Maria J. López de Alda

Liquid chromatography-tandem mass spectrometric analysis and regulatory issues of polar pesticides in natural and treated waters.

Pesticides are among the most detected contaminants in the aquatic environment. This is mainly due to their use in agriculture and their physico-chemical properties that enable transportation and a persistent or pseudo-persistent existence in the water media. Several directives and guidelines set maximum levels of pesticides in water in order to protect the human and environmental health. A brief discussion of the existing directives and guidelines concerning pesticides in water is presented, e.g., the new regulatory framework for the Registration, Evaluation and Authorisation of Chemicals (REACH), and the Directive 91/414/EEC concerning the placing of plant protection products on the market. Up-to-date analytical tools to support the REACH program are of prime importance to ensure its complete implementation. Since liquid chromatography (LC) coupled to mass spectrometry (MS) is considered the most appropriate technique for determination of most modern pesticides in environmental waters, the most recent developments and applications in this field are discussed in detail in this review.

Environmental behavior and analysis of veterinary and human drugs in soils, sediments and sludge

Human and veterinary drugs are continually being released in the environment mainly as a result of manufacturing processes, disposal of unused or expired products, and excreta. Because of their physical and chemical properties, many of these substances or their bioactive metabolites end up in soils and sediments, where they can accumulate and induce adverse effects in terrestrial or aquatic organisms. Among these effects, bacterial resistance is increasingly observed and is caused by the extensive use of antibiotics in animal and fish farming and the growing practice of adding manure and sewage sludge to agricultural fields, which is of particular concern. Literature on the environmental analysis and occurrence of drugs has addressed a very small percentage of these compounds, so very little information is available about the fate and the potential effects of drugs in the environment. This article presents an overview of recent developments in the determination of veterinary and human drugs in solid environmental matrices, including soil, sediment and sludge. The analysis of pharmaceuticals in the such samples has always been carried out by high-performance liquid chromatography coupled to ultraviolet detection, and, to a lesser extent, to mass spectrometry and fluorescence detection. In most cases, sample pretreatment includes extraction of the solid sample and further purification of the extract by solid phase extraction with C18 sorbents. In addition to analytical articles, this overview includes papers concerning usage of drugs, as well as sources, fate, persistence, and effects of pharmaceuticals in solid environmental matrices.

Drugs of abuse and their metabolites in the Ebro River basin: occurrence in sewage and surface water, sewage treatment plants removal efficiency, and collective drug usage estimation.

Drugs of abuse and their metabolites have been recently recognized as environmental emerging organic contaminants. Assessment of their concentration in different environmental compartments is essential to evaluate their potential ecotoxicological effects. It also constitutes an indirect tool to estimate drug abuse by the population at the community level. The present work reports for the first time the occurrence of drugs of abuse and metabolites residues along the Ebro River basin (NE Spain) and also evaluates the contribution of sewage treatment plants (STPs) effluents to the presence of these chemicals in natural surface waters. Concentrations measured in influent sewage waters were used to back calculate drug usage at the community level in the main urban areas of the investigated river basin. The most ubiquitous and abundant compounds in the studied aqueous matrices were cocaine, benzoylecgonine, ephedrine and ecstasy. Lysergic compounds, heroin, its metabolite 6-monoacetyl morphine, and Delta(9)-tetradhydrocannabinol were the substances less frequently detected. Overall, total levels of the studied illicit drugs and metabolites observed in surface water (in the low ng/L range) were one and two orders of magnitude lower than those determined in effluent (in the ng/L range) and influent sewage water (microg/L range), respectively. The investigated STPs showed overall removal efficiencies between 45 and 95%. Some compounds, such as cocaine and amphetamine, were very efficiently eliminated (>90%) whereas others, such as ecstasy, methamphetamine, nor-LSD, and THC-COOH where occasionally not eliminated at all. Drug consumption estimates pointed out cocaine as the most abused drug, followed by cannabis, amphetamine, heroin, ecstasy and methamphetamine, which slightly differs from national official estimates (cannabis, followed by cocaine, ecstasy, amphetamine and heroin). Extrapolation of the consumption data obtained for the studied area to Spain points out a total annual consumption of drugs of abuse of the order of 36 tonnes, which would translate into 1100million Euros in the black market.

Recent advances in the mass spectrometric analysis related to endocrine disrupting compounds in aquatic environmental samples.

An overview of mass spectrometric methods used for the determination of endocrine disrupting compounds (EDCs) in environmental samples is presented. Among the EDCs we have selected five groups of compounds that are of priority within European Union and US research activities: alkylphenols, polychlorinated compounds (dioxins, furans and biphenyls), polybrominated diphenyl ethers, phthalates and steroid sex hormones. Various aspects of current LC-MS and GC-MS methodology, including sample preparation, are discussed.

Analysis and environmental levels of endocrine-disrupting compounds in freshwater sediments

An overview of analytical methods for target endocrine-disrupting compounds (EDCs) in freshwater sediments is presented. Among the EDCs we have selected five groups of compounds that are of priority within European Union and USA research activities: alkylphenols, polychlorinated compounds (dioxins, furans and biphenyls), polybrominated diphenyl ethers, phthalates and steroid sex hormones. Various aspects of current analytical methodology, such as sample preparation, extraction, purification and final determination, are discussed. Levels found in freshwater sediment are reviewed.

Liquid chromatography-(tandem) mass spectrometry of selected emerging pollutants (steroid sex hormones, drugs and alkylphenolic surfactants) in the aquatic environment

Among the various compounds considered as emerging pollutants, alkylphenolic surfactants, steroid sex hormones, and pharmaceuticals are of particular concern, both because of the volume of these substances used and because of their activity as endocrine disruptors or as causative agents of bacterial resistance, as is the case of antibiotics. Today, the technique of choice for analysis of these groups of substances is liquid-chromatography coupled to mass spectrometry (LC-MS) and tandem mass spectrometry (LC-MS-MS). In the last decades, this technique has experienced an impressive progress that has made possible the analysis of many environmental pollutants in a faster, more convenient, and more sensitive way, and, in some cases, the analysis of compounds that could not be determined before. This article reviews the LC-MS and LC-MS-MS methods published so far for the determination of alkylphenolic surfactants, steroid sex hormones and drugs in the aquatic environment. Practical considerations with regards to the analysis of these groups of substances by using different mass spectrometers (single quadrupole, ion trap and triple quadrupole instruments, etc.), interfaces and ionization and monitoring modes, are presented. Sample preparation aspects, with special focus on the application of advanced techniques, such as immunosorbents, restricted access materials and molecular imprinted materials, for extraction/purification of aquatic environmental samples and extracts are also discussed.

Determination of steroid sex hormones and related synthetic compounds considered as endocrine disrupters in water by liquid chromatography–diode array detection–mass spectrometry

In this study, a procedure for the determination of various naturally occurring hormones and of some related synthetic chemicals, commonly used for birth control and treatment of certain hormonal disorders and cancers, in water is described. The procedure includes solid-phase extraction of 0.5 l of water and subsequent analysis of the extract by liquid chromatography with diode array detection and mass spectrometric detection in series (LC-DAD-MS). DAD has been performed at 197, 225, and 242 nm for quantification and confirmatory identification purposes. For MS detection two interfaces--electrospray and atmospheric pressure chemical ionization--in both the positive and the negative ion mode have been tested and the MS parameters influencing the MS signal optimized. DAD and MS have been intercompared for selectivity, sensitivity, precision, and linearity of response. Selected conditions have been applied to the determination of six estrogens (17beta-estradiol, estriol, estrone, ethynylestradiol, mestranol, and diethylstilbestrol) and four progestogens (progesterone, levonorgestrel, norethindrone and ethynodiol diacetate) in several types of water bodies, including sewage influents and effluents, surface water and drinking water. Recoveries greater than 83% and detection limits in the ng/l range have been achieved for most compounds.

Fully Automated Determination in the Low Nanogram per Liter Level of Different Classes of Drugs of Abuse in Sewage Water by On-Line Solid-Phase Extraction-Liquid Chromatography−Electrospray-Tandem Mass Spectrometry

The present work describes the first fully automated method, based on on-line solid-phase extraction (SPE)-liquid chromatography-electrospray-tandem mass spectrometry, developed for the determination of drugs of abuse (17 compounds and metabolites belonging to the classes of amphetaminics, cannabinoids, cocainics, opiates, and lysergics) in sewage waters. On-line SPE is performed by passing 5 mL of the water sample through a PLRP-s cartridge for analytes measured in positive ionization mode (all but cannabinoids) and through an Oasis HLB cartridge for analytes measured in negative ionization mode (cannabinoids). For unequivocal identification and confirmation two selected reaction monitoring transitions are registered per compound, thus achieving the four identification points requested by the European Union for banned substances. Quantitation is performed by the internal standard method, indispensable to correct for matrix effects. The main advantages of the method developed are high sensitivity (limits of determination between 0.69 and 5.97 ng/L), selectivity and reliability of results, minimum sample manipulation, full automation, and fairly high throughput (analysis time per sample is 2 x 35 min). As a part of the validation procedure, the method developed has been applied to the analysis of various influent and effluent samples from four Spanish sewage treatment plants.

Use of solid-phase extraction in various of its modalities for sample preparation in the determination of estrogens and progestogens in sediment and water

The environmental analysis of estrogens and progestogens at physiologically active concentrations (low ng/l range) requires the use of very sensitive and selective methods, which, in most cases, make necessary an extraction/purification step. In this study, various procedures for the determination of several estrogens (estriol, estradiol, ethynyl estradiol, estrone, and diethylstilbestrol) and progestogens (progesterone, norethindrone, and levonorgestrel) in environmental matrices, including water and river sediment, are described. In all procedures, final analysis of the target compounds is performed by reversed-phase liquid chromatography-diode array detection-mass spectrometry, whereas sample preparation always includes a solid-phase extraction (SPE) step. For this SPE step. various types of sorbents, protocols, and devices have been used, and their respective advantages and disadvantages are discussed. For the off-line SPE of estrogens and progestogens from water samples, a syringe type cartridge LiChrolut RP-18 (500 mg) was selected out of two other sorbents--LiChrolut EN (200 mg) and Isolut ENV (500 mg)--for use with the automated sample preparation instrument ASPEC XL. For the on-line SPE and analysis of water samples the 10 mm x 2 mm I.D. HySphere-Resin-GP cartridge, was preferred to the C18 Baker, the PLRP-S, and the Oasis HLB. for use with the Prospekt system. A completely manual protocol based on the use of Sep-Pak C18 Plus cartridges was developed for purification of sediment extracts. All procedures were shown to be linear over a wide range of concentration, exhibited satisfactory repeatability and accuracy, and reached limits of detection usually in the low ng/l and ng/g range. Comparatively, the on-line method was shown to be advantageous in terms of automation and general method performance.

Biosensors for environmental monitoring: A global perspective

The intention of this article is to reflect the advances and describe the trends on biosensors for environmental applications. Biosensors are useful analytical tools for environmental monitoring, capable of providing results in real time, simple to use, portable and cost-effective. Some examples of biosensors in advanced stage of development, which have been applied to real samples, as well as of commercial devices, are given. Biosensors designed for measurement of either specific chemicals or their biological effects, such as toxicity biosensors and endocrine effect biosensors, are discussed. This overview also addresses the support provided by public institutions for biosensor research in the USA, Japan and, especially, in Europe. Future prospects of biosensor technology, with special emphasis in the development of new sensing elements, are foreseen.