spectrophotometry and potentiometry: March 2009

Sunday, March 8, 2009

OVERVIEW OF ENVIRONMENTAL ANALYSIS

A. INTRODUCTION
1. Environmental Analysis
Environmental analysis, as used in these notes, is the chemical (or physical) characterization of some component of the natural or engineered environment. One may speak of four facets to environmental analysis:
1. Analytical Methods
2. Sampling Protocol
3. Quality Control
4. Data Analysis

B. TRADITIONAL CLASSIFICATION OF ANALYTICAL METHODS
I. Classical
A. Gravimetric
1. Evaporation
2. Filtration
3. Precipitation
4. Extraction
B. Volumetric Analysis or Titrimetric Analysis
1. Acid/Base
2. Precipitation
3. Complexation or Chelation
4. Oxidation/Reduction
II. Modern or Instrumental Methods
A. Spectroscopic Methods
1. Molecular
a. Molecular Absorption
i. Ultraviolet/Visible
ii. Infrared
b. Molecular Emission
2. Atomic
b. Atomic Absorption (AAS)
i. Flame
ii. Furnace
b. Atomic Emission
i. Flame
ii. Plasma
B. Electrochemical Methods
1. Potentiometry
a. Glass Electrode
b. Ion Selective Electrodes (ISE)
2. Amperometry
3. Voltammetry
4. Conductance
C. Chromatographic Methods
1. Planar Chromatography
2. Gas Chromatography
a. Flame Ionization Detection
b. Electron Capture Detection
c. Thermal Conductivity
3. Liquid Chromatography
D. Mass Spectrometry
a. Probe Introduction
b. GC Introduction (GC/MS)
c. LC Introduction (LC/MS)
E. Nuclear Methods
III. Biochemical Methods
A. Whole Organisms
B. Cell Cultures
C. Enzyme Systems

Articles

Saturday, March 7, 2009

12th General Conference of the Romanian Physical Society "TRENDS IN PHYSICS"

FOREWORD

The Romanian Physical Society (RPS) has been organizing, every year, the National Conference of Physics, since 1990, the date of society's post-war initiation. It however continues a tradition that the community of physicists managed to pursue for two decades earlier. There are important differences as comparing with the past in many respects: logistics, means, motivation of participation both of institutions and individuals, scope and aims. However from several points of view the word "continuity" has a factual support.

The main purpose of the national conference is to bring together physicists from various institutions, universities, research laboratories, colleges, and high schools, to discuss all matters referring to our profession and activity. And problems appear more and more acute in the present stage of historical development of our country.

Equally important is to watch to what extent the standard of research and education in physics correspond to the mainstream of the world science and to what extent we find the physics in Romania imbedded in .the world's civilization.

The sub-title "trends in physics" , adopted from the European general conferences, expresses exactly the desire of the organizers to have an overview of the status of research and education in physics in our country capable to constitute a frame for further steps and a signal for competent authorities in science policy - and for physicists themselves, too. From this point of view the Romanian Physical Society is the ideal institution, if not the only one, capable to engage on such a task. Specialized conferences more, or less successful, have been abundant during the last few years and they are extremely necessary. They solve punctual problems of scientific communication and cooperation. National conferences are expected to be a general real forum for physics promotion and advancement in Romania.

The present book contains the abstracts of contributions submitted to the conference. They will be catalogued by several international agencies (i.e. INIS-AIEA) and will be kept in the web page of RPS. As we have found an increase of the standard of presentation by the authors no paper was rejected, though we recognize that there are many misprints and language mistakes in many texts. The meaning and the intrinsic value of these texts are however transparent. Unfortunately the organizers did not have the means and time to make the necessary corrections; we operated in general to the printing aspect and uniformity of presentations. Regarding the content, spelling, grammar and logical flow, these remain entirely as the responsibility of the authors themselves.

Articles

Synthesis of a chitosan-based chelating resin and its application to the selective concentration and ultratrace determination of silver in environment

Abstract

A novel chelating resin using chitosan as a base material, ethylenediamine-type chitosan, has been synthesized for the first time in the present study, and applied to the collection/concentration of ultratrace amounts of silver in environmental water samples. In the present study, ultratrace amounts of silver collected on the resin were eluted and determined by ICP-MS. The resin packed in a 1 mL mini column could adsorb silver selectively and quantitatively at a flow rate of 2 mL min⁻¹ in the wide pH range from 1 to 8, and silver adsorbed on the resin could be easily recovered by passing 1 M nitric acid as an eluent into the column. High adsorption capacity for silver at pH 5, 0.37 mmol mL⁻¹ of the resin, was achieved, and t_1/2 of the adsorption is less than 5 min. The effect of chloride on the collection of silver was examined by varying chloride concentrations from 10⁻⁴ to 0.75 M; the results showed that the present resin can be used for the collection/concentration of ultratrace amounts of silver in natural waters, as well as seawater. To ensure the accuracy and the precision of the method, CASS-4 near shore seawater reference material from the NRCC has been analyzed. This is not a certified SRM for silver, but has been used for comparative silver analysis by several groups, who report very similar results to those that are reported here. The developed method using ethylenediamine-type chitosan resin gives 0.7 pg mL⁻¹ of the detection limit when 50-fold enrichment was used. The proposed method was successfully applied to the determination of silver in tap, river, and seawater samples.

Keywords: Chelating resin; Chitosan; Determination of silver; Environmental water samples; ICP-MS

Article Outline

1. Introduction
2. Experimental
3. Procedure
4. Results and discussion
5. Conclusion
Acknowledgements
References

Quality Traceability DependabilityWorld wide

ASTM D97 method for determination of the pour point of petroleum products. ...... K Ca Sc Ti V Cr Mn Fe Co Ni Cu Zn Ga Ge As Se Br Kr. Y Zr Nb ... Na Mg. Al. P. K Ca Sc Ti V. Cu Zn. As. Rb. Tc Ru Rh Pd Ag. In. Sb. Cs Ba La Hf Ta W Re Os .... Th Pa U. Mo. Mg. Al. P. Cr Mn Fe Co Ni. Ba. Pb. B. Na. Si. K. Ti V. Zn ...

[PDF] VHGCatalog_Final 92607B.qxp:Layout 1

SUMMARIES OF PHYSICAL RESEARCH IN METALLURGY, SOLID STATE PHYSICS, AND CERAMICS

I. PRODUCTION, TREATMENT, AND PROPERTIES OF MATERIALS
A. Metallurgy of Reactor Materials
Metallurgical and Other Investigations on Special Metals, Other Materials-5 and Processes
Purification of Alkali Halides-8
Physical Metallurgy of Uranium-9
Uranium A13 oys -10
Physical Metallurgy of Plutonium and Its Alloys-12
Niobium Phase Diagrams-13
System Zirconium-Iron-Tin -14
Uranium Phase Equilibria Studies-15
Bonding Fundamentals -16
Basic Studies Relevant to the Liquid Metal Fuel Reactor-17
Transformation Characteristics of Zirconium-Niobium Alloys-19
Study of Inclusions in Uranium-21
Fatigue Behavior of Dilute Alloys of Niobium -22
Physical Metallurgy of Uncommon Metals -23
Constitution of Uranium Alloys-24
Fundamentals of Diffusional Bonding-25
Phase Equilibria Studies of Alloy Systems Involving One or More Alkali
and Alkaline Earth Metals as Components -26
Basic Properties of Light Metal Hydrides -27
B. Materials Preparation
Preparation, Structure and Properties of Uranium Compounds-31
Metal Purification and Crystal Preparation-32
Preparation of Semiconducting Materials-33
C. Refractory Materials
Basic Research In Ceramics-37
Properties of Ceramics at Elevated Temperatures-38
Research on Graphite-39
Volume Change on Melting 1102 -40
Ceramics Research-41
D. Corrosion and Oxidation Studies
Basic Corrosion Studies-45
Scaling of Zirconium at Elevated Temperatures-46
Study of the Films Formed on Zirconium-Niobium Alloys in Oxygen Atmospheres -47
Investigation of Phenomena Related To Liquid Metal Corrosion-48
Corrosion of Nuclear Metals -49
Electrochemical Studies on the Corrosion of Nuclear Reactor Metals-50

[PDF] SUMMARIES OF PHYSICAL RESEARCH IN METALLURGY, SOLID STATE PHYSICS ..

Chelating Sorbents in Inorganic Chemical Analysis

INTRODUCTION
Accurate analysis of various complex samples (natural and waste waters, geological, biological and industrial materials, substances of high purity), especially at trace levels, is one of the most difficult and complicatedanalytical tasks.
The rapid development of electronic instrumentation has created powerful analytical tools for trace element determination. At the same time, matrix effects (which can give erroneous results) and the extent of separation chemistry in instrumental methods have become evident.1
In the last years, the importance of separation and concentration techniques involving chelating sorbents in the trace analysis has risen substantially.
Pre-treatment of an aqueous sample by the sorption technique not only increases the ion concentration to a detectable level but also eliminates matrix effects. The use of chelating sorbents can provide a concentration factor up to several hundred folds, better separation of interferent ions, high efficiency and rate of process, and the possibility of combining with different determination methods.2¿5
A chelating sorbent essentially consists of two components: the chelate forming functional group and the polymeric matrix or the support; the properties of both components determine the features and the applications of the respective material.

[PDF] Chelating Sorbents in Inorganic Chemical Analysis

Biosorption of heavy metals by Saccharomyces cerevisiae: A review

Abstract

Heavy metal pollution has become one of the most serious environmental problems today. Biosorption, using biomaterials such as bacteria, fungi, yeast and algae, is regarded as acosteffective biotechnology for the treatment of high volume and low concentration complex wastewaters containing heavy metal(s) in the order of 1 to 100 mg/L. Among the promising biosorbents for heavy metal removal which have been researched during the past decades, Saccharomyces cerevisiae has received increasing attention due to the unique nature in spite of its mediocre capacity for metal uptake compared with other fungi. S. cerevisiae is widely used in food and beverage production, is easily cultivated using cheap media, is also a by-product in large quantity as a waste of the fermentation industry, and is easily manipulated at molecular level.

The state of the art in the field of biosorption of heavy metals by S. cerevisiae not only in China, but also worldwide, is reviewed in this paper, based on a substantial number of relevant references published recently on the background of biosorption achievements and development. Characteristics of S. cerevisiae in heavy metal biosorption are extensively discussed. The yeast can be studied in various forms for different purposes. Metal-binding capacity for various heavy metals by S. cerevisiae under different conditions is compared. Lead and uranium, for instances, could be removed from dilute solutions more effectively in comparison with other metals. The yeast biosorption largely depends on parameters such as pH, the ratio of the initial metal ion and initial biomass concentration, culture conditions, presence of various ligands and competitive metal ions in solution and to a limited extent on temperature. An assessment of the isotherm equilibrium model, as well as kinetics was performed. The mechanisms of biosorption are understood only to a limited extent. Elucidation of the mechanism of metal uptake is a real challenge in the field of biosorption. Various mechanism assumptions of metal uptake by S. cerevisiae are summarized.

Article Outline

1. Introduction
2. Advantages of S. cerevisiae as biosorbents in metal biosorption
3. Forms of S. cerevisiae in biosorption research
4. Biosorption capacity of S. cerevisiae
5. Influential factors
6. Pretreatment
7. Biosorption equilibrium isotherm models and kinetics models
8. Biosorption mechanism by the cell of S. cerevisiae
9. Instrumental tools and techniques used in metal biosorption studies
10. Discussions and future directions
Acknowledgements
References

Organic Reagents in Spectrophotometric Analysis

Sergey B Savvin 1985 Russ. Chem. Rev. 54 1074-1090 doi: 10.1070/RC1985v054n11ABEH003158

PDF (2.45 MB) | References

Sergey B Savvin

Abstract.

The spectrophotometric analytical methods using organic reagents in modern chemistry are discussed. Certain new organic reagents, synthesised in recent years, are presented. New methodological procedures in spectrophotometric analysis and the possibilities of the available apparatus are examined. The advances achieved in the development of the theoretical principles of the action of organic reagents are described and a new approach to the explanation of the reactivity of organic compounds is put forward.
The bibliography includes 200 references.

Atomic Spectrometry Update. Industrial analysis: metals, chemicals and advanced materials

This Atomic Spectrometry Update is the latest in an annual series appearing under the title Industrial Analysis. Due to changes in the abstracting system that the ASU reviews depend upon, there has been a slight change in the quantity and quality of the abstracts that were presented to the writing team this year. For most of the review no significant changes have occurred. However, for several specialised topics such as Glasses and Catalysts the amount of information has both increased in relevance and quantity. In contrast Table 3 is reduced this year due to the abstracting changes. Hopefully, more refinements of the new system will bring in more benefits as to the quality of the review in the coming years.

New developments in solid sample introduction continue to be reported both for ferrous and non-ferrous metal analysis. The technique that has shown much promise in this area is laser induced breakdown spectrometry (LIBS) and several interesting reports were received.

In contrast to the 2000 review, where petroleum additives were a hot topic, only one paper referring to petroleum additives was received. Solid phase micro-extraction (SPME) has also been employed in conjunction with Raman spectroscopy to determine the petroleum contamination of water. The analysis of coal in this review period is split mainly into two areas: the analysis of total trace metals in the coal and the determination of elements which raise environmental concerns.

Papers detailing pre-concentration using various functionalised resins, e.g., XAD-2 and XAD-16, solid phase extraction and various organic chemicals have a large contribution to this year's review. This year there has been a more general application of analytical techniques for analysis of inorganic materials. As in previous years, solid sample analysis has been a prominent feature, with the development of a portable XRF device, several ETA-AAS studies and some interesting secondary ion mass spectrometry work being reported.

Inductively coupled plasma mass spectrometry (ICP-MS), in each of its variants, continues to be the dominant technique in the application of analytical atomic spectroscopy to the analysis of nuclear materials.

One point for avid review readers is the quantity of rare earth element papers mentioned in Table 3 this year. This may be due to either the new abstracting system or to the fact that our colleagues who publish in this area around the world are growing weary of this field of research.

Contents
1	Metals
Table 1	Summary of analyses of metals
1.1	Ferous metals and alloys
1.2	Non-ferrous metals and alloys
2	Chemicals
2.1	Petroleum and petroleum products
2.1.1	Petroleum products
2.1.2	Fuels
2.1.3	Oils
2.2	Organic chemicals and solvents
2.2.1	Chemicals
2.2.2.	Solvents
2.3.	Inorganic chemicals and acids
2.4.	Nuclear materials
Table 2	Summary of analyses of chemicals
3	Advanced materials
3.1	Polymeric materials and composites
3.2	Semiconductor and conducting materials
3.3	Glasses
3.4	Ceramics and refractories
Table 3	Summary of analyses of advanced materials
3.5.	Catalysts
4	References

Thursday, March 5, 2009

Spectrophotometric

Beckman Instruments, Inc.: Bulletin 134-D. Fullerton, California. ...... been the basis for many published methods for the determination of ...... ments Ag, Al, B, Ba, Be, Or, Co, Cu, Fe, Mn,. Mo, Ni, Pb, Sn, Sr, Ti, V, Zn, and Zr are deter- ... Al, Ba, Mn, Ni, Cs, Sn,. Sr, Cr, Zn, Pb, Mo and Cd are monitored with ...

PDF: SPECTROPHOTOMETRY

Study on color reaction of 2-(2-quinolylazo)-5-dimethylaminoanline with palladium and its application

Abstrasct

A new chromogenic reagent, 2-(2-quinolylazo)-5-dimethylaminoaniline (QADMAA) was synthesized. A sensitive, selective and rapid method for the determination of palladium based on the rapid reaction of palladium(II) with QADMAA was developed. In the presence of 0.5-2.5 mol/L of hydrochloric acid solution and cetyl trimethylammonium bromide (CTMAB) medium, QADMAA reacts with palladium to form a violet complex of a molar ratio 1:2 (palladium to QADMAA). The molar absorptivity of the chelate is 1.35¡Á105 L.mol-1.cm-1 at 600 nm. Beer¡¯s law is obeyed in the range of 0.01~ 0.6 m g/ml. The relative standard deviation for eleven replicate sample of 0.2 m g/ml level is 1.02 %. This method had been applied to the determination of palladium with good results.

Keywords 2-(2-quinolylazo)-5-dimethylaminoaniline; palladium; spectrophotometry

Articles

Study on color reaction of 2-(2-quinolylazo)-5-dimethylaminoanline with palladium and its application

Abstrasct

Keywords 2-(2-quinolylazo)-5-dimethylaminoaniline; palladium; spectrophotometry

Articles

Supramolecular function of fluorescent probe/cyclodextrincomplex sensors in water

This paper reviewed the supramolecular function of fluorescent probe/cyclodextrin (CyD) complexes for ion and molecule recognition in water. Benzo-15-crown-5 fluoroionophores, Cn-15C5 (n=1, 3, 5), with different alkyl spacer lengths were first examined to develop supramolecular Cn-15C5/γ-CyD complex sensors for alkali metal-ion recognition in water. In organic solutions, C3-15C5 shows moderate Na+selectivity based on 1:1 complex formation. However, the C3-15C5/γ-CyD complex is found to selectively respond to K+ion in water and to exhibit pyrene dimer emission. An equilibrium analysis of the γ-CyD inclusion complexes in water reveals that the major component for the dimer emission is a 2:1:1 complex of C3-15C5 with K+and γ-CyD. Although the K+sensitivity of the C5-15C5/γ-CyD complex is comparable to that of the C3-15C5/γ-CyD complex, it also responds to Na+. The fluoroionophore C1-15C5, which has the shortest methylene spacer, exhibits no response to alkali metal cations in the presence of γ-CyD. Thus, the response function is strongly affected by the alkyl spacer length of Cn-15C5, and the highest K+selectivity in water is obtained for the C3-15C5/γ-CyD complex. The boronic acid fluoroionophore C4-PB/β-CyD complex binds sugars and produces increased fluorescence emission in water. A pH-fluorescence profile for the C4-PB/β-CyD complex reveals that the fluorescence intensity increases upon the formation of the boronate conjugate base. Upon the addition of fructose, the apparent pKa decreases to a lower pH, resulting in increased fluorescence at neutral pH. The fluorescence emission response of the C4-PB/β-CyD complex upon sugar binding appears to be due to suppression of the photoinduced electron transfer (PET) from the pyrene donor to the trigonal arylboronic acid acceptor.

Articles

REVIEW OF HEAVY METALS

1. INTRODUCTION
In natural aquatic ecosystems, metals occur in low concentrations, normally at the nanogram to microgram per litre level. In recent times, however, the occurrence of metal contaminants' especially the heavy metals in excess of natural loads, has become a problem of increasing concern. This situation has arisen as a result of the rapid growth of population, increased urbanisation, expansion of industrial activities, exploration and exploitation of natural resources, extension of irrigation and other modern agricultural practices as well as the lack of environmental regulations.
At the global level the scientific community has investigated some of these problems and the results have been published in several reviews and books (Nriagu, 1989; Förstner and Wittmann, 1981; Salomons and Förstner, 1984). Most of the present introductory material is based on these sources.
Unlike other pollutants like petroleum hydrocarbons and litter which may visibly build up in the environment, trace metals may accumulate, unnoticed, to toxic levels. Thus problems associated with trace metal contamination were first highlighted in the industrially advanced countries because of their larger industrial discharges and especially by incidents of mercury and cadmium pollution in Sweden and Japan (Kurland et al., 1960; Nitta, 1972; Goldberg, 1976). In spite of the relatively low level of industrial activity in less developed regions such as Africa, there is nevertheless growing awareness of the need for rational management of aquatic resources including control of waste discharges into the environment. This becomes even more important in view of the expected increases in industrial and urban activities in all parts of the continent.
Existing information on various environmental problems has been reviewed by Dejoux (1988) in a monograph of pollution in African inland waters and by Phillips (1991) on a worldwide basis on tropical marine ecosystems. These publications showed that the existing information on Africa is scattered and scarce, and therefore demonstrated the need for a more precise and specific review of the occurrence of trace heavy metals in various aquatic environmental compartments in the continent.
For effective water pollution control and management there is a need for a clear understanding of the inputs (loads), distribution and fate of contaminants, including trace metals from land-based sources into aquatic ecosystems. In particular, the quantities and qualities need to be considered together with the distribution pathways and fate and the effects on biota.
The need to make an assessment of the level of heavy metal contamination in the African environment has led to the initiation of several pollution monitoring programmes and research work in various universities and scientific institutions in the region. The most relevant programmes are the Mediterranean pollution monitoring programme (MEDPOL) covering also North Africa, the West and Central Africa marine pollution and research programme (WACAF 2) and the Eastern Africa marine pollution and research programme (EAF/6).
During the last decade, there have also been considerable improvements in the sampling and analytical techniques for trace metals. These, coupled with international intercomparison exercises, have facilitated the generation of more reliable data. The present paper thus attempts to compile and analyze the available information on the occurrence of trace metals in both freshwater and marine ecosystems of Africa as a contribution towards the formulation of rational management policies for aquatic resources in the continent.
The decision to review freshwater and marine data jointly is a result of the need to have a holistic approach that could influence future control strategies.

Articles

SOIL GENESIS ON PERALKALINE FELSICS IN BIG BEND NATIONAL PARK, TEXAS

Abstract
Soil genesis involving felsic rocks frequently involves understanding the roles of climate and time on the transformations of the primary minerals into secondary products. This study focuses on the weathering of peralkaline felsics in a semiarid climate. Soils and fresh parent materials were collected from different microclimate regimes in the Chisos Mountains of Big Bend National Park, Texas. Soils in the Chisos mountains generally have either a mollic-argillic-rock or a mollic-rock horizon sequence, whereas other sites at lower and drier locations have an ochric-rock horizon sequence. Atmospheric deposition of Ca and Sr and wind deflation of clay are important attributes of soil genesis. Elemental loss rates of Si, Al, K, Na, and other elements are appreciable, suggesting that leaching has been important to the soil formation. Iron oxide formation, which is related to the moisture regime, is greater in soils having wetter microclimates. Solution chemistry suggests that Mg concentrations are appropriate for smectite synthesis and maintenance, potassium concentrations reflect the presence of feldspar, sodium concentrations reflect their loss rates because of leaching, and calcium reflects the presence of calcite. The rare earth elements similarly demonstrate loss rates consistent with chemical weathering. In general, chemical weathering of feldspars, atmospheric deposition of Ca and Sr, and wind deflation are important pedogenic processes.

ARTICLE LINKS:Fulltext PDF (138 K) Request Permission

Digestion of Solid Matrices Desk Study - Horizontal

SUMMARY
Choice of digestion methods
The report in hand concerns an evaluation of potential for horizontal standardisation for the digestion of samples prior to the determination of trace elements covering sludge, soil, treated biowaste and neighbouring fields.
The detailed comparison of standards for the digestion prior to the determination of trace elements demonstrates the possibility of preparing horizontal standards in this field, however
investigation has to be initiated prior to the establishment.
From an environmental impact evaluation perspective the composition derived from either "partial" or "total" digestion is hardly relevant, as the fraction which even under extreme environmental condition will be brought into solution (and made available for plants etc.) is several orders of magnitude lower. Thus for control purposes or for monitoring or evaluation of developments in element concentration, the use of "partial" methods are considered acceptable.
However, it is of vital importance that the methods provide comparable results with a sufficiently high reproducibility for the elements and matter in question.
In many European countries, digestion methods used for solid environmental samples such as waste, sludge and soil are based on the use of aqua regia in accordance with the relevant European and International standards for the different areas. However, in some European countries, e.g. the Nordic countries, the digestion methods are based on the use of nitric acid.
The reason for this choice being the smaller interference effects from using nitric acids on some of the subsequent analytical procedures.

[PDF] Digestion of Solid Matrices Desk Study - Horizontal

Polarized Zeeman Absorption Atomic Spectrophotometer

Easier Operation, Higher Reliable Analyses,
and Higher Sensitivity Than Ever Before 􀊕􀊕
This is the concept of Z-series of the polarized Zeeman AAS.
Three models are available to meet your specific need.
High Quality
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Excellent Sensitivity using Zeeman Method and Dual Detector.
Space of Installation is Reduced (Z-2300/2700 )
Slim designed with built-in Graphite Furnace Autosampler

[PDF] Untitled

Concentration Methods for the Determination of Trace Elements

Yurii A Zolotov 1980 Russ. Chem. Rev. 49 683-694 doi: 10.1070/RC1980v049n07ABEH002497

PDF (1.71 MB) References Articles citing this article
Yurii A Zolotov
Abstract. Methods of concentrating trace constituents are discussed, and the quantitative parameters used to describe them are defined. The main methods of concentration (extraction, sorption, coprecipitation, evaporation, etc.) are examined and compared. Rational combinations of methods of concentration and methods of determination of trace elements are recommended, and successful examples of such combinations are quoted. Special aspects of concentration methods applicable to the analysis of high-purity materials and of natural waters are discussed. 114 references.

FLUOROMETRIC DETERMINATION OF IRON WITH SOME N-ARYL-3-AMINOPROPIONIC ACIDS

Iron is essential to most life forms and to normal human physiology. Iron is an integral part of many proteins and enzymes that maintain good health. In humans, iron is an essential component of proteins involved in oxygen transport [ , ]. It is also essential for the regulation of cell growth and differentiation [ , ]. A deficiency of iron limits oxygen delivery to cells, resulting in fatigue, poor work performance, and decreased immunity [1, - ]. On the other hand, excess amounts of iron can result in toxicity and even death [ ].
Therefore the element is necessary for control in food products and objects of environment (corresponding norms are presented in table 1). Also small contents of iron are necessary for control in various metallurgical objects [8].

Articles

Wednesday, March 4, 2009

Highly Selective and Sensitized Spectrophotometric Determination of Iron (III) Following Potentiometric Study

Abstract References Full Text: PDF (Size: 261K) Related Articles Citation Tracking
Article
Highly Selective and Sensitized Spectrophotometric Determination of Iron (III) Following Potentiometric Study
Ardeshir Shokrollahi, Mehrorang Ghaedi *, Hamid Reza Rajabi
Chemistry Department Yasouj University Yasouj Iran 75914-353
email: Mehrorang Ghaedi (m_ghaedi@mail.yu.ac.ir)
*Correspondence to Mehrorang Ghaedi, Chemistry Department Yasouj University Yasouj Iran 75914-353, Tel.Fax. (+98)-741-2223048
setDOI("ADOI=10.1002/adic.200790067")
Abstract
A simple, selective and sensitized spectrophotometric method for determination of trace amounts of Fe3+ ion in tap and waste water solutions has been described. The spectrophotometric determination of Fe3+ ion using Ferron in the presence of N,N-Dodecytrimethylammonium bromide (DTAB) has been carried out. The Beer's law is obeyed over the concentration range of 0.05-2.6 g mL-1 of Fe3+ ion with the relative standard deviation (RSD %) <0.2 % and the molar absorptivity of complexes in pH 3.5 is 3.8×103 L mol-1 cm-1.
Potentiometric pH titration has been used for prediction of protonation constants of ferron, and evaluating its stoichiometry and respective stability constant with Fe3+ ion. As it is obvious the most likely species of ferron alone and its complexes are LH (log=7.64), LH2 (logK=10.52), LH3 (logK=11.74) and ML2 (log= 23.68), ML3 (log= 23.68), ML3H (log= 23.68), ML3H2 (log= 23.68) and ML(OH)2 (log=23.68) respectively.

Rapid Spectrophotometric Determination of Zirconium(IV)

Rapid Spectrophotometric Determination of Zirconium(IV) with 2,2,3,4-tetrahydroxy–3 -sulpho–5-chloroazobenzene in Alloys
A. Ali HÜSEYİNLİ,1†Fitnat KÖSEOĞLU,2 and Ülkü Dilek UYSAL1
1† Anadolu University, Faculty of Sciences, Department of Chemistry, 26470, Eskişehir, Turkey (E-mail: ahuseyin@anadolu.edu.tr)
2 Gazi University, Gazi Education Faculty, Teknikokullar, 06500, Ankara, Turkey
New o,o/–monoazo reagents have been synthesized using pyrogallol and 2-aminophenol-6-sulphonic acid or its derivatives. Spectrophotometric properties of the complexes formed by the reaction of synthesized monoazo reagents with Zr4+ have been investigated. According to the results it is found that the most sensitive and selective ligand for the Zr4+ is 2,2/,3,4-tetrahydroxy–3/-sulpho–5/-chloroazobenzene (tetrahydroxyazon SCl) and it was used for the direct spectrophotometric determination of Zr4+ion. Tetrahydroxyazon SCl reagent forms a red complex with Zr4+ ion in acidic media up to pH 6. The complex formation is fast and its absorbance reaches to a level immediately where remains constant for more than three days. The metal (M):ligand (L) ratio of the formed complex is 1:1 and the optimal wavelength of the
complex is 496 nm. Under optimum conditions Zr4+ ion acts in accordance with the Beer law at an ion concentration range of 0.08-3.20 μg/mL. The molar absorptivity was found as 34500 Lmol-1cm-1. The determination of Zr4+ was not interfered by Cu2+, Cd2+, Pb2+, Ni2+, Cr3+, Zn2+, Bi3+, U6+, Th4+, Al3+, Be2+, Co2+, Mn2+, Hg2+, halides, phosphates, sulfates, thiocyanides, urea, tartrate, ascorbic acid etc. This method is highly sensitive, selective, very rapid and a simple technique. It has been successfully applied to the determination of Zr4+ ion in an aluminum based certified alloys.

[PDF] Rapid Spectrophotometric Determination of Zirconium(IV) with 2,2 ...

Tungsten and Cobalt in Workplace Atmospheres (ICP Analysis)

Related Information: Chemical Sampling - Tungsten (as W) Insoluble Compounds, Tungsten (as W) Soluble Compounds, Cobalt, Metal, Dust & Fume (as Co)
Method Number: ID-213
Matrix: Air

Analytical Procedure:
The MCE filter is subjected to a sequence of digestion steps using ammonium hydroxide (aqueous ammonia), water, hydrochloric acid, nitric acid, and phosphoric acid. The resulting solution is analyzed by aspiration into the argon stream of an inductively coupled plasma atomic emission spectrometer (ICP-AES).

Articles

Monday, March 2, 2009

An Extractive Spectrophotometric Method of Determination of Molybdenum(VI) Using 3-Hydroxy-2-(4-methoxyphenyl)-6-methyl-4H-chromen-4-one

Abstract
3-Hydroxy-2-(4-methoxyphenyl)-6-methyl-4H-chromen-4-one (HL) behaved as a sensitive spectrophotometric reagent for molybdenum(VI). The metal ion formed a yellow complex with the reagent in acetic acid medium. The complex was extractable into 1,2-dichloroethane and the absorbance values remained unchanged for more than one week. Spectral data showed the formation of 1 : 2 species with λ_max value at 411 nm. Beer’s law was obeyed over the concentration range of 0—2.3 ppm. The molar absorptivity and Sandell’s sensitivity were calculated to be 5.61 × 10⁴ dm³ mol⁻¹ cm⁻¹ and 0.0017 μg Mo cm⁻² respectively, at 411 nm. The effect of as many as 41 cations and 28 anions and complexing agents was studied. Out of these only Sn(II), Ce(IV), citrate, oxalate, disodium dihydrogen ethylenediaminetetraacetate, and hydrogen peroxide interfered seriously. For ten replicate determinations of 1 μg Mo cm⁻³ the standard deviation was 0.008 with a relative mean error of ±0.09%. The method is simple, selective, precise and rapid. It has been applied satisfactorily to the determination of molybdenum in steels, waters and flue dust samples.

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Elemental analysis, Intertek USA

Method Summaries

Carbon, Hydrogen & Nitrogen (CHN)

Oxygen (O)

Pyrolysis

Sulfur,Chlorine,Bromine & Iodine (S,Cl,Br & I)

Colormetric Titration

Ion Chromatography

Inductively Coupled Plasma

Sulfur

Fluorine (F)

Inductively Coupled Plasma - Optical Emission Spectroscopy (ICP-OES)

Individual Elements

Inorganics

Inductively Coupled Plasma Optical Emission Spectrometry(ICP-OES)/Inorganic Elements

Supported Elements This analysis is suitable for the following elements; Ag, Al, As, Au, B, Ba, Be, Bi, Ca, Cd, Ce, Co, Cr, Cu, Dy, Er, Eu, Fe, Ga, Gd, Ge, Hf, Hg, Ho, In, Ir, K, La, Li, Lu, Mg, Mn, Mo, Na, Nb, Nd, Ni, Os, P, Pb, Pd, Pr, Pt, Re, Rh, Ru, S, Sb, Sc, Se, Si, Sn, Sr, Ta, Tb, Th, Ti, Tl, Tm, U, V, W, Y, Yb, Zn, and Zr. The elements Hg, Os and S may be analyzed by special arrangement with the laboratory. Solid samples requiring lower limits of detection must use ICPMS in most cases. Cesium can only be measured by ICPMS.
Semi Quantitative Scan

Inorganics

Inductively Coupled Plasma Optical Emission Spectrometry(ICP-OES)/Semi Quantitative Scan of Inorganic Elements

Supported Elements This analysis is suitable for the following elements; Ag, Al, As, Au, B, Ba, Be, Bi, Ca, Cd, Ce, Co, Cr, Cu, Dy, Er, Eu, Fe, Ga, Gd, Ge, Hf, Hg, Ho, In, Ir, K, La, Li, Lu, Mg, Mn, Mo, Na, Nb, Nd, Ni, Os, P, Pb, Pd, Pr, Pt, Re, Rh, Ru, S, Sb, Sc, Se, Si, Sn, Sr, Ta, Tb, Th, Ti, Tl, Tm, U, V, W, Y, Yb, Zn, and Zr. The elements Hg, Os and S may be analyzed by special arrangement with the laboratory. Solid samples requiring lower limits of detection must use ICPMS in most cases. Cesium can only be measured by ICPMS.

Inductively Coupled Plasma - Mass Spectroscopy (ICP-MS)

Individual Elements

Inorganics

Inductively Coupled Plasma Mass Spectrometry(ICP-Ms).
Inorganic Elements

Supported Elements This analysis is suitable for the following elements; Ag, Al, As, Au, B, Ba, Be, Bi, Ca, Cd, Ce, Co, Cr, Cs, Cu, Dy, Er, Eu, Fe, Ga, Gd, Ge, Hf, Hg, Ho, In, Ir, K, La, Li, Lu, Mg, Mn, Mo, Na, Nb, Nd, Ni, Os, P, Pb, Pd, Pr, Pt, Re, Rh, Ru, S, Sb, Sc, Se, Si, Sn, Sr, Ta, Tb, Th, Ti, Tl, Tm, U, V, W, Y, Yb, Zn, and Zr. The elements Hg, Os and S may be analyzed by special arrangement with the laboratory. Cesium can only be measured by ICPMS.
Semi Quantitative Scan

Inorganics

Inductively Coupled Plasma Mass Spectrometry(ICP-Ms)/Semi Quantitiative Scan of Inorganic Elements

Supported Elements This analysis is suitable for the following elements; Ag, Al, As, Au, B, Ba, Be, Bi, Ca, Cd, Ce, Co, Cr, Cs, Cu, Dy, Er, Eu, Fe, Ga, Gd, Ge, Hf, Hg, Ho, In, Ir, K, La, Li, Lu, Mg, Mn, Mo, Na, Nb, Nd, Ni, Os, P, Pb, Pd, Pr, Pt, Re, Rh, Ru, S, Sb, Sc, Se, Si, Sn, Sr, Ta, Tb, Th, Ti, Tl, Tm, U, V, W, Y, Yb, Zn, and Zr. The elements Hg, Os and S may be analyzed by special arrangement with the laboratory. Cesium can only be measured by ICPMS.

Flame Atomic Absorption Spectroscopy (FLAA)

Individual Elements

Flame Atomic Absorption Spectroscopy or emission.(FLAA) Inorganic Elements

Supported Elements This analysis is suitable for the following elements; Al, Ag, Ba, Bi, B, Ca, Cd, Cr, Co, Cu, Ga, K, Fe, Pb, Li, Mg, Mn, Mo, Na, Ni, Pd, Pt, Rh, Ru, Sb, Se, Si, Sn, Ti, V and Zn. Other elements may be analyzed by special arrangement with the laboratory. The technique is best used for alkali metals. Solid samples requiring lower limits of detection must use either GFAA, ICP or ICPMS depending on the element.

Graphite Furnace Atomic Absorption (GFAA)

Individual Elements

Graphite furnace atomic absorption.(GFAA) Inorganic Elements

Supported Elements This analysis is suitable for the following elements; Al, Ag, Ba, Bi, Cd, Cr, Co, Cu, Ga, Fe, Pb, Li, Mn, Mo, Ni, Pd, Pt, Rh, Ru, Se, Si, Sb, Sn, Ti, V and Zn. Other elements may be analyzed by special arrangement with the laboratory. Solid samples requiring lower limits of detection must use either ICP or ICPMS depending on the element.

Cold Vapor Atomic Absorption (CVAA)

Individual Elements

Cold Vapor Flame atomic absorption (CVAA)/Inorganic Elements

Supported Elements This analysis is suitable for Hg. Other elements (As, Sb, Se) may be analyzed by special arrangement with the laboratory.

Ion Chromatography (IC)

Individual Anions

IC

Anions/Inorganic Anions

Supported Elements Fluoride (F^-), Chloride (Cl^-), Bromide (Br^-), Sulfate (SO₄2^-), Phosphate (PO₄3^-), Nitrate (NO₃^-), and Nitrite (NO₂^-)
Anion Scan

IC

Anions/Inorganic Scan

Supported Elements Fluoride (F^-), Chloride (Cl^-), Bromide (Br^-), Sulfate (SO₄2^-), Phosphate (PO₄3^-), Nitrate (NO₃^-), and Nitrite (NO₂^-)
Trifluoroacetate (TFA)
Methanesulfonate (MSA)
Individual Cations

IC

Cations/Inorganic Cations

Supported Elements Cations (m⁺): Sodium (Na⁺), Potassium (K⁺), Lithium (Li⁺), and Ammonium (NH₄⁺)
Cation Scan

IC

Cations/Inorganic Scan

Supported Elements Cations (m⁺): Sodium (Na⁺), Potassium (K⁺), Lithium (Li⁺), and Ammonium (NH₄⁺)
Acetate
High Performance Liquid Chromatography (HPLC)
Liquid Chromatography - Mass Spectrometry (LC-MS)
Residual Solvents

GC

Fid/Known Compounds

Supported Elements This analysis is suitable for samples containing residual solvents at levels ranging from trace amounts (typical 0.01% quantitation limit using 100 mg sample size) to a relative high percentage.
Gas Chromatography (GC)

General Gas Chromatography

Supported Elements This analysis is suitable for samples containing residual solvents at levels ranging from trace amounts (typical 0.01% quantitation limit using 100 mg sample size) to a relative high percentage.
Gas Chromatography - Mass Spectrometry (GC-MS)

Gas Chromatography - Mass Spectrometry

Supported Elements This analysis is suitable for identification of unknown residual solvents at levels ranging from trace amounts (typical 0.05% quantitation limit using 100 mg sample size) to a relative high percentage.
Mass Spectrometry (MS)

MS

General/Unknown Compounds

Supported Elements This analysis is suitable for structure elucidation of unknown compounds.
Thermal Gravimetric Analysis (TGA)

Spectroscopy

Fourier Transform Infrared Spectroscopy (FT-IR)

FTIR

/FTIR

Supported Elements This analysis consists of acquiring the infrared spectrum of a given compound. The spectrum is indicative of the vibrations between atoms in the molecule. Therefore, it can be used to identify the structure of a molecule.
Optical Rotation (OR)
Ultraviolet and Visible Spectroscopy (UV-Vis)

UVvis

UVvis

Supported Elements This analysis consists of acquiring the ultraviolet and visible spectrum of a given compound. The spectrum is indicative of electron transitions between the orbitals in the molecule. Therefore, it can be used to identify the structural features of a molecule.

Water Determination

Coulometric Karl Fischer

Water Determination

Karl Fischer/Coulometric Titration

Supported Elements This analysis is suitable for samples containing water at levels ranging from trace amounts (typical 0.1% detection limit) to very large amounts.
Volumetric Karl Fischer

Water Determination

Karl Fischer/Volumetric Titration

Supported Elements This analysis is suitable for samples containing water at high levels, 0.5% to 10%. Additionally, a large amount of sample is usually required for accurate results. For smaller sample sizes and lower detection limits use Coulometric Karl Fischer titration.

Ashing

Micro Ash

Micro Ash

Supported Elements This analysis is suitable for samples requiring a detection limit of <0.1%.> Residue on Ignition.
Micro Residue on Ignition (ROI)

Residue on Ignition

Supported Elements This analysis is suitable for samples requiring a detection limit of <0.1%.> Residue on Ignition.
Melting Point
Total Organic Carbon (TOC)

TOC

Organic Carbon

Supported Elements Carbon (<1000ppm)>

Extractive Spectrophotometric Determination of Tungsten(VI) Using 3-Hydroxy-2-(2'-Thienyl)-4-OXO-4H-1- Benzopyran

Abstract
A simple, rapid, highly sensitive and selective spectrophotometric method for the determination of tungsten(VI) in trace amounts is developed using 3- hydroxy-2-(2'-thienyl)-4-oxo-4H-1-benzopyran (HTB) as a reagent for the complexation of metal ion and extracting the 1:2 (metal:ligand) complex into dichloromethane from 0.2 M HCl solution. It obeys Beer's law in the range 0-2.8

g Wml^-1 with molar absorptivity and Sandell's sensitivity at 415 nm as 6.45 x 10⁴ L mol^-1cm^-1 and 0.0029

g W(VI) cm^-2, respectively. The method is free from the interference of a large number (39) of elements and handles satisfactorily the analysis of various samples of varying complexity.

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Performance and frequency of use of NAA and other techniques during the certification of two new Polish CMRs prepared by INCT

Abstract
Two new candidate reference materials of biological origin, viz. Tea Leaves (INCT-TL-1) and Mixed Polish Herbs (INCT-MPH-2), were prepared, and world-wide interlaboratory comparison involving over 100 laboratories was organised with the aim to certify these materials for the content of possibly great number of trace elements. In this paper a preliminary analysis of the contribution of various analytical techniques to the certification of the new reference materials is presented and discussed with the emphasis on the role played by neutron activation analysis (NAA). The potential significance of “very accurate methods” by radiochemical NAA in the certification process is pointed out. An attempt is made to compare the outcome of the present intercomparison with those formerly organised by INCT as well as with some earlier IAEA intercomparisons in order to demonstrate similarities, differences and trends in the use of the various analytical techniques in trace analysis as a function of time.

http://www.springerlink.com/content/h526075810t74354/fulltext.pdf

Sunday, March 8, 2009

Saturday, March 7, 2009

Abstract

Article Outline

Abstract

Article Outline

Thursday, March 5, 2009

Wednesday, March 4, 2009

Monday, March 2, 2009

Colormetric Titration

Ion Chromatography

Inductively Coupled Plasma

Inorganics

Inductively Coupled Plasma Optical Emission Spectrometry(ICP-OES)/Inorganic Elements

Inorganics

Inductively Coupled Plasma Optical Emission Spectrometry(ICP-OES)/Semi Quantitative Scan of Inorganic Elements

Inorganics

Inductively Coupled Plasma Mass Spectrometry(ICP-Ms). Inorganic Elements

Inorganics

Inductively Coupled Plasma Mass Spectrometry(ICP-Ms)/Semi Quantitiative Scan of Inorganic Elements

Flame Atomic Absorption Spectroscopy or emission.(FLAA) Inorganic Elements

Graphite furnace atomic absorption.(GFAA) Inorganic Elements

Cold Vapor Flame atomic absorption (CVAA)/Inorganic Elements

IC

Anions/Inorganic Anions

IC

Anions/Inorganic Scan

IC

Cations/Inorganic Cations

IC

Cations/Inorganic Scan

GC

Fid/Known Compounds

General Gas Chromatography

Gas Chromatography - Mass Spectrometry

MS

General/Unknown Compounds

FTIR

/FTIR

UVvis

UVvis

Water Determination

Karl Fischer/Coulometric Titration

Water Determination

Karl Fischer/Volumetric Titration

Micro Ash

Residue on Ignition

TOC

Organic Carbon

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Inductively Coupled Plasma Mass Spectrometry(ICP-Ms).
Inorganic Elements