Sample atomic absorption spectrometry

Solid Sampling Atomic Absorption Spectrometry ICP Optical Emission Spectrometry ICP Mass Spectrometry... 

Magnesium deficiency has been long recognized, but hypermagnesia also occurs (Anderson and Talcott 1994). Magnesium can be determined in fluids by FAAS, inductively coupled plasma atomic emission spectrometry (ICP-AES) and ICP-MS. In tissue Mg can be determined directly by solid sampling atomic absorption spectrometry (SS-AAS) (Herber 1994a). Both Ca and Mg in plasma/serum are routinely determined by photometry in automated analyzers. 

Herber, R.F.M. (1991). Solid sampling atomic absorption spectrometry and matrix composition of organic reference materials. Pure Appl. Chem. 63,1213-1220 Herber, R.F.M. (1993). Solid sampling analysis in Seiler, H.G., Sigel, A. and Sigel, H. 

Analytical methods used in the determination of nickel in biological materials are the same as those used for environmental samples. Nickel is normally present at very low levels in biological samples. Atomic absorption spectrometry (AAS) and inductively coupled plasma-... 

SOLID SAMPLING ATOMIC ABSORPTION SPECTROMETRY BASIC PRINCIPLES... 

Other direct methods used more routinely for solid sampling analysis make use of an atomization cell, usually a graphite furnace, and optical spectrometry. Optical spectrometry techniques used are inductively coupled plasma (ICP) and atomic absorption spectrometry (AAS). This last technique, solid sampling atomic absorption spectrometry (SS-AAS), is used by far the most and thus will be dealt with more comprehensively. 

Highly sensitive iastmmental techniques, such as x-ray fluorescence, atomic absorption spectrometry, and iaductively coupled plasma optical emission spectrometry, have wide appHcation for the analysis of silver ia a multitude of materials. In order to minimize the effects of various matrices ia which silver may exist, samples are treated with perchloric or nitric acid. Direct-aspiration atomic absorption (25) and iaductively coupled plasma (26) have silver detection limits of 10 and 7 l-lg/L, respectively. The use of a graphic furnace ia an atomic absorption spectrograph lowers the silver detection limit to 0.2 l-ig/L. 

In this work, a method based on the reduction potential of ascorbic acid was developed for the sensitive detennination of trace of this compound. In this method ascorbic acid was added on the Cr(VI) solution to reduced that to Cr(III). Cr(III) produced in solution was quantitatively separated from the remainder of Cr(VI). The conditions were optimized for efficient extraction of Cr(III). The extracted Cr(III) was finally mineralized with nitric acid and sensitively analyzed by electro-thermal atomic absorption spectrometry. The determinations were carried out on a Varian AA-220 atomic absolution equipped with a GTA-110 graphite atomizer. The results obtained by this method were compared with those obtained by the other reported methods and it was cleared that the proposed method is more precise and able to determine the trace of ascorbic acid. Table shows the results obtained from the determination of ascorbic acid in two real samples by the proposed method and the spectrometric method based on reduction of Fe(III). 

The complex of the following destmctive and nondestmctive analytical methods was used for studying the composition of sponges inductively coupled plasma mass-spectrometry (ICP-MS), X-ray fluorescence (XRF), electron probe microanalysis (EPMA), and atomic absorption spectrometry (AAS). Techniques of sample preparation were developed for each method and their metrological characteristics were defined. Relative standard deviations for all the elements did not exceed 0.25 within detection limit. The accuracy of techniques elaborated was checked with the method of additions and control methods of analysis. 

COMPARISON OF MICROWAVE ASSISTED EXTRACTION METHODS FOR THE DETERMINATION OF PLATINUM GROUP ELEMENTS IN SOIL SAMPLES BY ELECTROTHERMAL ATOMIC ABSORPTION SPECTROMETRY AFTER PHASE SEPARATION-EXTRACTION... 

Direct atomic absorption spectrometry (AAS) analysis of increasing (e 0,10 g) mass of solid samples is the great practical interest since in a number of cases it allows to eliminate a long-time and labor consuming pretreatment dissolution procedure of materials and preconcentration of elements to be determined. Nevertheless at prevalent analytical practice iS iO based materials direct AAS are not practically used. 

Electrothermal vaporization can be used for 5-100 )iL sample solution volumes or for small amounts of some solids. A graphite furnace similar to those used for graphite-furnace atomic absorption spectrometry can be used to vaporize the sample. Other devices including boats, ribbons, rods, and filaments, also can be used. The chosen device is heated in a series of steps to temperatures as high as 3000 K to produce a dry vapor and an aerosol, which are transported into the center of the plasma. A transient signal is produced due to matrix and element-dependent volatilization, so the detection system must be capable of time resolution better than 0.25 s. Concentration detection limits are typically 1-2 orders of magnitude better than those obtained via nebulization. Mass detection limits are typically in the range of tens of pg to ng, with a precision of 10% to 15%. 

Cadmium and inorganic compounds of cadmium in air (X-ray fluorescence spectroscopy) Chromium and inorganic compounds of chromium m air (atomic absorption spectrometry) Chromium and inorganic compounds of chromium m air (X-ray fluorescence spectroscopy) General methods for sampling and gravimetnc analysis of respirable and mhalable dust Carbon disulphide in air... 

Figure 15-12 is a schematic illustration of a technique known as acid volatile sulfides/ simultaneously extracted metals analysis (AVS/SEM). Briefly, a strong acid is added to a sediment sample to release the sediment-associated sulfides, acid volatile sulfides, which are analyzed by a cold-acid purge-and-trap technique (e.g., Allen et ai, 1993). The assumption shown in Fig. 15-12 is that the sulfides are present in the sediments in the form of either FeS or MeS (a metal sulfide). In a parallel analysis, metals simultaneously released with the sulfides (the simultaneously extracted metals) are also quantified, for example, by graphite furnace atomic absorption spectrometry. Metals released during the acid attack are considered to be associated with the phases operationally defined as "exchangeable," "carbonate," "Fe and Mn oxides," "FeS," and "MeS."... 

Micro-pipetting instruments such as the "Eppendorf or "Oxford pipettors with disposable plastic cone tips are customarily employed to dispense the liquid samples into electrothermal atomizers. Sampling problems which are associated with the use of these pipettors are among the troublesome aspects of electrothermal atomic absorption spectrometry (67,75). The plastic cone-tips are frequently contaminated with metals, and they should invariably be cleaned before use by soaking in dilute "ultra pure nitric acid, followed by multiple rinses with demineralized water which has been distilled in a quartz still. 

Cruz, R. B. and Loon, J. C. van "A Critical Study of the Application of Graphite-Furnace Non-Flame Atomic Absorption Spectrometry to the Determination of Trace Base Metals In Complex Heavy-Matrix Sample Solutions". Anal. Chlm. Acta (1974), 72, 231-243. 

Kantor, T., Clybum, S. A., and Velllon, C. "Contlnuoiis Sample Introduction with Graphite Atomization Systems for Atomic Absorption Spectrometry . Anal. Chem. (1974), 46, 2205-2213. 

Nowka R, Muller H (1997) Direct analysis of solid samples by graphite furnace atomic absorption spectrometry with a transversely heated graphite atomizer and D2-background correction system (SS GF-AAS). Fresenius J Anal Chem 359 132-137. 

Pauwels J. De Angelis L, Grobecker KH (1991) Solid sampling Zeeman atomic absorption spectrometry in production and use of certified reference materials. Pure Appl Chem 63 1199-1204. 

Atsuya I, Itoh K, Akatsuka K (1987) Development of direct analysis of powder samples by atomic absorption spectrometry using the inner miniature cup technique. Fresenius Z Anal Chem 328 338-341. 

Backmank S, Karlsson RW (1979) Determination of lead, bismuth, zinc, silver and antimony in steel and nickel-base alloys by atomic-absorption spectrometry using direct atomization of solid samples in a graphite furnace. Analyst 104 1017-1029. 

Hinds MW (1993) Determination of gold, palladium and platinum in high purity silver by different solid sampling graphite furnace atomic absorption spectrometry methods, Spectrochim Acta 48B 435-445. 

Hofmann C, Vandecasteele C, Pauwels ] (1992) New calibration method for solid sampling Zeeman atomic absorption spectrometry (SS-ZAAS) for cadmium. Fresenius J Anal Chem 342 936-940. 

Klemm W, Baumeach G (1995) Trace element determination in contaminated sediments and soils by ultrasonic slurry sampling and Zeeman graphite furnace atomic absorption spectrometry. Fresenius J Anal Chem 353 12-15. 

LtiCKER E, Konig H, Gabriel G, Rosopulo A (1992) Analytical quality control by solid sampling graphite furnace atomic absorption spectrometry in the production of animal tissue reference materials. Fresenius J Anal Chem 342 941-949. 

Pauwels J, Hofmann C, Vandbcasteele C (1994) Calibration of solid sampling Zeeman atomic absorption spectrometry by extrapolation to zero matrix. Fresenius J Anal Chem 348 418-421. 

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