淺(qian)析PH電(dian)極使(shi)用(yong)維(wei)護(hu)的註(zhu)意事項(xiang)
發(fa)布(bu)時(shi)間(jian): 2018-06-20 點擊(ji)次數: 2973次
PH電(dian)極使(shi)用(yong)維(wei)護(hu)的註(zhu)意事項(xiang):
PH電(dian)極在(zai)測量前(qian)必須(xu)用(yong)已(yi)知(zhi)pH值(zhi)的標(biao)準緩(huan)沖(chong)溶液(ye)進行標(biao)定(至少2點),在(zai)每次標(biao)定、測量後(hou)進行下(xia)壹次操作(zuo)前(qian),應(ying)該(gai)用(yong)蒸餾(liu)水(shui)或(huo)去離(li)子水(shui)分(fen)清洗(xi)PH電(dian)極,再用(yong)被測液(ye)清洗(xi)壹次PH電(dian)極,取(qu)下(xia)PH電(dian)極護(hu)套(tao)時,應(ying)避(bi)免(mian)PH電(dian)極的敏感(gan)玻(bo)璃(li)泡與(yu)硬(ying)物(wu)接(jie)觸,因(yin)為任何破損或(huo)擦毛(mao)都(dou)使(shi)PH電(dian)極失(shi)效(xiao),測量結束,及時(shi)將(jiang)PH電(dian)極保(bao)護(hu)套(tao)套上(shang),PH電(dian)極套(tao)內應(ying)放(fang)少量飽和(he)KCL液(ye),以保(bao)持PH電(dian)極球泡的濕潤(run),切忌浸(jin)泡(pao)在(zai)蒸(zheng)餾水(shui)中。
PH電(dian)極的外(wai)參比(bi)補充(chong)液(ye)為3mol/L氯(lv)化鉀溶液(ye),補充(chong)液(ye)可以(yi)從(cong)PH電(dian)極上(shang)端(duan)小(xiao)孔(kong)加(jia)入(ru),PH電(dian)極不(bu)使(shi)用(yong)時,蓋(gai)上(shang)橡(xiang)皮(pi)塞,防止補(bu)充液(ye)幹(gan)涸(he),在線(xian)PH電(dian)極1般(ban)是凝膠的,所以不(bu)需(xu)要(yao)添(tian)加(jia)電(dian)解液(ye),PH電(dian)極的引出端(duan)必須(xu)保(bao)持清(qing)潔幹(gan)燥(zao),防止輸出兩(liang)端(duan)短(duan)路,否則將(jiang)導致(zhi)測量失(shi)準或(huo)失(shi)效(xiao),PH電(dian)極應(ying)與(yu)輸入阻抗較(jiao)高(gao)的pH計(ji)≥3×1011Ω 配(pei)套,以(yi)使(shi)其保(bao)持(chi)良好(hao)的特(te)性(xing)。
PH電(dian)極應(ying)避(bi)免(mian)長(chang)期(qi)浸(jin)在(zai)蒸(zheng)餾(liu)水(shui)、蛋(dan)白質溶液(ye)和(he)酸性(xing)氟(fu)化(hua)物(wu)溶液(ye)中,PH電(dian)極避(bi)免(mian)與(yu)有(you)機矽油接(jie)觸,PH電(dian)極經(jing)長(chang)期(qi)使(shi)用(yong)後(hou),如發現(xian)斜(xie)率(lv)略有(you)降(jiang)低,則可(ke)把PH電(dian)極下(xia)端(duan)浸(jin)泡(pao)在(zai)4%HF氫(qing)氟酸 中(3~5)s, 用(yong)蒸餾(liu)水(shui)洗(xi)凈(jing)、然後(hou)在0.1 mo l/L鹽酸溶液(ye)中浸(jin)泡(pao),使(shi)之復(fu)新,好(hao)更換PH電(dian)極,被測溶液(ye)中如(ru)含有易(yi)汙染敏感(gan)球泡或堵(du)塞(sai)液(ye)接(jie)界(jie)的物(wu)質而(er)使(shi)PH電(dian)極鈍(dun)化,會(hui)出現(xian)斜率(lv)降低(di),顯(xian)示讀(du)數不準現(xian)象。如發生該(gai)現(xian)象(xiang),則應(ying)根(gen)據汙染物(wu)質的性(xing)質(zhi),用(yong)適當(dang)溶(rong)液(ye)清洗(xi),使(shi)PH電(dian)極復(fu)新。