Flow injection-flame atomic

S. Cancela and M. C. Yebra, Flow-injection flame atomic absorption spectrometric determination of trace amounts of cadmium in solid and semisolid milk products coupling a continuous ultrasound-assisted extraction system with the online preconcentration on a chelating ami-nomethylphosphoric acid resin, J. AO AC Int., 89(1), 2006, 185-191. 

M. C. Yebra, S. Cancela and A. Moreno-Cid, Continuous ultrasound-assisted extraction of cadmium from vegetable samples with on-line preconcentration coupled to a flow injection-flame atomic spectrometric system, Int. J. Environ. Anal. Chem., 85(4-5), 2005, 305-313. 

M. C. Yebra-Biurrun, A. Moreno-Cid and L. Puig, Minicolumn field preconcentration and flow-injection flame atomic absorption spectrometric determination of cadmium in seawater, Anal. Chim. Acta, 524(1-2), 2004, 73-77. 

Fang Z. I. and Welz B. (1989) Optimisation of experimental parameters for flow injection flame atomic absorption spectrometry, J Anal At Spectrom 4 83-89. 

Arskan Z, Tyson JF. 1999. Determination of calcium, magnesium and strontium in soils by flow injection flame atomic absorption spectrometry. Talanta 50 929-937. 

I. Lopez Garcia, P. Vifias, N. Campillo, M. Hernandez Cordoba, Use of submicroliter-volume samples for extending the dynamic range of flow injection flame atomic absorption spectrometry, Anal. Chim. Acta 308 (1995) 85. 

For blood analysis, the use of matrix-matched standards is an efficient strategy to compensate for the influence of viscosity, as emphasised by Rocks and co-workers, who determined zinc and copper in blood serum by flow injection flame atomic absorption spectrometry [63]. Another possibility is to exploit the standard addition method, since different viscosities can also cause a matrix effect. This approach was demonstrated by Harrow and Janata in the potentiometric evaluation of pH in blood serum [64], where the effects of sample viscosity and the presence of solid particles were successfully compensated. 

Vinas P, Campillo N, Garcia IL and Cordoba MH (1993b) Flow-injection flame atomic absorption spectrometry for slurry atomization. Determination of calcium, magnesium, iron and manganese in vegetables. Anal Chim Acta 283 393-400. 

Fast Fourier Transform Flow Injection Analysis Field Ion Atom Probe Flame-Ionization Detector Field Ion Microscopy... 

Olsen et al. [660] used a simple flow injection system, the FIAstar unit, to inject samples of seawater into a flame atomic absorption instrument, allowing the determination of cadmium, lead, copper, and zinc at the parts per million level at a rate of 180-250 samples per hour. Further, online flow injection analysis preconcentration methods were developed using a microcolumn of Chelex 100 resin, allowing the determination of lead at concentrations as low as 10 pg/1, and of cadmium and zinc at 1 pg/1. The sampling rate was between 30 and 60 samples per hour, and the readout was available within 60-100 seconds after sample injection. The sampling frequency depended on the preconcentration required. 

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. 

A number of applications of flow-injection techniques have been made to flame atomic absorption spectrometry [22]. Although manifolds can be connected directly to the nebuhzer, the response of the spectrometer is dependent on the flow rate of the sample into the nebuhzer [23], and some adjustment to the manifold may be required. The optimum flow rate for maximum response when the sample enters the nebuhzer as a discrete sample plug can be different from that found for analysis of a continuous sample stream. 

Various methods ofachieving preconcentration have been applied, including Hquid -hquid extraction, precipitation, immobihzation and electrodeposition. Most of these have been adapted to a flow-injection format for which retention on an immobihzed reagent appears attractive. Sohd, sihca-based preconcentration media are easily handled [30-37], whereas resin-based materials tend to swell and may break up. Resins can be modified [38] by adsorption of a chelating agent to prevent this. Sohds are easily incorporated into flow-injection manifolds as small columns [33, 34, 36, 39, 40] 8-quinolinol immobilized on porous glass has often been used [33, 34, 36]. The flow-injection technique provides reproducible and easy sample handhng, and the manifolds are easily interfaced with flame atomic absorption spectrometers. 

A. Moreno-Cid and M. C. Yebra, Flow injection determination of copper in mussels by flame atomic absorption spectrometry after on-line continuous ultrasound-assisted extraction, Spectrochim. Acta, Part B, 57(5), 2002, 967-974. 

Sperling, M., Xu, S. and Welz, B. (1992) Determination of chromium (III) and chromium (VI) in water using flow injection on-line preconcentration with selective adsorption on activated alumina and flame atomic absorption spectrometric detection. Anal. Chem., 64, 3101-3108. 

Notes HG-AAS, Aydride generation atomic absorption spectrometry HG-AFS, /tydride generation atomic fluorescence spectrometry FI-CV-AAS, flow-injection cold-vapor atomic absorption spectrometry FAAS,flame atomic absorption spectrometry GF-AAS, graphite furnace atomic absorption spectrometry and ET-AAS, electrothermal atomic absorption spectrometry. 

Belal et al [40] reported on the use of flame atomic absorption spectroscopy (FAAS), coupled with ion-exchange, to determine EDTA in dosage forms. EDTA is complexed with either Ca(II) or Mg(II) at pH 10, and the excess cations retained on an ion-exchange resin. At the same time, the Ca(II) or Mg(III) EDTA complexes are eluted and determined by AAS. Calibration curves were found to be linear over the range of 4-160 and 2-32 pg/mL EDTA when using Ca(II) or Mg(II), respectively. The method could be applied to eye drops and ampoules containing pharmaceuticals. Another combined AAS flow injection system was proposed for the determination of EDTA based on its reaction with Cu(II). The calibration curve was linear over the range of 5-50 pg/mL, with a limit of detection of 0.1 pg/mL [41]. 

Qiao-Yun Ye, Yan Li Jiang, Xiu-Ping Yan, Determination of trace cadmium in rice by flows injection on-line filterless precipitation-dissolution preconcentration coupled with flame atomic absorption spectrometry, J. Agric. Food Chem., 51 (2003), 2111-2114. 

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. 

H. J. Salacinski, P. G. Riby, S. J. Haswell, Coupled flow-injection analysis-flame atomic absorption spectrometry for the quantitative determination of aluminum in beverages and waters incorporating on-line cation exchange, Anal. Chim. Acta, 269 (1992), 1-7. 

Tyson, J.F., Bysouth, S.R. Network flow injection manifolds for sample dilution and calibration in flame atomic absorption spectrometry. J. Anal. At. Spectrom. 3, 211-215 (1988)... 

The earliest work reported in this field was by Burguera et al. [103], who applied a flow injection system for on-line decomposition of samples and determined metals (Cu, Fe, Zn) by flame atomic absorption spectroscopy (F-AAS). The methodology involved the synchronous merging of reagent and sample, followed by decomposition of serum, blood, or plasma in a Pyrex coil located inside the microwave oven. This approach permits essentially continuous sample decomposition, drastically reduces sample processing time, and is suitable for those samples that require mild decomposition conditions (especially liquids). 

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