Certified Reference Material for the Quantification of Phthalates in Polyvinyl Chloride Resin (NMIJ CRM 8152) was written by Hanari, Nobuyasu;Orihara, Yukari;Matsuyama, Shigetomo. And the article was included in Analytical Letters in 2021.Formula: C20H26O4 This article mentions the following:
Phthalates are primary industrial chems. used as polyvinyl chloride (PVC) plasticizers. However, certain phthalates are controlled as restricted substances listed under Annex II of Directive 2011/65/EU, (EU)2015/863. Since an accurate quantification of phthalates is essential to monitoring their concentration levels, quality assurance during their analyses using certified reference materials (CRMs) is required. A PVC CRM for the quantification of phthalates (NMIJ CRM 8152) was provided by the National Metrol. Institute of Japan. This CRM was in the form of grayish-white pellets (3-mm diameter x 3-mm length). The anal. procedures adopted were isotope-dilution mass spectrometry, which was the primary method of measurement, and gas chromatog./mass spectrometry; these procedures were optimized and applied to the characterization. The mass fractions of five target phthalates calculated using the mean values were determined as the certified values of the CRM. The relative standard uncertainties attributed to the certification were combined, e.g., those for the characterization, inhomogeneity, and instability. The mass fractions of five phthalates were certified, and those of three phthalates and one adipate were acquired and are reported as tech. information. The CRM is shown to be applicable to assessing the validity of anal. methods during the quantification of phthalates in PVC resin and similar materials. In the experiment, the researchers used many compounds, for example, Dicyclohexyl phthalate (cas: 84-61-7Formula: C20H26O4).
Dicyclohexyl phthalate (cas: 84-61-7) belongs to esters. Esters are also usually derived from carboxylic acids. It may also be obtained by reaction of acid anhydride or acid halides with alcohols or by the reaction of salts of carboxylic acids with alkyl halides. Many esters have the potential for conformational isomerism, but they tend to adopt an s-cis (or Z) conformation rather than the s-trans (or E) alternative, due to a combination of hyperconjugation and dipole minimization effects. The preference for the Z conformation is influenced by the nature of the substituents and solvent, if present. Lactones with small rings are restricted to the s-trans (i.e. E) conformation due to their cyclic structure.Formula: C20H26O4
Referemce:
Ester – Wikipedia,
Ester – an overview | ScienceDirect Topics