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Kjeldahl tablets CX, 250 unit(s)

tablet 5,5 g
Examples of effect: Damage metals and burn body tissues; may cause serious eye damage. Safety: Avoid contact; wear safety spectacles and gloves. In the event of contact with eyes and skin, rinse with water.
Examples of effect: Are harmful to aquatic organisms, toxic or highly toxic, acute or with long-term effects. Safety: To be disposed of as hazardous waste only, do not allow into the environment under any circumstances.
Danger
H318-H410
i causes serious eye damage, very toxic to aquatic life with long lasting effects
P273 P280 P305+P351+P338
i avoid release to the environment, wear protective gloves/eye protection, IF IN EYES: Rinse cautiously with water for several minutes. Remove contact lenses, if present and easy to do. Continue rinsing
Related products
Pack Qty.
Pack.
Density (D) 2,7 g/cm³
Boiling point (bp) 1689 °C
Melting point (mp) 1067 °C
ADR 9 III
WGK 3
UN-Nr. 3077


Type analysis

CHF156.70/Pack Qty. 

excl. VAT. | 250 unit(s) per Pack Qty.

Art. No. 8236.1

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Kjeldahl tablets CX
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General information

Determination of Nitrogen according to Kjeldahl

The most common technique for measuring the amount of nitrogen in organic matter is the Kjeldahl method, which is used in a wide range of sectors such as environmental analysis, food analysis, water analysis and agricultural analysis, as well as in the pharmaceutical and chemical industries. In this traditional method, a precisely weighed sample is broken down using concentrated sulphuric acid, a process which digests its organic contents and reacts nitrogen to form ammonium sulphate.(CHNO)(s) → CO2 (g) + SO2 (g) + H2O (g) + NH4SO4 (solv, H2SO4)A catalyst or catalyst mixture consisting of copper, selenium, mercury and/or titanium is added to speed up the reaction. Sodium or potassium sulphate is used to give the sulphuric acid a higher boiling point. If the nitrogen is contained in a nitro, nitroso or azo compound, however, the mixture must be reduced with zinc before digestion takes place.
The nitrogen is now present in the sulphuric acid as ammonium sulphate. Adding a strong base (such as NaOH) neutralises the sulphuric acid and liberates ammonia from the solution.NH4SO4 (solv) + 2 NaOH (aq) → Na2SO4 (aq) + 2 NH3 (g) + 2 H2O (l) The ammonia is led into an acid (such as boric acid) by means of steam distillation.B(OH)3 (aq) + 2 H2O (l) + NH3 (g) → B(OH)4- (aq) + NH4+ (aq) The resulting strong base (borate ion) is back-titrated with a strong acid (hydrochloric acid or sulphuric acid). The excess weak boric acid is not captured in the process. A Tashiro's indicator that changes colour in the acid is used for titration. The amount of acid that has been used up can then be converted into the amount of nitrogen in the sample. NH4+ (aq) + B(OH)4- (aq) + HCl (l) → NH4Cl (aq) + B(OH)3 (aq) + H2O (l)To calculate the protein content of the sample, the varying nitrogen content of the amino acids must be checked and the relevant conversion factors applied. The nitrogen contained in food derives mainly from proteins, but different samples may also contain other sources of nitrogen.


Analysis of Food

Carl ROTH also offers reagents suitable for food analysis.

On the following pages, you will find the determination of
• Nitrogen according to Kjeldahl
• Sugar
• Mercury
• Trichinae
• Fat

and the determination of the
• Iodine value
• Acid value
• Peroxide value
• Saponification value

as well as other determining factors such as
• Viscosity
• Density
• Hydroxyl value
• Fluoride ions


Certificates of Analysis

You can search for and download your certificate of analysis for the selected product here. Please provide your batch number.
The following analysis certificates have been found:

Type analysis

Appearanceblue tablets  
Composition: K2SO4, CuSO4 · 5 H2O.

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