Thermo Fisher, ECBU4BT, Eutech™ pH Buffers and Solutions

Thermo Scientific Eutech pH 4.01 buffer solution is a ready-to-use calibration standard for pH meters and combination pH electrodes. It provides an acidic reference point at pH 4.01 at 25°C, supporting routine calibration checks and multipoint pH standardization in chemical analysis, water testing, food production, and life science laboratories. The red-colored solution is packaged in a 480 mL plastic bottle for convenient repeated laboratory use. In a two- or three-point calibration, it is commonly paired with near-neutral and alkaline buffer standards to establish electrode slope and offset across the expected sample range. Accurate calibration requires clean electrodes, suitable temperature compensation, uncontaminated aliquots, and proper rinsing between buffers. The solution is not intended to adjust the pH of culture media or process liquids as a general-purpose reagent. Use fresh aliquots and avoid returning dispensed liquid to the storage bottle. Record calibration temperature and electrode performance in the laboratory's calibration log.