Quantitative analysis of nonylphenol ethoxylates in textiles using ultrasonic/microwave-assisted extraction coupled with ultra-high-performance supercritical fluid chromatography-photodiode array-tandem mass spectrometry

A sensitive and robust analytical method was developed for the simultaneous determination of nonylphenol ethoxylates (NPEOs) in textiles. The method utilizes ultra-high-performance supercritical fluid chromatography with photodiode array detection (UHPSFC-PDA) to assess monomer proportions across varying polymerization degrees, followed by quantitation via tandem mass spectrometry (UHPSFC-MS/MS) in multiple reaction monitoring (MRM) mode. Under optimized conditions, NPEOs (n = 2–39) were separated within 7 min on a BEH C₁₈ column using compressed CO₂ and methanol as the mobile phase. Additionally, response surface methodology and Box-Behnken design were employed to optimize ultrasonic/microwave-assisted extraction (UMAE) parameters. The method demonstrated excellent linearity (R² > 0.99) for 13 NPEO homologues (n = 2–14), with limits of detection (LODs) and quantitation (LOQs) values ranging from 0.26 to 45.09 μg/kg and 2.28–188.06 μg/kg, respectively. Intra- and inter-day precision values ranged from 0.8 % to 4.23 % and from 1.34 % to 9.59 %, respectively. Recoveries at low, medium, and high spiking levels were between 71.1 % and 102.5 % (RSD ≤ 12.98 %). The method was validated using quality control standards and successfully applied to commercial textile samples, revealing NPEO concentrations up to 2626.63 μg/kg. The combination of UMAE with UHPSFC-PDA-MS/MS offers a rapid, sensitive, and environmentally friendly solution for comprehensive NPEO analysis in textiles.