Non-volatile and Volatile Buffer Systems

Non-volatile buffers for anion exchange chromatography

¹Ref: Handbook of chemistry and physics, 83rd edition, CRC, 2002–2003.

pH interval	Substance	Conc. (mM)	Counter-ion	pKa (25 °C)1	d(pKa)/ dT (°C)
4.3–5.3	N-Methylpiperazine	20	Cl-	4.75	-0.015
4.8–5.8	Piperazine	20	Cl- or HCOO-	5.33	-0.015
5.5–6.5	L-Histidine	20	Cl-	6.04
6.0–7.0	bis-Tris	20	Cl-	6.48	-0.017
6.2–7.2; 8.6–9.6	bis-Tris propane	20	Cl-	6.65; 9.10
7.3–8.3	Triethanolamine	20	Cl- or CH3COO-	7.76	-0.020
7.6–8.6	Tris	20	Cl-	8.07	-0.028
8.0–9.0	N-Methyldiethanolamine	20	SO42-	8.52	-0.028
8.0–9.0	N-Methyldiethanolamine	50	Cl- or CH3COO-	8.52	-0.028
8.4–9.4	Diethanolamine	20 at pH 8.4 50 at pH 8.8	Cl-	8.88	-0.025
8.4–9.4	Propane 1,3-Diamino	20	Cl-	8.88 -	0.031
9.0–10.0	Ethanolamine	20	Cl-	9.50	-0.029
9.2–10.2	Piperazine	20	Cl-	9.73	-0.026
10.0–11.0	Propane 1,3-Diamino	20	Cl-	10.55	-0.026
10.6–11.6	Piperidine	20	Cl-	11.12	-0.031

Non-volatile buffers for cation exchange chromatography

¹Ref: Handbook of chemistry and physics, 83rd edition, CRC, 2002–2003.

pH interval	Substance	Conc. (mM)	Counter-ion	pKa (25 °C)1	d(pKa)/ dT (°C)
1.4–2.4	Maleic acid	20	Na+	1.92
2.6–3.6	Methyl malonic acid	20	Na+ or Li+	3.07
2.6–3.6	Citric acid	20	Na+	3.13	-0.0024
3.3–4.3	Lactic acid	50	Na+	3.86
3.3–4.3	Formic acid	50	Na+ or Li+	3.75	+0.0002
3.7–4.7; 5.1–6.1	Succinic acid	50	Na+	4.21; 5.64	-0.0018
4.3–5.3	Acetic acid	50	Na+ or Li+	4.75	+0.0002
5.2–6.2	Methyl malonic acid	50	Na+ or Li+	5.76
5.6–6.6	MES	50	Na+ or Li+	6.27	-0.0110
6.7–7.7	Phosphate	50	Na+	7.20	-0.0028
7.0–8.0	HEPES	50	Na+ or Li+	7.56	-0.0140
7.8–8.8	BICINE	50	Na+	8.33	-0.0180

Volatile buffer systems

¹Ref: Handbook of chemistry and physics, 83rd edition, CRC, 2002–2003.

pH rang	Buffer system	Counter-ion	pKa-values for buffering ions1
3.3–4.3	Formic acid	H+	3.75
3.3–4.3; 4.8–5.8	Pyridine/formic acid	HCOO-	3.75; 5.25
3.3–4.3; 9.3–10.3	Trimethylamine/formic acid	HCOO-	4.75; 9.81
4.3–5.8	Pyridine/acetic acid	CH3COO-	4.75; 5.25
4.3–5.3; 9.3–10.3	Trimethylamine/acetic acid	CH3COO-	4.75; 9.81
3.3–4.3; 8.8–9.8	Ammonia/formic acid	HCOO-	3.75; 9.25
4.3–5.3; 8.8–9.8	Ammonia/acetic acid	CH3COO-	4.75; 9.25
5.9–6.9; 9.3–10.3	Trimethylamine/carbonate	CO32-	6.35; 9.81
5.9–6.9; 8.8–9.8	Ammonium bicarbonate	HCO3-	6.35; 9.25
5.9–6.9; 8.8–9.8	Ammonium carbonate/ammonia	CO32-	6.35; 9.25
5.9–6.9; 8.8–9.8	Ammonium carbonate	CO32-	6.35; 9.25
4.3–5.3: 7.2–8.2	N-ethylmorpholine/acetate	HCOO-	4.75; 7.72