pH o'lchagich uchun pH bufer eritmasining asosiy vazifasi nima?
⑴ pH o'lchagichni pH o'lchashdan oldin kalibrlash
PH o'lchagichning to'g'riligini tekshirish uchun, masalan, pH o'lchagichni pH 6,86 va pH 4,00 bilan kalibrlashdan so'ng, pH elektrodini pH 9,18 eritmasiga soling va asbob ko'rsatish qiymati standart eritmaning pH qiymatiga mos kelishini tekshiring;
⑶ Umumiy aniqlik oʻlchash vaqtida pH oʻlchagichni qayta kalibrlash zarurligini tekshiring. PH o'lchagichni kalibrlash va ishlatishdan keyin drift yoki o'zgarishlar yuz berishi mumkin. Shuning uchun, sinovdan oldin, elektrodni o'lchangan eritmaga yaqin bo'lgan standart tampon eritmasiga soling va xatolik kattaligiga qarab qayta kalibrlash zarurligini aniqlang.
⑷ pH elektrodlarining ishlashini tekshirish
pH standart bufer eritmasini qanday tayyorlash mumkin?
Umumiy pH o'lchash uchun pH tamponlash reagentlarining to'liq to'plami (250 ml tayyorlanishi mumkin) ishlatilishi mumkin. Eritmani tayyorlashda erigan karbonat angidridni olib tashlash uchun deionizatsiyalangan suvni ishlatish va oldindan 15-30 daqiqa davomida qaynatish kerak. Plastik qopni kesib oling va reagentni stakanga quying. Uni kerakli miqdorda deionizatsiyalangan suvda eritib oling, qadoqlash sumkasini yuving va keyin uni 250 ml hajmli o'lchov kolbasiga quying. Belgisigacha suyultiring va yaxshilab silkiting.
pH bufer eritmasini qanday qilib to'g'ri saqlash va ishlatish kerak;
After preparing the buffer solution, it should be placed in a glass bottle or a polyethylene bottle (alkaline pH buffer solutions such as pH9.18, pH10.01, pH12.46, etc. should be placed in polyethylene bottles). The bottle cap should be tightly closed and stored at low temperature (5-10 ℃) in the refrigerator. Generally, it can be used for about two months. If turbidity, mold or precipitation are found, it cannot be continued to be used. When using, prepare several 50ml polyethylene small bottles, pour the buffer solution from the large bottles into the small bottles, and let them stand at ambient temperature for 1-2 hours until the temperature is balanced before use. After use, it should not be poured back into the large bottle to avoid contamination. The buffer solution in the small bottle can be used for 2-3 days under environmental conditions of>10 daraja. Odatda, pH 7.00, pH 6.86 va pH 4.00 eritmalari uzoqroq vaqt davomida ishlatilishi mumkin. PH 9,18 va pH 10,01 eritmalarining pH qiymatlarini havodan CO2 yutilishi tufayli o'zgartirish nisbatan oson.
