Defective UiO-66-NH2 enrichment medium for effective extraction and sensitive analysis of haloacetic acid disinfection by-products in tea drinks

Haloacetic acid (HAA) disinfection by-products (DBPs) with high polarity, low concentration and significant health hazard are widely present during disinfection processes, particularly iodinated and brominated acetic acids. Due to the lack of selective enrichment media, current sample preparation methods are insufficient for efficient enrichment of low concentrations of HAA DBPs in complex samples, which usually influences the analytical sensitivity and accuracy. In this study, a modulator-induced defect formation strategy was employed to prepare defective UiO-66-NH 2 (D-UiO) as a selective enrichment medium which was further fabricated as membrane solid-phase extraction (M-SPE) to efficiently enrich HAA DBPs. The structure and enrichment performance of the D-UiO medium was studied in detail. D-UiO exhibited good extraction selectivity for the five target DBPs in the presence of structural analogs as interfering compounds. Then, a sensitive quantification method by D-UiO based M-SPE was developed for trace brominated and iodinated acetic acid DBPs in tea drinks coupled with ultra-performance liquid chromatography-tandem mass spectrometry. The limits of detection of the method were in the range of 5.0-15.0 ng/L, and the recoveries were in the range of 78.3%-124%. By combining a ten-pass syringe pump with M-SPE technology, this method enabled batch sample processing and significantly reduced pre-treatment time. The method developed was efficient, selective, sensitive, and accurate for the analysis of hazardous HAA DBPs in complex tea drinks.