Determination of testosterone propionate in cosmetics using excitation-emission matrix fluorescence based on oxidation derivatization with the aid of second-order calibration methods

A sensitive excitation-emission fluorescence method was proposed to determine testosterone propionate (TP) in several cosmetics with the aid of second-order calibration methods based on the self-weighted alternating trilinear decomposition (SWATLD) and parallel factor analysis (PARAFAC) algorithms. TP can be transformed into a highly fluorescent derivative through oxidation reaction with concentrated sulfuric acid (H₂SO₄). Both algorithms have been recommended to enhance the selectivity and attain TP concentration in cosmetics free from interference from potential interfering matrix contaminants introduced during simple cosmetic pretreatment procedure, even in the presence of other homogeneous drugs. Satisfactory results have been achieved for TP in complicated cosmetics, fully exploiting “second-order advantage”. The correlation coefficients of TP obtained by using both SWATLD and PARAFAC with N = 3 are 0.9968 and 0.9974, and the average recoveries, 99.3 ± 4.7% and 101.3 ± 5.9%, respectively. Furthermore, in order to investigate the performance of the proposed methods, some statistical parameters and figures of merit of SWATLD and PARAFAC, i.e., sensitivity (SEN), selectivity (SEL) and limit of detection (LOD) were evaluated, and the accuracy of both algorithms was also validated by the elliptical joint confidence region (EJCR) test.