Temperature-response polymer coating for in-tube solid-phase microextraction coupled to high-performance liquid...

Area of Science:

• Analytical Chemistry
• Materials Science
• Separation Science

Background:

• Developing sensitive and selective methods for analyzing trace contaminants in complex matrices like milk is crucial.
• Existing solid-phase microextraction techniques can be improved for better efficiency and reusability.

Purpose of the Study:

• To fabricate a novel poly(N-isopropylacrylamide) (PNIPAAm) modified silica nanoparticle (SiO2 NP)-deposited capillary for in-tube solid-phase microextraction (SPME).
• To evaluate the temperature-responsive extraction capabilities of the modified capillary for analytes like diethylstilbestrol (DES).
• To apply the developed method for the quantitative analysis of synthetic estrogens in milk samples.

Main Methods:

• Fabrication of SiO2 NP-deposited capillary via liquid phase deposition (LPD).
• Surface modification of the capillary with 3-(triethoxysilyl) propyl methacrylate and subsequent PNIPAAm polymerization.
• Application of the PNIPAAm-modified capillary in in-tube SPME coupled with high-performance liquid chromatography (HPLC).
• Method validation using diethylstilbestrol as a model analyte and analysis of synthetic estrogens in milk.

Main Results:

• The PNIPAAm-modified SiO2 NP-deposited capillary demonstrated significant temperature-responsive extraction behavior.
• The method achieved low detection limits for synthetic estrogens, ranging from 1.2-2.2 ng/g.
• High recovery rates (71.7-98.9%) and acceptable relative standard deviations (2.8-12.6%) were obtained for milk samples.

Conclusions:

• The developed PNIPAAm-modified SiO2 NP-deposited capillary is a promising material for in-tube SPME applications.
• The temperature-responsive nature of the PNIPAAm coating enhances extraction efficiency and selectivity.
• This method offers a sensitive and reliable approach for the analysis of synthetic estrogens in complex food matrices like milk.