Modern Instrumental Methods Of Analysis Research Articles

Определение тяжёлых металлов и пестицидов в траве Мяты азиатской современными инструментальными методами

The State Pharmacopoeia XIV edition sets a number of requirements for the quality of medicinal plant raw materials, including their safety. The determination of safety indicators is necessary to establish a likely threat to the health of patients, as well as the admissibility of the use of medicinal plant raw materials in medical practice. Therefore, the purpose of the study was to develop methods for determining safety indicators for heavy metals and pesticides in Mentha asiatica herb, recommended for introduction into medical practice on the territory of the Republic of Tajikistan, using modern instrumental methods of analysis. To determine heavy metals and trace element composition, the methods of atomic absorption spectrometry, stripping voltammetry, and inductively coupled plasma atomic emission spectrometry were used, and their results were compared. Organochlorine pesticides were determined by gas-liquid chromatography with a flame ionization detector. The herbal raw material complies with pharmacopoeial safety requirements, the results of atomic absorption spectrometry and inductively coupled plasma atomic emission spectrometry are comparable to the results of stripping voltammetry. Thus, in the analysis of Asian mint herb recommended for introduction into medical practice, the developed methods for determining heavy metals and pesticides, based on modern instrumental methods, may be applied.

Tincture of <i>Juglans nigra</i> L. bark: peculiarities of standardization

BACKGROUND: Juglans nigra L. is a species of trees in the Juglandaceae family. This plant of the genus Juglans L. has not been sufficiently studied in comparison with other species, including Juglans regia L. It is a perspective medicinal plant raw material, its derivatives have an antimicrobial, general tonic effect. The known antimicrobial and general tonic activity of Juglans L preparations presented on the pharmaceutical market is probably due to substances of a flavonoid nature. These data indicate the relevance of studying the flavonoids of the Juglans nigra L. bark.
 AIM: The aim of this study is to develop methods for qualitative analysis and quantitative determination of biologically active compounds for tincture of Juglans nigra L. bark with the using of spectrophotometry, thin layer chromatography, microcolumn high performance liquid chromatography.
 MATERIALS AND METHODS: The object of the study was the tincture of Juglans nigra L. bark, samples of which were prepared in March-April 2020 on the territory of the Botanical Garden of Samara University, standard samples of myricitrin, myricetin. UV spectra were recorded with the use of Specord 40 spectrophotometer (Analytik Jena). Chromatographic analysis was carried out by thin-layer chromatography (qualitative analysis), reversed-phase high performance liquid chromatography on a Milikhrom-6 microcolumn liquid chromatograph (quantitative analysis).
 RESULTS: As a result of the chromatographic study, myricitrin were revealed, it appeared to be the dominant flavonoid substance. This compound has Rf value of about 0.4 in the solvent system of chloroform-ethanol-water (25:18:2). A method for the quantitative determination of the total flavonoids calculated on myricitrin in tincture of Juglans nigra L. bark was developed by means of differential spectrophotometry. It was determined that the content of the total flavonoids calculated on myricitrin in the tincture of Juglans nigra L. bark was 0.84 0.07%. A method for the quantitative determination of myricitrin in tincture of Juglans nigra L. bark by high performance liquid chromatography was developed. The content of the dominant flavonoid as myricitrin (myricetin-3-O--L-rhamnopyranoside) in the tincture of Juglans nigra L. bark was 0.42 0.06%.
 CONCLUSIONS: The methods of qualitative analysis and quantitative determination of flavonoids for tincture of Juglans nigra L. bark with the use of modern instrumental methods of analysis (spectrophotometry, thin layer chromatography, high performance liquid chromatography) has been developed. These results can be used to standardize the tincture of Juglans nigra L. bark.

Salvia officinalis L.: prospects of using the raw material as a source of herbal medicines with the antioxidant and antimicrobic activity

There is a worldwide tendecy to increase the use of a specific proportion of medicines based on the medicinal plant raw materials. In this regard, there is a need to clarify the prospect for further research and use of Garden Sage (Salvia officinalis L.) herbal preparations as a plant of official medicine.Aim. To conduct an informative search of scientific data on the influence of the geographical origin, choice of the solvent and extraction methods on the chemical composition and the biological activity of herbal medicinal products from Garden Sage; to analyze the range of registered medicines from this plant in Ukraine; to determine the promising directions of its phytochemical and pharmacological studies.Materials and methods. The study objects were the search, analysis and comparison of the current data of scientific literature (2009-2019) concerning the chemical composition, biological activity and use of Garden Sage in medicine. Such databases as Scopus, PubMed, ScienceDirect, ResearchGate, and Google Scholar were used for search and analysis.Results and discussion. The paper includes the data of scientific literature over the last 10 years regarding the results of phytochemical and harmacological study of the raw material of Garden Sage and herbal products based on it. The major groups of biologically active substances found in Garden Sage include phenolic compounds (flavonoids, hydroxycinnamic acids, tannins) and terpenoids (essential oil, in which mono- and sesquiterpenoids predominate). Di- and triterpene compounds were also present in Garden Sage. The combination of these groups of biological active substances in different herbal medinal products from the Garden Sage provides their high antimicrobial and antioxidant potential. The maximum antioxidant effect was found after extraction using polar solvents due to a high content of polyphenols. The antimicrobial activity was manifested both by terpenoids and phenolic compounds. Currently, the use of opportunities to obtain cell and tissue culture in vitro, as well as modern instrumental methods of analysis, plays a significant role in isolation, identification and determination of the pharmacological activity of new compounds extracted from this plant raw material.Conclusions. The prospects of future research of the influence of new extraction methods and modern phytochemical methods on the isolation of valuable groups of biological active substances and the pharmacological activity of herbal medicines from Garden Sage have been determined. Leaves, inflorescences and herb of Garden Sage may be considered as a promising source for the development of new herbal medicinal products with the antioxidant and antimicrobial activities.

The synthesis and study of physicochemical properties of 1,2,4-triazole derivatives containing the phenethyl group in position 5

During the last decade, national and foreign scientists have been constantly examining an example of studying the physicochemical and biological properties of nitrogen containing heterocycles, particularly with the nucleus of 1,2,4-triazole. The main advantage of such substances is to exhibit low levels of acute toxicity with a wide spectrum of pharmacological activity. To date, a large number of medicines on the basis of 1,2,4-triazole has been created, namely fluconazole, voriconazole, anastrozole, itraconazole, and letrozole. Therefore, the creation of new molecules based on 1,2,4-triazole and the search for new biologically active compounds among them is an urgent task of modern synthetic and pharmaceutical chemistry. Aim . To study some aspects of 5-phenethyl-1 H -1,2,4-triazole-3-amine reactivity and investigate the physicochemical properties of synthesized compounds. Results and discussion . A series of 1-alkyl(aryl)-N-(5-phenethyl-1 H -1,2,4-triazolе-3-yl)methanimines has been synthesized and the reaction of their reduction has been studied. The structure and purity of the synthesized compounds have been confirmed by the complex of modern instrumental methods of analysis – elemental analysis, IR, 1 H NMR spectroscopy, LC-MS. Experimental part . The reaction of 5-phenethyl-1 H -1,2,4-triazole-3-amine with aldehydes at the ambient temperature in acetic acid medium gave 1-alkyl(aryl)-N-(5-phenethyl-1 H -1,2,4-triazolе-3-yl)methanimines. At the next stage, the selective reduction of the exocyclic C=N-group of 1-alkyl(aryl)-N-(5-phenethyl-1 H -1,2,4-triazolе-3-yl)methanimines by the action of sodium borohydride in the dimethylformamide was carried out. Conclusions . 13 new 1,2,4-triazole derivatives, namely 1-alkyl(aryl)-N-(5-phenethyl-1 H -1,2,4-triazolе-3-yl)methanimines and arylmethyl-(5-phenethyl-1 H -1,2,4-triazolе-3-yl)amines, have been obtained. The both structure and purity of the obtained substances have been confirmed by the complex of modern instrumental methods of analysis. Received : 12.08.2019 Revised : 18.09.2019 Received after correction : 27.12.2019 Revised : 25.04.2020 Accepted : 29.05.2020

Synthesis and structural features of 5-(4-(tert-butyl) phenyl)-4-((R)amino)-4H-1,2,4-triazole-3-thiols

Chemistry of heterocyclic compounds is one of the most popular sector in organic chemistry. Scientists allocate among them a class of derivatives of 1,2,4-triazole. This class of compounds attracts attention his broad spectrum of biological activity. There are antiviral, anti-inflammatory, anti-tubercular, antimicrobial, antioxidant, actoprotective, anti-cancer and other activities. The derivatives of 1,2,4-triazole have one more important advantage. It is low toxicity. This properties do this class of derivatives promising for researches their chemical structure and biological activity and purposeful search of biologically active substances.
 The purpose of the work is synthesis of 5-(4-(tert-butyl)phenyl)-4-((R)amino)-4H-1,2,4-triazoles-3-thiols from appropriate ylidene derivatives of 4-amino-5-(4 (tert-butyl)phenyl)-4H-1,2,4-triazoles-3-thiol and research of their physical and chemical properties.
 The objects of research were 10 new compounds, derivatives of 4-amino-5-(4-(tert-butyl)phenyl)-4H-1,2,4-triazoles-3-thiol. These compounds are the crystal substances which are odorless, insoluble in water and soluble in organic solvents. Investigation of the physical and chemical properties of this compounds was carried out according to the methods listed in the State Pharmacopoeia of Ukraine. The melting temperature of synthesized compounds was determined by device OptiMelt Stanford Research Systems MPA100. The structure of the compound was confirmed by 1H-NMR spectroscopy (Mercury 400) and gas chromatography-mass spectrometry (Agilent 1260 Infinity HPLC).
 10 new compounds, derivatives of 4-amino-5-(4-(tert-butyl)phenyl)-4H-1,2,4-triazoles-3-thiol, were synthesized in a study. The chemical structure of the new compounds was confirmed by modern instrumental methods of analysis. Results of the done work can be use in the future search of biologically active substances.

Results of chemical and pharmacological research of sulphide peloids of Adjara región

The use of natural healing factors for the treatment and prevention of various diseases represents the one of the actual tasks for modern medicine. The introduction of balneological methods of the treatment at the resorts as well as outside of them promotes the effective improvement of population’s health. In the world today, the demand for the preparations and cosmetics, made on peloids is increasing significantly, which is explained by the increased interest of the society to the ecologically clean raw materials of natural origin, they often replace expensive chemical preparations, which are frequently accompanied by some contraindications. The increased interest in peloids in the world put on the agenda the question of rational use of acting mud mines as well as the issue of cosmetic and medicinal preparations, developed on their basis. In the available literature there is found no data on the research of sulphide peloids of Adjara region with the purpose of their application in medical practice. The aim of our research was to carry the chemical and pharmacological research of sulphide peloids of Adjara region with the purpose of their application in medical and pharmaceutical practices. By using the physical-chemical and modern instrumental methods of analysis the chemical compositions of sulphide peloids have been studied, the contents of important balneological components have been stated in the study objects. The physical-chemical and technological characteristics of peloids have been determined. The content of bacteriophages in the study objectsd have been established by using the standard biological methods of analysis. On the basis of the conducted studies the formula and technology of preparation of the hydrogel on Ardagani lake sulphide silt peloid have been developed, it`s antiinflammatory activity has been established using formalin induced rat hind paw edema model. The results of determination of the main good-quality characteristics of the given hydrogel provide the desired quality and efficiency of the product.

Results of the research of hydromineral resources of Adjara region and prospects of their use in balneological practice

There are over 2000 healing waters discovered on the territory of Georgia, that have been used by the local population for curing reasons for centuries. The healing mineral waters effectively cure various diseases, and the efficiency of mineral waters are rising for several times in case they are accompanied by mountain air, sun rays and vitalizing greenery of the forest. Adjara is one of the regions of Georgia, rich in fresh and mineral water resources, which can be found on the seacoasts, as well as in the mountains. These resources have been known to the local population since the ancient times and have been widely used for the treatment of various diseases. In the available literature there is found scarce information on the use of hydromineral resources of Adjara region in balneological practice. The chemical compositions (micro- and macroelements) of 38 mineral waters located in Adjara region have been studied by using the chemical and modern instrumental methods of analysis. In almost all studied objects have been stated the contents of the following balneological components: iron, calcium, silicon and gases, hydrogen sulfide in some of them (Keda, Namonastrevi, Ghoma waters, Makhinjauri, Khulo, Khidistavi, Beshumi etc.). Based on the pharmacological studies have been established, that the mineral water “Shubani” of Shuakhevi municipality significantly stimulates the acid and enzyme producing function of stomach, while not affecting the peripheral blood composition; it stimulates the synthesis and release of bile acids, secretion of bilirubin. By loading of the body weight by 2% (single time) the mineral water mildly reduces the secretion of bile and bilirubin. The further development and practical realization of the results of conducted studies will promote the development of medical, particularly healthful tourism and arrangement of balneological resorts in Adjara region.

Results of the research of “barezhin” type peloids of Adjara region and prospects of their use in balneological practice

During studying the mineral waters widespread in Adjara region, it found out, that some mineral water is clean and transparent while running out on the surface, but it leaves lubricant mud at the place of coming out and when flowing into the pits. These types of peloids are successfully used in the balneological practice and are known in the literature by the names of the geographical locations, such as – according to city of Barezhin in the Pyrenees Mountains. In the available literature there is found no data on the research of type peloids widespread in Adjara region with the purpose of their application in balneological practice. The aim of our research was to study type peloids of Adjara region with the purpose of their use in balneological practice. The chemical compositions (micro- and macroelements) of 17 so called type peloids located in Adjara region have been studied by using the modern instrumental methods of analysis. It is noteworthy, that the studied peloids are saturated with micro- and macroelements. The results of X-Ray phase analysis have shown, that Kvirike and Chakhati peloids mainly represent rentgenoamorphous mass. The contents of the following minerals have been established in the objects: Ca-Na feldspar, K feldspar, Ca-montmorillonite, quartz (SiO2), hematite (Fe2O3), chlorite, magnetite, amphiboles, trace amounts of mica and chlorite. The presence of bacteriophages have been stated in the water extracts of Chakhati and Kvirike peloids, which have the ability of the lyses of E. Coli and Staphylococcus strains. Based on the pharmacological studies have been established, that the study objects (Chakhati and Kvirike peloids) are not characterized by general toxic, cumulative, local irritant, allergic, internal organs damaging and systemic actions during local administration. At present, the instructions for use in the balneological practice have been processed on 2 kinds of type peloids located in Adjara region.

Chemical and pharmaco-technological evaluation of Adjara region peat peloids

“Peloids” is an internationally recognized name of all kind medical muds. They are natural mixture of inorganic and organic materials and performs homogenous, finely dispersed mass with definite physical and chemical properties The effectiveness of peloids is due to high content of biologically active substances. High content of organic substances in peloids, such as chemically and biologically active organic carbon compounds formed by long-term chemical and microbiological processes, provides their application prospects in clinical practice. The objective of the research was evaluation chemical and pharmacotechnological properties of Adjara region Peat Peloids. The following tasks were to be solved to achieve the goal: Study chemical properties of Adjara region Peat Peloids; Determination spectrum of organic and inorganic substances; Formulation of nanocomposite containing sphagnum peat peloids; Formulation composition and development preparation technology of topical dosage form, plaster, containing nanocomposite of sphagnum peat peloids; Study antiinflammatory and antibacterial activity of peat peloids; The materilas of the research: sphagnum peat peloids of different ages (Ispani, Anaklia, Chirukhi, Peranga, Churia). Research strategy was to held experiments gradually from simple to complicated. Technological and biologic methods were used to solve research tasks. Research was held using modern instrumental methods of analysis&apparatus (UV spectrophotometer, Scanning Electron Microscopy, X ray fluorescence, Centrifuge, Dry oven, Ultraturax, AFM, XRD). It is estimated that Kolkheti sphagnum peat peloids contain a wide range of organic substances: humic acids, amino acids, fatty acids, carbohydrates and others. As a result of the research composition, design and preparation technology of plaster containing nanoconstructed system of sphagnum peat peloids is determined. Based on the research data Isapani sphagnum peat peloids and formulated dosage form (plaster) obtained anti-inflammatory action. Based on serial dilution (macro) method antibacterial activity of high concentration (1:1) sphagnum peat peloids (Ispani) was established.

Synthesis, physical-chemical properties of 2-((5-(adamantan-1-yl)-4-R-4H-1,2,4-triazole-3-yl)thio)acetic acid esters

The nitrogen-containing heterocyclic systems from the class of 1,2,4-triazole derivatives, which exhibit wide range of actions, occupy special place among the variety of heterocyclic compounds. Derived biologically active substances are actively introduced into practice as new original and effective drugs. We were interested in esters of 2-((5-(adamantan-1-yl)-4-R-4H-1,2,4-triazole-3-yl)thio)acetic acids, which exhibit high biological activity and can be intermediates for the synthesis of amides, hydrazides, ylidenderivatives of corresponding acids.The aim of this work is the synthesis of new esters of 2-((5-(adamantan-1-yl)-4-R-4H-1,2,4-triazole-3-yl)thio)acetic acids and the establishment of their physical-chemical properties.Materials and methods. Melting point was determined by open capillary method on the device OptiMelt MPA100. The elemental composition of the synthesized compounds was determined on the universal analyzer ElementarVario ЕL cube (CHNS) (standard – sulfanilamide). 1H NMR spectra were recorded on spectrometer Varian Mercury VX-200 (1H, 200 MHz) in the solvent dimethyl sulfoxide-d6 (tetramethylsilane internal standard) and decoded using a program ADVASP(tm) Analyzer program (Umatek International Inc.). Chromato-mass-spectral studies were performed on hazarding chromatograph Agilent 1260 Infinity HPLC equipped with mass spectrometer Agilent 6120 (ionization electro-spray (ESI).The results and discussion. Synthesis of 11 new compounds, namely esters of 2-((5-(adamantan-1-yl)-4-R-4H-1,2,4-triazole-3-yl)thio)acetic acids was carried out by two methods. According to the A method the alkylation of previously synthesized 3-(adamantan-1-yl)-1H-1,2,4-triazole-5-thiol was performed with the use of corresponding methyl ester of 2-chloroacetic acid and the presence of equivalent amount of sodium hydroxide. The B method involves the etherification of 2-((5-(adamantan-1-yl)-4-R-4H-1,2,4-triazole-3-yl)thio)acetic acid with the use of methyl, ethyl, i-propyl, n-propyl and n-butyl alcohols in the presence of concentrated sulfuric acid. Compounds, which were obtained by different methods, do not give depression of the melting point. It should be noted that the practical yield of the reaction according to the A method is a little bit higher in comparison with the B method. Conclusions. The study of 11 new synthesized compounds, namely esters of 2-((5-(adamantan-1-yl)-4-R-4H-1,2,4-triazole-3-yl)thio)acetic acids has been performed.The structure of the synthesized compounds has been confirmed by modern instrumental methods of analysis (1H NMR spectroscopy, IR spectrophotometry, gas chromatography-mass spectrometry and elemental analysis).

Synthesis, physical and chemical properties of 2-((4-R-3-(morfolinomethylen)-4H-1,2,4-triazole-5-yl)thio)acetic acid salts

Today’s medicine and pharmacy undoubtedly need new and effective drugs. The 1,2,4-triazole derivatives occupy a special place among the wide variety of active organic compounds. This interest is caused primarily by high biological activity of these derivatives, low toxicity and high accessibility in terms of synthesis. Thus, drugs from 1,2,4-triazoles are known and are used extensively in medicine. It is important that a sufficiently large number of scientists-synthetics are paying attention on the heterocyclic system. Although a huge amount of information in the scientific literature is devoted to the 1,2,4-triazole derivatives, the 2-((4-R-3-(morfolinometylen)-4H-1,2,4-triazole-5-yl)thio)acetic acid salts are virtually unexplored.The purpose of the work. Synthesis and establishing of the physical and chemical parameters of new 2-((4-R-3-(morfolinometylen)-4H-1,2,4-triazole-5-yl)thio)acetic acid salts.Materials and methods. The study of physical and chemical properties of the obtained compounds was conducted by the methods that are listed in the State Pharmacopoeia of Ukraine 2.0. The melting point was defined on the device which determines the melting point MPA100. The elemental composition of the compounds was found on the analyzer Elementar Vario ЕL cube (CHNS) . 1H NMR specters of obtained compounds were recorded by using a spectrometer Varian Mercury VX-200 (1H, 200 MHz) and decrypted by a computer program SpinWorks 3.1.8. Chromatography-mass spectral studies were conducted on the gas-liquid chromatograph Agilent 1260 Infinity HPLC equipped with a mass spectrometer Agilent 6120 (ionization in electrospray (ESI)).Results and discussion. As the source (starting) compounds 2-((4-R-3-(morfolinometylen)-4H-1,2,4-triazole-5-yl)thio)acetic acids (where, R = H, CH3, C2H5, C6H5, NH2) were taken. Further, by the action of ammonia hydroxide, sodium and potassium hidrogen carbonates, piperidine, morpholine, methylamine, monoethanolamine and tributylamine in alcohol or aqueous media the corresponding salts were obtained.Conclusions. In this study were synthesized 20 new compounds, salts of 2-((4-R-3-(morfolinometylen)-4H-1,2,4-triazole-5-yl)thio)acetic acid. The structure of the synthesized compounds in all cases was confirmed by modern instrumental methods of analysis (1Н NMR-spectroscopy, chromatography-mass spectrometry and elemental analysis). The synthesized compounds can be used in further biological studies.

Study of reduction of nickel (II) compounds by complex solid reducing agent

The article discusses the method of the chemical reduction, namely the use of hexamine for the reduction of compounds of nickel (II), namely, nickel (II) hydroxide. The main objective of the study is to determine the optimal process parameters (temperature and time of reduction), with the prospect of the introduction of the proposed method in the industry. The comparative analysis of currently used solid reducing agents indicates the benefit of hexamine application. The use of modern instrumental methods of analysis permits to carry out the analytical control over the completeness of reduction of Ni (OH) 2. The described in this paper thermographic studies permit to obtain technologically weighty information that is important to choose the best way of the chemical reduction of compounds of nickel (II) to metallic powder. The results can be used by experts working in the field of inorganic synthesis, as well as in the field of production of metals from secondary raw materials. The established process parameters allow the optimization of this process, not only from a technological point of view, but also from the economic.

Multivariate experimental methodology for the evaluation of sample preparation techniques used in simultaneous multielemental analysis using total reflection X-ray fluorescence spectroscopy

Modern instrumental methods of analysis now make large number of analytical measurements possible which if their full potential is to be realised require analytical protocols that are capable of isolating trends and features within and between analytical samples. Accessing such information requires good multivariate data acquisition and processing techniques and whilst considerable effort has been made in recent years to develop multivariate data calibration procedures, the selection of an appropriate sample preparation and instrumental measurement methodology remains an important and as yet less well studied feature of such analytical procedures. This paper describes a relatively simple but effective multivariate data analysis approach, based on cluster and principal components analysis, for identifying a suitable calibration procedure, matrix modifier and sample drying preparation methods for the simultaneous multi-elemental analysis of aqueous samples by TXRF.

Role of the ionic reactions in teaching and research in Finland

The status of ionic reactions in the chemistry curricula of the Finnish universities is outlined. In analytics their role is evidently changed. Qualitative analysis is no longer carried out by means of ionic reactions, but in modern instrumental methods of analysis these reactions are needed in sample preparation. Additionally, the ionic reactions are still important in teaching of analytical and inorganic chemistry. However, this topic should partly be taught already in the secondary school.

Structural and Chemical Characterization of Neopentyl Polyol Esters by Infrared Spectroscopy

Modern instrumental methods of analysis have been applied to the study of neopentyl-polyol-based synthetic ester lubricants. These provide information on the nature of the polyol(s), the component acyl groups and the composition in term of concentration and distribution of acyl groups. In most cases, the analyses are performed directly on the base oil or the lubricant without chemical modification. Infrared spectroscopy can play a major role in the analysis and, with suitable standards, it provides all of the important information for the chemical and structural characterization. Presented at the 40th Annual Meeting in Las Vegas, Nevada May 6–9, 1985

Liquid-phase polymer-based retention — the separation of metals by ultrafiltration on polychelatogens

The importance of trace-element analysis in geological, biological, environmental and industrial processes has been increasingly recognized. Although modern instrumental methods of analysis have been applied, preliminary enrichment techniques are required to separate the components to be determined from the interfering constituents of the sample1,2. For the separation of inorganic ions contained in natural waters, industrial fluids or dissolved solid materials, solvent extraction, sorption, ion exchange, precipitation and other methods have been used. However, techniques based on a two-phase distribution or on heterogeneous reactions often cause problems because, in contrast with homogeneous reactions, diffusion controlled processes must be used. Until now, no simple, rapid method has been available for the preconcentration and separation of metals in the homogeneous aqueous phase. Here we demonstrate a technique for the enrichment and separation of metals in aqueous solution using soluble non-crosslinked polymers with chelating groups (polychelatogens)3,4 called liquid-phase polymer-based retention (LPR).

Homogeneity Characterization of NBS Spectrometric Standards II: Cartridge Brass and Low-Alloy Steel*

AbstractMost modern instrumental methods of analysis depend on the use of known standards of composition for calibration. Newer analytical techniques, such as the solids mass spectrometer, laser probe and, especially, the electron-probe microanalyzer have reduced the amount of a sample which can be analyzed quantitatively to a range of about 0.1 to as small as 0.00005 μg. As a corollary to these microanalytical advances, homogeneity requirements have become severe to meet analytical standards. This paper describes a continuation of the National Bureau of Standards' effort to characterize more fully existing standards as to suitability for the new microanalytical techniques. An NBS cartridge brass sample in both the wrought (NBS-1102) and chill cast forms (NBS-C1102), as well as a low-alloy steel sample (NBS-463), have been investigated by means of electron-probe micreanalysis and optical metallography. Some 17 elements are contained in the brass, while 25 elements are found in the steel. Results for 10 elements in the steel and 6 elements in the brass are presented. In the steel, iron, nickel, copper, and silicon ate essentially distributed homogeneously at micron levels, while manganese, tantalum, niobium, zirconium, sulfur, and chromium are not. In the brass, copper and zinc are distributed homogeneously at micron levels while lead, sulfur, aluminum, and silicon are not. Electron-probe micreanalyzer results indicate that both NBS-1102 and NBS-C1102 brass are suitable for use as a calibration standard for electronprobe microanalysis as well as other microsnalyticat techniques, such as the solids mass spectrometer. The results for brass have been corroborated by a number of laboratories using the electron-probe analyzer.