Is palladium or palladium–ascorbic acid or palladium–magnesium nitrate a more universal chemical modifier for electrothermal atomic absorption spectrometry?

A comprehensive comparison was made between the performances of Pd, Pd–ascorbic acid and Pd–Mg(NO3)2 for the determination of Ag, As, Au, Bi, Cd, Ga, Ge, Hg, In, Mn, Pb, Sb, Se, Sn, Te and Tl in terms of charring temperatures available, characteristic mass values, background absorption, permissible interference range, capability of improving the atomization signal shapes and relative standard deviations of the determinations of trace elements in real samples. Generally, the performances of Pd, Pd–ascorbic acid and Pd–Mg are similar, except that the background absorption of the Pd–Mg modifier is 1–2 orders of magnitude greater than that of the Pd and Pd–ascorbic acid modifiers. Therefore, the need for the addition of ascorbic acid appears to be matrix-dependent, while the addition of Mg(NO3)2 is not recommended.