Sample Preparation by Fusion: 3 Common Questions Answered

por Geneviève Labrecque, Thursday, 18th July 2019

Tons of questions might come to your mind when preparing your samples prior to X-ray fluorescence (XRF) or inductively coupled plasma (ICP) analysis. We’ve collected frequently asked questions related to sample preparation by fusion, and here’s what our experts have to say about it.

That being said, we are perfectly aware that the sample preparation technique can generate many other questions. Feel free to ask our experts anytime: they will be more than happy to spread their knowledge and assist you.

Can we use one fusion method for all types of samples?

In an ideal world, we would have one fusion method used to prepare all types of samples. It would be so easy! Unfortunately, the answer to this question is no. The reality is that every type of sample has its own chemistry as well as oxidation requirements prior to fusion. Samples also dissolve differently in the flux depending on their composition. It is therefore important to use a specific method developed by experts who take all these points into consideration to ensure the success of the fusion.

What are non-wetting agents (NWAs), and why should I use them to prepare my samples?

NWAs are halides that can be already pre-fused with fluxes or that can be added as salt or as a solution. Their use is recommended since they increase the surface tension of the molten mixture, thus decreasing its tendency to stick to the platinumware. In addition, NWAs prevent the disks from cracking, allow better pouring and facilitate the cleaning of molds and crucibles.

Note that the use of NWAs ensures a high success rate in the preparation of “sticky” samples (containing copper, chromium, and manganese).

How do Malvern Panalytical fluxes differ from the competition?

People like to compare products and choose what’s best for them, nothing new about that. Our flux is the best option for sample preparation by fusion because it’s made of pre-fused vitreous beads, it’s anhydrous, stable and non-hygroscopic. In addition to having a high density and controlled granulometry, our flux is stable over time and leads to uniform mixtures. Malvern Panalytical also ensures batch to batch consistency (each batch is analyzed for contaminants) as well as high purity of the product.

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