Tus txheej txheem rau kev npaj pH meter calibration daws teeb meem
1) pH 4, potassium hydrogen phthalate tus qauv tsis:
Precisely hnyav 10.12g ntawm poov tshuaj hydrogen phthalate [KHC8H4O4] qhuav ntawm 115 ± 5 degree rau 2 mus rau 3 teev, ntxiv dej kom yaj thiab dilute mus rau 1000ml.
2) pH7, phosphate standard buffer (pH7.4):
Precisely hnyav 4.303g anhydrous disodium hydrogen phosphate thiab 1.179g potassium dihydrogen phosphate qhuav ntawm 115 ± 5 degree rau 2 mus rau 3 teev, ntxiv dej kom yaj thiab dilute mus rau 1000ml.
Tsis tas li ntawd ntxiv: Phosphate standard buffer (pH 6.8). Precisely hnyav 3.533g anhydrous disodium hydrogen phosphate thiab 3.387g potassium dihydrogen phosphate qhuav ntawm 115 ± 5 degree rau 2 mus rau 3 teev. Ntxiv dej kom yaj thiab dilute rau 1000ml. .
3) pH9, borax txheem tsis:
Precisely hnyav 3.80g ntawm borax [Na2B4O7·10H2O] (ceeb toom: tsis txhob huab cua), ntxiv dej kom yaj thiab dilute mus rau 1000ml, muab tso rau hauv ib lub raj mis polyethylene, kaw kom nruj kom tsis txhob sib cuag nrog carbon dioxide nyob rau hauv cov huab cua.
Cov ntsiab lus
Kev txiav txim siab los ntawm kev siv pH ntsuas tam sim no, hauv tsev tsim pH ntsuas los yog acidimeters hauv Suav teb muaj ob hom kev ntsuas calibration buffers:
1) Qhov ntawd yog, cov qauv kev daws teeb meem tuaj yeem yuav ntawm lub khw thiab feem ntau khaws cia rau hauv lub raj mis polyethylene kaw. Nws yog feem ntau pom zoo kom khaws cov qauv kev daws teeb meem rau 1 mus rau 2 lub hlis ntawm chav tsev kub. Yog tias pom muaj turbidity, pwm, lossis nag lossis daus, nws tsis tuaj yeem siv ntxiv. Khaws rau hauv lub tub yees 4 degree, thiab cov kev daws teeb meem siv tsis raug tso cai rov qab.
2) Koj tuaj yeem yuav tsis koj tus kheej thiab npaj nws tom qab. Txawm li cas los xij, thaum cov neeg tsim khoom feem ntau xa khoom, vim yog kev cai hauv tebchaws, qee cov kua lossis tshuaj tsis raug tso cai xa tawm, yog li lawv tuaj yeem tsuas muaj pH buffers qhuav. Cov neeg siv khoom yuav tsum npaj lawv tus kheej thaum siv lawv. Tsuav lawv tau yaj hauv dej ua ntej boil rau 15 ~ 30 feeb ntawm cov dej deionized kom zoo yaug cov tshuaj reagents nyob rau hauv lub hnab reagent. Ncuav rau hauv 250ml volumetric hwj, dilute rau ntim, thiab co zoo.
