Burettes
Burettes
Used to dispense and measure a variable amount of a chemical solution in analytical chemistry at the same time, burettes feature a long, graduated glass tube with a stopcock on its lower end for liquid measurement. The stopcock valve is used to control the flow of liquid from the burette in either a steady stream or drop-by-drop. Unlike a pipette, the sample quantity delivered by a burette is changeable. For gas measuring burettes, the stopcock is located at the top of the burette’s glass tube. Digital burettes that deliver exactly measured samples, increasing accuracy and precision, are also available.
Titrations are performed to determine the concentration of a specific substance by adding another substance that interacts with the first to neutralize it or to form another compound. Liquid is slowly dispensed from a burette into a flask or beaker that holds a known amount of the test substance. The burette has a solid glass or PTFE stopcock or other fitting to regulate the flow of the liquid.
The “unknown” substance is mixed constantly (via magnetic stirrer/stir bar or similar method) to ensure that the reaction is complete. Often, the end-point of the reaction is a specific change in the acidity or pH of the liquid; a chemical indicator may be used to produce a color change when the reaction is complete.
Burettes may be designed for single or multiple uses; replacement stopcocks, glassware, and other parts are available for most reusable versions.
Other burette features include:
- Material: Glass or plastic
- Size: Usually from 10 mL to 50 mL capacities
- Graduations: Choice of precision (0.01 or 0.1 mL)
- Certification: Class A or Class B, serialized and non-serialized
- Construction: Single-use or with replacement parts
- Types: Standard or self-filling/automatic
- Burets with PTFE-plug stopcocks
- Break-resistant, self-zeroing automatic burets
- Reservoir fill burets
Fisherbrand™ Schellbach Autozeroing PTFE Buret, Three-Way Stopcock
Provides high quality at an affordable price.
Thermo Scientific™ Nalgene™ Acrylic Burets with PMP Tip, TFE Stopcock and Plug
Accurately perform applications with these acrylic burets with PMP tip, TFE stopcock and plug, which meet ASTM E287 standards.
PYREX™ Class A Buret with Product Standard PTFE Stopcock Plug
Buret has colored markings, fine, sharp lines and large easy-to-read numbers
BrandTech™ BRAND™ Titrette™ Digital Bottle-Top Burets
Provides accuracy and precision within the tolerances of Class A glass burettes. Titrette™ Digital Bottle-top Burets are suitable for most titrants in concentrations up to 1 mol/L. Ideal for general chemistry, wastewater treatment applications, food/beverage analysis, industrial titrations, environmental fieldwork, and more.
DWK Life Sciences Kimble™ KIMAX™ Precision Bore Burets with PTFE Stopcock
Class A
Promotions are available
Fisherbrand™ Schellbach™ Automatic Zero Buret
Provided with durable black ceramic enamel scale.
Thermo Scientific™ Nalgene™ Break-Resistant Self-Zeroing Automatic Burets
Ensure repeatable, accurate results with these break-resistant, self-zeroing, automatic burets which meet ASTM E287.
Sartorius Biotrate Digital Burets
For trouble-free and reliable liquid dispensing directly from a supply bottle. Sartorius Biotrate Digital Burets offer high chemical resistance and is a smart solution for titrating various liquids accurately and safely.
Promotions are available
PYREX™ Serialized/Certified Class A Burets
Colored markings, fine, sharp lines and large easy-to-read numbers
PYREX™ Replacement Tip for stopcock assembly No. 2145-SO
For use with Polytetrafluorethylene (PTFE) non-locking stopcock assembly No. 2145-SO
PYREX™ Serialized/Certified Class A Precision Bore Buret
Sharply defined and easy-to-read colored graduations
PYREX™ Replacement Tip For 2116-LSO
For use with for Pyrex 25mL and 50mL Economy Grade Burets (Nos. 2116-25 and 2116-50)