Gravimetric deposition of microliter drops with radiometric confirmation

Appl Radiat Isot. 2023 Nov:201:111025. doi: 10.1016/j.apradiso.2023.111025. Epub 2023 Sep 9.

Abstract

A manual microliter gravimetric dispensing technique is demonstrated using a micropipettor modified for use with removeable microcapillaries. Liquid scintillation sources were prepared from a well-characterized 241Am reference solution, providing a radiometric check of dispensed masses. Further experiments confirmed controlled dispensing of drops onto gold foils with losses ≤0.34(4) % of the total drop activity. A detailed measurement equation for the weighing technique, including the corrections for evaporation, is presented with a full accounting of associated uncertainties.

Keywords: Absolute decay energy spectrometry; Am-241; Milligram mass metrology; Quantitative drop deposition; Uncertainty.