17. März 2017
Transfer of liquids with highest precision using Accurate Add
AppNote 187: Highly accurate standard addition and generation of standards and dilution series based on the Accurate Add function result in significantly improved quality of results
The manual transfer of liquid standards and solutions is usually part of the daily activities throughout the
analytical laboratory. For example, liquids must be transferred when creating calibration standard samples,
pipetting solvents, and combining liquids. The accurate and precise transfer of liquids can be critical to the analytical results. Liquids with low boiling points or high viscosities pose several challenges to achieving accurate and precise delivery of desired volumes. Verification of the volumes of liquids transferred would help verify the quality of the analytical procedure and ensure the high quality of the resulting data.
A single X-Y-Z coordinate autosampler and sample preparation robot commonly used for sample introduction in GC or HPLC can be used to perform a wide variety of sample preparation techniques using a single instrument and controlling software.
The sampler can be configured as part of a GC or LC system, or as a bench-top workstation independent of the analytical instruments used, and can also include an analytical balance to provide weight verification of liquid transfers. In this report, the automated transfer by the autosampler of a variety of liquid standards having a wide range of volatility and viscosity properties is discussed. A new vial venting tool that allows liquid samples to be transferred to a sealed vial while venting it is described and evaluated. Resulting weight verification, precision, and accuracy data from the assessment of example compounds transferred by the autosampler are provided that demonstrate the dramatic improvement in accuracy and precision for transferring these types of liquids.
Automating the Accurate Transfer of Highly Volatile to Highly Viscous Liquids using a Bench-top Workstation