Need support?

Please leave a message

BUCHI - Kjeldahl Distillation

BUCHI’s versatile solutions for digestion and steam distillation cover a broad range of applications. Maximized productivity is thereby essential, whether it is classical protein determination according to Kjeldahl, reflux digestion with aqua regia, or direct distillation of steam-volatile compounds.

We provide solutions for both potentiometric and colorimetric titrations. The KjelMaster K-375 meets the highest demands in usability, automation, user administration and sophisticated data management.

Established and proven

Kjeldahl is the most established reference method for protein determination in food, beverage, feed and forage. It commonly serves as reference for NIR calibrations.
It is compliant with all sorts of national and international regulations such as AOAC, ISO, DIN, LFGB and many more.


Changing matrices or highly heterogeneous samples are easily handled by Kjeldahl.
It copes with just a few samples per day or with a high throughput of up to 120 samples in a shift thanks to a flexible autosampler concept.
Acid digestion and steam distillation can be applied for the determination of various analytes such as N-containing compounds, COD, heavy metals, hydroxyproline, SO2, formaldehyde, CN, diacetyl, alcohol, TVBN, volatile acids, phenols etc.

For every budget

Our broad portfolio offers entry-level Kjeldahl products up to highly sophisticated fully automated systems. 

Available models

  • Compliant and flexible plug-and-measure titration concept (colorimetric / potentiometric)
  • Safe operation, user protection and guided routine operation
  • Different access levels of authorization according to GLP requirements
  • Reproducible results with the smart distillation mode “IntelliDist”
  • Data security supported by intelligent software


Perform Kjeldahl nitrogen or protein determination and additional steam distillation in the most flexible way. The modular setup allows to adapt the KjelFlex K-360 at any time including a wide selection of titrators to guarantee smooth and easy operation.

  • Customizable analysis methods for multi-purpose use
  • Modular concept to adapt to changing needs
  • Modern instrument software enabling convenient routine use
  • Connection to various external titrators for semi-automated processing

The KjelSampler K-376 or K-377 in combination with the KjelMaster K-375 meets upmost demands in high throughput Kjeldahl determination. The system provides a maximum degree of automation and flexibility.

  • Unattended operation of 24 samples (K-376) or 48 samples (K-377)
  • Perfect process synchronisation of all steps from digestion to automated sampling
  • Fully automated by the KjelMaster K-375
  • Continuous batch workflow using two independent rack trays (K-377)

 Convenient and safe

Perform Kjeldahl nitrogen or protein determinations compliant to officially approved methods in the most cost effective way. Expand your range of applications with the additional features of the K-355.

  • Entry level instrument for Kjeldahl and other steam distillations
  • Eco-friendly cooling water control to reduce water consumption
  • Plastic splash protector for extended lifetime
  • Pharmaceutical
  • Biopharmaceutical and Biotechnology
  • Education & Academics
  • Food & Beverage
Buchi LabortechnikFor 75 years BUCHI is a leading solution provider in laboratory technology for R & D, quality control and production worldwide. We serve a wide range of industries such as pharmaceuticals, chemicals, food & beverage, feed, environmental analysis and academia.