Qualitative and quantitative solid-phase microextraction gas chromatographic–mass spectrometric determination of the low-molecular-mass compounds released from poly(vinyl chloride)/polycaprolactone–polycarbonate during ageing

A solid-phase microextraction (SPME) method was developed to quantitatively determine the amount of 6-hydroxyhexanoic acid in aqueous solutions. The SPME method in combination with GC–MS was then applied to identify and quantify the low-molecular-mass compounds migrating from a new poly(vinyl chloride) (PVC) material, PVC/polycaprolactone–polycarbonate (PCL–PC) during ageing in water. It was shown that only a small amount of 6-hydroxyhexanoic acid, the final hydrolysis product of PCL–PC, migrated from the blend during ageing at 37 and 70 °C. If, however, the temperature was raised to 100 °C rapid hydrolysis of PCL–PC resulted. In addition to 6-hydroxyhexanoic acid, 6-hydroxyhexanoic acid dimer, caprolactone, different carboxylic acids, acetophenone and phenol were identified. SPME–GC–MS was also applied to monitor the low-molecular-mass compounds migrating from the PVC/PCL–PC blend during thermo-oxidation.