Fast Quantitative Analysis of Boric Acid by Gas Chromatography-Mass Spectrometry Coupled with a Simple and Selective Derivatization Reaction Using Triethanolamine

Abstract

A fast, selective, and sensitive GC-MS method has been developed and validated for the determination of boric acid in the drinking water by derivatization with triethanolamine. This analytic strategy successfully converts the inorganic, nonvolatile boric acid B(OH)3 present in the drinking water to a volatile triethanolamine borate B(OCH2CH2)3N in a quantitive manner, which facilitates the GC measurement. The SIM mode was applied in the analysis and showed high accuracy, specificity, and reproducibility, as well as reducing the matrix effect effectively. The calibration curve was obtained from 0.01 μg/mL to 10.0 μg/mL with a satisfactory correlation coefficient of 0.9988. The limit of detection for boric acid was 0.04 μg/L. Then the method was applied for detection of the amount of boric acid in bottled drinking water and the results are in accordance with the reported concentration value of boric acid. This study offers a perspective into the utility of GC-MS as an alternate quantitative tool for detection of B(OH)3, even for detection of boron in various other samples by digesting the boron compounds to boric acid