Product category:
Titration equipment
News Release from: Metrohm UK | Subject: 841 Titrando
Edited by the Laboratorytalk Editorial
Team on 01 August 2006
Water content in pasta by Karl Fischer
titration
The 841 Titrando has the sophisticated control algorithm of the Titrando which has been adapted to the characteristics of the Karl Fischer reaction and guarantees highly precise results
The water content of pasta (noodles, spaghetti, etc) can be determined by volumetric Karl Fischer titration Pasta with a low water content of about 10% can be stored for many years
This article was originally published on Laboratorytalk on 30 Apr 2007 at 8.00am (UK)
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Karl Fischer water determination in sweet products
The instrumentation needed is a volumetric Karl Fischer titrator, for example a Metrohm 841 Titrando, and a double platinum pin electrode is used to determine the endpoint
0.1 to 100% water content determinations
The volumetric Karl Fischer water determination is one of the most frequently applied laboratory methods; this titrator has been specifically adapted to produce precise results
Pasta containing much more than 12% of moisture has a considerably shortened shelf life as it can become musty and mouldy.
Prior to analysis the pasta is ground up as finely as possible in a cooled laboratory mill.
As the sample could heat up during grinding (resulting in water loss), cooling is crucial for obtaining correct results.
Extraction of the water from the powdery sample is accelerated by adding formamide and working at 50C.
This considerably shortens the time required for the Karl Fischer titration.
Analytical System from Metrohm for the water determination:.
841 Titrando 2.841.0010.
803 KF Titration Stand 2.803.0010.
800 Dosino 2.800.0010.
Dosing Unit 10ml 6.3032.210.
Titration vessel 50-150ml with thermostat jacket 6.1418.250.
The 841 Titrando has the sophisticated control algorithm of the Titrando which has been adapted to the characteristics of the Karl Fischer reaction and guarantees highly precise results.
You can choose between a polarized alternating current (Ipol) or a defined voltage (Upol) to be applied to the electrode.
Both working modes yield fast and precise results.
Different reagents require different parameters.
The 841 Titrando lets you select the appropriate method for each type of reagent.
Combined with the easy and intuitive user guidance this is the optimal instrument for routine operation e.g the KF icons show you at a glance whether the instrument is still busy conditioning or whether you can start the water determination.
The electrode test and the newly created safety stop parameter prevent cell run-over during conditioning.
If, for example, the electrode is not connected correctly or the titration cell is very humid, conditioning is stopped after a given time or a given volume of KF reagent added.
This new feature increases work safety in your laboratory.
Find more details in free application bulletin 69 (Titrimetric methods for the chemical analysis of pasta) and request a free Metrohm monograph: Water determination by Karl Fischer titration.
Request these from Metrohm UK using the links provided. Request a free brochure from Metrohm UK ...
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