buretilla

A buretilla is a diminutive term used in some Spanish-speaking laboratories to refer to a burette, an instrument designed to deliver precise volumes of liquid during quantitative chemical analyses, particularly titrations. It is typically a long, narrow glass or transparent plastic tube with a graduated scale and a stopcock near its lower end that controls the flow of liquid.

Construction and features: A buretilla usually consists of a vertical or slightly inclined tube with clear volume markings (commonly 0–50 mL or 0–25 mL). It is mounted on a stand with a clamp and fitted with a stopcock to regulate liquid release. The upper end is often capped or fitted with a funnel or overflow adapter to fill the tube without trapping air. The bottom end terminates in a small outlet, which can be opened or closed with the stopcock to deliver small, controlled amounts.

Operation: The buretilla is filled with the titrant, ensuring the level is above zero and free of air bubbles. The initial volume is read at eye level at the bottom of the meniscus. The stopcock is opened gradually to add the titrant to the solution being titrated, with careful observations of the endpoint. Readings are taken at the bottom of the meniscus to the nearest typical increment of 0.01–0.02 mL, depending on the instrument’s precision.

Applications and accuracy: Buretillas are central to volumetric analysis, enabling accurate determination of reaction endpoints in acid–base, redox, complexometric, and precipitation titrations. Proper calibration, cleanliness, and temperature control are important for achieving high precision.

Differences from other tools: Unlike pipettes that deliver fixed volumes, a buretilla allows controlled, variable dispensing of reagents and accurate measurement of the added volume.