Experience of designing and using crucible electrothermal atomizers for the atomic absorption analysis of solid samples

Sample preparation in crucible atomizers for determining cadmium and lead in natural water by atomic absorption

“…(1) Preconcentration in a microcolumn crucible on a DETATA sorbent, (2) preconcentration on a DETATA sorbent in a static mode (* under field conditions after collecting of samples, ** in a stationary laboratory, and *** estimation from the results of analyzing sus pended matter). [10]. Relative standard deviation of the results of determination usually lies in the range of 0.1-0.3, which is satisfactory for the purposes of environmental analytical control and geochemistry investigations.…”

“…1) are applicable for implementing two consecutive stages of sample preparation [10,11]. The dynamic preconcentration of elements and the sepa ration of suspended matter was carried out in graphite microcolumn crucibles (a height of 7.5-12 mm and an inner diameter of 2-3 mm) with microholes in the bottom and a graphite (or graphite + membrane) filter ( Fig.…”

“…Ele ments were preconcentrated and suspended matter was separated from unfiltered samples in a microcol umn crucible established in a specially equipped accommodation on the river bank (about 0.5 m from the river bank) both immediately after sample collec tion and in a stationary laboratory. The experience of dynamic preconcentration in microcolumn crucibles [9,10] was taken into account. A crucible holder of organic glass was mounted at a table.…”

“…Various techniques were used; i.e., the mode of preliminary sample thermal treat ment (ashing) was optimized, elements were evapo rated to an isothermal atomizer analytical zone, the rate of heating was increased, modifying reagents were added in an atomizer, pairs of elements were filtered off with graphite filters, and elements were selectively evaporated and condensed in an atomizer. The effi ciency of the analysis of complex organomineral con centrates and suspended matter with preliminary ther mal decomposition, and the selective fractional evap oration condensation of elements in an atomizer was shown [10,11]. The technique of selective separation concentration of elements, which was proposed long ago in the atomic emission method [4,12], has been employed in recent years for the AA analysis of sam ples with a complex composition.…”

“…The most promising technique is to obtain concentrates directly in the atomizer; under laboratory conditions, elements are concentrated on a solid diethylenetri amine tetraacetate (DETATA) sorbent and suspended matter is separated from water and solution samples in a microcolumn crucible. Next, the sample preparation is continued with the simultaneous application of sev eral techniques for suppressing the effect of the matrix components [9,10].…”