Flow injection systems atomic spectrometry

Fang et al. [661] have described a flow injection system with online ion exchange preconcentration on dual columns for the determination of trace amounts of heavy metal at pg/1 and sub-pg/1 levels by flame atomic absorption spectrometry (Fig. 5.17). The degree of preconcentration ranges from a factor of 50 to 105 for different elements, at a sampling frequency of 60 samples per hour. The detection limits for copper, zinc, lead, and cadmium are 0.07, 0.03, 0.5, and 0.05 pg/1, respectively. Relative standard deviations are 1.2-3.2% at pg/1 levels. The behaviour of the various chelating exchangers used was studied with respect to their preconcentration characteristics, with special emphasis on interferences encountered in the analysis of seawater. 

S. Rio Segade and J. F. Tyson, Determination of methylmercury and inorganic mercury in water samples by slurry sampling cold vapor atomic absorption spectrometry in a flow injection system after preconcentration on silica C18 modified, Talanta, 71(4), 2007, 1696-1702. 

Burguera, J.L., M. Burguera, and C.E. Rondon. 1998. Automatic determination of iron in geothermal fluids containing high dissolved sulfur-compounds using flow injection electrothermal atomic absorption spectrometry with an on-line microwave radiation precipitation-dissolution system. Anal. Chim. Acta 366 295-303. 

R. M. Cespon Romero, M. C. Yebra-Biurrun, M. P. Bermejo-Barrera, Preconcentration and speciation of chromium by the determination of total chromium(III) in natural waters by flame atomic absorption spectrometry with a chelating ion-exchange flow injection system, Anal. Chim. Acta, 327 (1996), 37-45. 

S. R. Segade, J. F. Tyson, Evaluation of two flow injection systems for mercury speciation analysis in fish tissue samples by slurry sampling cold vapor atomic absorption spectrometry, J. Anal. Atom. Spectrom., 18 (2003), 268-273. 

B.F. Reis, M.F. Cine, F.J. Krug, H. Bergamin-Filho, Multipurpose flow-injection system. Part 1. Programmable dilutions and standard additions for plant digests analysis by inductively coupled plasma atomic emission spectrometry, J. Anal. At. Spectrom. 7 (1992) 865. 

N.V. Semenova, L.O. Leal, R. Forteza, V. Cerda, Multisyringe flow-injection system for total inorganic arsenic determination by hydride generation-atomic fluorescence spectrometry, Anal. Chim. Acta 455 (2002) 277. 

A.O. Jacintho, E.A.G. Zagatto, H. Bergamin-Filho, F.J. Krug, B.F. Reis, R.E. Bruns, B.R. Kowalski, Flow injection systems with inductively-coupled argon plasma atomic emission spectrometry. Part 1. Fundamental considerations, Anal. Chim. Acta 130 (1981) 243. 

A.M.R. Ferreira, A.O.S.S. Rangel, J.L.F.C. Lima, Flow injection systems with stream splitting and a dialysis unit for the soil analysis of sodium and potassium by flame emission spectrometry, and calcium and magnesium by atomic absorption spectrophotometry, Commun. Soil Sci. Plant Anal. 26 (1995) 1532. 

In-line filtration without a filtering element is also feasible. To this end, a three-dimensional reactor [299], also called a knitted or knotted reactor (see 6.2.3.4), can be used, as emphasised in the landmark article reporting the flow injection determination of lead in blood and bovine liver by flame atomic absorption spectrometry [300]. The analyte was co-precipitated the complex formed was retained on the inner walls of a knitted reactor and then released by isobutyl methyl ketone and transported to the detector. Interference from iron(III) at high concentrations was circumvented, sensitivity was markedly improved and precise results were obtained. This innovation was recently exploited to remove organic selenium and determine the speciation of inorganic selenium in a flow-injection system with atomic fluorescence spectrometric detection [301]. 

C.A. Giacomozzi, R.R.U. Queiroz, I.G. Souza, J.A. Gomes-Neto, High current-density anodic electro-dissolution in flow-injection systems for the determination of aluminium, copper and zinc in non-ferroalloys by flame atomic absorption spectrometry, J. Autom. Method. Manag. Chem. 21 (1999) 17. 

Enriquez-Dominguez me, Yebra-Biurrun MC and Bermejo-Barrera MP (1998) Determination of cadmium in mussels by flame atomic absorption spectrometry with preconcentration on a chelating resin in a flow injection system. Analyst (London) 123 105-108. 

Gluodenis TJ and Tyson JF (1992) Flow injection systems for directly coupling on-line digestions with analytical atomic spectrometry. Part 1. Dissolution of cocoa under stopped-fiow, high-pressure conditions. J Anal Atom Spectrom 7 301-306. 

N. Yoza, Y. Aoyagi, S. Ohashi, and A. Tateda, Flow Injection System for Atomic Absorption Spectrometry. Anal. Chim. Acta, 111 (1979) 163. 

E. A. G. Zagatto, A. O. Jacintho, F. J. Krug, B. F. Reis, R. E. Bruns, and M. C. U. Araujo, Flow Injection Systems with Inductively-Coupled Argon Plasma Atomic Emission Spectrometry. Part 2. The Generalized Standard Addition Method. Anal, Chim. Acta, 145 (1983) 169. 

F. Malamas, M. Bengtsson, and G. Johansson, On-Line Trace Metal Enrichment and Matrix Isolation in Atomic Absorption Spectrometry by a Column Containing Immobilized 8-Quinolinol in a Flow Injection System. Anal. Chim. Acta, 160 (1984) 1. 

E. B. Milosavljevic, J. R04i5ka, and E. H. Hansen, Simultaneous Determination of Free and EDTA-Complexed Copper Ions by Flame Atomic Absorption Spectrometry with an Ion-Exchange Flow-Injection System. Anal. Chim. Acta, 169 (1985) 321. 

E. B. Milosavljevic, L. Solujic, J. H. Nelson, and J. L. Hendrix, Simultaneous Determination of Chromium(VI) and Chromium(III) by Flame Atomic Spectrometry with a Chelating Ion-Exchange Flow Injection System. Mikrochim. Acta, III (1985) 353. 

Correct design and downscaling of the normal flow injection system allow the incorporation of a variety of analytical techniques for the detection of different chemical species. Electrothermal atomic absorption spectrometry (Wang and Chen, 2008), inductively couple plasma atomic emission spectroscopy or mass spectrometry (Wang and Hansen, 2001), electrospray ionization mass spectrometry (Ogata et al., 2002, 2004), and chro-matographic/electrophoretic column separation systems coupled to UV-Vis or mass spec-trometric detection (Wu et al., 2003 Quintana et al., 2006) are among the detection and separation systems that have been coupled with flow injection devices. 

M. C. Yebra and A. Moreno-Cid, Optimisation of a field flow preconcentration system by experimental design for the determination of copper in sea water by flow-injection-atomic absorption spectrometry, Spectrochim. Acta, Part B, 57(1), 2002, 85-93. 

Cobo-Fernandez, M.G., Palacios, M.A. and Camara, C. (1993) Flow-injection and continuous-flow systems for the determination of Se (VI) and Se (IV) by hydride generation atomic absorption spectrometry with on-line prereduction of Se (IV) to Se (VI). Anal. Chim. Acta, 283, 386-392. 

Fernandez, C., A.C.L. Conceicao, R. Rial-Otero, C. Vaz, and J.L. Capelo. 2006. Sequential flow injection analysis system on-line coupled to high intensity focused ultrasound Green methodology for trace analysis applications as demonstrated for the determination of inorganic and total mercury in waters and urine by cold vapor atomic absorption spectrometry. Anal. Chem. 78 2494-2499. 

Boron, Li, Mo, Pb, and Sb were determined in the standard mode, while Al, Cd, Co, Ni, Mn, Rb, Sb, Sn, and V were determined in the DRC mode. The determination of Ni was done with a gas flow of 0.15 ml min-1 of CH4, while for the other elements NH3 was used as cell gas at 0.4 ml min-1. The determination of Se by flow injection hydride generation atomic absorption spectrometry (FI-HG-AAS) was carried out by means of the Perkin-Elmer FLAS 200 system, equipped with the Perkin-Elmer autosampler AS-90, and connected to an electrically heated quartz cell installed on a PerkinElmer absorption spectrometer AAS 4100. The analytical conditions are given in Table 10.3. 

Z.-L. Fang, M. Sperling, B. Welz, Comparison of three propulsion systems for application in flow-injection zone penetration dilution and sorbent extraction preconcentration for flame atomic absorption spectrometry, Anal. Chim. Acta 269 (1992) 9. 

Pyrolysis can also be used in flow-based determinations with electrothermal atomic absorption spectrometry, as demonstrated in the determination of nickel in environmental and biological reference materials using a sequential injection system with renewable beads [313]. After analyte sorption, the beads were directed towards the furnace of the spectrometer and stopped there pyrolysis was accomplished as usual in order to release the analyte and destroy the beads. This innovation has often been exploited in the lab-on-valve system, but spectrophotometric applications have not been proposed to date. 

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