Determine Nitrogen Efficiently and Effectively

The Kjeldahl method has been used to determine the nitrogen content of organic and inorganic substances for over 120 years. Its universality, precision, and reproducibility have made it the internationally-recognized method for ascertaining the level of protein in foods. Furthermore, this method is also employed in environmental analysis and the agricultural industry for determining nitrates and ammonium. There have been many advances in technique and devices over the years, but the basic principles are still applied in the food and drinks industry , in laboratories, and in quality control everywhere. The method works by converting nitrogen compounds (proteins, amines or organic compounds) into ammonia compounds. By adding caustics, free ammonia is released, which is then expulsed by distillation and titrated. Analysts use the result of this process to easily calculate the concentration of nitrogen (= proteins) in the sample.

Why Using Merck's Catalysts?

• Small, simple-to-use tablets
• PE bottles with integrated lid
• Flexibility for the customer’s needs:
  - 5 g tablets for the classical sample size
  - 3.5g for microscale systems, e.g. in pharmaceutical biotechnology
• Fine dosage: For the appropriate dosage of the catalyst, too much catalyst causes severe foaming; too little catalysator results in incomplete digestion.

What are the Benefits of Merck's Catalysts?

• Easy-to-open packs offering a tried and tested methodology
• Ideal for micro-scale systems
• Ultimate flexibility for setting the catalyst/sulfuric acid ratio
• Avoids foaming through finer dosage of catalyst
• Set ecological or temporal priorities in analysis

Which Catalyst is Right for Your Needs?

A mixed catalyst containing copper and titanium will usually be best for your needs, depending on your priority:

• Time matters: then choose either a mixture of titanium dioxide and copper sulfate, or a Wieniger1 catalyst, which reduces digestion time with certain substances such as fat-containing samples 
• Environmental issues come first: choose a Missouri2 catalyst, with low copper content