Spectrophotometric Determination of Lysozyme by On-line Preconcentration with A Microcolumn Containing La3+-TiO2-Zeolite

A spectrophotometric method for the determination of lysozyme was established based on the online preconcentration using a La3+-TiO2-zeolite microcolumn. Effects of operation parameters on the extraction efficiency were optimized as follows: eluent (methanol), eluent flow rate (2.0 mL min−1), sample pH (5.0), sample flow rate (1.2 mL min−1), sample volume (1.2 mL), and determination wavelength (280 nm). The proposed method was used for the determination of lysozyme in egg white, honey, and wine samples. The intraday and interday relative standard deviations were determined as 2.1% and 2.8%, respectively. The recoveries were higher than 90%. The method combining UV detection with online preconcentration using La3+-TiO2-zeolite as the adsorbent is simple, rapid, sensitive, and can be applied to analysis of lysozyme in egg white, honey, and wine samples.