Sample preparation of blue ballpoint pen ink for determining the composition of color components by RP HPLC method

Abstract

The paper presents various theoretical and practical aspects of sample preparation of blue ballpoint pen ink applied on paper for subsequent quantitative analysis using reverse-phase high-performance liquid chromatography (RP HPLC). Estimation of analytical characteristics of a variant of cutting out a paper fragment containing applied ink for reproducibility of analysis results is discussed; composition of the extraction system and extraction conditions were evaluated. Qualitative and quantitative characterization of the extracts was performed by RP HPLC with the diode array detection. Using a scalpel as a tool for cutting out sample fragments and an acidified mixture of solvents as an extractant with performing extraction in an ultrasonic bath at the room temperature for 2 minutes is recommended. It was shown that the influence of different degree of pressure on a ballpoint pen when applying ink to the paper can be minimized by using normalized peak areas of individual dyes. The proposed sample preparation conditions were tested when studying the processes of changes in the composition of applied ink during artificial aging under the influence of constant ultraviolet (UV) irradiation.