Automated weighing in the stable isotope lab: When less is more

Automated powder weighing is an elusive goal in scientific laboratories. The main problem is that powders are much more heterogeneous than liquids, making difficult the development of a unified automation solution for their handling. A compromise has been presented with miau, a low-cost, open-source autosampler for microbalance. Miau was demonstrably useful to perform the automated weighing of some powders, as long as the same powder is weighed repeatedly, which is useful for preparing standards to be measured along samples. However, in stable-isotope laboratories it is also necessary to weigh samples, which are often very heterogeneous, and thus not amenable for miau. Here it is demonstrated how miau can be adapted to handle not only standards, but also samples, using the “less is more” philosophy: • Miau is simplified to perform only the manipulation of weighing capsules, becoming “miau redux”; • Miau redux can be used not only for standards, but for a variety of samples as well; • Miau redux saves 64% of operator time when using a microbalance.