Characterization of a multimode sample introduction system (MSIS) for multielement analysis of trace elements in high alloy steels and nickel alloys using axially viewed hydride generation ICP-AES

Abstract

A commercial multimode sample introduction system (MSIS) was characterized for simultaneous multielement hydride and nonhydride-forming elements (As, Bi, Co, Cr, Fe, Mn, Mo, Ni, Sb, Se, Sn, Ti, V, W) in high alloy steels and nickel alloys by axially viewed ICP-AES. Vapor formed by the NaBH 4 reaction and aerosol from a specially designed dual conical spray chamber and pneumatic nebulizer were injected simultaneously into a robust plasma. Spectroscopic effects caused by major and minor elements and nonspectroscopic interferences induced by matrix concomitants were evaluated both for conventional nebulization and for hydride generation. The objective of the study was to establish optimized operating conditions whereby both nonhydride and hydride forming elements could be determined simultaneously. It was observed that the sensitivities of the 'hydride generating' elements using a MSIS, were similar to those observed using conventional hydride generation. In comparison to conventional pneumatic nebulization, hydride LODs, were enhanced significantly by factors varying from about 2-20. Limits of detection using the MSIS, for nonhydride elements (Co, Cr, Fe, Mn, Mo, Ni, Ti, V, W) were similar to those reported for the conventional sample introduction system. Several fundamental parameters such as Mg II 280.270/Mg I 285.213 nm ratios, excitation temperature (T ex ) and the effect of hydrogen were also determined. The effect of hydrogen, formed during hydride generation, on intensities of nonhydride and hydride forming elements and excitation temperature was evaluated. This is important because hydrogen can modify the properties of the ICP. The effect of variable concentrations of tartaric acid, L-cystein, EDTA, and 1,1,3,3-tetramethy-2-thiourea as retarding agents for reducing deleterious effects of Ni was investigated. The accuracy of the procedure was verified by analyzing several certified reference metallurgical samples. An important conclusion of this multielement study is that the application of the MSIS for simultaneous determination of hydride forming and non-hydride forming elements in complex metallurgical samples by ICP-AES is constrained by matrix derived spectral line interferences.

Combination of a multimode sample introduction system with a pre-evaporation tube to improve multi-element analysis by ICP-OES

“…This indicates that the hydrogen byproduct of hydride generation exerts a significant beneficial effect, as previously reported by others. 18,20,23 Thus, the Table 7 Instrumental precision (% RSD for 100 ng mL À1 , n ¼ 5) for PN/ USN-MSIS-PET using operating conditions in Table 1 Analyte improvement in plasma robustness obtained with PN/USN-MSIS-PET stems from the addition of hydrogen by-product from using the MSIS in dual mode and the preservation of water along with its pre-evaporation by the PET. In addition to the above robustness, no significant buildup of condensed products was observed either inside the pre-evaporation tube or inside the MSIS.…”

Aerosol generation of As and Se hydrides using a new Flow Blurring® multiple nebulizer for sample introduction in inductively coupled plasma optical emission spectrometry

“…Asfaw and Wibetoe [22] developed a procedure for the simultaneously analysis of hydride and non-hydride-forming species using the commercial multimode sample introduction system ® (MSIS) by ICP OES. Wiltsche et al [23] used the same MSIS for multielemental analysis of high alloy steels using masking agents by ICP OES. It must be pointed out that in all these works the HG systems require the use of other devices for solutions management, for controlling reactions and for gas-liquid separation.…”

Capabilities of femtosecond laser ablation ICP-MS for the major, minor, and trace element analysis of high alloyed steels and super alloys

“…Currently, trace contaminants in steels and super alloys are often analyzed by solution-based methods such as inductively coupled plasma optical emission spectroscopy (ICP-OES) or ICP-MS. To access the trace element concentrations by ICP-OES or ICP-MS, matrix separation prior to the trace element analysis is required to avoid matrix effects and interferences. In ICP-OES, the emission line-rich concomitant metal matrix causes severe spectral interferences [4]. The analysis of trace contaminants by ICP-MS is hampered by isobaric and polyatomic interferences from argides, oxides, chlorides, and doubly charged ions [5] of main matrix elements.…”

“…Moreover, clogging of the ICP-MS cones can only be circumvented by high sample dilution or the use of flow injection ICP-MS [13]. Matrix separation is often carried out by hydride generation or by liquid-liquid extraction [6,4,7]. The general disadvantage of matrix separation techniques is the lack of universality and general applicability as every protocol is suitable for a few elements only.…”