SUGAR-LUFF-SCHOORL METHOD 1: Scope and Field of Application This method is for the determination of glucose, reducing sugars expressed as glucose. This adaptation of the Schoorl method was designed for the determination of total The method is based on the Czech Standard ČSN 56 , Český. International Starch Institute Science Park Aarhus, Denmark ISI e Determination of Reducing Sugar, DE by Luff-Schoorl’s method.

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However in certain cases for example, with iron carbonate a special method must be used. Techniques, Methodologies and Equipment see more detailsmolasses molasses Subject Category: Reagents and apparatus Only special instruments or apparatus or those requiring special standards are mentioned in the description of the methods of analysis.

Close Find out more. Cool and transfer the solution to a ml volumetric flask. Procedure According to the sample’s carbonate content, weigh a portion of the sample as shown below: Determination of non-fermentable reducing substances in sugar cane molasses.

The sugars are extracted in dilute ethanol ; the methos is clarified with Carrez solutions I and II. Weigh 5 g of the sample to the nearest mg and place in a to ml beaker.

Carry out the measurements as indicated in 5. Please select author name in each record!

Sugar analysis – Proceedings of the Society for Analytical Chemistry (RSC Publishing)

Chapter 3 Volume 3 P. Fetching data from CrossRef. We may also use digital footprint connection information such as your IP address and other technical identifiers, to collect usage data, click stream data, and information about the pages you visited and searched, to analyse usage for the purpose of enhancing and improving our service. Heat carefully until the mixture is completely melted.


Stopper the flask and shake vigorously for five minutes. Stopper immediately and shake vigorously. Carbonise by setting light to the substance with a strip of ash-free filter paper. Calculation of results Calculate the weight of the residue by deducting the tare.

The Luff-Schoorl method for determination of reducing sugar in juices, molasses and sugar

In the case of low contents of urea, increase the sample as long as the filtrate remains transparent and colourless. In the case of higher levels of potassium dilute the solution to schorl analysed in suitable proportions before adding the loading agent.

The excess silver nitrate is titrated with a solution of ammonium thiocyanate. Weigh 20 g of the sample to the nearest 5 mg, place in 1 litre flat-bottomed flask and add 50 ml of water and 10 ml of sweet almond suspension 3.

Add 5 ml of Carrez solution II 3. Bring to the boil, add eight to ten drops of bromo-cresol green solution 3. In the case of products such as calcium-aluminium phosphate which are difficult to dissolve in acid, melt as follows by an alkaline process before dissolving ; mix the sample methos be analysed thoroughly in a platinum crucible with a mixture five times its weight, consisting of equal amounts of potassium carbonate and sodium carbonate.

Electric muffle-furnace with thermostat. The amount of chlorine wexpressed as sodium chloride, present in the volume of filtrate taken for titration is calculated by using the following formula:. Determination of total sugars after inversion Using a pipette take 50 ml of the solution and transfer to a ml volumetric flask. Observations It is not always necessary to add loading agent 3. Purpose and scope This method makes it possible to determine the level of urea in feeding-stuffs.


Purpose and scope This method makes it possible to determine the level of hydrocyanic acid, free and combined in the form of glycosides, in feeding-stuffs and in particular in products derived from flax seed, luf flour and certain species of beans.

Luff–Schoorl method

The urea content of the filtrate is determined after the addition of 4-dimethylaminobenzaldehyde 4-DMAB by measuring the meethod density at a wavelength of nm.

If the sample contains simple nitrogenous compounds such as amino acids, the optical density should be measured at nm. The chlorides are dissolved in water. A blank test may, if required, be carried out by applying the same procedure to 10 ml of sweet almond suspension 3.

You do not have JavaScript enabled. The Luff-Schoorl solution can be used for the Eynon and Lane titration method, the results agreeing with those obtained iodometrically Scuoorl.

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The sample’s HCN content may also be determined by titrating the acidified ammoniacal filtrate with nitric acid. Purpose and Scope This method makes it possible to determine the crude ash content of feeding-stuffs. Chapter 03 Volume P. To do this, dry the sample at a suitable temperature for an adequate length of time.