Non-Destructive Determination of Acetic Acid and Furfural in Books by Solid-Phase Micro-extraction (SPME) and Gas Chromatography-Mass Spectrometry (GC/MS)

A new method using solid-phase micro extraction (SPME) in combination with gas chromatography and mass spectrometry (GC/MS) has been developed to determine the concentration of volatile compounds within the solid matrix of book papers in a non-destructive way. The method involves sampling the headspace between two adjacent pages in a closed book, under equilibrium conditions. By determining the paper/air partition coefficient for the target substances it is possible to evaluate their concentrations within the paper from those quantified in the headspace with calibrated GC/MS analysis. The method has been used to determine the concentrations of acetic acid and furfural, potential chemical markers of paper instability and degradation, in books of different ages made of groundwood paper. Equilibration times for acetic acid and furfural in a typical book/headspace/SPME fibre system at room temperature were of 4 days, and 27 days, respectively. Paper-air partition coefficients determined for a reference groundwood paper were equal to 2.8 × 104 for acetic acid, and 6.0 × 104 for furfural. The concentrations of both compounds in the analysed books were within the range of 10–30 μg.cm-3. The method offers a sensitive, non-destructive diagnostic and monitoring tool that can provide valuable data to quantitatively support heritage institutions caring for paper-based collections to design more cost-effective air pollution control and other conservation strategies.