Reagents Useful in Preparing Buffers of a Specific pH Range

A buffer is a solution that can resist pH change, and is composed of a weak conjugate acid-base pair. It is able to neutralize small amounts of added acid or base, thus maintaining the pH of the solution relatively stable. This is important for processes and/or reactions which require specific and stable pH ranges. Therefore, buffers are often essential in analytical chemistry. Here, Alfa Chemistry lists the reagents useful in preparing buffers of a specific pH range. It is our hope that the reagent list presented herein can provide convenience for your work.

pH Range	pKa	Reagent
0–2		Hydrochloric acid; nitric acid; perchloric acid
0.3–5.3	1.3, 4.4	Oxalic acid, dihydrate; sodium oxalate; potassium tetroxalate, Dihydrate
0.9–2.9, 5.2–7.2	1.9, 6.2	Maleic acid
1.1–1.8		Potassium chloride
1.1–3.1, 6.2–10.1	2.1, 7.2, 12.4	Phosphoric acid; potassium phosphate, monobasic; potassium phosphate, dibasic; potassium phosphate, tribasic, n-hydrate; sodium phosphate, monobasic, monohydrate; sodium phosphate, dibasic, 7-hydrate; sodium phosphate, tribasic, 12-hydrate
1.8–3.8	2.8	Monochloroacetic acid; chloroacetic acid, sodium salt
1.9–6.4	2.9, 5.4	Phthalic acid; potassium biphthalate
2.0–5.4	3.0, 4.4	d-Tartaric acid; potassium tartrate, ½-hydrate
2.1–7.4	3.1, 4.8, 6.4	Citric acid, anhydrous; citric acid, monohydrate; potassium citrate, monohydrate
2.8–4.8	3.8	Formic acid; sodium formate
3.2–6.6	4.2, 5.6	Succinic acid
3.6–5.6	4.6	Acetic acid; sodium acetate, trihydrate
4.1–6.1	5.1	Hexamethylenetetramine
5.3–7.3, 9.3–11.3	6.3, 10.3	Carbonic acid; potassium bicarbonate; potassium carbonate, anhydrous; sodium bicarbonate; sodium carbonate, anhydrous; sodium carbonate, monohydrate
6.5–8.5	7.5	Imidazole
6.8	4.6 (acetic acid); 9.3 (ammonium hydroxide)	Ammonium acetate
6.8–8.8	7.8	Triethanolamine; TRIS hydrochloride
7.1–9.1	8.1	N,N-bis(2-hydroxyethyl)glycine (bicine); 4-(2-hydroxyethyl)-1-pi-perazineethanesulfonic acid (HEPES)
7.8–9.8	8.8	2-Amino-2-methyl-1,2-propanediol (AMP)
8.2–10.2	9.2	Boric acid; sodium borate, 10-hydrate
8.3–10.3	9.3	Ammonium hydroxide; ammonium chloride
12–14		Potassium hydroxide, 45% solution; sodium hydroxide, 50% solution
12.4 (saturated solution)		Calcium hydroxide