Milligram mass metrology for quantitative deposition of liquid samples

TL;DR

This paper introduces a precise method for measuring the mass of 1 microliter liquid droplets using a microcapillary pycnometer, calibration, and evaporation corrections, achieving high accuracy for small sample volumes.

Contribution

It presents a novel approach combining microcapillary pycnometry, calibration, and evaporation correction for accurate micro-liter liquid mass measurement.

Findings

Achieves 0.3% relative combined expanded uncertainty.

Enables accurate mass determination of 1 μl liquid droplets.

Addresses challenges of small-volume liquid dispensing.

Abstract

Quantitative dispensing of liquids by mass becomes increasingly difficult as sample volume decreases. Whereas ml quantities of liquid can be directly weighed as dispensed on an analytical balance or using pycnometer methods, {\mu}l samples are more challenging due to their milligram-scale mass and rapid evaporation. Here, a method for quantitative determination of the mass of 1 {\mu}l droplets of liquid is proposed. The weighing of a microcapillary pycnometer combined with traceable calibration masses and corrections for sample evaporation allows determination of the droplet mass on the order of 1 mg with relative combined expanded uncertainty of 0.3 %.