Bar Adsorptive Microextraction Approach for Trace Determination of Local Anesthetics in Urine Matrices

Area of Science:

• Analytical Chemistry
• Environmental Science

Background:

• Local anesthetics (lidocaine, procaine, tetracaine, benzocaine) are widely used but require sensitive detection in biological matrices.
• Existing methods for anesthetic detection in urine can be complex or less environmentally friendly.

Purpose of the Study:

• To develop and validate a sensitive analytical methodology for quantifying four local anesthetics in urine.
• To compare the efficiency of Solid-Phase Microextraction (SPME) LC Tips and Bar Adsorptive Microextraction (BAμE) for anesthetic extraction.
• To establish an environmentally friendly method for trace anesthetic analysis.

Main Methods:

• Optimization of microextraction and back-extraction parameters using Box-Behnken and full-factorial designs.
• Application of two preconcentration techniques: SPME LC Tips and BAμE.
• Analysis of extracted anesthetics using Gas Chromatography-Mass Spectrometry (GC-MS).

Main Results:

• Bar adsorptive microextraction (BAμE) demonstrated superior performance compared to SPME LC Tips.
• The validated BAμE/GC-MS method achieved low limits of detection (2-18 ng/mL) and good linearity (r² ≥ 0.9945).
• High recovery yields (30.3-97.9%), precision (%RSD ≤ 8.8%), and accuracy (bias % between -15.9 and 15.0%) were obtained.

Conclusions:

• The developed BAμE/GC-MS methodology is a sensitive, precise, and accurate tool for analyzing local anesthetics in urine.
• This method serves as an effective and environmentally friendly alternative for monitoring trace anesthetics in complex matrices.
• The technique was successfully applied to analyze local anesthetics in volunteer urine samples.