[Determination of Haloacetic Acids, Disinfection Byproducts, in Tap Water with Reversed-Phase Ultra-Performance Liquid Chromatography-High Resolution Mass Spectrometry]

Abstract

Objective: To establish a method for quantitative analysis of haloacetic acids (HAAs), disinfection byproducts, in tap water with reversed-phase ultra-performance liquid chromatography-quadrupole-orbitrap high resolution mass spectrometry.

Methods: Tap water samples were collected and 0.70 g/L ascorbic acid was added to eliminate residual chlorine. Then, the water samples were directly injected into the instrument for analysis after filtration. After separation on a pentafluorobenzene (PFP) column with an inner diameter of 1.0 mm at a higher linear velocity and a lower volume flow rate compared with those of a narrow-bore column, nine HAAs, namely, monochloroacetic acid (MCAA), monobromoacetic acid (MBAA), dichloroacetic acid (DCAA), bromochloroacetic acid (BCAA), dibromoacetic acid (DBAA), trichloroacetic acid (TCAA), bromodichloroacetic acid（BDCAA), chlorodibromoacetic acid (CDBAA) and tribromoacetic acid (TBAA), were examined by negative electrospray ionization and full MS/dd-MS ² acquisition mode. In order to adjust for the matrix effect, matrix matching calibration curves were used to quantitate the nine HAAs.

Results: Good linearity was obtained for each of the nine HAAs within their respective linear ranges. The detection limits and quantification limits of the method were 0.020-1.0 μg/L and 0.060-3.0 μg/L. The recoveries were 69.8%-119%.

Conclusion: The proposed method showed strengths in separation speed and qualitative accuracy. It did not require for complicated pretreatment procedures and can meet the need of tap water sample analysis.

Keywords: Dechlorinating agent; Haloacetic acids; High resolution mass spectrometry; Matrix effect; Ultra-performance liquid chromatography; Water safety.