FAQ: How often should I solvent flush my refractive index detector (RID)?

Answer: As often as needed is the simple answer. A good practice is every time when solvent is replaced, flush the RID several times and observe the trend of the baseline. Once the baseline stabilizes, only then you can assume the reference is filled with new solvent. On a day-to-day basis, flush your RID a minimum of once a day, preferably at the beginning of the working day and for good measure, flush again at the end of the working day. Following this procedure will help maintain the accuracy and repeatability of your RID measurements.

June 20th 2024

$FAQ: Why should I solvent flush my refractive index detector?$

FAQ: Why should I solvent flush my refractive index detector?

Answer: Here are 4 good reasons to solvent flush your refractive index detector (RID). Firstly, the reference cell in your RID must contain the same solvent as used as in the eluent channel, regular flushing assures this. Secondly, while eluant constantly flows through the sample cell, the reference cell content is static. In time, bubbles may collect in the cell causing an imbalance in the signal. Flushing will remove the bubbles. Thirdly, it is often the case that solvent mixtures change with time. This happens within the reference cell of a RID as well. Flushing makes sure fresh (and representative) solvent is in the reference cell. Finally, upon replacing solvent A with solvent B, you must ensure that your RID reference cell contains only the new solvent. Even the smallest traces of the previous solvent may ruin a measurement.

Learn more about RID detectors

HPLC gradient validation using non-invasive flowmeters.

The traditional method for validation of gradients in an HPLC system currently relies heavily on the assistance of a UV detector. This methodology does though have well documented limitations. This tech note describes the benefits of an alternative approach using non-invasive flowmeters, based on a thermal principle, which are proven as a fast and accurate tool for determination of flow rate in HPLC systems.

When a mass sensitive GPC/SEC detector is not enough.

Most modern GPC/SEC systems are equipped with a high-performance mass sensitive detector such as a MALS or a viscometer. However, where applications are more demanding, such as with highly branched lower molecular weight polymers or block copolymers, a single mass sensitive detector is not sufficient to fully characterize the sample under investigation. Absolute molecular weight, as delivered by MALS or obtained with a viscometer detector, is often only a secondary parameter in comparison to the more insightful Mark-Howink parameters. Information about the physical structure of a polymer, which determines its behavior and function, can only be obtained by combining different mass sensitive detectors in one system and combining their results into a single picture. For this, the combination of MALS and viscosity, together with refractive index detection for concentration data delivers the most information-rich results while also proving absolute molecular weight and intrinsic viscosity results.