Introduction

This patent consists of an innovative magnetic sample holder for Raman measurements using the maximum excitatory power, without damaging the sample. This sample holder can be inserted in a Raman spectroscopy cuvette, allowing to perform measurements on a moving sample.

Technical features

Due to its low sensitivity, Raman spectroscopy requires the use of medium power laser sources in order to attain a good signal-to-noise ratio in a short measurement time. In the case the sample is photosensitive, typically the laser power is reduced, causing a significant increase in the measurement time. Furthermore, this approach is sometime insufficient to prevent the sample from being damaged. The solution proposed to address this problem, is to perform the Raman measurements on a moving sample, such that each spot on the samples is exposed to the laser beam for a short time. In this way, the probability of thermal- and photo- degradation of the sample is reduced: this also allows the use of higher laser power, thus reducing the measurement time (compared to measurement in static mode). The sample is kept under movement by mounting it on small-sized cylindrical sample holder, containing a magnetic element. The movement is generated by an external magnetic stirrer, as commonly found in any chemical lab, easily adaptable to the Raman instrumentation.

Possible Applications

• Raman spectroscopy under Operando conditions (Catalysis, Synthesis, etc) [Top. Catal. 61 (2018) 1491];
• Raman spectroscopy for biological systems;
• Forensic chemistry [Talanta, 209 (2020) 120565];
• Surface Enhanced Raman Spectroscopy (SERS).

Advantages

• Low cost of the device;
• Easy integration with different Raman instruments and controlled atmosphere measurement cells;
• Decrease of the measurement time;
• Increased applicability of Raman spectroscopy;
• Increased statistical significance of measurements [Talanta, 209 (2020) 120565].