinda imiti urumuri, hitamo ibikoresho bya polimeri ku rugero ruto rw'ibishonze, kandi wandike urwego rw'ubuziranenge bw'irangi. Niba intego ari ugupima pH koko, koresha ikimenyetso nyakuri cya aside na baze cyangwa uruvange rwa Tashiro rufite ibigize bizwi. Tanga intera y'uruvange nk'intera y'uruvange, ntukayite na rimwe intera y'ubururu bwa methylene.

Ihame riguma risobanutse iyo aya mabwiriza yubahirijwe. Ubururu bwa methylene bwerekana imiterere ya okisidasiyo mu buryo busobanutse bidasanzwe kuko imiterere yabwo ibiri inyunyuza urumuri rugaragara mu buryo butandukanye cyane. Fata ibara nk'igisubizo cya redox cyasomwe kuri pH yavuzwe, mu mimerere ya ogisijeni n'urumuri yavuzwe, hamwe n'urwego rw'ubuziranenge bw'irangi rwavuzwe, maze rigire umwanya waryo ukwiye muri titirasiyo. Nurifata nka litimusi, rizakuyobya buri gihe nta kabuza.