acetatebuffers

Acetate buffers are buffering systems based on acetic acid (CH3COOH) and its conjugate base acetate (CH3COO−). They maintain pH in the acidic to near-neutral range by combining the weak acid and its conjugate base in solution. The pH of an acetate buffer is described by the Henderson–Hasselbalch equation: pH = pKa + log([A−]/[HA]), with pKa for acetic acid around 4.76 at 25°C. Consequently, acetate buffers are most effective near pH 4.5–5.6, and are often used in the range roughly 3.6–5.6, depending on temperature and ionic strength.

To prepare, mix acetic acid (glacial) with sodium acetate or other acetate salts to achieve the desired pH and ionic strength. Common working solutions are in the 10–100 mM range, though concentrations may be adjusted for buffer capacity. Temperature and ionic strength influence the effective pH and capacity of the buffer.

Applications include stabilization of pH in biochemical and molecular biology experiments, such as enzymatic assays that operate under mildly acidic conditions and nucleic acid workflows where pH control is needed without introducing strong buffers like phosphate. Acetate buffers are often favored for their simplicity, low cost, and compatibility with many enzymes, though their limited pH range means they are unsuitable when neutral or basic pH is required. Safety considerations include handling acetic acid, which is corrosive, and proper disposal of buffered solutions.