Prepare Solutions More Efficiently Without Reading the Meniscus

Mettler Toledo is changing the way standards and samples are prepared in analytical laboratories by introducing the new Quantos liquid dosing module. Quantos combines Mettler Toledo’s weighing competence with unique powder and liquid dosing technology. Up to now, when preparing a solution, the amount of substance to be dosed was determined by the required concentration and the available volumetric glassware.

Quantos instead weighs the amount of substance, which can be only a few milligrams, and automatically adds solvent to accomplish the correct concentration. Instead of the glassware, the user decides on the amount of substance and may thus realize significant savings. Substance and solvent can directly be dispensed into the target vial instead of a volumetric flask, simplifying the solution preparation process. Automation makes the process error-resistant, reducing out-of-specification results.

In analytical laboratories, preparing samples and standards for example for high-performance liquid chromatography (HPLC) analysis is a time consuming, repetitive and error prone task. When preparing solutions for HPLC, the amount of substance is defined by the glassware and target concentration. The tolerance on the concentration defines how exact that amount must be dosed. For example, preparing a concentration of 1:1000 to within +/-10% requires dosing between 90 and 110mg into a 100ml volumetric flask. This can be a challenge especially when the substance is a paste or crème that is hard to dose.
Quantos instead weighs the amount of substance which can be only a few milligrams and automatically adds solvent to accomplish the correct concentration. There is no need to dose substance to a defined value, as the over/under weight of the solid is compensated for by adjusting the solvent addition to reach the exact concentration.

Today’s advancements in preparing solutions make it possible to realize significant cost savings as the required amount of solution for today’s analytical methods is very low. For example, typical HPLC instruments need 10-20 µl of solution per injection. Greater than 99% of prepared solutions are typically disposed of without being used. When using Quantos, the amount of substance is no longer determined by volumetric flasks but by the minimum weight of the balance. Therefore, in the example, savings of greater than 90% of substance and solvent can be realized. Substance and solvent can now be dispensed directly into the target vessel with unprecedented speed and accuracy, eliminating the associated expense of glassware management and wasted stock solutions.

Out-of-specification results in an analytical laboratory require significant resources and time to resolve. Questions that arise are: was the correct flask used, was the calculation and transcription done correctly, was the meniscus aligned with the mark? Automating the solution preparation process using Quantos gravimetric dispensing technology will reduce the potential sources of error and thereby reduce the risk of out-of-specification results.