Simultaneous analysis of 11 haloacetic acids by direct injection-liquid chromatography-electrospray ionization-triple quadrupole tandem mass spectrometry and high resolution mass spectrometry: occurrence and evolution in chlorine-treated water

Comparison of three sorbents for thin film solid phase microextraction of haloacetic acids from water

Water disinfection inevitably leads to disinfection byproduct formation, such as haloacetic acids. Many disinfection byproducts reportedly have adverse health effects and, in many instances, including four haloacetic acids, are classified as potential carcinogens. As the global awareness of these compounds increases, more regulatory bodies include certain disinfection byproduct groups in their regulations. Rugged, fast, and cheap analytical quantification methods are therefore crucial. In this paper, a thin film extraction method for haloacetic acids is outlined. Thin films were synthesized in-house using a spin coating procedure, which allowed for easy adjustment of the sorbent choice and film geometry. PDMS, Carboxen®, and HLB were of interest and their extraction potential for HAAs from spiked water was tested in three film variations. PDMS films impregnated with HLB or Carboxen® improved the extraction drastically compared to PDMS films. Specifically, HLB impregnated films achieved excellent extraction efficiencies for tri-substituted analytes (51% for BDCAA, 77% for CDBAA, and 92% TBAA), which are often present at extremely low concentrations in water. In addition to the extraction experiment, a computational model was applied to compare PDMS and HLB. Trends observed in the computational data reflected in the experimental results, showing the validity of the model and confirming that physisorption through hydrogen bonding was mainly responsible for successful extraction.

Enhanced detection of monoiodoacetic acid at ng/L level by ion chromatography with novel derivatization-free pretreatment

Concerns have recently arisen regarding the formation of carcinogenic and genotoxic iodinated haloacetic acids (HAAs), such as monoiodoacetic acid (MIAA), during the disinfection of iodine-containing water with chloramine. Existing detection methods for MIAA rely on either labor-intensive derivatization operations or expensive instruments, making analysis challenging. To bypass these issues, this study proposed a novel two-step liquid-liquid extraction strategy to enrich MIAA and then pioneered the integration of common ion chromatography (IC) with an ultraviolet detector to measure trace MIAA precisely. This novel approach achieved a remarkable 155.6-fold enrichment of MIAA and significantly reduced the need for water and chemicals, hence enhancing its efficiency and environmental friendliness. Besides, this method effectively removed coexisting anions and separated MIAA from other interferents by adjusting IC column and eluent conditions. The method detection limit of MIAA is an impressive 21.44 ng/L, and the recoveries in synthetic and real water samples ranged from 85 to 113%, with maximum deviations of 7.59%. We validated the reliability of our approach by comparing it with the USEPA 552.3 method. In conclusion, this IC-based method proves to be a robust and environment-benign solution for detecting trace MIAA in complex water components.

Insights to estimate exposure to regulated and non-regulated disinfection by-products in drinking water

BACKGROUND

Knowledge about human exposure and health effects associated with non-routinely monitored disinfection by-products (DBPs) in drinking water is sparse.

OBJECTIVE

To provide insights to estimate exposure to regulated and non-regulated DBPs in drinking water.

METHODS

We collected tap water from homes (N = 42), bottled water (N = 10), filtered tap water with domestic activated carbon jars (N = 6) and reverse osmosis (N = 5), and urine (N = 39) samples of participants from Barcelona, Spain. We analyzed 11 haloacetic acids (HAAs), 4 trihalomethanes (THMs), 4 haloacetonitriles (HANs), 2 haloketones, chlorate, chlorite, and trichloronitromethane in water and HAAs in urine samples. Personal information on water intake and socio-demographics was ascertained in the study population (N = 39) through questionnaires. Statistical models were developed based on THMs as explanatory variables using multivariate linear regression and machine learning techniques to predict non-regulated DBPs.

RESULTS

Chlorate, THMs, HAAs, and HANs were quantified in 98-100% tap water samples with median concentration of 214, 42, 18, and 3.2 μg/L, respectively. Multivariate linear regression models had similar or higher goodness of fit (R2) compared to machine learning models. Multivariate linear models for dichloro-, trichloro-, and bromodichloroacetic acid, dichloroacetonitrile, bromochloroacetonitrile, dibromoacetonitrile, trichloropropnanone, and chlorite showed good predictive ability (R2 = 0.8-0.9) as 80-90% of total variance could be explained by THM concentrations. Activated carbon filters reduced DBP concentrations to a variable extent (27-80%), and reverse osmosis reduced DBP concentrations ≥98%. Only chlorate was detected in bottled water samples (N = 3), with median = 13.0 µg/L. Creatinine-adjusted trichloroacetic acid was the most frequently detected HAA in urine samples (69.2%), and moderately correlated with estimated drinking water intake (r = 0.48).

SIGNIFICANCE

Findings provide valuable insights for DBP exposure assessment in epidemiological studies. Validation of predictive models in a larger number of samples and replication in different settings is warranted.

IMPACT STATEMENT

Our study focused on assessing and describing the occurrence of several classes of DBPs in drinking water and developing exposure models of good predictive ability for non-regulated DBPs.

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.

Indirect potable water reuse to face drought events in Barcelona city. Setting a monitoring procedure to protect aquatic ecosystems and to ensure a safe drinking water supply

The climate change and increasing anthropogenic pressures are expected to limit the availability of water resources. Hence, active measures must be planned in vulnerable regions to ensure a sustainable water supply and minimize environmental impacts. A pilot test was carried out in the Llobregat River (NE Spain) aiming to provide a useful procedure to cope with severe droughts through indirect water reuse. Reclaimed water was used to restore the minimum flow of the lower Llobregat River, ensuring a suitable water supply downstream for Barcelona. A monitoring was performed to assess chemical and microbiological threats throughout the water treatment train, the river and the final drinking water, including 376 micropollutants and common microbiological indicators. The effects of water disinfection were studied by chlorinating reclaimed water prior to its discharge into the river. Data showed that 10 micropollutants (bromodichloromethane, dibromochloromethane, chloroform, EDDP, diclofenac, iopamidol, ioprimid, lamotrigine, ofloxacin and valsartan) posed a potential risk to aquatic life, whereas one solvent (1,4-dioxane) could affect human health. The chlorination of reclaimed water mitigated the occurrence of pharmaceuticals but, conversely, the concentration of halogenated disinfection by-products increased. From a microbiological perspective, the microbial load decreased along wastewater treatments and, later, along drinking water treatment, ultimately reaching undetectable values in final potable water. Non-chlorinated reclaimed water showed a lower log reduction of E. coli and coliphages than chlorinated water. However, the effect of disinfection vanished once reclaimed water was discharged into the river, as the basal concentration of microorganisms in the Llobregat River was comparable to that of non-chlorinated reclaimed water. Overall, our study indicates that indirect water reuse can be a valid alternative source of drinking water in densely populated areas such as Barcelona (Catalonia - NE Spain). A suitable monitoring procedure is presented to assess the related risks to human health and the aquatic ecosystem.

Occurrence of brominated disinfection by-products in thermal spas

Thermal spas are gaining more and more popularity among the population because they are used for recreational purposes. Disinfecting these baths without losing the health benefits poses a challenge for swimming pool operators. Previous studies have mainly focused on regulated chlorinated DBPs in freshwater pools with no bromide or seawater pools with very high bromide content. Thermal water pools have a low bromide content and in combination with chlorine can lead to chlorinated, brominated and mixed halogenated DBP species. The occurrence of brominated and mixed halogenated DBPs in these types of pools is largely unexplored, with very few or limited studies published on regulated DBPs and even fewer on emerging DBP classes. In the field of swimming pool water disinfection, apart from extensive studies in the field of drinking water disinfection, only a few studies are known in which >39 halogenated and 16 non-halogenated disinfection by-products, including regulated trihalomethanes (THM) and haloacetic acids (HAA), were investigated in swimming pool water. Calculated bromine incorporation factor (BIF) demonstrated that even small amounts of bromide in swimming pool water can lead to a large shift in DBP species towards brominated and mixed halogenated DBPs. Dihaloacetonitriles (DHANs) accounted for >50% of the calculated cytotoxicity and genotoxicity on average. Comparison of the target analysis with the TOX showed that a major part of the measured TOX (69% on average) could be explained by the regulated classes THMs, HAAs, and the unregulated class of HANs. This study aims to help operators of swimming pools with bromide-containing water to gain a better understanding of DBP formation in future monitoring and to fill the knowledge gap that has existed so far on the occurrence of DBPs in thermal water pools.

Formation potential and analysis of 32 regulated and unregulated disinfection by-products: Two new simplified methods

Water disinfection is an essential process that provides safe water by inactivating pathogens that cause waterborne diseases. However, disinfectants react with organic matter naturally present in water, leading to the formation of disinfection by-products (DBPs). Multi-analyte methods based on mass spectrometry (MS) are preferred to quantify multiple DBP classes at once however, most require extensive sample pre-treatment and significant resources. In this study, two analytical methods were developed for the quantification of 32 regulated and unregulated DBPs. A purge and trap (P&T) coupled with gas chromatography mass spectrometry (GC-MS) method was optimized that automated sample pre-treatment and analyzed volatile and semi-volatile compounds, including trihalomethanes (THMs), iodinated trihalomethanes (I-THMs), haloacetonitriles (HANs), haloketones (HKTs) and halonitromethanes (HNMs). LOQs were between 0.02-0.4 µg/L for most DBPs except for 8 analytes that were in the low µg/L range. A second method with liquid chromatography (LC) tandem mass spectrometry (MS/MS) was developed for the quantification of 10 haloacetic acids (HAAs) with a simple clean-up and direct injection. The LC-MS/MS direct injection method has the lowest detection limits reported (0.2-0.5 µg/L). Both methods have a simple sample pre-treatment, which make it possible for routine analysis. Hyperchlorination and uniform formation conditions (UFC) formation potential tests with chlorine were evaluated with water samples containing high and low TOC. Hyperchlorination formation potential test maximized THMs and HAAs while UFC maximized HANs. Ascorbic acid was found to be an appropriate quencher for both analytical methods. Disinfected drinking water from four water utilities in Alberta, Canada were also evaluated.

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

A highly selective, sensitive, and simple analytical method for identification and quantification of nine haloacetic acids, bromate, and dalapon has been developed. This method uses ion chromatography (IC) coupled with electrospray ionization-high-resolution mass spectrometry (IC-ESI-HRMS) to directly analyze water samples on a high capacity anion-exchange column, eliminating the need for sample pretreatment/derivatization. Our study compared the following three types of targeted quantitation experiments using a quadrupole-orbitrap hybrid mass spectrometer, full-scan MS with data-dependent tandem mass spectrometry (full MS/dd-MS2 with inclusion list), targeted selected ion monitoring (SIM) with data-dependent tandem mass spectrometry (t-SIM/dd-MS2), and parallel reaction monitoring (PRM). Sensitivity, linearity, accuracy, and precision were validated following the guidelines of U.S. EPA Method 557. Single laboratory lowest concentration minimum reporting levels (LCMRLs) for the analytes using three different acquisition modes ranged from 0.0011 to 0.18 μg/L. All three quantitation modes showed good linearity for the eleven analytes with coefficients of determination of 0.9981- 0.9993. This IC-ESI-HRMS method was successfully applied to the analysis of commercial bottled water, tap water from San Francisco Bay Area, and the same tap water that has been through a filtered drinking water faucet. Both t-SIM/dd-MS2 and PRM modes were sensitive to confirm the trace-level presence of all nine HAAs, bromate, and dalapon in the tap water sample. Full-scan HRMS data acquisition provided the benefits of simultaneous data collection for both targeted and non-targeted components, and thus, suitability for simultaneous quantification of an unlimited number of compounds. Data-dependent MS/MS (dd-MS2) product-ion spectra were used for confirmation. All three modes showed good quantitative performance and obtained similar values. Single laboratory precision and accuracy data are presented for three water matrices: reagent water, laboratory synthetic sample matrix (LSSM), and tap water. Single laboratory precision was 0.078- 8.04%, and accuracy was in the range 70-130% for the three MS modes.

Simultaneous Determination of Chlorinated and Brominated Acetic Acids in Various Environmental Water Matrixes by High-Performance Liquid Chromatography-Inductively Coupled Plasma Tandem Mass Spectrometry without Sample Preparation

The halogenated acetic acids (HAAs) are generally considered as environmental contaminants and are suspected to pose a major public health concern. The inductively coupled plasma mass spectrometry (ICPMS) has been improved by coupling with the tandem mass spectrometry technology (ICPMS/MS), enabling ultratrace determination of heteroatoms. There have been few reports about the determination of chlorine-containing analytes by high-performance liquid chromatography (HPLC)-ICPMS/MS but none about utilizing this technique for the speciation analysis of organic halogenated compounds in environmental matrixes. We report a rapid method for the simultaneous determination of up to nine chlorinated and brominated acetic acids by HPLC-ICPMS/MS in Austrian surface, ground, and tap water. The chromatographic separation of the main five regulated haloacetic acids (so-called HAA5: chloroacetic acid, dichloroacetic acid, trichloroacetic acid, bromoacetic acid, and dibromoacetic acid) could be achieved in <6 min with limits of detection of 1.4-1.6 μg Cl L-1 and 0.8-1.5 μg Br L-1 for the chlorinated and brominated acetic acids, respectively. The method was validated through recovery experiments at four concentration levels (10-500 μg L-1) as well as by analyzing the U.S. Environmental Protection Agency (EPA) 552.2 CRM (certified reference material) in pure water and in three different water matrixes (tap, river, and groundwater), and thereby validated for repeatability (RSD% 1-10%), accuracy (±1.0-15%), and linearity (r2 = 0.9996-0.9999). The method fulfills the regulatory concentration limits by the EPA for HAA5 [maximum contaminant level (MCL) 60 μg L-1] and the limits currently being reviewed by the European Union for HAA9 (80 μg L-1) and demonstrates the advantages of HPLC-ICPMS/MS for the analysis of environmental water samples for halogen-tagged contaminants.