Flame Atomic Absorption Method Research Articles

Literature survey of the on-line preconcentration in flow-injection atomic spectrometric analysis

The literature on the use of “on-line” preconcentration in flow injection atomic spectrometric analysis is reviewed, taking into account its application both in flame and electrothermal atomic absorption methods as well as in plasma emission spectrometry. The basis of the different preconcentration approaches, such as liquid-liquid extraction, column preconcentration and “on-line” precipitation are discussed. The literature survey reveals the analytical performance of the developed methodologies.

Some observations on the analytical utility of inductively coupled plasma-atomic emission spectrometry for the indirect determination of some drugs and surfactants

Numerous amine hydrochlorides, quaternary ammonium chlorides, and some reducing agents were determined indirectly by inductively coupled plasma-atomic emission spectrometry (ICP-AES). The method employed is based on measurement of excess silver following precipitation of halide with silver nitrate. The accuracy and precision of ICP-AES results are superior to those from titrimetric or flame atomic absorption methods.

Field determination of copper, manganese and Zinc in sulphide materials by flameless atomic absorption spectrometry

A field-portable analytical method is described for the semi-quantitative determination of Cu, Mn and Zn in oceanic sulphide minerals. Samples were prepared on board ship and analyzed using the AAZ-2 field portable atomic absorption spectrophotometer. The method has general applicability to a variety of field locations at sea or on land. Analyte concentrations ranging from the ppm to percent levels could be determined by selecting the appropriate analytical wavelengths and sample dilution factors. Samples were dissolved using hydrochloric and nitric acids in sealed teflon vessels. Concentrations of Cu, Mn and Zn were determined with an accuracy of approximately 10% when field results were compared with determinations subsequently carried out on the same samples in the laboratory by flame atomic absorption methods.

Field determination of copper, manganese and zinc in sulphide materials by flameless atomic absorption spectrometry

Abstract A field-portable analytical method is described for the semi-quantitative determination of Cu, Mn and Zn in oceanic sulphide minerals. Samples were prepared on board ship and analyzed using the AAZ-2 field portable atomic absorption spectrophotometer. The method has general applicability to a variety of field locations at sea or on land. Analyte concentrations ranging from the ppm to percent levels could be determined by selecting the appropriate analytical wavelengths and sample dilution factors. Samples were dissolved using hydrochloric and nitric acids in sealed teflon vessels. Concentrations of Cu, Mn and Zn were determined with an accuracy of approximately 10% when field results were compared with determinations subsequently carried out on the same samples in the laboratory by flame atomic absorption methods.

Volatilisation studies of cadmium compounds by the combined quartz furnace and flame atomic absorption method: effects of magnesium chloride and ascorbic acid additives

A flame atomic absorption spectrometer was coupled to a modified thermoanalytical quartz furnace for the element-specific detection of evolved decomposition products. Heating programmes with a constant heating rate (0.8 °C s–1) and with an exponentially decreasing heating rate (typically 50–5 °C s–1) were applied in the range 25–950 °C. Sample holders made of platinum, electrographite and solid pyrolytic graphite were used in furnace atmospheres of variable oxygen concentration. Decomposition and vaporisation of Cd(NO3)2, CdCl2, MgCl2, ascorbic acid and mixtures of these compounds were studied. The radiation scatter of the aggregates formed from the ascorbic acid by decomposition was detected in a flow cuvette. Because of the extremely long life of the atomic cadmium vapour, cold vapour detection of this species was also feasible in the combined system. This was used to supplement the flame atomic absorption measurements in elucidating vaporisation mechanisms. Samples in the form of aqueous solutions and occasionally as solids were applied to the furnace. It was found that the hydrolysis of CdCl2 and MgCl2 takes place to a lesser extent on increasing the sample mass and the heating rate and by using pyrolytic graphite and platinum sample holders. The enhanced rate of hydrolysis on the surface of porous graphite is explained by an adsorption effect (adsorption hydrolysis). The fraction of a hydrolysing chloride salt evolved in chloride form is also dependent on the pre-heating conditions. In the presence of ascorbic acid, Cd(l), CdO(s) and MgO(s) are formed from both chloride and nitrate salts of these elements in the first period of heating. On the surface of the pyrolytic sample holder, the formation of Cd(l) is enhanced in the presence of ascorbic acid and thus complete evaporation of cadmium can be achieved at low temperature (320–460 °C). The vaporisation of CdO(s) takes place by thermal dissociation from both platinum and graphite surfaces at a temperature (ranging from 580 to 800 °C) that depends on the effective oxygen concentration close to the sample. The decomposition products of the nitrate anion activate the graphite surface, which enhances the vaporisation rate of CdO(s) from such a surface.

Determination of cadmium in calcium chloride extracts of soils by atom-trapping atomic absorption spectrometry

A method is described for the determination of cadmium in 0.05 M calcium chloride extracts of soils by atom-trapping atomic absorption spectrometry (ATAAS). The technique of ATAAS has been applied to such determinations of cadmium as the levels encountered are too low for detection by conventional flame atomic absorption methods. Examination of the effects of major elements present in the extracts on the cadmium response demonstrates that this method is relatively free from interference problems. A comparison of the results obtained with those determined by a separation procedure using a chloroform extract of the dithizonate with back-extraction into HCl and conventional atomic absorption spectrometry has been made. The method has been used for the determination of cadmium in a number of Scottish topsoils.

乳の無機成分定量のための試料の前処理および分析法について

A practical technique for pretreatment and analytical methods suitable for the determination of mineral components in milk has developed using wet ashing coupled with flame emission, atomic absorption, ICP and colorimetric methods, The major elements Na, K, Mg, Ca and P were well determined using a 0.1ml milk sample which was decomposed with nitric acid. Ten milliliters of milk was digested with nitric acid and/or mixed acid systems (HNO3-H2SO4 and HNO3-H2SO4-HClO4) for the trace elements Fe, Cu, Zn and Sr. Sulfuric acid and perchloric acid gave precipitates CaSO4 and KClO4, respectively, resulting in lower values of Ca and K. The mineral composition of cow, human and giraffe milk and the mammary gland secretion of the giant panda was tabulated.

Atomic absorption and atomic fluorescence methods of analysis: their merits and limitations

Atomic absorption methods involve conversion of the sample into an atomic vapour and measurement of the absorbance of this vapour at a specific wavelength, characteristic of the analyte element. Flames and electrical furnaces are the most widely used means of atomization. Flame atomic absorption methods are rapid and precise, can be carried out on simple equipment, and are applicable to the determination of 67 elements. There have been no major recent advances in such methods. Electrothermal methods of atomization give much better sensitivity and are applicable to much smaller samples. They are generally less precise and slower than flame methods. There have, however, been important recent advances in electrothermal methods and further improvements in the near future are to be expected. There has been some progress in the development of atomization techniques based on cathodic sputtering. The main limitations of atomic absorption methods are associated with the incomplete atomization of the sample. Simultaneous multi-element analysis is generally not possible since the optimum atomization conditions vary according to the analysis to be carried out. Rapid sequential analysis is, however, now in widespread use. At present, atomic fluorescence methods are seldom used, possibly because they have most of the limitations of atomic absorption methods and are not so widely applicable. They are, however, superior for some analyses and many of these can be carried out on simple non-dispersive systems that have many attractive features. In this paper I discuss the merits and limitations of the atomic absorption methods of elemental analysis that have been developed during the past 30 years and are now in widespread use. I also discuss some of the methods developed during this period that involve the measurement of atomic fluorescence, a phenomenon having its origin in atomic absorption. These fluorescence techniques currently find little application in analytical laboratories but merit discussion in view of their many attractive features and their possibilities for further development.

Application of atomic absorption spectrophotometry for the determination of lanthanides in ores and rare earth concentrates

Concentrations of La, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb and Y were determined in rare earth ores and concentrates by the flame atomic absorption method, those of Eu, Gd, Dy, Ho, Er, Tm, Yb and Y also by the flameless method with a graphite cell. Accuracy was checked by using a standard lanthanides mixture. The results of the determinations in concentrates (by flame and by furnace AAS, both direct measurement and standard addition method) were compared with those obtained by spectrophotometry. Detection limits were defined in a HGA-70 graphite cell with application of a standard graphite tube. The results of the examinations revealed that both the AAS methods are suitable for lanthanide determinations in the above materials. Heavy lanthanides can be determined in lower concentrations than by spectrophotometry.

Determination of dimethylpolysiloxanes in fats and oils

AbstractA direct aspiration, flame atomic absorption method has been developed for the determination of dimethylpolysiloxanes (DMPS) in fats and oils. The detection limit of the method is approximately 1 ppm with a standard deviation for samples containing 1–10 ppm DMPS of 0.3. The technique is reasonably rapid, requires a minimum of sample preparation, and is applicable to the analysis of both hydrogenated and nonhydrogenated products.

Comparison of three analytical methods for the determination of trace elements in whole blood

Three different analytical techniques were compared in a study of the role of trace elements in multiple sclerosis. Data for eight elements (Cd, Co, Cr, Cu, Mg, Mn, Pb, Zn) from neutron activation, flame atomic absorption and electrothermal atomic absorption methods were compared and evaluated statistically. No difference (probability less than 0.001) was observed in the elemental values obtained. Comparison of data between suitably different analytical methods gives increased confidence in the results obtained and is of particular value when standard reference materials are not available.

Comparison of flameless atomic absorption for the analysis of the metallic content of sewage sludge with flame atomic absorption and colorimetric methods

Determination of the metallic content of sewage sludge is of increasing importance in order to assess the suitability of these sludges for disposal to agricultural land. The methods currently used for the determination of cadmium, chromium, copper, nickel, lead and zinc can be time-consuming. A rapid flameless atomic absorption procedure utilising homogenisation as the only pretreatment is described. This method is compared with flame atomic absorption and colorimetric methods in a statistically designed experiment. The precision of the rapid flameless atomic absorption procedure compares well with flame atomic absorption and is superior to colorimetric methods. Time saved by the use of this method is substantial and it could be used advantageously for routine analysis.

Comparison of a rapid flameless atomic absorption procedure for the analysis of the metallic content of sewages and sewage effluents with flame atomic absorption methods

Determination of the metallic content of sewages at various points within the sewage treatment process is of increasing importance. The methods currently used for the determination of lead, cadmium, copper, chromium, nickel and zinc are time-consuming. A rapid procedure is described and data derived from the analysis of individual samples by several methods are presented.

The determination of cadmium, copper, iron, lead and zinc in aerosols by atomic-absorption spectrometry

The determination of five elements in filter papers loaded with air particulate matter has been investigated. After a wet destruction of about 10 cm 2 of filter material by a standard procedure, analysis was carried out with a flame atomic absorption method for zinc and a flameless procedure for Cd, Cu, Fe and Pb. Furnace program parameters for each of the elements in different acid solutions are reported. The interferences of some common anions and the most abundant cations in aerosol material are described. For some urban and industrial samples, the results are compared with those obtained by energy-dispersive x-ray fluorescence. Accuracy was checked against standard samples.

Solid Sampling Atomic Absorption Determination Of Silver in Silicate Rock Reference Samples. Application to a Homogeneity Study of Silver In a One‐Ton Two‐Mica Granite Reference Sample

Silver content of silicate rook samples rarely exceeds 200 ppb. For determining such low levels of silver, a solid sampling flame atomic absorption method has been developed and has been applied to the analysis of several silicate rock reference samples. These results are compared with the sparse published data. Using silver as an example, the usefulness of solid sampling procedures for testing the repartition of volatile trace elements during the processing of new rock reference samples is illustrated.

Characterization of a dc Plasma as an Excitation Source for Multielement Analysis

A commercial dc plasma has been evaluated as an excitation source for multielement spectrometric analyses. Plasma temperatures have been measured and typical excitation profiles determined. Detection limits have been determined using a direct reading spectrometer equipped for simultaneous background correction measurements. The results indicate that precise multielement analyses can be carried out at low concentration levels comparable to those that can be obtained by flame atomic absorption methods.

Measurement of Chelating Agent Levels in Media with High Concentrations of Interfering Metal Ions

Abstract An ion-exchange method for the measurement of levels of chelating agents in media with high levels of metal ions has been developed. The test solution is passed through a specially prepared ion-exchange column, which both removes metal ion interferences, and places the chelating agent in the copper form. The copper levels in the column effluent are then measured by flame atomic absorption methods, the copper levels corresponding in a 1:1 ratio to the levels of chelating agent in the sample. The detection limit for this method is on the order of 1 ppm copper equivalent chelating capacity, and is applicable in situations where the interfering metal ions are at concentrations in the range of 10−2 M. The method is reproducible in the pH ranges of 4 to 9 Precision and

A rapid and sensitive catalytic method for determination of iron in blood serum

A simple, rapid and sensitive method is proposed for the determination of iron in blood serum. Because of the high sensitivity of the method (0.001 μg/ml) a serum sample of only 0.05 ml is used in the analysis. The procedure is reduced to a usual photometric measurement. The determination is carried out without previous deproteinisation. A single determination takes about 45 min but in case of serial analysis 10 samples are analysed per hour. The coefficient of variation is in the range 1.8–4.8%, depending on the serum iron content. The method is compared with the bathophenantroline, nitroso-R-salt and flame atomic absorption methods. The best correlation is found for the data of the catalytic and the bathophenantroline methods, the reasons for this being discussed in the paper.

Ultramicro Method for Determination of Iron in Serum with the Graphite Furnace

Abstract An ultramicro method is described for determining iron in 50 µl of serum. Hot trichloroacetic acid is used to remove protein and hemoglobin iron, and atomic absorption analysis of 10 µl of the supernatant fluid is carried out with use of a graphite furnace and a specially grooved graphite tube. Results correlate well with those obtained by a conventional flame atomic absorption method for iron that requires a 1-ml sample of serum. A standard graphite tube can be used if the trichloroacetic acid extract is first diluted with water, but we rejected this procedure because of the extra time and effort involved and because of the increased problem of artifactual contamination with iron. When serum was analyzed with no pretreatment, results were higher, probably because of hemoglobin iron present in serum, even serum with no visible hemolysis.

Biological Applications of the Carbon Rod Atomizer in Atomic Absorption Spectroscopy. 2. Determination of Copper in Small Samples of Tissue

Abstract A simple technique is presented for the analysis for copper in small fragments of tissue. Dissolution of the tissue in concentrated nitric acid is the only preparative step required. Copper content is then determined by comparison with standards, by using the carbon rod atomizer previously described. Sample volumes of less than 2 µl are used for each measurement. The method gives results that compare well with both colorimetric and flame atomic absorption methods, and also with neutron activation analysis, and appears to be applicable to the analysis of other metals in tissue.