Robust Nuclear Magnetic Resonance (NMR) Spectroscopy Method for the Identification and Quantification of Phthalates in Fragments of Polyvinyl Chloride (PVC) Toys

An efficient nuclear magnetic resonance (NMR)-based method was developed to detect and quantify the presence of phthalates in plastic fragments obtained from a children’s toy and cosmetic product containers. Bis-2-ethyl hexyl phthalate (BEHP) was present at a concentration of 8.5% w/w in the plastic toy residue. This indicates levels of phthalates above the permitted threshold (e.g., <0.1% w/w) imposed by EU and USA regulations restricting the use of plasticizers in plastic toys for children aged 0 to 3 years. An added value of this method is that the tetramethylsilane (TMS) internal standard present at a concentration of 2.2 mmol/L in commercially available CDCl3 solvents may be conveniently used for the quantitative nuclear magnetic resonance (qNMR) analysis. The protocol described here is highly reproducible and may be easily applied to large scale investigations of plasticizers content into polyvinyl chloride (PVC) polymers.