Transverse heated filter atomizer: atomic absorption spectrometric determination of Pb and Cd in whole blood

Abstract

A transverse heated filter atomizer (THFA) was applied to the direct determination of Cd and Pb in blood, and its analytical performances were investigated using a Perkin Elmer SIMAA 6000 atomic absorption spectrometer. Seronorm human blood reference materials (RM) and samples of bovine whole blood spiked with Pb were used for the method validation. The blood samples diluted 5 or 10 times with water to reduce their viscosity were injected in the THFA at temperature about 110-120 1C together with blank or analyte solution in 0.2% HNO 3 . Compared to the transverse heated graphite atomizer with a platform (THGA), the THFA provided significant reduction of non-specific background absorption and more than 90% recovery of Cd and Pb, without the use of chemical modifiers. The 'hot' sampling and injection of ethanol together with the blood solution improved repeatability of analytical signals. Periodical cleaning at elevated temperature after each 15-20 measurements prevented building up of solid residues in the THFA cavity. Limits of detection achieved for Cd and Pb were 0.05 and 1 mg L À1 , respectively.

Feasibility of filter atomization in high-resolution continuum source atomic absorption spectrometry

“…Taking into account this assumption, the investigation of analytical performances of the GFA in this work was undertaken using 40 mg of carbon fiber as collector. An examination of other than carbon fiber materials for collectors [20][21][22][23][24] was beyond the scope of this research. …”

“…According to the information dispersed in [16][17][18][19][20][21][22][23][24], erosion of the components can affect analytical performances and lifetime of the GFA. Apart from high atomization or cleaning temperatures, aggressive action of steam during hot drying and that of sample matrix during the pyrolysis and atomization steps can be expected [21].…”

“…Optical arrangement of the line source based AA instruments employed earlier with filter atomization [15][16][17][18][19][20][21][22][23][24] place rigorous restrictions on both parameters. Light losses due to reduced aperture of the light beam and intense radiation from the filter at high temperatures caused increase of noise from the photo detectors and, respectively, limited opportunities for the determination of less volatile elements.…”

“…Filter atomization in conventional AAS based on line sources was used as alternative to the traditional platform tube technique for the direct determination of high and medium volatile elements in samples associated with strong spectral and chemical interferences [11][12][13][14][15][16][17][18][19][20][21][22][23][24]. It provided reduction of interferences without involvement of chemical modifiers and the possibility for using larger sampling volumes of organic or inorganic liquids, while keeping the temperature program short.…”

“…It provided reduction of interferences without involvement of chemical modifiers and the possibility for using larger sampling volumes of organic or inorganic liquids, while keeping the temperature program short. Analytical characteristics of the transversely heated filter atomizer (THFA) have been verified in the analysis of organic extracts [18], fuels [19] and biological samples [20][21][22][23][24]. The atomizers were produced modifying commercial transversely heated graphite atomizers (Perkin Elmer) by furnishing the tube with filter and collector, instead of a platform.…”