Cov cuab yeej thiab cov khoom siv raw rau calibrating pH meter
Standard buffer (tus qauv buffer uas nws tus nqi pH yog ze rau qhov kev ntsuam xyuas yuav tsum tau xaiv). Tam sim no, muaj xya hom kev daws teeb meem, thiab peb hom kev daws teeb meem hauv qab no feem ntau siv hauv Suav teb: (thaum tus nqi pH yog 25 degree)
1, potassium hydrogen phthalate (KHC8H4O4) pH4.003; 0,05m ua.
2. Mixed phosphate (Na2HPO4): cov ntsev tov ntawm poov tshuaj dihydrogen phosphate thiab disodium hydrogen phosphate yog pH 6.864; 0.025M.
3. Borax (Na2B4 O7 L0H2O) pH 9.182; 0.01M.
Cov txheej txheem configuration ntawm peb tus qauv buffers no yog raws li nram no:
1. pH4, poov tshuaj hydrogen phthalate tus qauv tsis: raug hnyav 10.12g ntawm potassium hydrogen phthalate [KHC8H4 O4] qhuav ntawm 115 5 degree rau 2 ~ 3 teev, ntxiv dej kom yaj thiab dilute nws mus rau 1000ml.
2. pH7, phosphate standard buffer (pH7.4): Yog hnyav 4.303g ntawm anhydrous disodium hydrogen phosphate thiab 1.179g ntawm potassium dihydrogen phosphate qhuav ntawm 115 5 degree rau 2-3 teev, ntxiv dej kom yaj thiab dilute rau 1000 ml.
Ntxiv rau: phosphate standard buffer (pH6.8) raug hnyav 3.533g anhydrous disodium hydrogen phosphate thiab 3.387g potassium dihydrogen phosphate qhuav ntawm 115 5 degree rau 2 ~ 3 teev, ntxiv dej kom yaj thiab dilute mus rau 1000ml.
3, pH9, borax standard buffer: raug hnyav 3.80g ntawm borax [Na2B4 O7 10H2O] (ceeb toom: zam huab cua), ntxiv dej kom yaj thiab dilute nws mus rau 1000ml, muab tso rau hauv ib lub raj mis polyethylene, thiab nruj nreem ntsaws nws kom tsis txhob sib cuag nrog carbon dioxide nyob rau hauv cov huab cua.
