Development of novel analytical methods to detect emerging contaminants in aqueous environmental matrices using large-volume injection

It is the responsibility of humans, as environmental stewards, to monitor our impact on the environment so that efforts can be made to remediate the effects of our actions and change behaviors. To better understand our environmental footprint, sensitive and simple analytical methods are needed to quantify the contaminants that we discharge into our natural surroundings. Emerging environmental contaminants are of particular concern because there is limited or no information available on their occurrence, fate, and toxicity. As a result, the implications of using these chemicals are not well understood. Therefore, accurate environmental data are needed to help scientists and government policy-makers make informed decisions on research directions and chemical regulation. However, challenges exist for the analysis of emerging contaminants, including a lack of suitable analytical standards and internal standards, their broad range of chemical properties, and that they are frequently present at trace levels and in complex environmental matrices. The work presented within this dissertation focuses on the development, validation, and comparison of analytical methodologies based on large-volume injection high-performance liquid chromatography (HPLC) tandem mass spectrometry (MS/MS) for the analysis of emerging environmental contaminants in aqueous environmental matrices. Large-volume injection (e.g. 900 μL to 4,500 μL) is an analytical technique that eliminates sample preparation associated with pre-concentration by injecting larger-than-traditional volumes of sample directly onto a HPLC column. In Chapter 2, a direct aqueous large-volume injection method was developed and validated for the quantification of natural and synthetic androgenic steroids in wastewater influent, wastewater effluent, and river water. This method was then applied to hourly composite samples of wastewater influent that were taken over the course of a single day. This work expands on the research of the endocrine-disrupting chemicals that occur in wastewater and provides an estimate of the community use/abuse of synthetic androgenic steroids. Environmental analytical methods should be as environmentally friendly as possible and efforts should be made to reduce the waste generated during analysis while maintaining analytical performance. In Chapter 3, a method based on large-volume injection was compared to two methods based on solid-phase extraction. The purpose of this comparison was to demonstrate that the same method performance could be achieved by large-volume injection as that by solid-phase extraction while reducing waste, labor, and costs. Estrogens and perfluorinated chemicals were used as model analytes and wastewater influent was used as a model matrix. The results of this study provide convincing reasons for analysts to adopt large-volume injection as an alternative to solid-phase extraction. In Chapter 4, a novel analytical method was developed and validated to quantify newly-identified and legacy fluorinated chemicals in groundwater. The final method combined micro liquid-liquid extraction, non-aqueous large-volume injection, and orthogonal chromatographic separations. Ground water samples collected from six different U.S. military bases was used to demonstrate the method. This is the first report on the occurrence of these newly-identified fluorinated chemicals in any environmental media and serves as a rational for conducting future research on their environmental fate and toxicity. The breadth of the research presented in this dissertation advances the field of environmental analytical chemistry in several areas. First, classes of environmental contaminants for which there is limited (synthetic androgenic steroids) or no (newly-identified fluorochemicals) environmental data were studied. Second, novel methods based on direct-aqueous and non-aqueous large-volume injection were developed and validated to identify and quantify those contaminants. Third, it was demonstrated that solid-phase extraction is not a "necessary evil" needed to develop methods for emerging environmental contaminants in aqueous matrices. Finally, this work is a platform on which other environmental chemists can use to develop large-volume injection methods in the future

Analysis of Androgenic Steroids in Environmental Waters by Large-Volume Injection Liquid Chromatography Tandem Mass Spectrometry

A new method was developed for the analysis of natural and synthetic androgenic steroids and their selected metabolites in aquatic environmental matrices using direct large-volume injection (LVI) high performance liquid chromatography (HPLC) tandem mass spectrometry (MS/MS). Method accuracy ranged from 88 to 108% for analytes with well-matched internal standards. Precision, quantified by relative standard deviation (RSD), was less than 12%. Detection limits for the method ranged from 1.2 to 360 ng/L. The method was demonstrated on a series of 1-hr composite wastewater influent samples collected over a day with the purpose of assessing temporal profiles of androgen loads in wastewater. Testosterone, androstenedione, boldenone, and nandrolone were detected in the sample series at concentrations up to 290 ng/L and loads up to 535 mg. Boldenone, a synthetic androgen, had a temporal profile that was strongly correlated to testosterone, a natural human androgen, suggesting its source may be endogenous. An analysis of the sample particulate fraction revealed detectable amounts of sorbed testosterone and androstenedione. Androstenedione sorbed to the particulate fraction accounted for an estimated five to seven percent of the total androstenedione mass

Trace analysis of environmental matrices by large-volume injection and liquid chromatography-mass spectrometry

The time-honored convention of concentrating aqueous samples by solid-phase extraction (SPE) is being challenged by the increasingly wide spread use of large-volume injection (LVI) liquid chromatography-mass spectrometry (LC-MS) for the determination of traces of polar organic contaminants in environmental samples. Although different LVI approaches have been proposed over the last 40 years, the simplest and most popular way of performing LVI is known as single column LVI (SC-LVI), in which a large-volume of an aqueous sample is directly injected into an analytical column. For the purposes of this critical review, LVI is defined as an injected sample volume that is ≥ 10% of the void volume of the analytical column. Compared to other techniques, SC-LVI is easier to set up, as it only requires small hardware modifications to existing autosamplers and, thus, will represent the main focus of the current review. Although not new, SC-LVI is gaining acceptance and the approach is emerging as a technology that will render SPE nearly obsolete for many environmental applications. In this review, we discuss 1) the history and development of various forms of LVI, 2) the critical factors that one needs to consider when creating and optimizing SC-LVI methods and 3) example applications that demonstrate the range of environmental matrices, to which LVI is applicable such as drinking water, groundwater and surface water including seawater as well as wastewater. Furthermore, we give responses to answer a set of ‘frequently asked questions’ typically encountered from audiences and we indicate future directions and areas that need to be addressed to fully delineate the limits of SC-LVI.Keywords: Direct injection, Soil, Water, LC-MS/MS, Sample preparation, Large-volume injection, Wastewater, Solid-phase extraction, Liquid chromatograph

Evidence of Remediation-Induced Alteration of Subsurface Poly- and Perfluoroalkyl Substance (PFAS) Distribution at a Former Firefighter Training Area

Poly- and perfluoroalkyl substances (PFASs) are a class of fluorinated chemicals that are utilized in firefighting and have been reported in groundwater and soil at several firefighter training areas. In this study, soil and groundwater samples were collected from across a former firefighter training area to examine the extent to which remedial activities have altered the composition and spatial distribution of PFASs in the subsurface. Log K[subscript oc] values for perfluoroalkyl acids (PFAAs), estimated from analysis of paired samples of groundwater and aquifer solids, indicated that solid/water partitioning was not entirely consistent with predictions based on laboratory studies. Differential PFAA transport was not strongly evident in the subsurface, likely due to remediation-induced conditions. When compared to the surface soil spatial distributions, the relative concentrations of perfluorooctane sulfonate (PFOS) and PFAA precursors in groundwater strongly suggest that remedial activities altered the subsurface PFAS distribution, presumably through significant pumping of groundwater and transformation of precursors to PFAAs. Additional evidence for transformation of PFAA precursors during remediation included elevated ratios of perfluorohexane sulfonate (PFHxS) to PFOS in groundwater near oxygen sparging wells

Trace analysis of environmental matrices by large-volume injection and liquid chromatography-mass spectrometry

The time-honored convention of concentrating aqueous samples by solid-phase extraction (SPE) is being challenged by the increasingly widespread use of large-volume injection (LVI) liquid chromatography–mass spectrometry (LC–MS) for the determination of traces of polar organic contaminants in environmental samples. Although different LVI approaches have been proposed over the last 40 years, the simplest and most popular way of performing LVI is known as single-column LVI (SC-LVI), in which a large-volume of an aqueous sample is directly injected into an analytical column. For the purposes of this critical review, LVI is defined as an injected sample volume that is ≥10% of the void volume of the analytical column. Compared with other techniques, SC-LVI is easier to set up, because it requires only small hardware modifications to existing autosamplers and, thus, it will be the main focus of this review. Although not new, SC-LVI is gaining acceptance and the approach is emerging as a technique that will render SPE nearly obsolete for many environmental applications.In this review, we discuss: the history and development of various forms of LVI; the critical factors that must be considered when creating and optimizing SC-LVI methods; and typical applications that demonstrate the range of environmental matrices to which LVI is applicable, for example drinking water, groundwater, and surface water including seawater and wastewater. Furthermore, we indicate direction and areas that must be addressed to fully delineate the limits of SC-LVI

An Ultrasensitive (Parts-Per-Quadrillion) and SPE-Free Method for the Quantitative Analysis of Estrogens in Surface Water

An analytical method is presented here that is sensitive to the parts-per-quadrillion (pg/L) for estrogens in surface water. The estrogens included for study were estrone, 17β-estradiol, estriol, 17α-ethinylestradiol, and equilin. The method consisted of the small-scale liquid–liquid extraction of surface water followed by derivation with dansyl chloride. Analyte separation and detection were performed by high-pressure liquid-chromatography and tandem mass-spectrometry. A large volume (100 μL) of the sample was injected on-column to increase the analyte mass sent to the detector. The detection limits of the method were 0.045 ng/L for estrone, 0.086 ng/L for 17β-estradiol, 0.030 ng/L for estriol, 0.049 ng/L for 17α-ethinylestradiol, and 0.13 ng/L for equilin. The whole-method accuracy ranged from 93 ± 5.8% to 105 ± 4.5% for all the analytes at two different spike levels. Similarly, the precision of the method was less than 8.0% relative standard deviation. The final method was used to analyze a series of samples from the Mississippi River spanning 51 river miles. Estrone was detected in all of the samples and 17β-estradiol was detected in one. Concentrations of estrone ranged from between the detection and quantification limits up to 0.63 ng/L. Increases in the concentration of estrone could be observed downstream from potential sources including a drinking water treatment plant. 17β-estradiol was detected below its quantitation limit in a sample taken downstream from a wastewater treatment plant

Is SPE Necessary for Environmental Analysis? A Quantitative Comparison of Matrix Effects from Large-Volume Injection and Solid-Phase Extraction Based Methods

Environmental analysis by large-volume injection (LVI) was compared to solid-phase extraction (SPE) based methods using matrix effects as a quantitative indicator of analytical signal quality. LVI was performed by the direct injection of 900 μL of wastewater onto a high-performance liquid chromatography (HPLC) column while SPE-based methods utilized octadecyl silane (C18) and hydrophobic-lypophilic balance (HLB) solid phases to preconcentrate wastewater prior to analysis. Model analytes from three classes of environmental contaminants were selected for study including four estrogens (estrone, estradiol, estriol, and ethinylestradiol), eight perfluoroalkyl carboxylates (C4–C11), and five perfluoroalkyl sulfonates (C4, C6–C8, and C10). The matrix effects on analytes were assessed by two approaches (quantitatively by calculating percent matrix effects and qualitatively with postcolumn infusions) and compared across LVI- and SPE-based methods at constant (high and low) analyte-to-matrix mass ratios. The results from this study demonstrated that the LVI-based method produced analytical signals of quality similar to the two SPE-based methods. Furthermore, LVI presented a clear advantage over SPE because it was performed at lower cost, required fewer materials, involved less labor and eliminated the analyte loss associated with SPE

FieldJenniferEMTAnalysisAndrogenicSteroids.pdf

A new method was developed for the analysis of natural and synthetic androgenic steroids and their selected metabolites in aquatic environmental matrices using direct large-volume injection (LVI) high performance liquid chromatography (HPLC) tandem mass spectrometry (MS/MS). Method accuracy ranged from 88 to 108% for analytes with well-matched internal standards. Precision, quantified by relative standard deviation (RSD), was less than 12%. Detection limits for the method ranged from 1.2 to 360 ng/L. The method was demonstrated on a series of 1-hr composite wastewater influent samples collected over a day with the purpose of assessing temporal profiles of androgen loads in wastewater. Testosterone, androstenedione, boldenone, and nandrolone were detected in the sample series at concentrations up to 290 ng/L and loads up to 535 mg. Boldenone, a synthetic androgen, had a temporal profile that was strongly correlated to testosterone, a natural human androgen, suggesting its source may be endogenous. An analysis of the sample particulate fraction revealed detectable amounts of sorbed testosterone and androstenedione. Androstenedione sorbed to the particulate fraction accounted for an estimated five to seven percent of the total androstenedione mass

FieldJenniferEMTAnalysisAndrogenicSteroids_SupplementaryData.pdf

A new method was developed for the analysis of natural and synthetic androgenic steroids and their selected metabolites in aquatic environmental matrices using direct large-volume injection (LVI) high performance liquid chromatography (HPLC) tandem mass spectrometry (MS/MS). Method accuracy ranged from 88 to 108% for analytes with well-matched internal standards. Precision, quantified by relative standard deviation (RSD), was less than 12%. Detection limits for the method ranged from 1.2 to 360 ng/L. The method was demonstrated on a series of 1-hr composite wastewater influent samples collected over a day with the purpose of assessing temporal profiles of androgen loads in wastewater. Testosterone, androstenedione, boldenone, and nandrolone were detected in the sample series at concentrations up to 290 ng/L and loads up to 535 mg. Boldenone, a synthetic androgen, had a temporal profile that was strongly correlated to testosterone, a natural human androgen, suggesting its source may be endogenous. An analysis of the sample particulate fraction revealed detectable amounts of sorbed testosterone and androstenedione. Androstenedione sorbed to the particulate fraction accounted for an estimated five to seven percent of the total androstenedione mass

Evidence of Remediation-Induced Alteration of Subsurface Poly- and Perfluoroalkyl Substance Distribution at a Former Firefighter Training Area

Poly- and perfluoroalkyl substances (PFASs) are a class of fluorinated chemicals that are utilized in firefighting and have been reported in groundwater and soil at several firefighter training areas. In this study, soil and groundwater samples were collected from across a former firefighter training area to examine the extent to which remedial activities have altered the composition and spatial distribution of PFASs in the subsurface. Log <i>K</i>_oc values for perfluoroalkyl acids (PFAAs), estimated from analysis of paired samples of groundwater and aquifer solids, indicated that solid/water partitioning was not entirely consistent with predictions based on laboratory studies. Differential PFAA transport was not strongly evident in the subsurface, likely due to remediation-induced conditions. When compared to the surface soil spatial distributions, the relative concentrations of perfluorooctanesulfonate (PFOS) and PFAA precursors in groundwater strongly suggest that remedial activities altered the subsurface PFAS distribution, presumably through significant pumping of groundwater and transformation of precursors to PFAAs. Additional evidence for transformation of PFAA precursors during remediation included elevated ratios of perfluorohexanesulfonate (PFHxS) to PFOS in groundwater near oxygen sparging wells