Flame atomic absorption spectrometry FAAS

An analyte transport efficiency of nearly 100% has been obtained with an interface for flame atomic absorption spectrometry (FAAS) [3]. It has been used for the determination of lead in blood [5] and for coupHng with a high-performance Hquid chromatograph (HPLC) [6]. 

Flame atomic absorption spectrometry (FAAS) can be used to detect most elements present at levels greater than about 100 pg 1 . For more sensitive determinations graphite furnace atomic absorption spectrometry (GFAAS) is the technique of choice. In addition, if the volume of the fraction is limited GFAAS is ideally suited for the determination because only a few microfitres (5-20 pi) of sample... 

Hydride generation for analytical use was introduced at the end of the 1960s using arsine formation (Marshal Reaction) in flame atomic absorption spectrometry (FAAS). A simple experimental setup for a hydride generator is shown in Figure 5.18. Today, hydride generation,91,92 which is the most widely utilized gas phase sample introduction system in ICP-MS, has been developed into... 

Atomic spectrometric methods Here, the entire sample is atomized or ionized either by flame or inductively coupled plasma and transferred into the detector. The most common techniques in this class are flame atomic absorption spectrometry (FAAS) and inductively coupled plasma mass spectrometry (ICPMS). A general characteristic of these methods is the determination of the total concentration of the analyte without the direct possibility of distinguishing its specific forms in the sample. 

Tawali, A.B. and Schwedt, G. (1997) Combination of solid phase extraction and flame atomic absorption spectrometry (FAAS) for differentiated analyses of labile iron (II) and iron (III) species. Fresenius J. Anal. Chern., 357, 50-55. 

Spectrometric techniques based on atomic absorption or the emission of radiation flame atomic absorption spectrometry (FAAS), electrothermal atomic absorption spectrometry (ETAAS), inductively coupled plasma-optical emission spectrometry (ICP-OES), inductively coupled plasma-mass spectrometry (ICP-MS), and cold vapor (CV)/hydride generation (HG), mainly for trace and ultratrace metal determinations. 

Protein Precipitation Procedures involving protein precipitation with trichloroacetic acid for Cu, Fe, and Zn have been developed for flame atomic absorption spectrometry (FAAS) determinations in body fluids [20, 21]. The physical separation of caseins and fat from milk whey can also be achieved using centrifugation at 30,000g. 

The most widely used spectrochemical methods are flame atomic absorption spectrometry (FAAS), electrothermal atomization atomic absorption spectrometry (ETA-AAS), and inductively coupled plasma atomic emission spectrometry (ICP-AES). Some work has been performed using inductively coupled plasma mass spectrometry (ICP-MS) and the unique properties of Hg have allowed the use of cold vapor (CV) A AS. It is beyond the scope of this chapter to describe these well-established and well-accepted spectrochemical techniques. The reader is referred to several excellent texts which describe in detail the basic principles, instrumentation, and method development of these analytical techniques [1-4]. The most toxic elements, such as As, Cd, Cr, Pb, and particularly Hg have been the most widely studied. Other metals, such as Ba, Cu, Fe, Mn, V, and Zn, have also been investigated. 

Since some form of liquid sample presentation is common to most atomic spectrometric techniques, these may be considered as the method of choice for the identification and quantification of trace metals in liquid foods. In spectrometric techniques, after conversion of the sample into microspray, chemical flames as in flame atomic absorption spectrometry (FAAS) and atomic... 

The disadvantages of electrothermal atomisation (ETA) — atomic absorption spectrometry (AAS) are the physical, chemical and spectral interferences, these being more severe than with flame atomic absorption spectrometry (FAAS), and which depend critically upon the experimental and operational conditions within the atomiser and the nature of the chemical pretreatment used. It is not intended to discuss here the theoretical aspects of these interferences which have been reviewed excellently elsewhere [2], but it is pertinent to consider briefly how these interferences affect the various stages of the analysis and how they may be minimised. 

For the analytical determination of metals (Cd, Cu, Fe, Mn, Pb and Zn) in surface sediments, suspended particulate matter and biological matrices, digestion with a 3 1 HNO3-HCIO4 mixture under controlled temperature was used (36). Analysis of sediments and suspended particulate matter were made by Flame Atomic Absorption Spectrometry (FAAS) with air-acetylene flame and deuterium background correction. The analysis of metals in lichens and molluscs were performed by ICP-AES. The operating conditions for FAAS and Inductively Coupled Plasma Atomic Emission Spectrometry (ICP-AES) analysis are shown in Tables 6.1 and 6.2, respectively. 

Flame Atomic Absorption Spectrometry (FAAS) Electrothermal Atomic Absorption Spectrometry (ETAAS) e.g. Graphite Furnace Atomic Absorption Spectrometry (GFAAS) Inductively Coupled Plasma Optical Emission Spectrometry (ICP-OES) Inductively Coupled Plasma Mass Spectrometry (ICP-MS) Anodic Stripping Voltammetry (ASV)... 

Many of the analytical methods for detecting vanadium in biological samples have also been used to measure vanadium in environmental samples. They are detailed in Table 6-2. These include GFAAS, spectrophotometry, IDMS, and ICP-AES. Other techniques employed for measuring vanadium in environmental samples are flame atomic absorption spectrometry (FAAS) and direct current plasma- atomic emission spectrometry (DCP-AES). The most widely used methods utilize some modification of atomic absorption spectrometry (AAS). In general, similar methods are employed for preparation and clean up of environmental and biological samples prior to quantification of vanadium (see Section 6.1). 

For the homogeneity and stability studies, the trace element contents (Cd, Cr, Cu, Ni, Pb and Zn) were determined by flame atomic absorption spectrometry (FAAS) or electrothermal atomic absorption spectrometry with Zeeman background correction (ZETAAS), strictly following the sequential extraction procedure. Differences between the within-bottle and between-bottle CVs observed for the step 2 were considered to be rather an analytical artefact than an indication of inhomogeneity which would have been reflected in the spread of results submitted in the certification. The material is then considered to be homogeneous for the stated level of intake (1 g). 

For the homogeneity studies, the extractants (0.05 mol L EDTA, 0.43 mol L" acetic acid and 0.005 mol L DTPA) were prepared as laid out in the certification reports [15, 17], The trace element contents (Cd, Cr, Cu, Ni, Pb and Zn) in the extracts were determined by inductively coupled plasma atomic emission spectrometry (ICP-AES) for the CRMs 483/484, flame atomic absorption spectrometry (FAAS) or electrothermal atomic absorption spectrometry with Zeeman background correction (ZETAAS) for the CRM 600. In the case of the CRM 483, little analytical difficulty was experienced as illustrated by the good agreement obtained between the within-bottle and between-bottle CVs for the CRM 484, lower extractable contents, closer to the detection limits and consequent poorer analytical precision was observed in particular for Cr (EDTA extractable contents), Cd and Pb (acetic acid extractable contents). No particular difficulties were experienced for the CRM 600. On the basis of these results, the materials were considered to be homogeneous at a level of 5 g for EDTA- and acetic acid-extractable contents and 10 g for DTPA-extractable contents (as specified in the extraction protocols). 

The choice of an analytical method depends on its performance characteristics (detection limits, accuracy and precision, speed etc). Other conditions to be reached are the concerned element, the concentration in the sample of interest, the variability of their concentration. The concentration of metal ions in studied Seaside Lakes were determined by flame atomic absorption spectrometry (FAAS) (Chirila et al., 2003a), inductively coupled plasma atomic emission spectrometry (ICP-AES) (Chirila et al., 2002), molecular absorption spectrometry in visible (Chirila and Carazeanu, 2001). These investigations were carried out in the biotope (sediment and water) and biocenosis (different plants and fish) from one ecosystem (Tabacarie Lake) and in water samples from the other Seaside lakes. 

Flame atomic absorption spectrometry (FAAS) is used primarily for liquids. The sample is converted into an aerosol by the nebuliser, atomised to free atoms, mixed with the combustible gases and ignited in the flame, which can rise to a temperature of 2600 °C. A long burner is used to increase the pathlength. The most commonly used flames are air-acetylene and nitrous oxide-acetylene mixtures. 

Atomic absorption spectrometry, belonging to a class of techniques also defined as optical atomic spectrometry, has been for some four decades - and continues to be - one of the most important, dominant determinative techniques. It includes flame atomic absorption spectrometry (FAAS), electrothermal atomization atomic absorption spectrometry (ETAAS) (including graphite furnace AAS (GFAAS), carbon rod AAS, tantalum strip AAS), and gaseous generation (cold vapor AAS for Hg, hydride gener-... 

---