Solid‐Phase Room‐Temperature Phosphorescence

Abstract

Solid‐phase phosphorescence (SPP) has become an established approach for the trace analysis of organic compounds. More recently, SPP has been successfully applied to the trace analysis for inorganic species. In this mini review, initially a brief overview of SPP is given. Then the important aspects related to adsorption of the phosphors on the solid phase are discussed. In addition, the basic photophysical aspects of phosphorescence are presented. The physicochemical interactions in SPP, such as the rigidity of the solid phase, effects of oxygen and moisture, heavy‐atom salts, and temperature, are considered. Finally, several recent applications of SPP to both organic and inorganic compounds are discussed.     

Multielemental Analysis of Yew,Pine and Spruce Needles by ICP-AES

Abstract

Concentrations of 22 trace and nutritional elements in yew, pine and spruce needles collected from urban and industrial areas were determined by inductively coupled plasma atomic emission spectrometry. Dependence of concentrations of trace elements in conifers species on sampling site was investigated. Various procedures of sample digestion (different acids, conventional hot plate and microwave digestion methods, dry ashing) were examined and discussed.     

Determination of Atmospheric Halocarbon Concentrations by Gas Chromatography-Mass Spectrometry

Abstract

GC-MS methods have been developed which provide either analysis of eleven halocarbons in ambient air samples or only rapid analyses of CH₃CI and CH₂CI₂, two species for which GC-ECD is particularly insensitive. Detection limits and precision of analysis for the remaining species are generally not as good as with GC-ECD, but the methods provide separate checks for more certain identification of the particular species of interest. In addition, the methods exhibit more uniform sensitivity for all of the halocarbons, and the GC oven can be temperature-     

Abstracts to Forthcoming Papers

Abstract

The determination of metal species in solutions is important to evaluate their biological activity in natural ecosystems. The practical possibilities of different analytical techniques to determine and speciate metals in soil systems are discussed. Separative techniques such as ion exchange chromatography and gelpermeation chromatography allow a species estimation based on charge characteristics or molecular size of water soluble metal compounds. Electrochemical techniques such as potentiometry with ion-selective electrodes and polarography provide more detailed information about complex formation and stability.     

Chemical Speciation and Fractionation in Soil and Sediment Heavy Metal Analysis: A Review

Abstract

Today it is generally recognized that the particular behaviour of trace metals in the environment is determined by their specific physicochemical forms rather than by their total concentration. Several chemical speciation and fractionation methods for heavy metal analysis in soils and sediments have been and are still being developed and applied. They primarily are intended to understand the particular environmental behaviour of metals, present in a variety of forms and in a variety of matrices.

Analytical developments, modifications of existing methods, and recent new approaches are reviewed and discussed. Techniques used include chemical extractions, ion-exchange/gel chromatography, filtration, centrifugation and sieving, selective solvent extraction.

Moreover, the application of these various techniques in different research fields over the last years is explored. The value and the limitations of speciation and fractionation techniques applied in specific experimental work is outlined. It is discussed to what extent these methods have, up to now, filled in the expectations or have been satisfactory in particular applications.     

Crude Oil Hydrocarbon Group Separation Quantitation

Abstract

The petroleum industry like most other industrial segments are continuously developing new and sophisticated techniques of analysis and at the same time are working to automated routine techniques. In the petroleum industry, the source of supply has generally become less stable and economics has dictated new thinking, both in processing and in the analysis of composition to support these new trends. In addition, this industry is faced with having a new raw material, shale oil, and coal liquids, in the near future.     

Multicomponent Analysis Of Environmental Matrices

Abstract

The paper reviews several modalities of multicomponent analysis, namely: multilinear regression by using single or multiple standards, non-linear optimization systems by using the Gauss-Newton or the Simplex methods and factor analysis, which have been used by the authors in recent papers.

These multicomponent methods have been applied to environmental samples by different analysis techniques, such as UV- visible spectrophotometry, fluorimetry, polarography-voltametry, simultaneous kinetic processes. monitoring of liquid-liquid extraction processes and HPLC (resolution of overlapped peaks). In this way, the advantages and limitations of the methodology of multicomponent analysis are shown.     

Sample Preparation Techniques—An Important Part in Trace Element Analysis for Environmental Research and Monitoring

Abstract

For the determination of minute amounts of elements in environmental samples combined analytical procedures are frequently employed. The combination of suitable sample preparation techniques with adequate detection methods lead to powerful analytical procedures. Decomposition methods are an important part of combined procedures for the determination of trace elements in solid samples. After a short summary of the potential sources for systematic errors two new decomposition methods are described that are suitable for the ashing of organic environmental samples. In one method the organic sample is ashed in a high-frequency excited oxygen plasma. The second method is a high pressure decomposition that permits mineralization of the sample in sealed quartz vessels with nitric acid at temperatures up to 320°C.

For both methods the ratio of sample weight to decomposition reagents is comparatively high. This makes these methods in combination with adequate detection methods suitable for the determination of elements at very low concentrations.

X-ray fluorescence spectrometry combined with adequate preconcentration methods is very well suited for the simultaneous determination of trace elements. Following a critical evaluation of various preconcentration techniques the analytical characteristics of filter paper with immobilized complexing agents are described. Particular emphasis is given to filter papers with dithiocarbamates as chelating group.     

Modern Analytical Methods for Monitoring Workplace Atmospheres

Abstract

Since measurements of exposure to hazardous substances were made obligatory in Germany under the Hazardous Material Regulation and Regulations for Accident Prevention there has been a need for widely-applicable, economic methods for determining airborne organic substance concentrations at workplaces. The relevant limits, which are based on toxicological and industrial hygiene data, are drawn up annually by the German Science Foundation and published as “Technische Regel für gefährliche Arbeitsstoffe” (TRgA 900) by the Ministry of Employment and Welfare.

Most organic substances, that have been assigned limits can be determined by gas liquid chromatography. The system described here is based on multicomponent GLC analysis. It has been used at BASF, the chemical-manufacturing company, where since 1979 approximately fifteen thousand workplaces have been evaluated. Hazardous substances have been detected at levels down to a few micrograms per cubic meter.

The standard system encompasses:

–-personal air samplers operating for 8 h;

–-adsorption by a solid sorbent;

–-desorption by solvent;

–-simultaneous GLC-separation on two different capillary columns;

–-computer correlation of the qualitative and quantitative data of the two chromatograms (plausibility check);

–-automatic print-out of the analytical report;

–-transfer of the results to a data bank for documentation.

Details are given of the method involving adsorption on activated charcoal and desorption with carbon disulfide. Benefits, cost advantages, and limitations are discussed.

Special sampling by means of other adsorbents (e.g. silica gel) in conjunction with special desorption, formation of derivatives, headspace analysis, and adsorption by liquids are techniques used to supplement the standard method of organic trace analysis in the field of industrial hygiene.     

An Assessment of Dust Analyses: With Particular Reference to Lead and Certain Other Metals

Abstract

The last few years have shown an increase in the number of publications describing studies on dust as indicators of environmental pollution, especially by trace metals. The techniques of sampling and analysis used in these studies are reviewed, with particular attention to inconsistencies and differences which make data incomparable. The need for work on the development of standard methods is demonstrated. Only by the application of good quality control, reference materials and reliable techniques will an unsatisfactory situation be improved.     

Improvement of Analytical Measurements within the BCR-Programme: Single and Sequential Extraction Procedures Applied to Soil and Sediment Analysis

Abstract

The determination of extractable trace metal contents in soil and sediment, using respectively single and sequential extraction procedures, is currently performed in many laboratories to assess the bioavailable metal fraction (and related phyto-toxic effects) and the accessability to the environment (e.g. contamination of ground waters).

Owing to the need for validation of the extraction schemes used and of the analytical techniques, the Community Bureau of Reference (BCR) decided to organize a project for the improvement of the quality of determinations of extractable trace metal contents in soil and sediment. The implementation of this project follows a stepwise approach involving feasibility studies, intercomparisons to detect and remove sources of errors in the application of the analytical methods, and the certification of the extractable compounds. This paper describes the organization of the work completed so far (feasibility studies and first intercomparison) and discusses its further development.     

Dual Electrode Liquid Chromatography-Electrochemical Detection (LCEC) for Platinum-Derived Cancer Chemotherapy Agents

Abstract

Trace methods of analysis and speciation have now been developed for a number of platinum derived anti-cancer chemotherapeutic agents, drugs such as: cis-dichloro diammine platinum (CDDP), cis-diammine-1,1-cyclobutane dicarboxylate platinum (CBDCA), and cis-dichloro-trans-dihydroxy diisopropylamine platinum (CHIP). It is possible to utilize parallel dual electrode operations for all three of these Pt derivatives, with overall improved analyte specificity and identification. At the same time, these approaches provide calibration plots of detector sensitivity as a function of the particular working electrode potentials in use via dual electrode LCEC. These response ratios as a function of the applied potentials then become quite unique for individual Pt compounds. By suitably selecting the operating electrode potentials in parallel operation, it is possible to alter the detectability of individual Pt analytes and to drastically vary the resultant LCEC chromatograms. The overall analyte selectivity possible via dual electrode LCEC surpasses that thus far possible via LC-polarographic reduction or single electrode LCEC operations. Glassy carbon as well as gold/mercury electrodes can readily be used for some of these Pt derivatives. These overall trace methods of analysis and speciation for the Pt anti-cancer agents have also been applied to plasma samples spiked with known levels of each drug. It is also possible to utilize these single or dual electrode approaches for the analysis of each of these Pt derivatives in cancer patients undergoing chemotherapy treatment.     

Ira Remsen,Saccharin, and the Linear Model

Abstract

While working in the chemistry laboratory at Johns Hopkins University, Constantin Fahlberg oxidized the 'ortho-sulfamide of benzoic acid' and, by chance, found the result to be incredibly sweet. Several years later, now working on his own, he termed this stuff saccharin, developed methods of making it in quantity, obtained patents on these methods, and went into production. As the industrial and scientific value of saccharin became apparent, Ira Remsen pointed out that the initial work had been done in his laboratory and at his suggestion. The ensuing argument, carried out in the courts of law and public opinion, illustrates the importance of the linear model to scientists who staked their identities on the model of disinterested research but who also craved credit for important practical results.     

Characterization and Purity Determination of Trans (±) 1,2-Diaminocyclohexane Platinum (Iv) Tetrachloride Using Liquid Chromatography With A Platinum Selective Detector

Abstract

An important aspect of drug development is the reliable determination of the purity of a bulk drug substance. In the case of Trans (±) 1,2-Diaminocvclohexane Platinum (IV) Tetrachloride, classical techniques such as differential scanning calorimetry and phase solubility analysis cannot be used because of the compound's poor tabulation of the fractions (percent) of platinum contained in each peak as measured with d.c. plasma and a corresponding response factor for the UV detector. the power of the d.c. plasma detector in producing unequivocal information on the platinum-containing species and its application in elucidating the data obtained with the UV detector is well demonstrated in this case.     

Applications of Laser-Induced Fluorometry to the Analysis of Ultratrace Levels of Uranium in an Industrial Environment

Abstract

Laser-induced fluorometric analysis of ultratrace levels of uranium in industrial environmental samples is compared with commonly used spectroscopic techniques for uranium analysis.     

Analytical Chemistry in Poland

ABSTRACT

The paper presents the main achievements of analytical chemistry in Poland on the basis of papers published mainly in the last decade. The selection is somewhat arbitrary but should show the most important directions of research. The citations generally refer to papers published in regular journals. The following topics were discussed: general aspects, chemical methods and reagents, spectrophotometry, speciation studies, atomic spectrometry, electrochemical methods, chemo- and biosensors, chromatography and related techniques.

Short reviews on the history and present status of analytical chemistry have been published elsewhere^{1, 2} and this review is intended to present the more detailed overview of the recent fields of interest, based on some selected publications from the nineties. Such selection is obviously to some extent arbitrary and this is mainly based on information sent by colleagues from various centres. It seemed, however, necessary to indicate where appropriate, the roots and earlier achievements.     

Laboratory Robots: Partners in Productivity

Abstract

The widening acceptance of the robot in industrial and clinical laboratories leads to the expectation that the robot will soon be viewed as a standard item in the laboratory environment. To become such a generally accepted product, the robot manufacturer must provide a system which will suit the needs of a wide variety of users, and the specific application of the device may not always be well defined. In addition, the robot must be designed such that almost anyone can use it with a minimum of training and with which they can become familiar and comfortable. I would like to describe the characteristics of a robotic system which has these attributes and which will augment the laboratory staff and provide great gains in operational productivity.

In the laboratory, the robot of choice should be relatively straightforward in its design and operation. For the largest proportion of laboratory tasks, complete replication of human capabilities is not appropriate. Pattern recognition, vision, etc. are capabilities which are not generally required, although reference (1) speculates on some clever means of adding sensory capabilities in future designs. What is required, however, is a motion manufacturer of products to the industrial and clinical laboratory, Fisher Scientific is expanding its product lines to be compatible with its robotics systems. This expansion comes in response to the needs of our customers to whom productivity improvement has become mandatory. As product competition in robotics increases, the customer will recognize a coincident increase in product value. At the same time, the robot itself will become more nearly a commodity appliance, much as IBM compatible PC's have become a commodity product. The added value will then come from a supplier's capability to render support services, including application programming, training, installation assistance, repair services and accessory development. With the MAXX-5 product, Fisher Scientific Company is entering the laboratory robotics market, already well positioned to offer these necessary support services.     

Microchip Electrophoresis: A New Platform for Metal Speciation

Abstract

Metal speciation is of considerable interest to the scientific community, due to the significant roles played by individual metal species in biomedicine and in the environment. Microchip electrophoresis, as specifically applied to metal speciation, is reviewed here. The review covers microchip-based determinations of metal cations (directly), metal cations as complexed species using laser induced fluorescence, absorbance (LED) and chemiluminescence detection, oxidation states, and the speciation of simultaneously existing metal complex species. Rapid microchip analysis clearly opens up the potential for species distribution analysis of environmentally and biologically important metal complexes.     

Inductively coupled plasma mass spectrometry in separation techniques: recent trends in phosphorus speciation

Inductively coupled plasma-MS (ICP-MS) and its combined use with molecular mass spectrometric techniques have become the most promising detection techniques in speciation studies. High sensitivity and element specificity of ICP-MS has the advantage of detecting trace amounts of the species of interest in complex matrices. This review is divided into two parts. In the first part, suitable use of ICP-MS either online or offline with currently used separation techniques such as HPLC, CE, and gel electrophoresis in speciation analysis is briefly discussed. In the second part, recent applications (1999-2005) of phosphorus speciation is presented to elucidate the importance of ICP-MS in separation methods and to illustrate its importance in nonmetal detection.     

Comparative Efficiencies of Trace Metal Extraction from Municipal Incinerator Ashes

Abstract

Five laboratory solvent extraction methods for the determination of leachable trace metals from municipal incinerator fly and bottom ashes are evaluated. The trace elements of interest were cadmium, chromium, copper, manganese and lead. Five different extractants, 0.1NHCl, 1.0 N ammonium acetate, methyl isobutyl ketone (MIBK), chloroform and hexane were used on each ash to determine comparative extraction efficiencies.

Extraction efficiencies of the five solvents were determined based on total metal concentration, and were found to rank in the following order: 0.1NHCl<1.0N ammonium acetate < MIBK < chloroform < hexane. No one solvent was optimal for obtaining environmentally available values for all five metals. The inorganic solvents, 0.1NHCl and 1.0N ammonium acetate, exhibited higher removal of trace metals from ash particles relative to the organic solvents. Manganese concentrations were removed more efficiently by 0.1NHCl, whereas 1.0 N ammonium acetate was more efficient for removing copper concentrations. Cadmium, Cr, and Pb could effectively be extracted by either of the two inorganic solvents. Concentrations of trace metals extracted from refuse ash appeared to be a function of the elemental boiling point and the species that exist on combustion. However, the classification of elements for refuse ash in this study strayed somewhat from the traditional geochemical classification scheme into which coal ash is placed.