Application of palladium- and rhodium-plating of the graphite furnace in electrothermal atomic absorption spectrometry

Abstract

Palladium-and Rh-plating of the graphite furnace has been evaluated as a method of introducing the metallic form of Pd and Rh for chemical modification in electrothermal atomic absorption spectrometry. It is shown that by electroplating Pd and Rh onto the inner surface of the tube, the pretreated graphite surface may resemble the behaviour of the corresponding modifier. The resulting metallic layer is very effective in inhibiting the loss of volatile elements (e.g., As and Se), as well as reducing the influence of oxide and carbide formation (e.g., Si). The advantage of the proposed procedure of introduction of a solid chemical modifier is that the pretreated tubes exhibit an extended analytical lifetime for the determination of As and Se, up to 80 and 160 firings in the presence of Pd and Rh, respectively. In the case of Si the Rh-plated graphite tube could last for about 100 firings.

Effectiveness of Palladium–Sodium Azide Modifier for the Direct Determination of Urinary Cadmium by Graphite-Furnace Atomic Absorption Spectrometry

“…[13][14][15][16] This probability was also investigated using sodium azide, NaN 3 as a reducing reagent. Under conditions optimized in the presence of 10 µg Pd (ashing, 500˚C; atomization, 1500˚C), the effect of different amounts of sodium azide on the absorbance of cadmium was investigated.…”

“…[7][8][9][10][11][12][13] Recent studies have indicated that the stability effect of palladium for volatile elements is concerned with its metallic form. 9,[13][14][15][16] Therefore, palladium as a modifier is commonly used under reducing conditions. Palladium has been used with several reducing agents together, such as hydrazine, hydroxyl ammin hydrochloride and ascorbic acid.…”

Iridium as a permanent modifier for determination of cadmium and lead in sediment and biological samples by furnace atomization plasma emission spectrometry

“…In such case, the modifier is introduced prior to the analysis by thermodeposition, electrodeposition or sputtering processes [9][10][11] and persists in the atomizer for numerous atomization cycles. For elements such as Pb, the modifying capability of Ir may last beyond 1100 firing cycles, even in the presence of complex matrices such as urine and blood, if the proper coating temperature program is used.…”

Determination of Mercury in Biological Tissues by Graphite-furnace Atomic Absorption Spectrometry with an in-situ Concentration Technique

“…In addition, graphite-furnace atomic absorption spectrometry (GFAAS) was also applied using different chemical matrix modifiers for the determination of a low level of mercury with higher sensitivity and a lower detection limit with various matrix modifiers, [14][15][16] especially when the mercury vapor had been concentrated in the graphite furnace with palladium and palladium-rhodium as an absorbent and matrix modifiers. 16,17 However, the instrumentation and chemical reagent of the GFAAS technique are often expensive.…”