A validated high performance liquid chromatography method for simultaneous determination of PPO and POPOP in plastic scintillators

Plastic scintillators are the solid solutions of active additives to polymer matrices and widely used in various fields of science and technology such as high-energy physics, radiation chemistry, nuclear-power engineering, dosimetry and medical imaging. 2,5-diphenyloxazole (PPO) and 1,4-bis(5-phenyl-2- oxazolyl)benzen (POPOP) are the most widely used fluorescent additives (fluors) which lead to scintillation. Since the composition of the fluors determines the photon yield and optical properties of the scintillators, it is important to determine their concentration in the fabricated material. This paper describes a method, for the first time, for accurate determination of PPO and POPOP in plastic scintillators. A complete validation of the analytical procedure (sample preparation + HPLC method) has been performed using three spiking levels at 0.1, 10 and 100 mg L-1 and real plastic scintillator samples. Based on the results, calibration plots of PPO and POPOP were linear over the 0.01 to 150 mg L-1 concentration ranges. The limit of detection and limit of quantification were 0.92 and 2.80 mu g L-1 for PPO and 2.11 and 6.39 mu g L-1 for POPOP, respectively. The performance of the analytical procedure was also verified through the determination of fluors in a plastic scintillator fabricated via bulk thermal polymerization. As a consequence, the data indicate that the proposed analytical procedure for PPO and POPOP determination in plastic scintillators provides good linearity, sensitivity, accuracy, precision and robustness, which allows a novel, simple, fast, economical, and reliable qualitative and quantitative analysis.