We're using a fluorometer (Horiba Aqualog) to analyze fluorescent dissolved organic matter (FDOM) in water samples. The samples are analyzed in quartz cuvettes, which must be bathed in a solution of 50% nitric acid for 24hrs. In theory, the nitric acid bath can be reused between multiple runs.

I'm now trying to find a lidded container that can safely hold 50% H2NO3 at 20 degrees C inside a fumehood for a week or more without damage. Minimum internal dimensions would be approximately 15cm square bottom and 3cm deep. We've considered jars or large beakers, but we need something wide enough to fit a butyl-gloved hand into to handle the delicate cuvettes.

In terms of materials, plastic options exist (https://www.calpaclab.com/chemical-compatibility-bottles-containers/). Teflon would be the "gold star" but I've found no teflon tanks available from suppliers. I'm currently looking at a Nalgene LLDPE rectangular tank with lid. Another idea is a glass bakeware dish with lid (much cheaper and AFAIK 50% nitric won't attack glass).

But I'm curious to know what others are using.