Ion Chromatography for Rapid and Sensitive Determination of Three Alkylamines in Wastewater after Headspace Single-Drop Microextraction

Abstract

A novel headspace single drop microextraction method coupled with ion chromatography was developed for the determination of propylamine, sec-butylamine, and butylamine in industrial wastewater. The method was based on a deionized water microdrop (10 µL) which hung in the headspace of the sample bottle. The ammonium ion produced in the microdrop was measured subsequently by ion chromatography. The conditions for the single-drop microextraction process were optimized by employing an orthogonal experimental design. The enrichment factors of propylamine, sec-butylamine, and butylamine were 40, 73, and 45, respectively, under the optimal conditions. Baseline separation of three alkylamines was achieved within 15 min in concentrations varying from 0.5 to 15.0 mg L⁻¹ (, , ) and the detection limits (signal-to-noise ratio of 3) were 0.96, 4.28, and 8.18 µg L⁻¹ by using 30 mmol L⁻¹ methanesulfonic acid as the eluent. The method was successfully employed to determine the three aliphatic amines in industrial wastewater with recoveries of 97.2% to 102.9%. The relative standard deviation, according to peak area, was 0.96%. The experimental results showed that headspace single-drop microextraction combined with ion chromatography is a simple, rapid, and low-cost method for the determination of the alkylamines.

Keywords:

• Alkylamine
• Headspace
• Industrial wastewater
• Ion chromatography
• Single drop microextraction

Acknowledgments

Financial support from NSF China (No. 40730741) is acknowledged.

Notes

^a Linearity of TMA.

^b Mean recovery of TMA (n = 5).