Ezinye izihloko zokuxazulula izinkinga ze-LC aziphelelwa yisikhathi, njengoba kunezinkinga ekusebenzeni kwe-LC, njengoba ubuchwepheshe bezinsimbi buyathuthuka ngokuhamba kwesikhathi.Kunezindlela eziningi lapho izinkinga ezingavela khona ohlelweni lwe-LC futhi zigcine zisesimweni esibi kakhulu.
Kube kumnandi ukubhala le kholomu ethi “LC Troubleshooting” kanye nokucabanga ngezihloko inyanga ngayinye, ngoba ezinye izihloko aziphumi esitayeleni. Ngenkathi emkhakheni we-chromatography cwaninga izihloko ezithile noma imibono iyaphelelwa yisikhathi njengoba ithathelwa indawo imibono emisha nengcono, emkhakheni wokuxazulula izinkinga, njengoba i-athikili yokuqala yokuxazulula izinkinga yavela kulo magazini (i-LC Journal) isasebenza ngesikhathi 1983(1).Kule minyaka embalwa edlule, ngigxile ezigabeni ezimbalwa zokuxazulula izinkinga ze-LC kumathrendi esimanje athinta i-liquid chromatography (LC) (isibonelo, ukuqhathanisa okuhlobene nokuqonda kwethu umphumela wengcindezi ekugcineni [2] Intuthuko Entsha) Ukuchazwa kwethu kwemiphumela ye-LC kanye nendlela yokuxazulula inkinga ngochungechunge lwami lwe-LC lwanamuhla (3) oluqale uchungechunge lwami lwe-LC lwango-December. 2021, egxile kwezinye zezihloko "zokuphila nokufa" zokuxazulula izinkinga ze-LC - izici ezinhle kunoma yisiphi isixazululi sezinkinga zibalulekile, kungakhathaliseki ubudala besistimu esiyisebenzisayo.Isihloko esiyinhloko salolu chungechunge sihambisana kakhulu neshadi lodonga "LC Troubleshooting Guide" le-LCGC (4) elilenga ezindaweni eziningi zokucwaninga. izici.Ngokumangalisayo, ishadi lodonga libala izimbangela ezihlukene ezingu-44 ezingaba khona zokuma okubi kwesiqongo!Asikwazi ukucabangela zonke lezi zinkinga ngokuningiliziwe esihlokweni esisodwa, ngakho kulesi sitolimende sokuqala esiphathelene nesihloko, ngizogxila kwezinye engizibona kaningi.Ngithemba ukuthi abasebenzisi be-LC abancane nabadala bazothola amathiphu nezikhumbuzi eziwusizo ngalesi sihloko esibalulekile.
Ngizithola ngiya ngokuya ngiphendula imibuzo yokuxazulula inkinga ngokuthi “kungenzeka noma yini”. Le mpendulo ingase ibonakale ilula uma ngicabangela ukuqaphela okunzima ukukuhumusha, kodwa ngikuthola kufaneleka kakhulu. Ngezizathu eziningi ezingaba khona zokuma okubi kakhulu, kubalulekile ukugcina umqondo ovulekile lapho ucabangela ukuthi inkinga ingaba yini, futhi sikwazi ukubeka phambili izimbangela ezingaba khona ukuze siqale imizamo yethu yokuxazulula izinkinga, ukugxila kulawo maphuzu abaluleke kakhulu, okungenzeka kakhulu.
Isinyathelo esibalulekile kunoma yimuphi umsebenzi wokuxazulula inkinga - kodwa engicabanga ukuthi sisezingeni eliphansi - ukuqaphela ukuthi kunenkinga okufanele ixazululwe.Ukubona ukuthi kunenkinga ngokuvamile kusho ukuqaphela ukuthi okwenzeka ethuluzini kuhlukile kulokho esikulindele, okubunjwa ngethiyori, ulwazi olunohlonze, nolwazi (5) .I-"peak shape" okubhekiselwa kuyo kuphela lapha, i-shapeal ye-referral ye-referric i-asymmetrical, bushelelezi, i-fluffy, unqenqema oluholayo, umsila, njll.), kodwa futhi ububanzi.Okulindelekile kwethu ngesimo esiphezulu sangempela kulula.Ithiyori (6) isekela kahle ukulindela kwencwadi yokufunda ukuthi, ezimweni eziningi, iziqongo ze-chromatographic kufanele zilingane futhi zivumelane nokuma kokusabalalisa kwe-Gaussian, njengoba kukhonjisiwe kule nkinga, esizoyilindela kusuka ku-Figure and Complex. isihloko esihlokweni esizayo.Ezinye izimo eziphezulu kuMdwebo 1 zibonisa ezinye zezinye izinto ezingase zibonwe—ngamanye amazwi, ezinye zezindlela izinto ezingase zingahambi kahle.Engxenyeni esele yalesi sitolimende, sizochitha isikhathi sixoxa ngezibonelo ezithile zezimo ezingaholela kulezi zinhlobo zomumo.
Kwesinye isikhathi iziqongo azibonwa nhlobo ku-chromatogram lapho okulindeleke ukuthi zikhishwe khona.Ishadi lodonga elingenhla libonisa ukuthi ukungabikho kwenani eliphakeme (ngokucabangela ukuthi isampula empeleni iqukethe i-analyte eqondiwe ekugxiliseni okufanele yenze impendulo yomtshina yanele ukuyibona ngaphezu komsindo) ngokuvamile ihlobene nenkinga yensimbi ethile noma izimo zesigaba seselula ezingalungile (uma zibonwa nhlobo). iziqongo, ngokuvamile kakhulu “zibuthakathaka”).Uhlu olufushane lwezinkinga ezingaba khona nezisombululo kulesi sigaba zingatholakala kuThebula I.
Njengoba kushiwo ngenhla, umbuzo wokuthi kungakanani ukunwetshwa kwesiqongo okufanele kubekezelelwe ngaphambi kokunaka nokuzama ukusilungisa kuyisihloko esiyinkimbinkimbi engizoxoxa ngaso esihlokweni esizayo.Okuhlangenwe nakho kwami ​​ukuthi ukunwetshwa okubalulekile kwesiqongo kuvame ukuhambisana noshintsho olubalulekile ekubunjweni kwepeak, futhi umsila we-peak uvame kakhulu kunokuqala noma ukuhlukaniswa.
Ngayinye yalezi zindaba ixoxwe ngokuningiliziwe ezindabeni zangaphambilini zokuxazulula izinkinga ze-LC, futhi abafundi abanentshisekelo kulezi zihloko bangabheka lezi zihloko zangaphambilini ukuze bathole ulwazi ngezimbangela kanye nezixazululo ezingaba khona kulezi zinkinga. Imininingwane eyengeziwe.
Umsila ophakeme, ukugqama okuphambili, nokuhlukanisa konke kungabangelwa izenzakalo zamakhemikhali noma ezibonakalayo, futhi uhlu lwezixazululo ezingaba khona zalezi zinkinga luyahlukahluka kakhulu, kuye ngokuthi sibhekene nenkinga yamakhemikhali noma engokomzimba. Ngokuvamile, ngokuqhathanisa iziqongo ezihlukene zechromatogram, ungathola izinkomba ezibalulekile mayelana nokuthi iyiphi imbangela. kuthinteke isiqongo esisodwa noma ezimbalwa kuphela, kodwa okunye kubukeka kuhle, imbangela cishe ingamakhemikhali.
Izimbangela zamakhemikhali ze-peak tailing ziyinkimbinkimbi kakhulu ukuthi zingaxoxwa kafushane lapha.Umfundi onentshisekelo ubhekiselwa omagazini bakamuva "I-LC Troubleshooting" ukuze uthole ingxoxo ejulile (10). Nokho, into elula ukuyizama ukunciphisa isisindo sohlazi olujovwe futhi ubone ukuthi isimo esiphezulu siyathuthuka. ama-analyte mass, noma izimo ze-chromatographic kufanele zishintshwe ukuze kutholwe umumo omuhle ophakeme ngisho noma kujovwe ubuningi obukhulu.
Kukhona futhi izizathu eziningi ezingaba khona ezithinta umsila omkhulu.Abafundi abathanda ingxoxo enemininingwane yamathuba badluliselwa kolunye udaba lwakamuva lwe-"LC Troubleshooting" (11).Enye yezimbangela ezivame kakhulu zomsila we-peak uxhumo olungeluhle endaweni ethile phakathi komjovo nomtshina (12).Isibonelo esidlulele siboniswa kuMfanekiso 1d, uhlelo olusha olwakhiwe emasontweni ambalwa edlule. esasingazange sisebenzise ngaphambili, futhi safaka iluphu yomjovo wevolumu encane ene-ferrule eyayibunjwe ku-capillary yensimbi engagqwali.Ngemuva kokuhlolwa okuthile kokuxazulula inkinga, saqaphela ukuthi ukujula kwembobo ku-stator ye-valve yomjovo kwakujule kakhulu kunalokho ebesikujwayele, okubangele ivolumu enkulu efile ezansi kwembobo. susa ivolumu efile phansi kwechweba.
Iziqongo ezifana nalezo ezikhonjiswe kuMfanekiso 1e nazo zingabangelwa izinkinga ezingokomzimba noma zamakhemikhali.Imbangela evamile engokomzimba yonqenqema oluholayo ukuthi umbhede wezinhlayiyana wekholomu awugcwele kahle, noma ukuthi izinhlayiya zihlele kabusha ngokuhamba kwesikhathi.Njengokuba umsila ophakeme obangelwa yile nto ebonakalayo, indlela engcono kakhulu yokulungisa lokhu ukufaka esikhundleni sekholomu futhi siqhubeke nokususa lokho okuvela kumakhemikhali aqala ukuvela, okuvame ukuvela ku-pemental shape. Izimo zokugcina "ezingezona umugqa".Ngaphansi kwezimo ezikahle (eziqondile), inani le-analyte eligcinwe yisigaba esimile (ngakho-ke, isici sokugcina) lihlobene ngokuhambisana nokugxilisa i-analyte kukholomu.Ngokwe-Chromatographically, lokhu kusho ukuthi njengoba inqwaba ye-analyte ejovwe kukholamu ikhula, inani eliphakeme liba lide, kodwa ukuziphatha komugqa kungabi banzi lapho ubudlelwano bungeyona ebanzi. iziqongo azigcini nje ngokuba zinde kodwa futhi ziba banzi njengoba kujovwa isisindo esiningi.Ngaphezu kwalokho, umumo ongewona umugqa unquma umumo weziqongo zechromatographic, okuholela emaphethelweni aholayo noma alandelanayo.Njengokuba nomthwalo osindayo obangela umsila ophakeme (10), ukuhola okuphezulu okubangelwa ukugcinwa okungenamugqa kungabuye kutholwe ngokunciphisa umjovo womjovo omjovwe ukuze uthuthukise ukwakheka komjovo wokuhlaziya, ukuze umjovo wekhwalithi uthuthukiswe. unqenqema oluphambili, noma izimo ze-chromatographic kufanele zishintshwe ukuze kuncishiswe lokhu kuziphatha.
Kwesinye isikhathi sibona lokho okubonakala kuwukuqothuka “kokwehlukana”, njengoba kuboniswe kuMfanekiso 1f. Isinyathelo sokuqala ekuxazululeni le nkinga siwukuba sinqume ukuthi ukuma okuphezulu kungenxa yokuhlangana okuyingxenye (okungukuthi, ukuba khona kwezinhlanganisela ezimbili ezihlukene kodwa ezisondelene kakhulu ezicacisayo). Iziqongo “zokwehlukana” zihlobene nokubonakalayo Ukusebenza akuhlobene nakancane nekholomu ngokwayo.Isikhathi esiningi, inkomba ebaluleke kakhulu kulesi sinqumo ukuthi zonke iziqongo zechromatogram zikhombisa ukuhlukana komumo, noma okukodwa noma okubili.Uma kukodwa noma kubili nje, kungenzeka ukuthi kuyinkinga yokubambisana; uma zonke iziqongo zihlukaniswa, mhlawumbe inkinga engokomzimba, okungenzeka ukuthi ihlobene nekholomu ngokwayo.
Iziqongo zokuhlukaniswa ezihlobene nezici ezibonakalayo zekholomu ngokwayo ngokuvamile ngenxa yokuvinjelwa kancane kwe-inlet noma i-outlet frits, noma ukuhlelwa kabusha kwezinhlayiya zekholomu, okuvumela isigaba seselula ukuthi sigeleze ngokushesha kunesigaba seselula ezindaweni ezithile zokwakheka kwesiteshi sekholomu .kwezinye izifunda (11).I-frit evaleke kancane ngezinye izikhathi ingasulwa ngokuhlehlisa; ukugeleza kwekholomu; nokho, ngokuhlangenwe nakho kwami, lokhu kuvame ukuba yisixazululo sesikhashana kunesikhathi eside.Lokhu kuvame ukubulala ngamakholomu anamuhla uma izinhlayiya ziphinde zihlangane ngaphakathi kwekholomu.Kuleli qophelo, kungcono ukufaka esikhundleni sekholomu futhi uqhubeke.
Ukuphakama ku-Figure 1g, futhi kusukela esikhathini sakamuva elebhu yami, ngokuvamile kubonisa ukuthi isignali iphakeme kangangokuthi isifinyelele ekupheleni okuphezulu kwebanga lokuphendula.Kuma-optical absorbance detectors (i-UV-vis kulesi simo), lapho ukugxila kwe-analyte kuphezulu kakhulu, i-analyte idonsa iningi lokukhanya okudlula emtshinini wokugeleza kweseli, ishiya izimo ezincane kakhulu zokubona isithombe esivela kugesi. ithonywe kakhulu imithombo ehlukahlukene yomsindo, njengokukhanya okunhlanhlathayo kanye "nobumnyama obumnyama", okwenza isignali "ifiphele" kakhulu ngokubukeka futhi ingazimele ekugxilweni kwe-analyte. Uma lokhu kwenzeka, inkinga ngokuvamile ingaxazululwa kalula ngokunciphisa umthamo womjovo we-analyte—ukunciphisa umthamo womjovo, ukuhlambulula isampula, noma kokubili.
Esikoleni se-chromatography, sisebenzisa isignali yomtshina (okungukuthi, i-axis ka-y ku-chromatogram) njengenkomba yokugxiliswa kwe-analyte kusampula. Ngakho-ke kubonakala kungavamile ukubona i-chromatogram enesignali engaphansi kweziro, njengoba incazelo elula iwukuthi lokhu kubonisa ukugxiliswa kwe-analyte okunegethivu - okuyinto engenakwenzeka ngokomzimba. (isb, UV-vis).
Kulesi simo, ukuphakama okunegethivu kusho ukuthi ama-molecule aphuma kukholomu amunca ukukhanya okuncane kunesigaba seselula ngokwaso ngokushesha ngaphambi nangemuva kwesiqongo.Lokhu kungenzeka, isibonelo, uma kusetshenziswa amaza amaza okubona aphansi (<230 nm) kanye nezithasiselo zesigaba seselula ezimunca iningi lokukhanya kulawa maza obude.Izithasiselo ezinjalo zingaba izingxenye zesigaba seselula ze-solvent noma izingxenye ezifana ne-ocenethanothanologies ezifana ne-ocenethanote. sebenzisa iziqongo ezingezinhle ukuze ulungise ijika lokulinganisa futhi uthole ulwazi lobuningi olunembile, ngakho-ke asikho isizathu esibalulekile sokuzigwema ngese futhi (le ndlela ngezinye izikhathi ibizwa ngokuthi “ukutholwa kwe-UV engaqondile”) (13). Nokho, uma ngempela sifuna ukugwema iziqongo ezingezinhle ngokuphelele, esimweni sokutholwa kokumunca, ikhambi elingcono kakhulu ukusebenzisa i-absorption ehlukile ukuze ibambe i-waveleng yeselula ehlukile ukuze ikwazi ukumunca i-waveleng yeselula ehlukile. isigaba ukuze Bamunce ukukhanya okuncane kunama-analytes.
Iziqongo ezingezinhle zingavela futhi uma kusetshenziswa ukutholwa kwe-refractive index (RI) uma inkomba ye-refractive yezingxenye ngaphandle kwe-analyte kusampula, njenge-solvent matrix, ihlukile kunkomba ye-refractive yesigaba seselula.Lokhu kwenzeka futhi ngokutholwa kwe-UV-vis, kodwa lo mphumela uvame ukuncishiswa ngokuhlobene nokutholwa kwe-RI. Kuzo zombili izimo, ukuqoqwa okunegethivu okufinyezwayo ngokuqanjwa kwesampula encane kakhulu kungase kube isampula encane yokuqanjwa kwe-matrix yeselula. isigaba.
Engxenyeni yesithathu esihlokweni esiyisisekelo sokuxazulula inkinga kwe-LC, ngixoxile ngezimo lapho umumo wenani eliphakeme elibhekiwe uhluka esimeni esiphezulu esilindelekile noma esivamile.Ukuxazulula inkinga okuphumelelayo kwezinkinga ezinjalo kuqala ngolwazi lokwakheka okuphezulu okulindelekile (okusekelwe embonweni noma okuhlangenwe nakho kwangaphambilini ngezindlela ezikhona), ngakho-ke ukuphambuka kulokhu okulindelekile kusobala.Izinkinga zomumo ophakeme zinezimbangela eziningi ezihlukene ezingaba khona, ukuhola kakhulu ekufakeni, njll. izizathu engizibona kaningi.Ukwazi le mininingwane kunikeza indawo enhle yokuqala ukuxazulula inkinga, kodwa akubambi konke okungenzeka.Abafundi abathanda uhlu olujulile lwezimbangela nezisombululo bangabhekisela kushadi lodonga le-LCGC “LC Troubleshooting Guide”.
(4) Ishadi lodonga le-LCGC “LC Troubleshooting Guide”.https://www.chromatographyonline.com/view/troubleshooting-wallchart (2021).
(6) A. Felinger, Ukuhlaziywa Kwedatha kanye Nokucubungula Kwezimpawu ku-Chromatography (Elsevier, New York, NY, 1998), amakhasi 43-96.
(8) Wahab MF, Dasgupta PK, Kadjo AF kanye no-Armstrong DW, Anal.Chim.Journal.Rev. 907, 31–44 (2016).https://doi.org/10.1016/j.aca.2015.11.043.