Showing papers in "Trends in Analytical Chemistry in 2007"

A practical guide to analytical method validation, including measurement uncertainty and accuracy profiles

Abstract: The objective of analytical method validation is to ensure that every future measurement in routine analysis will be close enough to the unknown true value for the content of the analyte in the sample. Classical approaches to validation only check performance against reference values, but this does not reflect the needs of consumers. A holistic approach to validation also takes into account the expected proportion of acceptable results lying inside predefined acceptability intervals. In this article, we give a detailed step-by-step guide to analytical method validation, considering the most relevant procedures for checking the quality parameters of analytical methods. Using a holistic approach, we also explain the estimation of measurement uncertainty and accuracy profiles, which we discuss in terms of accreditation requirements and predefined acceptability limits.

Determination of pKa values of active pharmaceutical ingredients

Abstract: The acid dissociation constant is an important physicochemical parameter of a substance, and knowledge of it is of fundamental importance in a wide range of applications and research areas. We present a critical review of published methods and approaches for the determination of acid dissociation constants, with a special emphasis on the p K a values of active pharmaceutical ingredients.

Biomedical and clinical applications of immunoassays and immunosensors for tumor markers

Abstract: Cancer is one of the most threatening diseases for human beings. The detection of tumor biomarkers, including serum tumor markers and potential prognostic factors for tumors, plays an important role in clinical diagnoses and evaluation of treatment for patients with certain tumor-associated diseases. Many immunoassay methods and immunosensors are being developed for detection of tumor-related biomarkers. This review summarizes the state of immunoassay technologies for tumor diagnostics. It also focuses on a growing number of applications and progress in immunosensors for tumor markers. It covers the basic principles and biomedical and clinical applications of immunosensors, and indicates the future prospects in this field.

UV filters : From sunscreens to human body and the environment

Abstract: Recognition of the harmful effects of ultraviolet (UV) radiation on the skin has triggered development of organic chemicals (commonly referred as UV filters) that can absorb UV radiation and attenuate the negative effects of sunlight exposure. Depending on the properties and the intended degree of protection, a wide array of combinations is being marketed as delivering protection against most kinds of UV-induced skin damage. However, some UV filters have dermatological implications, so maximum applicable concentrations have been established. To monitor to what extent commercial products comply with the mandatory limits, several analytical methods have been used for their determination in cosmetics and related products. Further research on the efficacy of UV filters applied on the skin surface has brought to light a gradual attenuation of their UV-protective capacity that cannot solely be attributed to photo-induced decomposition. Investigations carried out to elucidate the reasons underlying this behaviour concluded that UV filters may be systematically absorbed through the skin surface or even released during bathing and washing activities. These observations gave rise to numerous studies aiming to investigate the magnitude and effects of skin penetration as well as accumulation in the water environment. Because of the need for more in-depth investigation into the behavior of UV filters, the initial demand for product certification has been extended to include reliable analytical methods to determine these substances at low concentration levels and in complex matrices (e.g., biological and environmental samples). Until now, most of the available methods, although designed to cover a large variety of substances, quantify them at only high-mg/L levels; however, recently, researchers have paid special attention to developing more sensitive procedures able to determine these substances in biological tissues and fluids or environmental samples at ng/L levels without matrix interferences. This article gives a comprehensive outline of the accumulated knowledge on UV-filter determination in biological and environmental samples and encourages further research in this new, challenging field of analytical, health and environmental science.

Metabolomics technologies and metabolite identification

Abstract: Metabolomics studies rely on the analysis of the multitude of small molecules (metabolites) present in a biological system. Most commonly, metabolomics is heavily supported by mass spectrometry (MS) and nuclear magnetic resonance (NMR) as parallel technologies that provide an overview of the metabolome and high-power compound elucidation. Over and above large-scale analysis, a major effort is needed for unequivocal identification of metabolites. The combination of liquid chromatography (LC)-MS and NMR is a powerful methodology for identifying metabolites. Better chemical characterization of the metabolome will undoubtedly enlarge knowledge of any biological system.

Second- and third-order multivariate calibration: data, algorithms and applications

Abstract: We review second- and third-order multivariate calibration, based on the growing literature in this field, the variety of data being produced by modern instruments, and the proliferation of algorithms capable of dealing with higher-order data. We primarily emphasize the relevance of the subject to analytical chemistry. We intend, in the terminology section, to clarify some confusing features relating to the definition of sample constituents in second-order calibration. We then classify and compare instrumental data and available algorithms. We provide insight into the relative advantages and disadvantages of the existing algorithms (e.g., in terms of: achieving second-order advantage (the ability to cope with varying amounts of potential interferents in test samples), presence of linear dependency in the data, handling trilinear deviations, using incomplete calibration data, extension to higher-order information, handling missing values; and, providing physico-chemical information. Finally, we present a number of applications, selected from recent second- and third-order experimental works based on data obtained through excitation-emission fluorescence spectroscopy, spectral-kinetic and spectral-pH measurements, and hyphenated techniques.

Analytical methods for tracing pharmaceutical residues in water and wastewater

Abstract: The focus of environmental analysis and determination of chemicals in the environment has recently been extended from the more classical pollutants to new contaminant categories including pharmaceuticals This is attributed mainly to the development of new analytical techniques including liquid chromatography with tandem mass spectrometry (LC-MS 2 ) and gas chromatography with mass spectrometry (GC-MS), which enable the determination of such compounds down to the ng/l level This article reviews the most recent developments and applications within water and wastewater environmental matrices

Analytical strategies to determine quinolone residues in food and the environment

Abstract: Contamination of the environment by pharmaceuticals, quinolones among them, is recognized as an emerging issue of concern to scientists and the public. Literature on the environmental analysis of quinolones has addressed a very small percentage of these compounds, and the analytical methods developed to determine them are very scarce. By contrast, a large number of methods have been proposed for their analysis in food, which has classically been considered the source of these residues for human beings. Although both matrices, food and environment, differ, most of the information obtained from one field can be applied to the other. However, to be able to do this, there is need for critical discussion about how analytical determination is carried out in each case. This review summarizes the most relevant issues that condition the analogies and the contrasts between food and environmental matrices in the analysis of quinolones. We describe and compare the target analytes and their relevant levels. We also critically review the approaches to extraction (e.g., solvent extraction (SE), pressurized liquid extraction (PLE) and solid-phase extraction (SPE)), depending on the sample characteristics. We also detail the main analytical techniques (e.g., liquid chromatography (LC) and capillary electrophoresis (CE) combined with UV, fluorescence (FLD) and mass spectrometry (MS), immunoassays and biosensors) used to identify and to quantify quinolone residues in both matrices. We present an updated overview of the recent uses and future prospects for the different analytical methods employed in food and environmental samples.

What do metals tell us about wine

Abstract: This article focuses on analysis of metals in wine in the literature devoted to analytical atomic spectrometry in the past decade. It emphasizes the role of metals in wine and processes involved in winemaking. It covers endogenous and exogenous sources of metals in wine, changes in metal composition during vinification, methods of wine analysis, techniques of wine classification corresponding to distinctive metal patterns, and, finally, approaches to operationally-defined fractionation analysis of metals carried out to understand their nutritional value and bioavailability in wine.

Sample preparation in analysis of pharmaceuticals

Abstract: Sample preparation is a very important and essential step in environmental analysis. This article presents an overview of extraction methods for environmental samples, focusing especially on pharmaceuticals as there is great concern about them as pollutants.

Antibiotic residue determination in environmental waters by LC-MS

Abstract: Pharmaceuticals, identified as emerging contaminants, are used in large quantities in human and veterinary medicine for treatment of different diseases. Among pharmaceuticals, antibiotics in the aquatic environment are of great concern as prolonged exposure to low doses may promote antibiotic resistance. The rapid development of liquid chromatography (LC) coupled to mass spectrometry (MS) and tandem MS (MS2) in the environmental field has transformed this combined technique into a valuable tool for the determination of antibiotics in water samples. To be of real value from the environmental and public health point of view, the analysis performed should meet the scientific standards established to assure data quality. These require not only accurate quantitative methods but also reliable confirmative methods, at the low concentration levels expected for antibiotics in water. We present a critical review of published methods based on LC-MS or LC-MS2 for the determination of antibiotic residues in environmental waters. We evaluate different approaches for screening, quantification and confirmation of these compounds, giving special attention to dealing with the intrinsic difficulties of confirming analytes with confidence at low-ng/L levels.

Direct analysis of solid samples by fs-LA-ICP-MS

Abstract: We review the emerging potential of femtosecond laser-ablation inductively-coupled-plasma mass spectrometry (fs-LA-ICP-MS) for the direct analysis of solid materials. Although LA-ICP-MS has been widely explored and is highly accepted for the determination of major and trace elements, as well as for the measurement of isotope ratios, it still suffers from several limitations that restrain its development as a potential alternative to other, more established techniques. The occurrence of non-stoichiometric effects in the transient signals, defined as elemental fractionation, together with the lack of reference materials for the wide variety of samples of interest often restricts the quantitative analysis to a few elements of identical fractionation behavior. In this sense, significant improvements in the processes responsible for fractionation effects have been recently observed with the use of ultra-short laser pulses. The confinement of pulse energy guarantees better performances in spatial resolution and improves the analytical figures of merit. This review aims to summarize the main differences between the LA mechanisms of short (>1 ps) and ultra-short (

Dissolved silver measurements in seawater

Abstract: There is a paucity of data on dissolved silver in the world's oceans and almost no data for European marine waters. The available data indicate that silver co-varies with silicate in oceanic environments, suggesting a link to biological processes. Nevertheless, silver is a highly toxic element. The main sources of silver for the marine environment derive from anthropogenic inputs, so silver can be used as a tracer for inputs of domestic and industrial pollution. Typical concentrations in seawater samples are very low (pmol/L). These low concentrations, combined with the complexity of the seawater-sample matrix, make the determination of silver in these samples extremely challenging. Developments in sensitive sector field inductively coupled plasma mass spectrometry (SF-ICP-MS) instruments, combined with effective approaches for removal of the seawater matrix, have resulted in powerful analytical methods that can be used to overcome these challenges and help to improve our knowledge on the distribution, effect and fate of silver in the marine environment. This article briefly reviews the analytical techniques used for silver determination in seawater, and describes new trends in analyzing dissolved silver in seawater. © 2007 Elsevier Ltd. All rights reserved.

GC-MS and HPLC-MS analysis of bioactive pharmaceuticals and personal-care products in environmental matrices

Abstract: We review analytical methods published between January 2001 and January 2007 using either gas chromatography (GC) or high-performance liquid chromatography (HPLC) separations and mass spectrometric (MS) detection technologies for the analysis of bioactive pharmaceuticals and personal-care products (PPCPs) in environmental matrices. We emphasize sample preparation, the pros and cons of available MS techniques, the benefits of using quality control and quality assurance (QC/QA) protocols during routine analysis, and the difficulties associated with the matrix effect in the electrospray ionization (ESI) source. We discuss the need for a concerted approach to determine numerical values associated with limits of detection in this emerging area of environmental analysis, along with the use of QC/QA samples and low-level data qualifiers with recommended solutions.

The new wave of ion-selective electrodes

Abstract: During the last decade, the capabilities of potentiometric analysis have changed fundamentally in that the lower limit of detection (LOD) of ion-selective electrodes (ISEs) has improved by a factor of up to one million and the discrimination factor of interferences from ions by up to one billion. These spectacular improvements are related to the control of ion fluxes through the ion-selective membrane. Nowadays, ISEs can be used for trace measurements in environmental samples. Furthermore, by reducing the volume of the samples, the LOD in terms of the amount of analytes has been reduced to the attomole range. This is promising for bioanalysis using metal nanoparticle labels. Other recent progress includes the excellent fundamental understanding of the working mechanism, the introduction of a novel kind of calibration procedure that reduces the demands on signal stability and reproducibility, and the advent of pulsed amperometric methods.

Determination of pesticide residues in olive oil and olives

Abstract: Pesticide-residue determination in olive oil is becoming a very important and challenging issue. The present article provides a review of the most significant methods for determining pesticides in olive oil. The discussion of sample-treatment procedures is focused on not only the final product (olive oil), but also the direct analysis of the raw material (olive fruits). We outline extraction and clean-up procedures (e.g., liquid-liquid partition, gel-permeation chromatography (GPC), solid-phase extraction (SPE), matrix solid-phase dispersion (MSPD) and Quick, Easy, Cheap, Effective, Rugged and Safe (QuEChERS). However, we pay specially attention to the clean-up stage, which plays an important role in the whole process. In addition, identification and quantitation of pesticides have been carried out by gas chromatography (GC) coupled to different detectors (flame-ionization (FID), nitrogen-phosphorus (NPD) and electron-capture (ECD), although either GC-mass spectrometry (GC-MS) in selected ion monitoring (SIM) mode or GC-tandem MS (GC-MS2) are becoming the combination of choice, because of higher selectivity and confirmation capabilities. In recent years, the appearance of new, more polar pesticides has prompted the use of liquid chromatography-MS (LC-MS) instead of GC-MS, and we outline its advantageous features for the analyses of polar pesticides in olive oil.

Residue analysis of veterinary drugs and growth-promoting agents

Abstract: Two major trends are observed in the analysis of veterinary drugs and growth-promoting agents. First is the selection of sample material for monitoring the use of registered veterinary drugs. Traditionally meat, kidney and liver were analyzed but, due to the food scandals in which meat was very often involved, the consumption of alternative products (e.g., eggs and fish) has become more popular and therefore more of interest for residue-monitoring programmes. Most food scandals started with contamination of animal feed, so feed has also gained interest for monitoring purposes. For the detection of unauthorized substances (e.g., growth-promoting agents), the matrix hair is frequently used because residues can be detected in hair even a long time after treatment. Second, the techniques used for residue analysis are moving from target-orientated methods, mainly based on liquid chromatography in combination with triple-quadrupole mass-spectrometric detection (LC–QqQ-MS), towards accurate mass full-scan MS techniques (e.g., time-of-flight (ToF)-MS and Fourier-transform(FT)-MS. Full-scan MS techniques enable retrospective analysis (i.e. without re-injecting the sample) and real multi-residue analysis (including different classes of veterinary drugs). The application of full-scan MS also has consequences for separation and extraction techniques, which have to be applicable to a broad range of compounds differing in physical and chemical properties. Experience shows that ToF-MS in combination with ultra-performance LC (UPLC) is very powerful for multi-residue analysis. The introduction of new MS techniques also has consequences for European Union (EU) criteria defined for confirmation of the identity of compounds. It is suggested that both mass-resolution and mass-accuracy data influence identity confirmation and both parameters should be implemented in the revision of European Commission Decision 2002/657/EC.

Analysis of tetracycline antibiotics in soil : Advances in extraction, clean-up, and quantification

Abstract: Residues of tetracyclines end up in the environment due to the common practice of land application of manure from treated animals. The environmental behavior and the fate of tetracyclines in manure and soil after cropland application remain largely unknown. The lack of information on the nature of the biodegradation products of tetracyclines formed at environmentally-relevant concentrations is mostly due to analytical difficulties encountered when trying to analyze trace levels of these compounds in the presence of complex matrices. Liquid chromatography coupled to mass spectrometry (LC-MS) has become widely used in detecting polar pollutants such as antibiotics. In applying LC-MS for environmental investigations, the analyst is faced with two major challenges: poor detectability of analytes; and, highly variable matrix interferences that compromise quantification. To improve our understanding of the fate and effects of tetracycline antibiotics in the environment, improved methods for detection, quantification, and unknown identification are needed. In this review, we discuss strategies for sample preparation, extraction, clean-up using solid-phase extraction (SPE) and molecularly-imprinted polymers (MIPs), and analysis of tetracyclines and their transformation products in soil, in order to facilitate future environmental fate studies, and to challenge analytical chemists to develop the necessary tools to allow a complete risk assessment of other pharmaceutical contaminants in the environment.

Analytical extractions with water at elevated temperatures and pressures

Abstract: Water can be used effectively as solvent in pressurized hot water extraction (PHWE) because the physico-chemical properties of water are readily altered through changes in temperature and pressure. Temperature is the main parameter affecting extraction, but time and flow rate are also essential in solubility-limited extractions. PHWE has been applied to a variety of analytical extractions (e.g., organic pollutants, pesticides, flavors, fragrances, and metals). PHWE has often shown similar or better extraction recoveries and efficiencies than many conventional methods (e.g., Soxhlet, accelerated solvent extraction and supercritical fluid extraction). PHWE systems can easily be coupled to chromatographic separation (e.g., LC or GC).

Comparative evaluation of software for deconvolution of metabolomics data based on GC-TOF-MS

Abstract: Traditional options available for deconvolution of data from gas chromatography-mass spectrometry (GC-MS) experiments have mostly been confined to semi-automated methods, which cannot compete with high-throughput and rapid analysis in metabolomics. In the present study, data sets acquired using GC with time-of-flight MS (GC-TOF-MS) were processed using three different deconvolution software packages (LECO ChromaTOF, AMDIS and SpectralWorks AnalyzerPro). We paid attention to the extent of detection, identification and agreement of qualitative results, and took interest in the flexibility and the productivity of these programs in their application. We made comparisons using data from the analysis of a test-mixture solution of 36 endogenous metabolites with a wide range of relative concentration ratios. We detected differences in the number of components identified and the accuracy of deconvolution. Using the AMDIS Search program, the resulting mass spectra after deconvolution were searched against the author-constructed retention index/mass spectral libraries containing both the mass spectra and the retention indices of derivatives of a set of metabolites. We based analyte identifications on both retention indices and spectral similarity. The results showed that there were large differences in the numbers of components identified and the qualitative results from the three programs. AMDIS and ChromaTOF produced a large number of false positives, while AnalyzerPro produced some false negatives. We found that, in these three software packages, component width is the most important parameter for predicting the accuracy of the deconvoluted result.

Comprehensive screening of target, non-target and unknown pesticides in food by LC-TOF-MS

Abstract: In pesticide residue analysis (PRA), as well as traditional quantitative analysis of target compounds – mainly pesticides in their parent form – there is now remarkable interest in screening pesticides in a comprehensive way, including not only common pesticides but also less common or relatively new pesticides (non-target) or unknown transformation products (unknowns). To address this interest, liquid chromatography coupled to mass spectrometry (LC-MS) with time-of-flight (TOF) analyzers (TOF-MS or QTOF-MS) is most suitable, taking into account accurate mass analysis, resolving power, enhanced selectivity and high sensitivity in full-scan acquisition mode. In this article, we discuss the main features and the advantages of LC-TOF-MS instruments for PRA in food – advantages and pitfalls of the instruments. We make a critical comparison, including examples, of the application of LC-TOF-MS to screening, identification and confirmation of target, non-target and unknown pesticides in foodstuffs.

Recent trends in liquid chromatography-tandem mass spectrometry to determine pesticides and their metabolites in food

Abstract: The applications of liquid chromatography-mass spectrometry (LC-MS) have exploded in innumerable analytical fields, including pesticide-residue determination. There is no doubt that LC-MS is currently competing with gas chromatography (GC)-MS for the status of ‘reference’ analytical technique to determine pesticide residues and that its ever-increasing application is bound to the evolution of modern instruments and their growing performance qualities. We highlight the large number and variety of pesticides that can be readily determined using such instruments, the respective merits of the different mass analyzers, and the improvements brought about by tandem MS (MS 2 ). We also discuss new applications of LC-MS in this field, such as “non-target” screening procedures and unknown identification by MS or MS n presenting the different solutions proposed to solve this challenging problem. Finally, we address the opportunities afforded by the most recent instrument designs.

Water sampling : Traditional methods and new approaches in water sampling strategy

Abstract: This article outlines the issues that need to be considered when planning water sampling for chemical monitoring and provides guidance on the work required. In addition, it considers the limitations associated with current monitoring practices based on spot sampling and presents some existing technologies that may used to complement standard spot sampling.

Bioanalytical applications of solid-phase microextraction

Abstract: The development of solid-phase microextraction (SPME) has experienced significant growth since its introduction as a new approach to sample preparation in the early 1990s. In comparison to existing technologies, such as liquid-liquid or solid-phase extraction, SPME offers many advantages, including simplicity, speed, solventless extraction, and a convenient format for the analyst. The objective of this review is to discuss the most recent developments and future challenges in the application of SPME to in vivo and in vitro bioanalytical problems. We discuss applications of fiber SPME for determination of binding constants and free concentrations, inside living organisms or in conventional samples. We show that the ability to perform direct and selective extraction of analytes from complex samples greatly extends the applications of SPME into the field of bioanalysis.

Progress in analysis of residual antibacterials in food

Abstract: Residual antibacterials in food constitute a risk to human health. Although epidemiological data on the real magnitude of their adverse effects are very scarce, they indicate that food could be an important avenue for evolution and dissemination of antibiotic-resistant bacteria. Analysis of these residues plays a key role in ensuring food safety, to the point that the European Union has not only established maximum residue limits but also requirements concerning the performance of analytical methods and the interpretation of the results. These specifications have had a great influence on protocols and techniques applied. In this review, we discuss the progress of rapid screening methods and the use of accurate liquid chromatography-tandem mass spectrometry (LC-MS 2 ) to confirm the identity and the quantity of antibacterials present. We cover challenges and achievements in this field, emphasizing developments in the past five years, and the impact of Commission Decision 2002/657/EC and its application in food. We also outline future perspectives and promising alternatives to well-established procedures.

Application of advanced MS techniques to analysis and identification of human and microbial metabolites of pharmaceuticals in the aquatic environment

Abstract: This overview reviews current knowledge on identification, presence and distribution of drug metabolites in the environment. We compare the metabolic routes of environmentally relevant pharmaceuticals in the human body to those of biotransformations brought about by mixed consortia of microorganisms in natural and engineered wastewaters and surface waters. We describe the characteristics of modern mass-spectrometric instrumentation coupled to liquid-chromatographic separation techniques and review their application in profiling metabolites. We set out analytical methodologies for quantitative analysis of drugs and their degradates in sewage and surface waters and give results of monitoring obtained from their application.

LC-MS for identifying photodegradation products of pharmaceuticals in the environment

Abstract: Abiotic processes, such as direct and indirect photolysis, are of great importance in determining the aquatic fate of pharmaceutical compounds. Photolytic reactions are often complex, involving various competing or parallel pathways and leading to multiple reaction products. The identification of transformation products and the elucidation of photolysis-reaction pathways are of crucial importance in understanding their fate in the aquatic environment, but are complicated and cumbersome. This article focuses on advanced liquid chromatography-mass spectrometry (LC-MS) methods for identifying transformation products of abiotic processes that lead to the transformation of pharmaceutical compounds in environmental systems (direct and indirect photolysis) and photocatalytic transformations in water- and wastewater-treatment systems, using titanium dioxide or the photo-Fenton process. We discuss the capabilities and the limitations of single-MS, tandem-MS and hybrid-MS techniques, and present practical examples (triple-quadrupole-MS analysis of phototransformation products of fluoxetine, ion-trap-MS analysis of photoproducts of carbamazepine, and time-of-flight-MS elucidation of the reaction pathways of photolytic and photocatalytic degradation of diclofenac).

Advanced mass spectrometric methods applied to the study of fate and removal of pharmaceuticals in wastewater treatment

Abstract: This overview is of analytical methodologies based on gas chromatography-mass spectrometry and liquid chromatography-mass spectrometry, applied in environmental monitoring of pharmaceutical residues and their known degradation products. We also consider the ability of time-of-flight (TOF) and quadrupole-TOF instruments to provide sufficiently accurate-mass measurements and full-scan spectra for unequivocal confirmation of target compounds and investigation of their degradation products, which are either known or unknown. We focus attention on the fate and the behavior of pharmaceutical residues during conventional and advanced wastewater treatments. Wastewater-treatment plants are designed to remove conventional pollutants (e.g., suspended solids and biodegradable organic compounds), but not low concentrations of synthetic pollutants (e.g., pharmaceutically active compounds). Membrane bioreactor systems represent a new generation of processes that have proved to outperform conventional activated sludge treatment in terms of sludge production and effluent quality. In the past few years, there has been much attention paid to their capability for removing trace organic contaminants from sewage. This review highlights their improved performance in removing pharmaceutical residues from wastewater compared to conventional treatment.

Using restricted-access materials and column switching in high-performance liquid chromatography for direct analysis of biologically-active compounds in complex matrices

Abstract: In the bioanalytical field, sample preparation is often considered the time-limiting step. Indeed, extraction techniques (e.g., liquid–liquid extraction (LLE) and solid-phase extraction (SPE)) are commonly used off-line for biological matrices. To perform high-throughput analysis, there have been efforts to develop a faster sample-purification process. Special extraction sorbents, such as restricted-access materials (RAMs), allow direct, repetitive injection of complex biological matrices onto these supports. Coupling RAMs to column-switching high-performance liquid chromatography (HPLC) systems is a very attractive approach to biological sample preparation. This technique leads to automation, simplification and speeding up of the sample-preparation process. In this article, we review coupling of RAMs to column-switching systems and give particular attention to commercially available supports. These RAMs are used in single-column or column-switching configurations for direct analysis of compounds in various biological fluids.

LC-MS analysis of basic pharmaceuticals (beta-blockers and anti-ulcer agents) in wastewater and surface water

Abstract: Given the concern for assessing environmental exposure due to the presence of pharmaceuticals and their potential impact, most studies carried out in this field have been on the development of analytical methods. Beta-blockers and anti-ulcer agents are pharmaceuticals with amine functionalities and basic sites in the molecules that can cause difficulties in their analysis. This review compiles the advances presented in the current literature as approaches to solving the difficulties in the analysis of basic pharmaceuticals by using liquid chromatography with mass spectrometry systems and sample treatment for complex matrices. We also compile environmental findings for beta-blockers and anti-ulcer agents in this review.