Jump to content Jump to navigation menu

Kjeldahl tablets (free of mercury and selenium), 250 unit(s)

tablet 5 g
H412
i harmful to aquatic life with long lasting effects
P273 P501
i avoid release to the environment, dispose of contents/container in accordance with local/regional/national/international regulations
Related products
Pack Qty.
Pack.
Density (D) 2,7 g/cm³
WGK 2

For determination of nitrogen.

Type analysis
€129.50 /Pack Qty.

€103.60/Pack Qty.  Campaign price!

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

Art. No. HN19.1

In stock
Free of shipping costs from 125 €
Delivery fast, simple and reliable!
Carl Roth subscription service

Now recurring orders conveniently delivered as a subscription!

With the new Carl Roth Replenishment Service you can let products be ordered automatically which you need regularly in your lab!

How it works:
1

Put all products for your subscription in the desired quantity in the basket.

2

In the shopping cart, select the option "Order shopping cart as subscription" Order as subscription.

3

Set Starty point and interval for your subscription and submit order!

By the way: Through your account you can customize or delete your subscriptions anytime.

Any questions about this product?

Do you have a question about this product?

In the general information or Product details, we have compiled extensive descriptions and downloads for each product.
If you can not find an answer to your question in the Certificates of Analysis and Application Examples , feel free to contact us!
Contact Service
Kjeldahl tablets (free of mercury and selenium)
Selected quantity:   0
  1. Subtotal:  0.00
Order No. Pack Qty. Pack. Price Quantity
HN19.1 250 unit(s) plastic €103.60
HN19.2 1,000 unit(s) plastic €364.00
In stock
Available at short notice
Not available
Delivery date currently unknown
Selected quantity:   0
  1. Subtotal:  0.00

Downloads


General information

Analysis of Food

Analysis of FoodCarl 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


Determination of Nitrogen according to Kjeldahl

Determination of Nitrogen according to KjeldahlThe 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.


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

Appearancelight grey tablets  
Composition: TiO2, CuSO4, K2SO4 and Na2SO4.

0 Reviews

0.0 out of five stars