Electrothermal atomizer

3 Electrothermal Atomizers. In principle, electrothermal atomization is a very suitable method for AFS since, when an inert gas atmosphere is used, the fluorescence quenching will be minimized without losing atomization efficiency. On the other hand, the strong background emission of the hot graphite tube will decrease the signal/noise ratio. [Pg.211]

In electrothermal AFS two techniques have been used for sample introduction (i) the total sample is injected into the atomizer, or (ii) the sample as an aerosol is introduced continuously into the atomizer. In the first case, a multistep temperature programme is employed as in GF-AAS. In the latter case, the sample is first led to a spray chamber and then to a graphite furnace atomizer. [Pg.211]

Several different electrothermal atomizers such as carbon rod, graphite ribbon, graphite furnace, and metal loop atomizers, have been designed for AFS measurements. In general, the electrothermal atomization method is time-consuming and expensive with respect to flame atomization. It is, thus, appropriate to use electrothermal atomization only when the sample amount or analyte concentration restrict the use of flames or plasmas. [Pg.211]

Modern graphite furnace atomizers have a separate power supply and programmer that control the electrical power, the temperature program, the gas flow, and some spectrometer functions. For example, the spectrometer can be programmed to read, that is, collect absorbance data, only when the furnace reaches the atomization temperature. This saves data storage space and data processing time. [Pg.453]

Researchers have developed other types of ETAs over the years, including filaments, rods, and ribbons of carbon, tantalum, tungsten, and other materials, but the only commercial ETA available is the graphite furnace atomizer. [Pg.453]

Element Wavelength, nm Flame emission Flame atomic absorption Electrothermal atomic absorption Argon ICP Plasma atomic fluorescence... [Pg.718]

The section on Spectroscopy has been retained but with some revisions and expansion. The section includes ultraviolet-visible spectroscopy, fluorescence, infrared and Raman spectroscopy, and X-ray spectrometry. Detection limits are listed for the elements when using flame emission, flame atomic absorption, electrothermal atomic absorption, argon induction coupled plasma, and flame atomic fluorescence. Nuclear magnetic resonance embraces tables for the nuclear properties of the elements, proton chemical shifts and coupling constants, and similar material for carbon-13, boron-11, nitrogen-15, fluorine-19, silicon-19, and phosphoms-31. [Pg.1284]

Atomization The most important difference between a spectrophotometer for atomic absorption and one for molecular absorption is the need to convert the analyte into a free atom. The process of converting an analyte in solid, liquid, or solution form to a free gaseous atom is called atomization. In most cases the sample containing the analyte undergoes some form of sample preparation that leaves the analyte in an organic or aqueous solution. For this reason, only the introduction of solution samples is considered in this text. Two general methods of atomization are used flame atomization and electrothermal atomization. A few elements are atomized using other methods. [Pg.412]

An electrothermal atomizer that relies on resistive heating to atomize samples. [Pg.414]

Electrothermal Atomizers A significant improvement in sensitivity is achieved by using resistive heating in place of a flame. A typical electrothermal atomizer, also known as a graphite furnace, consists of a cylindrical graphite tube approximately... [Pg.414]

Atomic absorption using either flame or electrothermal atomization is widely used for the analysis of trace metals in a variety of sample matrices. Using the atomic absorption analysis for zinc as an example, procedures have been developed for its determination in samples as diverse as water and wastewater, air, blood, urine, muscle... [Pg.415]

Ionization interferences occur when thermal energy from the flame or electrothermal atomizer is sufficient to ionize the analyte... [Pg.420]

When possible, a quantitative analysis is best conducted using external standards. Unfortunately, matrix interferences are a frequent problem, particularly when using electrothermal atomization. Eor this reason the method of standard additions is often used. One limitation to this method of standardization, however, is the requirement that there be a linear relationship between absorbance and concentration. [Pg.420]

Scale of Operation Atomic absorption spectroscopy is ideally suited for the analysis of trace and ultratrace analytes, particularly when using electrothermal atomization. By diluting samples, atomic absorption also can be applied to minor and major analytes. Most analyses use macro or meso samples. The small volume requirement for electrothermal atomization or flame microsampling, however, allows the use of micro, or even ultramicro samples. [Pg.422]

Accuracy When spectral and chemical interferences are minimized, accuracies of 0.5-5% are routinely possible. With nonlinear calibration curves, higher accuracy is obtained by using a pair of standards whose absorbances closely bracket the sample s absorbance and assuming that the change in absorbance is linear over the limited concentration range. Determinate errors for electrothermal atomization are frequently greater than that obtained with flame atomization due to more serious matrix interferences. [Pg.422]

Precision For absorbances greater than 0.1-0.2, the relative standard deviation for atomic absorption is 0.3-1% for flame atomization, and 1-5% for electrothermal atomization. The principal limitation is the variation in the concentration of free-analyte atoms resulting from a nonuniform rate of aspiration, nebulization, and atomization in flame atomizers, and the consistency with which the sample is heated during electrothermal atomization. [Pg.422]

Gran plot a linearized form of a titration curve, (p. 293) graphite furnace an electrothermal atomizer that relies on resistive heating to atomize samples, (p. 414) gravimetry any method in which the signal is a mass or change in mass. (p. 233)... [Pg.773]

Miscellaneous. Trace analyses have been performed for a variety of other materials. Table 9 Hsts some uses of electrothermal atomic absorption spectrometry (etaas) for determination of trace amounts of elements in a variety of matrices. The appHcations of icp /ms to geological and biological materials include the following (165) ... [Pg.251]

ELECTROTHERMAL ATOMIZATION IN GRAPHITE FURNACE A KINETIC MODEL WITH TWO INDEPENDENT SOURCES... [Pg.105]

INDIRECT DETERMINATION OF ASCORBIC ACID BY ELECTROTHERMAL ATOMIC ABSORPTION SPECTROMETRY... [Pg.154]

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... [Pg.290]

The development of methods using sorbents modified with analytical reagents that enable analytical signal measuring directly on the surface by solid-phase spectrometry, visually or by electrothermic atomic absorption spectroscopy (ETAAS) after elution is now a subject of growing interest. [Pg.292]

ACTING MECHANISM OF INORGANIC CHEMICALS MODIFIERS IN ELECTROTHERMAL ATOMIC ABSORPTION... [Pg.414]

Lead in soil slurries Electrothermal atomic absorption spectrometry... [Pg.318]

Tetra-alkyl lead compounds in air Personal monitoring with atomic absorption analysis or electrothermal atomization or X-ray fluorescence spectrometry or on-site colorimetry 9... [Pg.363]

Electrothermal Atomic Absorption Spectrometry of Trace Metals in Biological Fluids... [Pg.248]

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