Improving the Detectability of Sequential Injection Chromatography (SIC): Determination of Triazines by Exploiting Liquid Core Waveguide (LCW) Detection

Abstract

Coupling a liquid core waveguide cell to a sequential injection chromatograph improved the detection limits for determination of triazine herbicides without compromising peak resolution. Separation of simazine, atrazine, and propazine was achieved in water samples by a 25 mm long C₁₈ monolithic column. Detection was made at 238 nm using a type II LCW (silica capillary coated with Teflon® AF2400) cell with 100 cm of optical path length. Detection limits for simazine, atrazine, and propazine were 2.3, 1.9, and 4.5 µg L⁻¹, respectively. Reduced analysis time and low solvent consumption are other remarkable features of the proposed method.

Keywords:

• Liquid core waveguide
• Sequential injection analysis
• Simultaneous determinations
• Triazines

Acknowledgments

This paper was submitted as part of a Special Issue on Flow Injection Analysis.

Financial Support and fellowships from FAPESP, CAPES, and CNPq are gratefully acknowledged.

Notes

^a Based on seven measurements at each concentration level.

^a Standard deviation of triplicate of experiments;

^b Critical value of |t| for 4 degrees of freedom and 95% confidence level = 2.78 [26];

^c River or reservoir waters;

^d Tap water.