Siz pH standart bufer eritmasini bilasizmi?
1. pH standart bufer eritmasi nima? Uning xususiyatlari qanday?
PH bufer eritmasi pH qiymatini barqaror ushlab turadigan eritmadir. Agar bu eritmaga oz miqdorda kislota yoki asos qo‘shilsa yoki eritmadagi kimyoviy reaksiya natijasida oz miqdorda kislota yoki asos hosil bo‘lsa va eritma to‘g‘ri suyultirilsa, eritmaning pH qiymati asosan barqaror bo‘ladi. Ishqor katta yoki suyultirilgan bo'lib, pH qiymatini o'zgarmagan eritma bufer eritma deb ataladi.
Standart pH buferi quyidagi xususiyatlarga ega:
(1) Standart eritmaning pH qiymati ma'lum va belgilangan aniqlikka etadi;
(2) Standart eritmaning pH qiymati yaxshi takrorlanuvchanlik va barqarorlikka ega va katta bufer sig'imi, kichik suyultirish qiymati va kichik harorat koeffitsientiga ega;
(3) Eritmani tayyorlash usuli oddiy;
2. pH standart bufer eritmasi qanday tayyorlanadi? Umumiy pH o'lchash uchun pH reagentlarining to'liq to'plami (250 ml tayyorlanishi mumkin) ishlatilishi mumkin. Eritmani tayyorlashda erigan karbonat angidridni olib tashlash uchun deionizatsiyalangan suvdan foydalanish va oldindan 15-30 daqiqa qaynatish kerak. Plastik paketni kesib oling va reagentni stakanga quying, uni kerakli miqdorda deionizatsiyalangan suv bilan eritib oling, o'rash qopini yuving, so'ng uni 250 ml hajmli o'lchov kolbasiga quying, belgigacha suyultiring va yaxshilab silkiting.
3. How to store and use pH buffer solution correctly? After the buffer solution is prepared, it should be packed in a glass bottle or a polyethylene bottle (alkaline pH buffer solution, such as pH=9.18, pH=10.01, pH=12.46, etc., should be packed in a polyethylene bottle) and the cap should be tightly closed , Stored in the refrigerator at low temperature (5-10°C), it can generally be used for about six months. If the mixer is found to be turbid, moldy or precipitated, it cannot be used any longer. When using, several 50mL polyethylene vials should be prepared, pour the group flushing solution in the large bottle into the vials, and place it at ambient temperature for 1 to 2 hours, and then use it after the temperature is balanced. Do not pour it into a large bottle after use to avoid contamination. The buffer solution in the bottle can be used for 2 to 3 days under the environmental conditions of >10 daraja. Odatda pH=7.00, pH=6.86 va pH=14.00 ning uchta eritmasidan foydalanish mumkin. uzoq vaqt. Uzoqroq bo'lsa, pH=9.18 va pH{9}}.01 eritmalarining pH qiymati havodagi karbonat angidridning singishi tufayli osonroq o'zgaradi.
4. PH bufer eritmasidan qanday foydalaniladi?
(1) pH o'lchashdan oldin pH o'lchagichni kalibrlang va sozlang.
(2) pH o'lchagichning to'g'riligini tekshirish uchun, masalan, pH=6.86 va pH=14.00 dan foydalaning, pH o'lchagichni kalibrlashdan so'ng, pH elektrodini pH=9.18 eritmasiga soling va asbobning ko'rsatilgan qiymati standart eritmaning pH qiymatiga mos kelishini tekshiring.
(3) Umumiy aniqlikni o'lchashda pH o'lchagichni qayta kalibrlash zarurligini tekshiring. PH o'lchagich kalibrlangandan va ishlatilgandan so'ng u siljishi yoki o'zgarishi mumkin. Shuning uchun, sinovdan oldin, elektrodni sinovdan o'tadigan eritmaga yaqin bo'lgan standart tampon eritmasiga soling va xato o'lchamiga ko'ra uni qayta kalibrlash kerakligini aniqlang.
(4) pH elektrodining ishlashini tekshiring.
