Buffer solution pH 4.00 / 7.00 / 9.00 (25 °C) in single use sachets, colourless
The buffer is traceable to NIST. The buffers are independently determined both in house and by an external akkredited laboratory. Both independent measurements must compare within the stated measurement uncertainty.
The Metrohm pH buffer solutions are sterile-filtered and bottled under controlled conditions. The solutions are tested by the UFAG Laboratories (Switzerland, Swissmedic no. 08-187), which are certified to GMP standards, for microbial contamination according to Ph. Eur. (current ed.), aerobic germs and microorganisms (2.612 and 2.6.13). These tests are performed with different samples of finished product. The limit of detection of CFU < 1 must not be exceeded.