Determination of haloacetic acids in water by liquid chromatography-electrospray ionization-mass spectrometry using volatile ion-pairing reagents

Abstract

A method for the determination of nine haloacetic acids (HAAs) in drinking water was developed using liquid chromatography-electrospray ionization-mass spectrometry (LC-ESI-MS) employing volatile ion-pairing reagents. The separation and sensitivity of all the compounds were optimized using three volatile amines (di-n-butylamine, N,N-dimethyl-n-butylamine and tri-n-butylamine) and optimized conditions were obtained with 5 mmol l⁻¹ dibutylamine (DBA). The sample preparation of this method was very simple involving filtration of the sample and the addition of 100 mmol l⁻¹ DBA. With DBA as ion-pairing reagent and propan-2-ol as mobile phase modifier, a water sample spiked with 0.1–100 ng ml⁻¹ of nine HAAs could be determined by LC-ESI-MS using time-scheduled selected ion monitoring. The correlation coefficients for all target analytes were higher than 0.999. The detection limits ranged from 24 to 118 pg ml⁻¹. The repeatability and reproducibility were in the range 1.5–9.1% and 5.9–12.4%, respectively.