Automated Powder and Liquid Dosing

The Quantos autosampler QS30 allows up to 30 vials to be automatically filled with the powder dosing system and is an accessory to the XPE analytical balance. It is much faster than manual dosing and is used to boost productivity in the lab. The autosampler system has the unique ability to dose different amounts per vial and records the fill weight in one step. Different-sized containers, including capsules and vials, are filled quickly and automatically. Six racks with five positions are placed in the autosampler and make exchanging vials easy.

The powder dosing module is mounted on the XPE analytical balance and provides the dispensing functionality. The dosing unit allows both powder and liquid dispensing based on dosing heads. Quantos uses an automated process to dose free-flowing powders directly into a target container.

Solvents are dispensed automatically into the container on the balance. The Quantos liquid dosing module dispenses liquids in a fine jet with individual drops weighing less than 1 mg. To achieve a desired concentration, the liquid dosing module dispenses the correct amount of solvent according to the actual dosed amount of substance. Quantos automatically calculates the amount of liquid needed based on the concentration specified at the start of the process.

Typical applications include capsule filling, HPLC analysis, formulation and standard preparation, where the accuracy of the final results depends on precise and accurate sample weighing. Automated dosing with Quantos eliminates out-of-specification errors and avoids costly reworking.

Typical applications include pesticide residue testing, oil analysis and pharmaceutical analytical workflows. The liquid module achieves exact concentrations for stock solutions and standard preparation applications.

Gravimetric sample preparation is a sample preparation method that uses mass as the basis for measurement, rather than volume. It involves adding liquid by weight based on the recorded weight of previously dosed solids. While the principle works with both manual and automated methods, using a balance with the ability to automatically dose liquid solvent based on the mass of weighed-in solids allows precise concentrations to be achieved every time with less operator input.

Volumetric sample preparation

Flask-based, volumetric sample preparation has not changed significantly in decades. The workflow is manual and time consuming, and the technique relies on subjective assumptions and steps with a high potential for human error, as well as variable and uncertain sources.

Gravimetric sample preparation

Gravimetric sample preparation involves adding liquid by weight based on the recorded weight of previously dosed solids. It is a mass-based sample preparation method that avoids error-prone manual steps by relying on objective balance readings, rather than subjective optical interpretation of volume for precise concentrations.

Using disposable vials eliminates the need for a robust flask-washing system and the risk of cross-contamination that occurs when cleaning SOPs are not followed.

Cross contamination can also be avoided by using separate dose heads for different powder substances and sealing powders within the dosing head. Once the dosing head is filled, work proceeds with no powder contact.

Automated dosing and weighing can reduce the minimum sample weight of a balance by up to 30%. The Minimum Weight of an automated system is lower than in a manual process. Quantos dispenses powders in a closed weighing chamber with minimum user interference.

Exact concentrations can be prepared by using a sample preparation method that uses mass as the basis for measurement, rather than volume. Liquid is added by weight based on the recorded weight of previously dosed solids. While the principle works with both manual and automated methods, using a balance with the ability to automatically dose liquid solvent based on the mass of weighed-in solids means precise concentrations can be achieved every time with less operator input.

The weighing process can be simplified by using an automated process to dose free-flowing powders directly into a target container. With an automated dosing system, a level of accuracy can be achieved which is impossible to match in a manual process, even by the most skillful hands. Simply enter the target weight and Quantos will dose the exact amount. It’s no longer necessary for operators to weigh-in potent or toxic compounds using a spatula and weighing paper. With an automated dosing process, operators work safely without exposure to substances during weighing.

Accuracy can be increased by using an automated process to dose free-flowing powders directly into a target container. Quantos can dose from 1 milligram to 5 grams of free-flowing powder directly into a target container. The highly-accurate dosing process eliminates variability and out-of-specification results.

Direct dosing into the target container avoids spillages which may occur when powder is transferred. Additionally, the reduced cleaning effort required further minimizes operator exposure to toxic materials. With a Quantos powder dosing system, powder remains sealed within a dosing head so aerosol formation is kept to a minimum. Hands-free dosing of the powder directly into the target container significantly lowers the risk of exposure.

Powders exhibit a diverse range of characteristics; particles vary in size, shape, surface texture, and density, which causes them to behave differently. Mettler-Toledo's range of dosing heads is ideal for dosing fine, fluffy, static, compacted, granular, and heterogeneous substances.

A pin in the head pushes the powder down and seals the head once dosing is complete. One dosing head is dedicated to one substance for the duration of its lifetime to avoid cross contamination. Dosing heads are used in various laboratories across a wide range of industries.

Quantos dosing heads have been designed to handle a range of different powder characteristics, even hard to handle and electrostatically-charged powders are accurately dosed to target.

Automated dosing with powder and liquid dispensing modules can reduce the minimum net sample weight of a balance by up to 30%. This minimum weight reduction means only the minimum amount of valuable or toxic substances is required for sample preparation. In addition, the risk of overdosing is reduced, helping to avoid waste and save costs, which is crucial when working with rare or expensive materials.

The Quantos powder dosing module is compatible with all XPE analytical balances. The dosing module is easy to attach to a balance and allows powder dosing to commence immediately.