Direct determination of trace impurities in niobium pentaoxide solid powder with slurry sampling fluorination assisted electrothermal vaporization inductively coupled plasma mass spectrometry

Abstract

A method of fluorination assisted electrothermal vaporization inductively coupled plasma mass spectrometry (FETV-ICP-MS) was developed to directly determine the trace impurities in niobium pentaoxide solid powder in which a poly(tetrafluoroethylene) (PTFE) emulsion was used as fluorinating modifier to promote the vaporization of refractory elements from a graphite furnace and to avoid the formation of thermally stable carbides. The solid sample was introduced into the graphite furnace in the form of slurry without any chemical pretreatments. The electrothermal vaporizer device was connected to the ICP system by a laboratory-built interface, and the flow rates of sample carrier gas and auxiliary carrier gas were optimized experimentally. The potentially polyatomic interferences resulting from the pyrolysates of PTFE were evaluated. A new method by stepwise diluting the sample matrix is proposed for investigating the matrix effect and the results showed that no obvious matrix effect was observed with a sample matrix (Nb 2 O 5 ) concentration of less than 200 mg L 21 . Under the optimal conditions, the absolute limits of detection for FETV-ICP-MS determination of Ta, Ti, Cr, W, Ni, Cu and Mn were in the range of 0.026-1.1 pg. For one analysis run, only 0.002 mg of Nb 2 O 5 sample was required. The proposed method has been applied to determining the trace impurities in Nb 2 O 5 powder, and both the results obtained from the external calibration method and the standard addition method were in a good agreement with those obtained by conventional nebulization ICP-MS.

Simultaneous speciation of inorganic arsenic, selenium and tellurium in environmental water samples by dispersive liquid liquid microextraction combined with electrothermal vaporization inductively coupled plasma mass spectrometry

“…Details on the modification of the graphite furnace and its connection with ICP-MS have been described previously [36]. The polyethylene tubing transfer line (6 mm i.d.)…”

Determination of some refractory elements and Pb by fluorination assisted electrothermal vaporization inductively coupled plasma mass spectrometry with platform and wall vaporization

“…The original silica windows (diameter of 2 cm) at the two ends of the graphite furnace were removed and replaced by two PTFE cylinders, and one of them was connected to the injector tube of the plasma torch, as has been detailed in previous work [12]. A polyethylene tubing transfer line with an i.d.…”

Micro‐Column Separation/Pre‐Concentration Combined with Fluorinating Electrothermal Vaporisation‐Inductively Coupled Plasma‐Mass Spectrometry for Determination of Trace Refractory Elements in Seawater, Soil and Sediment

“…The original silica windows at the two ends of the graphite furnace were removed and replaced with two PTFE cylinders, detailed in previous work (Li et al 2004). The original silica windows at the two ends of the graphite furnace were removed and replaced with two PTFE cylinders, detailed in previous work (Li et al 2004).…”

“…In temperature programme 2, the operating conditions were based on previous work performed in our laboratory (Li et al 2004, Zhang et al 2006). …”

“…Of all these methods, ICP-MS is one of the most commonly used techniques nowadays for determination of trace refractory elements ( B e c ke r 2 0 0 5 , Ya n g a n d P i n 2 0 0 2 ) . It is well established that the analytical performance of ETV-ICP-MS could be improved by the use of a suitable chemical modifier (for example, PTFE emulsion for refractory elements) (Hu et al 1996, He et al 2005, Li et al 2004, Zhang et al 2006 or by the use of suitable pre-concentration/ separation techniques (Xiong et al 2000, Pu et al 2006a). Electrothermal vaporisation (ETV) (Sturgeon and Lam 1999), as a versatile sample introduction for ICP spectrometry, has some attractive features including in situ separation of analyte from the matrix, high sampling efficiency, low detection limits and low sample consumption (Sturgeon and Lam 1999, Li et al 2004, Zhang et al 2006, and has been widely used for the determination of trace elements in different samples.…”