Metrohm USA Debuts a New Look and New Products

Thermometric titration is a very versatile determination method and an ideal complement to potentiometric titration. In principle it is suitable for any reaction that produces a sufficiently large temperature change in the sample solution. It is particularly suitable for applications for which no suitable potentiometric sensor is available, for which no suitable reference electrode is available, in which the sample affects the indicator electrode or destroys it, for which no solvent is available that is suitable for potentiometry. The 859 Titrotherm combines innovative sensor technology with Metrohm's titration know-how. The temperature sensor based on semiconductor technology (thermistor), has a short response time of 0.3 s and a high resolution of 10-5 K. This makes the Thermoprobe the ideal sensor for thermometric titration, as it can follow any change in temperature quickly and accurately. Metrohm's Dosino technology has defined a new standard for volumetric titration. The Dosing Unit with its drive motor is mounted on the reagent bottle and thus guarantees maximum precision with minimum space requirements. The clearly laid out Titrotherm software allows adaptation of the screen view to the particular method parameters and thus provides rapid access to important commands or parameters. The endpoints are determined by calculating the first and second derivatives of the titration curve; by means of additional optimization parameters, the reproducibility can be improved even further.

Thermal sample preparation in Karl Fischer titration. For various reasons many substances are not suitable for a direct Karl Fischer titration: – They release their water only slowly – The water is released at high temperatures only – The substances are poorly soluble in alcohols – They undergo side reactions with KF reagents – They contaminate the titration cell or the electrodes By using the KF oven method the above-mentioned problems can be avoided. The substance under investigation is heated in a hermetically sealed vial in the oven. The water vapor released is transferred to the titration cell by a carrier gas. This means that no noxious solubilizers have to be used, side reactions as well as matrix effects are absent and the contamination of the titration cell is avoided. Depending on the sample’s water content, the determination can be carried out either by coulometric or volumetric Karl Fischer titration.

The highly efficient Robotic USB Sample Processor XL with two stations and four pump connections carries out complex laboratory automation tasks in combination with a Titrando. Together with the Swing Head the capacity is increased, for example, to 100 x 75 mL samples. The daisy-chain function of the MSB connections allows the direct control of Dosinos for «extended liquid handling» and/or of stirrers; including control cable. For rinsing the titration vessels and electrodes and for aspirating off the titrated solution up to four external peristaltic or membrane pumps can be connected. The methods are programmed with the handy Touch Control or PC-controlled - with the tiamo titration software. • Large sample volumes and large numbers of samples • Parallel operation • Automated liquid handling - pipetting • Karl Fischer automation • Automatic sample preparation • Two external titration stations