A Certified Reference Material of Polyvinyl Chloride Containing Phthalic Esters (NMIJ CRM 8156-a) for Screening Device Applications

Abstract

Phthalic esters (PEs) are used as plasticizers for plastic products especially for polyvinyl chloride (PVC). Owing to their adverse effects on human health, certain types of PEs are subjected to regulatory measures. Accurate and precision analyses of such regulated PEs are essential for monitoring compliance with regulatory standards; thus, the use of certified reference materials (CRMs) for quality assurance is recommended. To quantify the PE content of PVC products, the National Metrology Institute of Japan has developed a CRM, designated as NMIJ CRM 8156-a. This CRM is designed for validating the analytical methods and screening devices at low concentration levels (ca. 0.01%). Isotope-dilution mass spectrometry, the primary methods of measurement, has been employed for certification in conjunction with optimized gas and liquid chromatography/mass spectrometry techniques. Based on the mean mass fractions of target PEs derived from these two methods, eight certified values were determined for the CRM. The uncertainties associated with these certified values were estimated considering various factors such as characterization, homogeneity, and stability. Furthermore, the NMIJ CRMs were tested in screening devices such as pyrolyzers and thermal desorption mass spectrometers, confirming their suitability for generating calibration curves as well as the semi-quantitative analysis of target PEs. In summary, these CRMs are effective for validating quantitative and screening analytical methods for PEs in PVC and related substances.