Rapid In-Syringe-Based Ultrasonic-Energy Assisted Salt-Enhanced Homogeneous Liquid-Liquid Microextraction Technique Coupled with HPLC/Low-Temperature Evaporative Light-Scattering Detector for Quantification of Sodium Hyaluronate in Food Products

Abstract Sodium-hyaluronate (Na-HA) is a biopolymer-based active ingredient in various dietary and beauty care supplements. However, the existing analytical methods for Na-HA analysis are laborious, less sensitive, and time-consuming. This study demonstrates a simple, low-cost, and green rapid analytical methodology using a novel in-syringe-based ultrasonic energy-assisted salt-enhanced homogeneous liquid-liquid microextraction (IS-USE-SE-HLLME) technique coupled with HPLC/low-temperature evaporative light scattering detector (LT-ELSD) for the sensitive quantification of Na-HA in nutraceutical products. This method utilizes ultrasound energy to extract Na-HA from an aqueous sample solution using a low volume water-miscible extraction solvent with a high salt concentration. Size-exclusion column-based HPLC was applied to separate target Na-HA from co-matrices and quantified using LT-ELSD for sensitive analysis. Under optimal conditions, excellent linearity was observed between 1∼500 ng mL-1 with a correlation coefficient of 0.9974. Detection and quantification limits were 0.5 ng mL-1 and 1.0 ng mL-1, respectively. The developed (IS-USA-SE-HLLME/HPLC/LT-ESLD) method was applied to analyze Na-HA in commercial nutraceutical and beauty care products. Spiked recoveries of real samples showed between 96.1∼105.9%, with the precision