# Application of microsublimation for sample purification in compound-specific radiocarbon analysis

## TL;DR

This paper introduces a new microsublimation method to purify small samples for more accurate radiocarbon analysis.

## Contribution

A novel microsublimation apparatus is developed to reduce contamination in compound-specific radiocarbon analysis.

## Key findings

- The apparatus achieved a blank mass of 1.35 µg of carbon with F14C of 0.33, showing minimal contamination.
- It was effective for high-melting-point compounds like amino acids but less so for alkanes.
- The method improves post-chromatography sample purity and 14C measurement accuracy.

## Abstract

This article presents the development and application of a microsublimation apparatus aimed at improving the purity of ultra-small samples for compound-specific radiocarbon analysis. Accurate radiocarbon (14C) measurements require the effective isolation of biomarkers, yet procedural steps, such as chromatography and sample transfer, introduce contamination risks that can skew results. Here, we present a novel approach to remove contamination resulting from chromatographic isolation. The apparatus, constructed primarily from aluminum, allows solvent-free sublimation of multiple samples under vacuum. A constant contamination assessment showed a blank mass of 1.35 µg of carbon with a F14C of 0.33, indicating minimal contamination with 14C-depleted carbon. The apparatus demonstrated high efficacy for compounds with higher melting points, such as amino acids and dyes, while compounds like alkanes showed lower recovery rates. These findings confirm the potential of microsublimation to enhance post-chromatography sample purity and improve the accuracy of 14C measurements, though challenges remain for certain compound classes.