Analysis of Phenoxyethanol: Instrumental Parameters and Effects

In the last 10 to 15 years several examination methodologies have been proposed that rely on the quantitative analysis of semi-volatile components in writing ink, such as Phenoxyethanol (PE), for the purpose of determining the date of production of the writing. These examination methodologies require the use of analytical instrumentation that is capable of determining with great sensitivity and specificity both the identity and quantity of these components. The instrumentation of choice is gas chromatography/mass spectrometry (GC/MS) with the sample introduction methods varying from solvent injection to thermal desorption.
This work addresses the impact that various instrumental conditions and parameters will have on the ability to accurately and precisely measure the quantity of semi-volatile components. Instrumental components ranging from the injector, through the column, to the source were evaluated by sequential analysis of a range of standard solutions, both before and after maintenance procedures. Since most of the examination methodologies involve the comparison of writing ink samples both with and without exposure to artificial aging conditions, such samples were also included in the examination scheme.
Analysis of the above referenced samples resulted in an effective evaluation of the extent to which any instrumental parameter affects the ability to accurately determine the amount of semi-volatile components present in a writing ink sample. Linear relationships were determined between standard solutions of varying concentrations and among writing ink samples of varying concentrations. The condition of instrumental components was found to have a minimal, measurable effect upon quantitative determinations of the concentration of semi-volatile components. Ultimately, the comparison of writing ink samples with artificially aged samples was found to produce data that was capable of reliably determining the age of the examined writings and was not affected by the instrumental parameters that were tested.