Targeted Quantitation Mode Comparison of Haloacetic Acids, Bromate, and Dalapon in Drinking Water Using Ion Chromatography Coupled to High-Resolution (Orbitrap) Mass Spectrometry

Analysis of brominide disinfection by-products (DBPs) in aquaculture water using ultra-high performance liquid chromatography-quadrupole-time of flight mass spectrometry (UPLC-Q-tof/MS)

BACKGROUND

halogenic disinfectants have been shown to produce toxic and carcinogenic disinfection by-products in the water disinfection process. Dibromohydantoin (DBDMH) is a commonly used water disinfectant in aquaculture. Aquaculture water has more complex matrix, and the analytical method for disinfection by-products (DBPs) have not been reported. Since the content of DBPs is related to the external conditions such as ultraviolet irradiation, temperatures, pH and humic acid. The semi-target screening method for mainly DBPs based on tracing mass spectrometry fragments of bromide and accurate mass of high resolution mass spectrometry was established by ultra performance liquid chromatography-quadrupole-time of flight-mass spectrometry (UPLC-Q-tof/MS). Br-DBPs as a important class of DBPs from DBDMH, which quantification analysis methods were developed based on accurate mass of high resolution mass spectrometry.

METHODS

through screening method to identify unknown Br-DBPs and quantitative analysis of the typical 4-bromophenol by-product of accurate mass was established. The conditions of the instrument parameters of mass spectrometry and SPE sample preparation procedure in complex real sample were optimized. The high efficiency method was demonstrated for the determination of Br-DBPs with a good linear correlation (R2 = 0.999) in the range of 0.500-200 μg L-1 and limit of detections (LODs) and limit of quantifications (LOQs) were 0.0250 ng L-1 and 0.0834 ng L-1, respectively.

CONCLUSION

the developed screening and quantification analytical strategy for Br-DBPs is rapid, accurate and sensitivity applicable for environmental in aquaculture water monitoring.

Optimization of a ultra-high-pressure liquid chromatography-tandem multiple reaction monitoring mass spectrometry method for monitoring haloacetic acids as chlorinated disinfection by-products in the fresh-cut industry

Haloacetic acids (HAAs) are one of the most important chlorinated disinfection by-products generated during water disinfection in the fresh-cut industry, and they can remain in the product, resulting in a consumer health risk. In this study, ultra-high-pressure liquid chromatography-tandem multiple reaction monitoring mass spectrometry (UHPLC-MRM) analysis used for drinking water was optimized and applied for the quantification of nine HAAs (HAA9) in fresh-cut lettuce and process water samples, with the complex matrix interferences for separation, and quantification problems. The method showed good selectivity, specificity and linearity, satisfactory values for trueness (recoveries of 80-116 %), precision (<22 %), and uncertainty (<55 %). Quantification limits varied from 1 to 5 µg L-1 or µg kg-1. The matrix effect for tribromoacetic, bromochloroacetic and chlorodibromoacetic acid was corrected by matrix-matched calibration and standard addition. After storage at -20 °C, only monobromoacetic acid was the HAA which loss happened after 7 days. The application of the methodology in lettuce and process water samples from the industry was successfully implemented. Therefore, this method could be employed for the quality control and regulatory analysis of HAAs in fresh products and process water from the fruit and vegetable industry.

Non-targeted and suspect screening analysis using ion exchange chromatography-Orbitrap tandem mass spectrometry reveals polar and very mobile xenobiotics in Danish drinking water

Non-targeted and suspect screening analysis is gaining approval across the scientific and regulatory community to monitor the chemical status in the environment and thus environmental quality. These holistic screening analyses provides the means to perform suspect screening and go beyond to discover previously undescribed chemical pollutants in environmental samples. In a case study, we developed and optimized a high-resolution tandem mass spectrometry platform hyphenated with anion exchange chromatography to screen drinking water samples in Denmark. The optimized non-targeted screening method was able to detect anionic and polar compounds and was successfully applied to drinking water from two drinking water facilities. Following a data analysis pipeline optimization, anionic pesticide residues and other environmental contaminants were detected at confidence identification level 1 such as dimethachlor ESA, mecoprop, and dichlorprop in drinking water. In addition to these three substances, it was possible to detect another 1662 compounds, of which 97 were annotated at confidence identification level 2. More research is urgently needed to health risk prioritize the detected substances and to determine their concentrations.

Analysis of environmental pollutants using ion chromatography coupled with mass spectrometry: A review

The rise of emerging pollutants in the current environment and requirements of trace analysis in complex substrates pose challenges to modern analytical techniques. Ion chromatography coupled with mass spectrometry (IC-MS) is the preferred tool for analyzing emerging pollutants due to its excellent separation ability for polar and ionic compounds with small molecular weight and high detection sensitivity and selectivity. This paper reviews the progress of sample preparation and ion-exchange IC-MS methods in the analysis of several major categories of environmental polar and ionic pollutants including perchlorate, inorganic and organic phosphorus compounds, metalloids and heavy metals, polar pesticides, and disinfection by-products in past two decades. The comparison of various methods to reduce the influence of matrix effect and improve the accuracy and sensitivity of analysis are emphasized throughout the process from sample preparation to instrumental analysis. Furthermore, the human health risks of these pollutants in the environment with natural concentration levels in different environmental medias are also briefly discussed to raise public attention. Finally, the future challenges of IC-MS for analysis of environmental pollutants are briefly discussed.

Target analysis and retrospective screening of contaminants in ready-to-eat cooked ham samples through UHPLC-Q-Orbitrap HRMS

The use of veterinary drugs (VDs) is widely administered to animals for both therapeutic and prophylactic purposes. However, their improper use may involve their occurrence in the final products intended for human consumption. In this scientific work, a method for the investigation of target (n = 30) VDs residues and retrospective suspect screening followed by confirmation using analytical standards of others 38 contaminants in ready-to-eat cooked ham by ultra-high performance liquid chromatography coupled with high-resolution mass spectrometry (UHPLC-Q-Orbitrap HRMS) was developed. The extraction was performed based on the QuEChERS approach and validated in accordance with the European Regulation 2021/808. The application of the in-house validated method to ready-to-eat cooked ham showed the occurrence of fourteen VDs residues. Despite the important incidence, the concentration levels found were below the maximum residue limits set for VDs in porcine muscle, except for colchicine. Constant monitoring of animals derived food is strongly recommended to ensure the food safety of consumers.

Synergistic cytotoxicity of bromoacetic acid and three emerging bromophenolic disinfection byproducts against human intestinal and neuronal cells

Halogenated disinfection byproducts (halo-DBPs) are drinking water contaminants of great public health concern. Nine haloaliphatic DBPs have been regulated by the U.S. Environmental Protection Agency and various halophenolic compounds have been identified as emerging DBPs. In this study, we evaluated the cytotoxic interactions of the regulated bromoacetic acid and three emerging bromophenolic DBPs, i.e., 2,4,6-tribromophenol, 3,5-dibromo-4-hydroxybenzoic acid, and 3,5-dibromo-4-hydroxybenzaldehyde. Cytotoxicity was measured for each DBP individually as well as each of their mixtures using in vitro human epithelial colorectal adenocarcinoma (Caco-2) and neuroblastoma (SH-SY5Y) cells. Concentration addition (CA) model and isobolographic analysis were employed to characterize the interactions among the DBPs. Our results show that the cytotoxicity of four bromo-DBPs against both cell-types followed the descending rank order of bromoacetic acid > 2,4,6-tribromophenol > 3,5-dibromo-4-hydroxybenzaldehyde > 3,5-dibromo-4-hydroxybenzoic acid. Compared with the toxicity data in literature, our finding that bromoacetic acid showed higher cytotoxicity than bromophenolic DBPs was consistent with the results from Chinese hamster ovary cells (a commonly used in vitro model of DBP toxicological studies); but different from the results obtained from in vivo biological models. Significantly, with CA model prediction, we found that mixtures of four bromo-DBPs exhibited synergistic cytotoxic effects on both human cell types. Isobolographic analysis of binary DBP mixtures revealed that, for Caco-2 cells, bromoacetic acid, 2,4,6-tribromophenol, and 3,5-dibromo-4-hydroxybenzoic acid induced synergism; for SH-SY5Y cells, bromoacetic acid induced synergism with all three bromophenolic DBPs. The production of reactive oxidative species (ROS) induced by DBP mixtures could be an important reason for the synergistic cytotoxicity.