HPLC中(zhong)的(de)幹(gan)擾(rao)峰(feng)是(shi)廣(guang)大(da)色(se)譜(pu)工(gong)作(zuo)者(zhe)甚(shen)為(wei)頭(tou)疼(teng)的(de)事(shi)情(qing),我(wo)們(men)通(tong)過(guo)對(dui)幹(gan)擾(rao)峰(feng)的(de)來(lai)源(yuan)進(jin)行(xing)分(fen)類(lei),對(dui)其(qi)產(chan)生(sheng)原(yuan)因(yin)進(jin)行(xing)分(fen)析(xi)探(tan)究(jiu),以(yi)便(bian)大(da)家(jia)進(jin)行(xing)參(can)考(kao)快(kuai)速(su)解(jie)決(jue)同(tong)類(lei)問(wen)題(ti)。
關於其幹擾峰,我們簡單分為三類:試劑或溶劑、器材以及液相係統。下麵我們會對每一類幹擾峰來源做簡單的分析。
試劑或溶劑
HPLC中,常用的試劑主要是有機溶劑、各(ge)種(zhong)鹽(yan)類(lei)及(ji)水(shui)。有(you)機(ji)溶(rong)劑(ji)一(yi)般(ban)多(duo)為(wei)購(gou)買(mai)的(de)色(se)譜(pu)級(ji),所(suo)以(yi)出(chu)現(xian)問(wen)題(ti)的(de)幾(ji)率(lv)較(jiao)小(xiao)。但(dan)是(shi)分(fen)裝(zhuang)出(chu)的(de)有(you)機(ji)溶(rong)劑(ji),由(you)於(yu)多(duo)次(ci)使(shi)用(yong),被(bei)汙(wu)染(ran)的(de)概(gai)率(lv)較(jiao)大(da),因(yin)此(ci)引(yin)入(ru)幹(gan)擾(rao)峰(feng)的(de)幾(ji)率(lv)較(jiao)高(gao)。其(qi)次(ci)是(shi)水(shui),水(shui)中(zhong)的(de)雜(za)質(zhi)是(shi)幹(gan)擾(rao)峰(feng)的(de)主(zhu)要(yao)來(lai)源(yuan)之(zhi)一(yi),這(zhe)是(shi)大(da)家(jia)極(ji)易(yi)忽(hu)視(shi)的(de)問(wen)題(ti)。
caijibochangjiaodidejiancefangfa,jianyishiyonggaopinzhishui,zheyangkeyibimianhenduoyinweishuizhidailaidewenti。zaicishigezhongyanlei,zheyeshisepuganraofengdezhuyaolaiyuanzhiyi。duiyuwujiyanyinrudeganraofeng,zaifangfakaifachuqiyibanjiuhuigeiyanguanzhu,xunzhaojiejuefangan。fangfaquedinghou,yandepinzhongjijibieyetongshiqueding,yinciyanduifangfadeyingxiangjibenkekong。
水shui和he無wu機ji鹽yan引yin起qi的de幹gan擾rao峰feng,比bi較jiao快kuai捷jie的de解jie決jue方fang案an是shi安an裝zhuang鬼gui峰feng補bu集ji柱zhu,這zhe樣yang可ke以yi有you效xiao的de避bi免mian此ci類lei幹gan擾rao。如ru果guo使shi用yong離li子zi對dui試shi劑ji,則ze需xu選xuan擇ze不bu影ying響xiang離li子zi對dui試shi劑ji的de鬼gui峰feng補bu集ji柱zhu。
研創鬼峰柱
器材
幹擾峰來源的第二個方麵是流動相配製及樣品前處理過程中接觸的各種器材。
首先是流動相配製過程中接觸的器材,包括燒杯、玻璃棒、pH計、濾杯、濾膜、流動相瓶等。燒杯、玻璃棒是配製流動相首先接觸的器材,因此建議配製流動相的燒杯、玻(bo)璃(li)棒(bang)專(zhuan)用(yong)。濾(lv)杯(bei)實(shi)驗(yan)人(ren)員(yuan)隻(zhi)要(yao)清(qing)洗(xi)幹(gan)淨(jing)一(yi)般(ban)不(bu)會(hui)帶(dai)來(lai)汙(wu)染(ran)。需(xu)要(yao)注(zhu)意(yi)的(de)是(shi),如(ru)果(guo)過(guo)濾(lv)含(han)有(you)離(li)子(zi)對(dui)的(de)流(liu)動(dong)相(xiang),建(jian)議(yi)增(zeng)加(jia)清(qing)洗(xi)次(ci)數(shu),避(bi)免(mian)清(qing)洗(xi)不(bu)幹(gan)淨(jing)汙(wu)染(ran)後(hou)續(xu)流(liu)動(dong)相(xiang)。因(yin)此(ci),對(dui)濾(lv)杯(bei)的(de)清(qing)洗(xi)應(ying)該(gai)建(jian)立(li)基(ji)本(ben)的(de)洗(xi)滌(di)規(gui)程(cheng),保(bao)證(zheng)實(shi)驗(yan)人(ren)員(yuan)對(dui)使(shi)用(yong)的(de)器(qi)材(cai)清(qing)洗(xi)到(dao)位(wei)。濾(lv)膜(mo)也(ye)是(shi)幹(gan)擾(rao)峰(feng)引(yin)入(ru)源(yuan)頭(tou)之(zhi)一(yi)。如(ru)圖(tu)3所suo示shi,乙yi腈jing經jing過guo有you機ji係xi濾lv膜mo過guo濾lv後hou,在zai梯ti度du洗xi脫tuo中zhong會hui引yin入ru較jiao大da幹gan擾rao峰feng。鑒jian於yu色se譜pu級ji試shi劑ji廠chang家jia已yi經jing過guo膜mo,且qie多duo數shu儀yi器qi都dou有you脫tuo氣qi機ji,所suo以yi我wo們men建jian議yi無wu需xu再zai對dui甲jia醇chun、yijingdengchunyoujixiangguolv。liudongxiangpingyinruganraofengdexianxiangzhuyaochuxianzaixiaji,zheshiyouyuxiajiwendugao,chunshuixiangrongyizishengxijun。houxudeliudongxiangpingshiyongrenyuanqingxibudaowei,suoyidaozhiyinruganraofeng。yinciliudongxiangpingdeqingxiyaojianliyangedexidiguicheng。
再次樣品前處理過程中接觸的器材。前處理過程中接觸的器材主要包括容量瓶、濾頭、注射器及進樣瓶。容量瓶的清洗同流動相瓶、過濾裝置一樣,要建立良好的清洗規程。移液器材以及濾頭、注射器,多為塑料製品,其化學惰性較玻璃製品差,因此容易引入幹擾峰。如下圖4、圖5、圖6所示案例,此方法檢測波長為210納米,溶劑為正己烷-異丙醇(90:10),溶劑分別接觸移液槍槍頭、一次性吸管、一次性注射器後,均引入不同的幹擾峰。
進樣小瓶若為一次性使用,一般不會引入幹擾峰。如果進樣瓶反複清洗,多次使用,則應建立清洗規程並對其清洗幹淨程度進行確認。
液相係統
yuqianliangleiganraofengxiangbi,yexiangxitongganraofengdejiejuegengjiakunnan。yexiangxitongshiyigedongtaiguocheng,suoyicileiwentijiejueguochenghaofeishijianchang,erqieyaoqiushiyanrenyuanyouhengaodesepusuyang。womenduicileiwentilaiyuanzhuyaoguijieweisanlei:強保留物質、離子對汙染和管路滋生細菌。
首shou先xian是shi強qiang保bao留liu物wu質zhi的de幹gan擾rao,其qi主zhu要yao特te征zheng是shi寬kuan峰feng。此ci類lei問wen題ti多duo數shu發fa生sheng在zai等deng度du洗xi脫tuo中zhong,梯ti度du洗xi脫tuo主zhu要yao出chu現xian在zai高gao比bi例li有you機ji相xiang處chu。這zhe是shi由you於yu強qiang保bao留liu物wu質zhi在zai當dang次ci進jin樣yang中zhong未wei洗xi脫tuo出chu,在zai後hou續xu進jin樣yang洗xi脫tuo出chu來lai所suo致zhi。
對dui於yu此ci類lei幹gan擾rao峰feng,可ke通tong過guo延yan長chang采cai集ji時shi間jian或huo增zeng加jia洗xi脫tuo強qiang度du來lai消xiao除chu對dui後hou續xu樣yang品pin的de幹gan擾rao。至zhi於yu如ru何he延yan長chang采cai集ji時shi間jian,大da家jia可ke通tong過guo下xia麵mian的de公gong式shi計ji算suan得de到dao。
N=5.54*(tR/Wb/2)^2(1)
由公式(1)推導可知
tR=Wb/2 *(N/5.54)^(1/2)(2)
其中,N-塔板數,在等度洗脫中N對所有峰相同;tR-保留時間;Wb/2-色譜峰半峰寬。
由公式(2)推知,tR2=tR1* W2b/2/W1b/2。積分結果顯示,圖7中,7min處的色譜峰W1b/2=0.12min,9min處的寬峰W1b/2=0.32min,由此可推知,圖7中9min處的寬峰保留時間tR2=7*0.32/0.12=18.6min。圖8為延長采集時間的圖譜,20min處即為圖7中9min處(chu)的(de)色(se)譜(pu)峰(feng),與(yu)公(gong)式(shi)推(tui)導(dao)結(jie)果(guo)基(ji)本(ben)接(jie)近(jin)。延(yan)長(chang)采(cai)集(ji)時(shi)間(jian)後(hou),後(hou)續(xu)圖(tu)譜(pu)幹(gan)擾(rao)峰(feng)消(xiao)失(shi)。盡(jin)管(guan)按(an)照(zhao)此(ci)公(gong)式(shi)計(ji)算(suan)會(hui)有(you)一(yi)定(ding)誤(wu)差(cha),但(dan)這(zhe)足(zu)以(yi)讓(rang)色(se)譜(pu)工(gong)作(zuo)者(zhe)對(dui)其(qi)進(jin)行(xing)預(yu)判(pan),設(she)置(zhi)合(he)理(li)的(de)采(cai)集(ji)時(shi)間(jian)。
係統幹擾峰第二個方麵是離子對、螯合劑這種難以洗脫的試劑對液相係統的汙染。此類汙染物多半是由於使用完畢含有離子對、螯ao合he劑ji之zhi類lei的de流liu動dong相xiang後hou,對dui係xi統tong的de衝chong洗xi不bu徹che底di所suo致zhi。此ci類lei汙wu染ran物wu主zhu要yao對dui一yi些xie采cai集ji波bo長chang較jiao低di的de方fang法fa產chan生sheng幹gan擾rao,普pu遍bian表biao現xian是shi基ji線xian噪zao音yin大da或huo者zhe幹gan擾rao峰feng,但dan隨sui著zhe方fang法fa的de運yun行xing會hui逐zhu漸jian趨qu於yu正zheng常chang。
xitongganraofengdisangefangmianshixitongzishengxijun。duiyuxitongzishengxijun,duoshudajiakenengjiaodebukesiyi,yinweiyexiangxitongshiyongwanbidouhuiyongyoujixiangchongxibaocun。muqianhenduofangfaliudongxiangA都(dou)是(shi)水(shui)相(xiang),雖(sui)然(ran)水(shui)相(xiang)每(mei)日(ri)都(dou)會(hui)新(xin)配(pei)製(zhi),但(dan)如(ru)果(guo)由(you)濾(lv)頭(tou)到(dao)比(bi)例(li)閥(fa)這(zhe)一(yi)段(duan)管(guan)路(lu)長(chang)時(shi)間(jian)在(zai)水(shui)相(xiang)中(zhong)就(jiu)會(hui)滋(zi)生(sheng)細(xi)菌(jun)。隨(sui)著(zhe)時(shi)間(jian)的(de)運(yun)行(xing),梯(ti)度(du)洗(xi)脫(tuo)中(zhong)會(hui)逐(zhu)漸(jian)的(de)產(chan)生(sheng)幹(gan)擾(rao)峰(feng)。此(ci)類(lei)問(wen)題(ti)雖(sui)然(ran)比(bi)較(jiao)隱(yin)蔽(bi),但(dan)比(bi)較(jiao)容(rong)易(yi)解(jie)決(jue),隻(zhi)要(yao)每(mei)日(ri)對(dui)放(fang)置(zhi)純(chun)水(shui)相(xiang)的(de)通(tong)道(dao)用(yong)有(you)機(ji)相(xiang)衝(chong)洗(xi)即(ji)可(ke)避(bi)免(mian)此(ci)類(lei)問(wen)題(ti)。
以yi上shang便bian是shi對dui幹gan擾rao峰feng來lai源yuan的de簡jian單dan分fen析xi。然ran而er對dui於yu幹gan擾rao峰feng的de產chan生sheng,要yao具ju體ti問wen題ti具ju體ti分fen析xi,因yin為wei其qi還hai與yu具ju體ti色se譜pu條tiao件jian有you關guan。同tong一yi種zhong試shi劑ji,在zai方fang法faA中產生幹擾,但在方法B中可能完全沒有幹擾。因為采集波長,有機相初始比例及最終比例等因素,都可能會對幹擾峰的出現產生影響。
圖片來源於網絡,侵刪
實shi際ji工gong作zuo中zhong,色se譜pu工gong作zuo者zhe遇yu到dao的de最zui大da困kun難nan是shi如ru何he識shi別bie判pan斷duan幹gan擾rao峰feng屬shu於yu哪na一yi類lei。由you於yu找zhao不bu清qing問wen題ti根gen源yuan,所suo以yi也ye就jiu難nan以yi有you針zhen對dui性xing的de解jie決jue問wen題ti。下xia麵mian為wei大da家jia簡jian單dan分fen享xiang一yi下xia解jie決jue幹gan擾rao峰feng的de小xiao經jing驗yan:
首先,判斷幹擾峰是來自係統還是供試品。此時需要運行兩次采集:隻zhi運yun行xing梯ti度du與yu正zheng常chang進jin樣yang。如ru果guo隻zhi運yun行xing梯ti度du,未wei進jin樣yang品pin,依yi然ran有you幹gan擾rao峰feng,這zhe種zhong情qing況kuang下xia多duo半ban是shi係xi統tong所suo致zhi,此ci時shi解jie決jue方fang向xiang應ying針zhen對dui液ye相xiang體ti係xi,而er不bu是shi針zhen對dui供gong試shi品pin。鑒jian於yu有you些xie型xing號hao的de儀yi器qi,如ru果guo不bu進jin樣yang,不bu會hui執zhi行xing進jin樣yang的de動dong作zuo。因yin此ci,對dui於yu此ci類lei儀yi器qi,建jian議yi執zhi行xing正zheng常chang進jin樣yang與yu減jian少shao進jin樣yang量liang兩liang次ci采cai集ji,根gen據ju幹gan擾rao峰feng的de大da小xiao來lai判pan斷duan是shi係xi統tong原yuan因yin還hai是shi供gong試shi品pin原yuan因yin。
其qi次ci,調tiao查zha儀yi器qi使shi用yong記ji錄lu,與yu實shi驗yan人ren員yuan交jiao流liu。一yi般ban建jian議yi查zha看kan儀yi器qi使shi用yong記ji錄lu,了le解jie近jin期qi運yun行xing哪na些xie方fang法fa以yi及ji這zhe些xie方fang法fa的de流liu動dong相xiang組zu成cheng。查zha看kan完wan相xiang關guan記ji錄lu後hou,再zai跟gen實shi驗yan人ren員yuan交jiao流liu,了le解jie其qi操cao作zuo過guo程cheng。比bi如ru,對dui於yuA通tong道dao滋zi生sheng細xi菌jun問wen題ti,我wo們men可ke以yi通tong過guo儀yi器qi使shi用yong記ji錄lu發fa現xian,出chu現xian幹gan擾rao峰feng的de儀yi器qi近jin一yi周zhou都dou是shi在zai運yun行xing同tong一yi個ge方fang法fa。實shi驗yan記ji錄lu顯xian示shi,此ci方fang法fa的de流liu動dong相xiang為wei0.1%的(de)磷(lin)酸(suan)水(shui)溶(rong)液(ye),因(yin)此(ci)可(ke)能(neng)是(shi)係(xi)統(tong)滋(zi)生(sheng)細(xi)菌(jun)所(suo)致(zhi)。但(dan)實(shi)驗(yan)人(ren)員(yuan)告(gao)知(zhi),每(mei)天(tian)晚(wan)上(shang)都(dou)會(hui)用(yong)有(you)機(ji)相(xiang)衝(chong)洗(xi)色(se)譜(pu)柱(zhu),不(bu)可(ke)能(neng)滋(zi)生(sheng)細(xi)菌(jun)。再(zai)次(ci)詢(xun)問(wen)得(de)知(zhi),實(shi)驗(yan)人(ren)員(yuan)每(mei)晚(wan)的(de)衝(chong)洗(xi)是(shi)切(qie)換(huan)成(cheng)C通道執行,而A通道卻一直在0.1%的磷酸水溶液中。因此,切換通道衝洗係統這種不規範操應盡量避免。
disan,caiqudanyinsushiyanjiejuewenti。meicizhigaibianyigeyinsu,zhubuzhaodaoganraofengdelaiyuan。cileizuofakansibijiaofeishifeili,danquerangsepugongzuozheduigeleisepuwentichanshengyuanyinyoulixingrenzhi,zengqianglesepugongzuozhejiejuewentinengli,youzhuyuhouqiwentidejiejuepaizha。
手機版




