Showing papers in "Critical Reviews in Analytical Chemistry in 2003"

Analysis of Pharmaceuticals and Biological Fluids Using Modern Electroanalytical Techniques

Abstract: A review of the principles and application of modern electroanalytical techniques, namely, cyclic voltammetry, linear sweep voltammetry, differential pulse voltammetry, differential pulse polarography, square wave voltammetry, square wave polarography, stripping voltammetric, and stripping polarographic techniques, is presented. The use and advantages of these techniques at different electrodes are discussed. The analytical applications of these techniques to pharmaceutical compounds in dosage forms and biological media are also discussed. Various selected studies on these subjects since 1995 are reviewed.

Analysis of Trace Amounts of Metal Ions Using Silica-Based Chelating Resins: A Green Analytical Method

Abstract: This review is concerned mainly with the applications of chelating resins, based on silica gel, for the separation and preconcentration of trace metal ions from various substrates. General methods of preparations of silica-based resins have been discussed. A synthesis of various silica-based chelating resins and their applications in the extraction of trace amounts of metal ions have been reviewed critically and have also been reported in tabular form.

Determination of Toxic Substances Based on Enzyme Inhibition. Part II. Electrochemical Biosensors for the Determination of Pesticides Using Flow Systems

Abstract: Enzyme inhibition coupled to flow injection systems set-ups are a powerful tool for the monitoring of environmental toxics. The present review examines the latest contributions to this field where electrochemical detection is used. The advantages and limitations of the FIA technique in the context of enzyme inhibition analytical procedures are discussed. The present review is organized in accordance to the enzyme (cholinesterases, tyrosinases, or alkaline phosphatase) used in the measurement.

Modern Techniques of Extraction of Organic Analytes from Environmental Matrices

Abstract: Isolation and/or preconcentration of analytes from samples characterized by complicated composition of the matrices consist an essential step of analytical procedures used for determination of trace organic components. Different analytical approaches used in analytical practice can be classified according to parameters as follow: • labor and time consumption • consumption of solvents and other reagents • mode and efficiency of extraction process • level of the automation of the operation There are plenty of original works focused on elaboration of new techniques of extraction of wide spectrum of analytes. This article deals with an trial of systematization of information available connected with new methodological and technical proposals in this field.

Sample Preparation and Chromatographic Analysis of Acidic Herbicides in Soils and Sediments

Abstract: This article reviews sample preparation of soil and sediment samples for the chromatographic determination of acidic herbicides of phenolic and carboxylic acid classes. The common methods of acidic herbicides enrichment and isolation from soils and sediments were discussed, mainly supercritical fluid extraction, pressurized solvent extraction, subcritical water extraction, microwave-assisted extraction, and also traditional extraction with organic solvents and aqueous basic solutions. Derivatization to make herbicides analyzable by means of gas chromatography and/or to improve detectability by GC and LC—and also extraction efficiency were described.

Electrothermal Vaporization — Inductively Coupled Plasma–Mass Spectrometry (ETV-ICP-MS): A Valuable Tool for Direct Multielement Determination in Solid Samples

Abstract: Solid Sampling-Electrothermal Vaporization-Inductively Coupled Plasma-Mass Spectrometry (SS-ETV-ICP-MS) is an attractive technique for the direct simultaneous determination of trace metals in solid samples. During recent years, some important developments dealing with ETV-ICP coupling and with analyte transport efficiencies have been reported, and so SS-ETV-ICP-MS has received a renewed interest by the atomic spectroscopy community. Thus, the present review highlights the inherent capabilities of SS-ETV-ICP-MS for the simultaneous determination of trace metals. In addition, technical aspects of ETV-ICP coupling as well as more recent applications are reported. It is concluded that this technique is a powerful tool for sorting out some of the current analytical challenges, and future advances are to be expected in order to widen the field of application.

Determination of Urea Pesticide Residues in Vegetable, Soil, and Water Samples

Abstract: The main physico-chemical, toxicological, and environmental properties of urea pesticides are summarized. General characteristics of analytical methods for residues of phenylurea herbicides (PUHs), sulfonylurea herbicides (SUHs), and Benzoylurea insecticides (BUIs) in crops, soil, and water samples, employed in the last 5 years are reviewed. Provided it is information about liquid-liquid and solid-phase extraction of the samples and clean-up steps. The applications of gas chromatography (GC), liquid chromatography (LC), and capillary electrophoresis (CE) techniques in the analysis of these compounds are exposed in tabular form and commented on. Sensitivity and instrument conditions of liquid and gas chromatographic techniques coupled to mass spectrometric detectors are outlined. The advantages and drawbacks of the analytical methods developed recently are discussed.

Remediation of Mercury Polluted Sites Due to Mining Activities

Abstract: During the 500 years of mercury mining in Idrija, large quantities of Hg were released into the environment. Due to chemical transformation (reduction, methylation, oxidation, demethylation) and the transport of mercury enriched particles into the river system and the Gulf of Trieste, the mercury problem is of local, regional, and global concern. The results of some studies indicate that Hg is actively accumulated in terrestrial and aquatic food webs, which leads to an increased exposure of inhabitants frequently consuming food, particularly, fish produced in a contaminated area. In order to understand the impact of mercury mining on the environment and human health, it is necessary to integrate the experience of various disciplines (e.g., chemists, biologists, geologists, hydrologists, epidemiologists, economists, etc.). Political support at the local and regional level in Slovenia and Italy is as well an ultimate requirement for the successful implementation of remediation, based on scientifically based...

Thermal Lens Spectrometry as Analytical Tool

Abstract: Thermal lens spectrometry as an analytical technique is summarized. Specific applications to the determination of metal ions, pesticides, fatty acids, carotenoids, and some interesting biomolecules as nucleotides or hepatitis B antigen are described. The possibilities and limitations of this TLS detection system is evaluated.

Flow Injection Methods of Analysis for Waters. II. Organic Pollutants

Abstract: A comprehensive, critical and updated review for the applications of flow-injection analysis (FIA) techniques for the analysis of organic pollutants in several types of water samples, except marine waters, is presented. The methods of indirect determination of organic pollutants in water by using flow injection coupled with atomic absorption spectroscopy are also discussed.

Polycrystalline Diamond-Based Electrochemical Sensors and Their Applications in Inorganic and Organic Analysis

Abstract: Boron-doped polycrystalline diamond electrodes have been used extensively in the field of electroanalysis. The development of knowledge about the mechanism of diamond film deposition, boron doping, and charge transfer reactions rendered the quality of analytical information. New aspects regarding the design of diamond-based electrodes, and mechanisms of redox reactions at their surface are briefly discussed. Recent applications of the diamond-based sensor in inorganic and organic analysis are presented.

Preparation of Gaseous Standard Mixtures: Methods for Controlling the Amount of Components Generated in the Process of Thermal Decomposition of Immobilized Compounds

Abstract: Gaseous standard mixtures play an important role in characterizing and checking the applicability of new analytical procedures. In this case gaseous standard mixtures can be treated as a special kind of reference material (validation process requires the use of so-called matrix reference materials). The selection of a method of generation of gaseous standard mixtures with the desired characteristics depends on the nature of the analyte and diluent gas, as well as on the required concentration of analytes in the mixture. Recently, dynamic methods of generation of gaseous standard mixtures are becoming more and more common. These include the method based on thermal decomposition of immobilized compounds. The generation of the measured component takes place as a result of heating of a sample of solid support with chemically modified surface. During a chemical reaction initiated by sufficiently high temperature, the immobilized compound undergoes decomposition or rearrangement accompanied by the release of a ...

Safe Disposal of Chromium-Rich Waste Materials

Abstract: Speciation analysis plays a crucial role in the investigations of transformation and mobility of Cr in the environment. In order to investigate the conditions for safe disposal of chromium-rich waste materials, appropriate speciation techniques regarding specific characteristics of sample matrix should be applied. Partitioning of Cr between various phases in waste materials, in soils, and in waste materials mixed with soils give useful data for the assessment of the environmental hazards. For this purpose, it is necessary to apply long-term experiments and to study possible oxidation-reduction processes of Cr after disposal of waste to various soils. On the basis of complex investigations estimation can be done on conditions for safe disposal of chromium-rich waste materials.

Laser-induced degradation of organophosphates and monitoring of their toxicity by cholinesterase biosensors

Abstract: Laser-induced photo-oxidation of organophosphorus compounds in aqueous media and the applicability of an acetylcholinesterase based bioanalytical method for evaluation of organohosphate's toxicity has been investigated. Rapid decomposition has been achieved within two hours following the irradiation for the range of concentrations, limited by the solubility of pesticide (up to 40 mgL−1). The compounds detected in the irradiated samples suggest that diazinon is converted directly into 2-isopropyl-4-methyl-6-hydroxypyrimidine without the formation of more toxic diazoxon. This transformation involves oxidation of the sulphur atom to the sulphate anion. A recently developed biosensor was tested for detection of toxic organophosphate and carbamate compounds. Sufficient sensitivities to different pesticides (carbofuran, propamocarb, oxydemeton-methyl, and parathion-ethyl) and LOD's, as low as 0.1 ng/mL, can be achieved in samples of salad, iceberg lettuce, and onion without time-consuming sample preparation pro...

Protection of Groundwater in Classical Karst Systems

Abstract: Water quality is of great interest in any development or management of water resources. With increased demand for water and with the intensification of its use, it is becoming the limiting factor in the development and use of water resources. According to its objectives, groundwater pollution protection can be regarded as a part of the general environmental protection or, more specifically, only as water resources protection. In the first case, groundwater with little or no water resource value is protected as a potential transmitter of pollution to other groundwater and surface water bodies and to the rest of the environment. In the second case, protection refers to the aquifers representing actual or potential water resources and to water supply catchments. In the first instance, we try to prevent any release of toxic substances from their source into the environment and to contain existing pollution within a given volume of rocks and of aquifers. In the second instance, groundwater protection consists of a complex combination of protection, prevention, and intervention measures and activities, initiated with the aim to keep the supplied water quality within the prescribed standards (Veseli, 1996). When speaking of groundwater protection, we are generally thinking of protection from pollution only. But, this is only one aspect of the protection of natural resources. Apart from the quality protection, we also have to protect quantity. Economic activities have reduced groundwater quantity in many places without, at the same time, damaging the quality. The concept of groundwater degradation (Veseli, 1995) tries to involve both aspects of groundwater deterioration. Therefore, groundwater protection is to be understood as a prevention of their overall degradation and a reclamation of their local degradation. In matters of sustainable water resources management, it is advisable that policies follow exactly this approach. Science is there to assist politics with this respect.

Application of Environmental Isotopes in Evaluation of Pollutants

Abstract: Environmental isotopes, isotopes of light elements (hydrogen, carbon, nitrogen, oxygen, sulfur, chlorine) are used as a modern, specific, and reliable technique for studies of global element cycles [1], hydrology [2], authentication of food and drinks [3], medical research [4], and pollution monitoring. Some of them, such as tritium (3H) and radioactive carbon (14C) are radioactive, while the others are stable (2H, 13C, 15N, 18O, 34S and 37Cl). The former spontaneously undergo decay with time, the latter do not. Due to energy considerations, the lighter isotopic species will react slightly faster than the heavier (although there are exceptions), resulting in a change in isotopic composition going from reactant to product compounds. The application of environmental isotopes is based on the different and distinct isotopic composition of the given molecules, due to isotopic fractionation caused by their origin and any transformation process the products underwent. They can be used at either their natural abundance or artificially enriched abundance, in labeled compounds at tracer levels. Pollution of surface water may be remedied by concerted prevention and controls, but it is more serious when pollution enters the groundwater. Polluted groundwater may remain in aquifers for centuries, even millennia, and is very difficult, if not impossible, to be cleaned. Therefore, the studies of the interaction of groundwater and surface water are of a great interest in developing control policy on land close to groundwater sources in preventin the pollution of public supplies derived from aquifers. WATER RESOURCES MANAGEMENT

Reducing the Toxicity of Pesticides

Abstract: (2003). Reducing the Toxicity of Pesticides. Critical Reviews in Analytical Chemistry: Vol. 33, No. 4, pp. 281-284.

Assessment and mitigation of environmental impacts of industrial processes in Macedonia

Abstract: The environmental situation in Macedonia is comparable to that of other Central and Eastern European countries, where development was shown mainly in terms of increasing industrial and energy production that led to environmental degradation and over-exploitation of natural resources [1]. In 1997, the National Environmental Action Plan (NEAP) was developed with input from governmental and non-governmental representatives, establishing the following main national environmental policy goals: air and water quality improvement, biodiversity conservation, forest renewal and preservation, as well as strengthening the environmental management capacity of institutions responsible for monitoring and enforcement. In this paper, the contribution of industrial processes to environmental pollution in Macedonia is considered. For illustration, more detailed results concerning greenhouse gases (GHG) emissions are presented. In conclusion, some key areas and strategies for improvements are recommended.

Biodegradation and photooxidation studies of model organic pollutants

Abstract: In the paper we present the results of biodegradation and photooxidation studies of halosubstituted benzyl alcohols. The basic goal of our research was to examine the effect of the type and position of the halogen atom in the aromatic ring on the degradation rate and to use the experimental data for the development of HQSAR models for predicting degradation rates. Biodegradation results of 2-halosubstituted benzyl alcohols correlate with the size of the halogen atom, while for 4-halosubstituted benzyl alcohols, a good correlation with the energy of C—X bond was observed. In the photooxidation process, the impact of position of the halogen on the rate of reaction is smaller. The HQSAR model was derived only for photooxidation data sets, while for the biodegradation it was not possible to obtain a model with satisfactory statistical characteristics.

Management of drinking, surface, and underground water polluted by waste from aluminum industry

Abstract: The Parliament of the Republic of Montenegro in 1991 adopted a decision about proclaiming Montenegro to be the first Ecological State, which was also included in the Agenda 21 at the Rio Summit. The same decision was incorporated in Article One of the Montenegrin Constitution, which reads: “Montenegro is a democratic, civic, and ecological state.” The rationale of such a determination by the citizens of Montenegro originated from the fact that 12% of their country’s territory consists of National parks, habitats, and monuments of nature, of which two parks are listed as UNESCO’s world heritage, and one is registered on the list of Ramsar Convention on Wetlands of International Importance. Montenegro’s biodiversity ranks as number one in Europe in proportion with the size of its territory. Being fully aware that the healthy drinking water is the greatest wealth of a country, and especially of a Mediterranean one (all of these coastal countries have a considerable deficit in good-quality drinking water supply), the greatest attention is being paid to the protection and management of abundant resources of so far unpolluted water. A relatively preserved good quality of most of our surface and underground water is due to the fact that Montenegro is still industrially underdeveloped. Nevertheless, Montenegro joined many other countries in striving to achieve their industrial development, so that in the preceding period it started constructing industrial facilities by implementing inadequate technologies. The most negative example is the Aluminum Plant Podgorica (KAP). This plant was built in the Zeta valley near the Lake of Skadar, which has been registered on the Ramsar list of protected wetland. It is the largest lake in the Balkans, and it is positioned above a unique compacted set of water springs of the highest water quality that spreads to 200 kilometers. On average, the springs feed the lake with water in the quantity of 6.34 cubic meters per sec. or 200 × 106 cubic meters per annum. Located in the Zeta valley area is the capital town of Montenegro, as well as some 38 settlements housing a total of 140,000 inhabitants. Their activities (aluminum industry, large plantations of vineyards and orchards owned by the Agricultural company (Agrokombinat July 13), the city landfill, communal sewage collectors, and other polluters) have a considerable impact on the quality of underground water that is drained into the lake of Skadar. The Aluminum plant operations, that is the inappropriate technologies for alumina and metal processing, as well as the improper storage of toxic waste, have the consequences of polluting a portion of the underground wells with alkaline hydroxides, fluorides, PCBs, PAHs, phenols, mineral oils, cyanides etc.

University Support for Establishing a Strategy for Industrial and Special Waste Management in Sarajevo Canton

Abstract: (2003). University Support for Establishing a Strategy for Industrial and Special Waste Management in Sarajevo Canton. Critical Reviews in Analytical Chemistry: Vol. 33, No. 4, pp. 321-326.