What solvent is used in the preparation of Ninhydrin to prevent ink runnage on paper?

Using Freon 113 in the preparation of Ninhydrin is significant because it acts as a solvent that effectively prevents ink runnage on paper. When applying chemical reagents like Ninhydrin to surfaces, it is essential to use a solvent that will not dissolve or smear the ink, as this can compromise the visibility and integrity of the latent prints being analyzed. Freon 113 has properties that allow it to dissolve Ninhydrin properly while minimizing the risk of affecting the paper's ink, making it a suitable choice for this application.

In contrast, other candidates like acetone and isopropanol are more likely to interact with various types of inks, potentially leading to smudging or runnage. Hexane, while a non-polar solvent, does not possess the specific qualities needed to dissolve Ninhydrin effectively without damaging the ink. Therefore, Freon 113 stands out for its ability to maintain the integrity of the paper and the prints during the development process.