The ABC’s of Platinumware for Sample Preparation by Fusion

by Geneviève Labrecque, Thursday, 6th September 2018

Platinumware is used in sample preparation by fusion for XRF and ICP analysis. Crucibles (used for XRF and ICP analysis) and molds (only used for XRF) are made of 95% Pt and 5% Au.

Why use platinum and gold?

Image6It has been proven that this alloy has a high melting point and can withstand extreme heat. Platinum has a great thermal conductivity and ensures very low contamination of the molten mixture during fusion. The addition of gold has a non-wetting effect. In short, the alloy of these two precious metals allows the obtention of the best analytical results. However, always remember that platinumware must be used adequately to meet high expectancies.

 

Taking care of your molds

The deterioration of the mold surface will, of course, decrease your fusion success rate and have bad consequences on your analytical results. The analytical surface of the mold therefore needs to be entirely flat, without any scratches, as well as oil and dust-free. Molds can be polished in the laboratory to get a mirror finish.

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Taking care of your crucibles

Keep your crucibles free of bumps and scratches since these imperfections impact the pouring step. In fact, particles of the melted mixture tend to adhere to scratches, thus resulting in an incomplete transfer into the mold. Crucibles that are not used or cleaned adequately can lead to a non-homogeneous heating transfer to the molten mixture.

Cleaning your labware

It’s simpler than you think. Always clean your platinumware when disks particles are left (molds) or whenever you change the sample to fuse to avoid contamination (crucibles). Also, keep in mind that platinum items must be cleaned in an acidic bath.

Image7Some questions remain unanswered?

Please contact our experts to have more information. They will be glad to provide you with more details.


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