Organic UV filters in marine environments: An update of analytical methodologies,occurrence and distribution

Ultraviolet filters (UV Filters) are compounds that are widely employed in personal care products such as sunscreens to protect the skin from sun damage, but they are also added to other products, such as food packaging, plastics, paints, textiles, detergents, etc. The continuous use of these products causes the release of a substantial amount of these products into the marine environment through direct input or wastewater discharge, and thus they are becoming an important class of contaminants of emerging concern. A correlation between their occurrence and different negative effects on marine biota has been reported.Taking into account all the possible impacts on the environment, knowledge of their presence and distribution in the different compartments of the ecosystems, ranging from waters and sediments to aquatic organisms, which potentially suffer from bioaccumulation and biomagnification processes, is essential. High concentrations of ultraviolet filters have been found in samples collected from across the entire planet, even in polar regions, revealing their global distribution.Therefore, interest in the sensitive determination of ultraviolet filters in several marine matrices has increased. In this article, an overall review of the more recently reported analytical chemistry methods for identifying and quantifying these compounds in marine environmental samples is presented. We compare and discuss the potential advantages and disadvantages of every step involved in the analytical procedure, including the pre-treatment, treatment and extraction processes that are required to avoid matrix effects. Moreover, we describe the worldwide occurrence and distribution of those most important UV filters.     

Pharmaceuticals and personal care products in biosolids/sewage sludge: the interface between analytical chemistry and regulation

Modern sanitary practices result in large volumes of human waste, as well as domestic and industrial sewage, being collected and treated at common collection points, wastewater treatment plants (WWTPs). In recognition of the growing use of sewage sludge as fertilizers and soil amendments, and the scarcity of current data regarding the chemical constituents in sewage sludge, the US National Research Council (NRC) in 2002 produced a report on sewage sludge. Among the NRC’s recommendations was the need for investigating the occurrence of pharmaceuticals and personal care products (PPCPs) in sewage sludge. PPCPs are a diverse array of non-regulated contaminants that had not been studied in previous sewage sludge surveys but which are likely to be present. The focus of this paper will be to review the current analytical methodologies available for investigating whether pharmaceuticals are present in WWTP-produced sewage sludge, to summarize current regulatory practices regarding sewage sludge, and to report on the presence of pharmaceuticals in sewage sludge.     

Monitoring organic microcontaminants in the marine environment: principles, programmes and progress

Monitoring trace organic microcontaminants in the marine environment has been on-going for several decades. However, the compounds considered in most programmes are still mainly the ‘old’ organochlorines, the polynuclear aromatic hydrocarbons, several metals and metal-containing compounds. However, the marine environment is threatened by a much larger suite of organic microcontaminants. In recent years, European and other international organisations have been moving towards extending their lists of priority hazardous substances. Simultaneously, there have become available novel analytical techniques that offer new possibilities for monitoring in the marine environment.     

Validation and qualification: the fitness for purpose of mass spectrometry-based analytical methods and analytical systems

The context of validation for mass spectrometry (MS)-based methods is critically analysed. The focus is on the fitness for purpose depending on the task of the method. Information is given on commonly accepted procedures for the implementation and acceptance of analytical methods as ‘confirmatory methods’ according to EU criteria, and strategies for measurement. Attention is paid to the problem of matrix effects in the case of liquid chromatography-mass spectrometry-based procedures, since according to recent guidelines for bioanalytical method validations, there is a need to evaluate matrix effects during development and validation of LC-MS methods “to ensure that precision, selectivity and sensitivity will not be compromised”. Beneficial aspects of the qualification process to ensure the suitability of the MS analytical system are also evaluated and discussed.     

Occurrence of pharmaceuticals and their metabolites in sewage sludge and soil: A review on their distribution and environmental risk assessment

The recycling and recovery of organic matter and nutrients from sewage sludge for application in agricultural soils is gaining interest, while the presence of pharmaceutically active compounds (PhACs) in this matrix may have a great impact on the environment and human health. The aim of this review paper is to outline recent research on the occurrence of PhACs and their metabolites in sewage treatment lines. A total of 32 classes of therapeutic groups including 180 PhACs and 45 metabolites have been included. In a first part, a summary of the analytical methods with a critical overview of the extraction and determination techniques, quality control issues and methodological challenges for their determination is included. Subsequently, the study gives a snapshot of the concentration levels and distribution patterns found in primary, secondary, digested (aerobically and anaerobically), dehydrated and composted sludge. Data have been systematically summarized and categorized according to matrix type, treatment processes available for PhAC degradation in sludge, and geographical areas. Our literature review showed that antimicrobials, antibiotics, non-steroidal anti-inflammatory drugs (NSAIDs), antidepressants and antidiabetics were the most abundant PhACs found in sludge matrices.Overall, attenuation of PhACs concentrations occurs during sludge stabilization, in particular during anaerobic digestion and composting. PhAC sorption onto sludge is strongly affected by the physicochemical properties, the sludge matrix and the operating and environmental conditions. Lastly, the paper discusses the impact of PhACs on sludge-amended agricultural land. The potential ecotoxicological risk associated with the presence of PhACs in amended soil is medium-low for most PhACs. The most critical compounds found in sludge-amended soil are ciprofloxacin, 17α-ethinylestradiol, 17β-estradiol, and triclocarban and triclosan.     

Pharmaceuticals in biota in the aquatic environment: analytical methods and environmental implications

The presence of pharmaceuticals in the aquatic environment is an ever-increasing issue of concern as they are specifically designed to target specific metabolic and molecular pathways in organisms, and they may have the potential for unintended effects on nontarget species. Information on the presence of pharmaceuticals in biota is still scarce, but the scientific literature on the subject has established the possibility of bioaccumulation in exposed aquatic organisms through other environmental compartments. However, few studies have correlated both bioaccumulation of pharmaceutical compounds and the consequent effects. Analytical methodology to detect pharmaceuticals at trace quantities in biota has advanced significantly in the last few years. Nonetheless, there are still unresolved analytical challenges associated with the complexity of biological matrices, which require exhaustive extraction and purification steps, and highly sensitive and selective detection techniques. This review presents the trends in the analysis of pharmaceuticals in aquatic organisms in the last decade, recent data about the occurrence of these compounds in natural biota, and the environmental implications that chronic exposure could have on aquatic wildlife.     

A computer program for ranking analytical methods according to their fitness for purpose

A program for conducting automatic searches for analytical methods, selecting the most suitable ones according to quality requirements, and ranking them based on quality indices calculated from various pre-selected quality parameters is proposed. The program uses an externally updated database (Analytical Abstracts CD-ROMs or other) and customised quality schemes based on accuracy, precision, sensitivity, applicability to real samples, determination range (ratio), throughput and impact factor (from the Citation Index). It can, therefore, be used for a variety of purposes in analytical chemistry.     

Detection and identification of phenazone-type drugs and their microbial metabolites in ground and drinking water applying solid-phase extraction and gas chromatography with mass spectrometric detection

A new analytical method applying in situ derivatization was developed to enable the extraction of polar drug metabolites from water samples by solid-phase extraction (SPE). An additional derivatization by silylation was used to enhance the sensitivity of analyte detection by gas chromatography-mass spectrometry (GC-MS). Thus, the two metabolites 1,5-di-methyl-1,2-dehydro-3-pyrazolone (DP) and 4-(2-methylethyl)-1,5-dimethyl-1,2-dehydro-3-pyrazolone (PDP), postulated for the degradation of phenazone and propyphenazone, were identified and detected up to the microg/L level in raw and drinking water samples from public water supply.     

Multi-residue analytical methods using LC-tandem MS for the determination of pharmaceuticals in environmental and wastewater samples: a review

Multi-residue analytical methodologies are becoming the preferred and required tools against single group analysis, as they provide wider knowledge about the occurrence of pharmaceuticals in the environment necessary for further study of their removal, partition and ultimate fate. However, simultaneous analysis of compounds from different groups with quite different physico-chemical characteristics requires a compromise in the selection of experimental conditions, which in some cases are not the best conditions for all the analytes studied. In this article, an overview of analytical methodologies focusing on the simultaneous determination of acidic, neutral and basic compounds belonging to different therapeutical classes is presented. The state-of-the-art of LC-MS/MS for multi-class analysis is reviewed, highlighting the specific requirements for such analysis.     

Biodegradability of nylon 4 film in a marine environment

Biodegradability of nylon 4 in seawater from Tokyo Bay was investigated by weight loss and biochemical oxygen demand (BOD) of nylon 4 films. The remaining weight of nylon 4 film decreased with incubation time in the seawater, and the percentage of weight loss of nylon 4 film was 30% after 3 weeks. BOD biodegradability of nylon 4 film was approximately 80% within 25 days. Scanning electron microscopy images of the nylon 4 film before and after the seawater treatment revealed that the surface of the nylon 4 films was eroded after biodegradation in seawater. The average molecular weights of the nylon 4 films indicated no significant difference between before and after 30% weight loss of the film. Based on the present data, nylon 4 film was degraded on the surface of the film in the seawater. Furthermore, microbial degradation seemed to be one of the main degradation mechanisms of nylon 4.     

Critical review of analytical methods for determination of inorganic mercury and methylmercury compounds

This review describes determinations of mercury compounds under three categories: total mercury; separate determinations of inorganic mercury(II) and organomercury compounds by selective reduction; and speciation of inorganic mercury(II), monomethylmercury cation, and dimethylmercury. Topics described for each category include sample treatment, separation, detection, and limit of detection. Finally, we note that most methods would not detect dimethylmercury if it were present.     

Monitoring anthropogenic particles in the environment: Recent developments and remaining challenges at the forefront of analytical methods

Anthropogenic particles at the microscale and nanoscale are posing risks to human health and the ecosystem. Engineered nanomaterials, microplastics and nanoplastics, soot, road and tire wear are a few prominent examples of particles that are either intentionally manufactured or incidentally produced and released into the environment. Analytical developments in the past few decades have made it possible to study particles in the microscale and nanoscale; however, there is still no universal protocol of analysis and caveats exist in the use of the most prominent techniques. The task is challenging because of the large variety of particle properties and the complexity of environmental media. This review discusses a selected group of techniques most likely to play a key role in future monitoring activities and their recent developments and inherent shortcomings.     

Sample preparation and analytical methods for polycyclic aromatic hydrocarbons in sediment

Polycyclic aromatic hydrocarbons (PAHs) are a large category of ubiquitous persistent environmental pollutants, some of them have strong carcinogenicity to human and animals. These pollutants can easily enter the river through multiple ways including rainfall, dry deposition and water washout, and deposit in the sediment. However, it is easy for them to re-enter the river water and pollute water sources, as well as aquatic animals and plants, bringing potential harm to human health. Therefore, it is requisite to accurately analyze the PAHs in sediment. In this review, the analytical methods of PAHs in sediment, focused on the methods of sample extraction, purification, concentration and determination, are summarized.     

The Electro-Optical Kerr Effect in Conformational Analysis. New analytical methods (10)

Birefringence induced in a material by application of an electric field is known as the Kerr effect. The great sensitivity of this property to variations of molecular geometry and environment has made it the basis of a potent method for studying the conformations of molecules. It has, in addition, been effectively applied to investigations of the geometry of solvation and of solute aggregation. An outline is presented of the general technique of measurement of the Kerr effect, the extraction of directed effective polarizabilities of solute molecules and of structural groups, the calculation of theoretical Kerr constants for candidate structures of molecules, and the procedures used to determine solute conformations. The scope and limitations of the method are illustrated by specific conformational problems drawn from the literature. In the case of highly flexible molecules analysis of the measured Kerr constant is inhibited by uncertainties in conformational energy data. This paper is concerned mainly with the specification of detailed conformational energy data. This paper is concerned mainly with the specification of detailed conformational features of molecules. Reference is made, however, to the utilization of pulsed orienting fields to study shapes and dimensions of biological macromolecules.     

Benefits arising from proficiency testing schemes: The comparison of analytical methods

 The primary objective of proficiency testing (PT) is in the provision of information and support to participating laboratories, to enable them to monitor and improve the quality of their measurements. However, other benefits can be obtained from PT. These include the comparison of data for a given measurement by different methods, the validation of new methods, and the provision of information for laboratories' customers and accreditation bodies. This paper considers the subject of method comparison, and highlights some of the approaches which can be followed, as well as the practical use to which this can be put, to benefit the analytical community more widely. This is illustrated by a case study concerning the measurement of haze in beer. In this study the United Kingdom Institute of Brewing (IoB) conducted a survey of participants in the Brewing Analytes Proficiency Scheme (BAPS). From the survey data taken together with data from the BAPS scheme, the IoB is now in a position to give guidance on the use of particular instruments and procedures, as well as consider changes to the scope of the BAPS scheme to provide greater benefits for participants concerned with measuring haze. Received: 3 March 1998 · Accepted: 9 June 1998     

A new and consistent parameter for measuring the quality of multivariate analytical methods: Generalized analytical sensitivity

Generalized analytical sensitivity (γ) is proposed as a new figure of merit, which can be estimated from a multivariate calibration data set. It can be confidently applied to compare different calibration methodologies, and helps to solve literature inconsistencies on the relationship between classical sensitivity and prediction error. In contrast to the classical plain sensitivity, γ incorporates the noise properties in its definition, and its inverse is well correlated with root mean square errors of prediction in the presence of general noise structures. The proposal is supported by studying simulated and experimental first-order multivariate calibration systems with various models, namely multiple linear regression, principal component regression (PCR) and maximum likelihood PCR (MLPCR). The simulations included instrumental noise of different types: independently and identically distributed (iid), correlated (pink) and proportional noise, while the experimental data carried noise which is clearly non-iid.     

Analytical approaches on some selected toxic heavy metals in the environment and their socio-environmental impacts: A meticulous review

Heavy metals are a group of metals and metalloids that have relatively high density and are toxic even at ppb levels. The excess intake of heavy metals in human bodies though the environment may cause various humans health problems. Analytical approaches of some selected toxic heavy metals in the environment and their socio-environmental impacts are discussed in this review. In this present investigation, we have also discussed the design and development of nanomaterials for the detection of metal ions along with kinetic approaches. The isolation or pre-concentration and determination of heavy metals from complex matrices become challenging for analytical chemists and researchers. The fundamentals on sample preparation and analysis of some selected heavy metals employing different analytical tools for qualitative and quantitative determination of these pollutants in real samples are also discussed. In addition, this compiled work enhanced our knowledge in learning about pathway mechanisms and the degree of their risk assessment.     

Validation of analytical methods involved in dissolution assays: Acceptance limits and decision methodologies

Dissolution tests are key elements to ensure continuing product quality and performance. The ultimate goal of these tests is to assure consistent product quality within a defined set of specification criteria. Validation of an analytical method aimed at assessing the dissolution profile of products or at verifying pharmacopoeias compliance should demonstrate that this analytical method is able to correctly declare two dissolution profiles as similar or drug products as compliant with respect to their specifications. It is essential to ensure that these analytical methods are fit for their purpose. Method validation is aimed at providing this guarantee. However, even in the ICHQ2 guideline there is no information explaining how to decide whether the method under validation is valid for its final purpose or not. Are the entire validation criterion needed to ensure that a Quality Control (QC) analytical method for dissolution test is valid? What acceptance limits should be set on these criteria? How to decide about method's validity? These are the questions that this work aims at answering. Focus is made to comply with the current implementation of the Quality by Design (QbD) principles in the pharmaceutical industry in order to allow to correctly defining the Analytical Target Profile (ATP) of analytical methods involved in dissolution tests. Analytical method validation is then the natural demonstration that the developed methods are fit for their intended purpose and is not any more the inconsiderate checklist validation approach still generally performed to complete the filing required to obtain product marketing authorization.