Ezi ntlanzi zingasetyenziselwa kwizicelo ze-biological kwi-pH engekufutshane
Iimpawu ezintathu ze-pKa ze-phosphoric acid (ukusuka kwi-CRC Handbook yeKhemistry kunye neFiziki) zi-2.16, 7.21 kunye ne-12.32. I-Monosodium phosphate kunye ne-conjugate base, i-disodium phosphate isetyenziselwa ukuvelisa amaxabiso e-pH malunga no-7, kwizicelo ze-biological, njengoko kuboniswe apha.
Ukwenza oku kuluhlu kunzima kunokwenza i-TAE ne-TBE buffers. Akunzima kakhulu, nangona kunjalo. Umyinge nje. Kufuneka kuthathe malunga nemizuzu eyi-10 ukubethelela le khowudi. Nantsi indlela.
1. Gqiba kwiiMpahla zeMpahla
Ngaphambi kokuba wenze i-tampon, kufuneka uqale wazi ukuba imfuno ofuna ukuba yintoni, yintoni umthamo wokwenza kunye nento efunwa yi-pH. Uninzi lwabathengi lusebenza kakuhle kwiimitha eziphakathi kwe-0.1 M ne-10 M. I-pH kufuneka ibe ngaphakathi kweyunithi ye-pH ye-acid / conjugate base pKa. Ukuze kube lula, oku kubalwa kweesampuli kuya kuba li-1 litre yeetampu.
2. Misela iRatio ye-Acid kwi-Base
Sebenzisa i-Henderson-Hasselbalch equation (ngezansi) ukugqiba ukuba yeyiphi i-acid ye-asidi yokusekwa kufuneka ukuba wenze i-pH ye-pH efunwayo. Sebenzisa ixabiso le-pKa elisondeleyo kwi-pH oyifunayo kwaye ubukhulu buya kubhekisela kumbini we-acid-base conjugate efana neyo pKa.
HH Equation: pH = pKa + log ([Isiseko] / [i-Acid])
Ukufumana i-pH 6.9, [Base] / [Acid] = 0.4898
Inxalenye ye- [Acid] kunye neSombululo se- [Base]
I-molarity efunwayo yesikhombisi isisombululo se- [Acid] + [Isiseko].
I-1 M buffer, [Base] + [Acid] = 1 kunye [I-base] = 1 - [I-Acid]
Ngokufaka endaweni ye-equation ratio, ukusuka kwisinyathelo 2, ufumana:
[Acid] = 0.6712 i-moles / L
Sombulula i [Acid]
Ukusebenzisa i-equation: [Base] = 1 - [Acid], unokubala ukuba:
[Base] = 0.3288 ii-moles / L
3. Hlanganisa i-acid kunye ne-Conjugate Base
Emva kokuba usebenzisa i-Henderson-Hasselbalch equation ukubala ukuba yeyiphi i-acid isiseko ekufuneka isetyenzisi sakho, lungiselela ngaphantsi kweyure le-1 ilitha yesisombululo usebenzisa izixa ezichanekileyo ze-monosodium phosphate kunye ne-disodium phosphate.
4. Khangela i-pH
Sebenzisa iprogram ye-pH ukuqinisekisa ukuba i-pH efanelekileyo ye-buffer ifinyelelwe. Lungisa kancane njengoko kuyimfuneko, usebenzisa i-phosphoric acid okanye i-sodium hydroxide (i-NaOH).
5. Phatha uMqulu
Emva kokuba i-pH efunwayo ifumaneka, velisa umthamo we-buffer kwi-1 litre. Emva koko hlaziya i-buffer njengoko uyifunayo. Le khoyunithi efanayo iya kuhlanjululwa ukuze idale izibhengezo ze-0.5 M, 0.1 M, 0.05 M okanye nantoni na phakathi.
6. Iingcebiso zeBuff
Khumbula ukuba i-pKa ayinakulinganiswa lula kwixabiso elichanekileyo. Amanani athile ahlukeneyo anokufumaneka kwiincwadi ezivela kwimithombo eyahlukeneyo.
7. Yintoni oyifunayo
Ukwenza i-tampon, uzakufuna izinto ezintathu, ngelixa izinto eziseleyo zixhobo. Ezi zinto ziyi-monosodium phosphate, i-disodium phosphate, kunye ne-phosphoric acid okanye i-sodium hydroxide ukulungisa i-pH.
Uzakufuna kwakhona imitha ye-pH kunye neeprogram kunye nee-labware ezifanelekileyo. Oku kubandakanya i-flaum volumetric, i-cylinders ezigqityiweyo, iibakers kunye nemivalo yokugubha.
Ekugqibeleni, uya kufuna i-hotplate eshukumisayo.