Waters XBridge Protein BEH, C4, 300A, 3.5 µm Columns - Manual (Page 5)

5
[ CARE AND USE MANUAL ]
XBridge Protein BEH C
4
, 300Å, 3.5, 5, 10 �m
Additive/Buffer pKa Buffer
range (±1
pH unit)
Volatility Used for
Mass
Spec
Comments
TFA 0.3 Volatile Yes Ion pair additive, can suppress MS signal, used in the 0.02–0.1% range.
Acetic Acid 4.76 Volatile Yes
Maximum buffering obtained when used with ammonium acetate salt.
Used in 0.1–1.0% range.
Formic Acid 3.75 Volatile Yes
Maximum buffering obtained when used with ammonium formate salt.
Used in 0.1–1.0% range
Acetate (NH
4
C
2
COOH) 4.76 3.76 –5.76 Volatile Yes
Used in the 1–10 mM range. Note that sodium or potassium salts are
not volatile.
Formate (NH
4
COOH) 3.75 2.75–4.75 Volatile Yes
Used in the 1–10 mM range. Note that sodium or potassium salts are
not volatile
Phosphate 1 2.15 1.15–3.15 Non-volatile No Traditional low pH buffer, good UV transparency.
Phosphate 2 7.2 6.20 –8.20 Non-volatile No
Above pH 7, reduce temperature/concentration and use a guard column
to maximize lifetime
Phosphate 3 12.3 11.3–13.3 Non-volatile No
Above pH 7, reduce temperature/concentration and use a guard column
to maximize lifetime.
4-Methylmorpholine 8.4 7.4–9.4 Volatile Yes Generally used at 10 mM or less.
Ammonia (NH
4
OH) 9.2 8.2–10.2 Volatile Yes Keep concentration below 10 mM and temperatures below 30 ˚C.
Ammonium
Bicarbonate
10.3
(HCO
3
- )
9.2 (NH
4
+ )
8.2–11.3 Volatile Yes
Used in the 5– 10 mM range (for MS work keep source >150 ˚C). Adjust
pH with ammonium hydroxide or acetic acid. Good buffering capacity at
pH 10. Note: use ammonium bicarbonate (NH
4
HCO
3
), not ammonium
carbonate ([NH
4
2 CO
3
).
Ammonium (Acetate) 9.2 8.2–10.2 Volatile Yes Used in the 1–10 mM range.
Ammonium (Formate) 9.2 8.2–10.2 Volatile Yes Used in the 1–10 mM range.
Borate 9.2 8.2–10.2 Non-Volatile No
Reduce temperature/concentration and use a guard column to maximize
lifetime.
CAPSO 9.7 8.7–10.7 Non-Volatile No
Zwitterionic buffer, compatible with acetonitrile, used in the 1–10 mM
range. Low odor.
Glycine 2.4, 9.8 8.8–10.8 Non-Volatile No Zwitterionic buffer, can give longer lifetimes than borate buffer.
1-Methylpiperidine 10.2 9.3–11.3 Volatile Yes Used in the 1–10 mM range.
CAPS 10.4 9.5–11.5 Non-Volatile No
Zwitterionic buffer, compatible with acetonitrile, used in the 1–10 mM
range. Low odor.
Triethylamine
(as acetate salt)
10.7 9.7–11.7 Volatile Yes
Used in the 0.1–1.0% range. Volatile only when titrated with acetic acid
(not hydrochloric or phosphoric). Used as ion-pair for DNA analysis at
pH 7–9.
Pyrrolidine 11.3 10.3–12.3 Volatile Yes Mild buffer, gives long lifetime.
Table 2: Buffer Recommendations for Using XBridge Protein BEH C
4
, 300Å Columns from pH 1 to 12