ABSTRACT
A direct current glow discharge mass spectrometry ( GD-MS) for the determination of Li, Be, Na, Mg, Si, P, K, Ca, Ti, V, Cr, Mn, Co, Ga, Sr, Mo, Ag, Cd, Sn, Sb, W and Pb in nickel-zinc ferrites was developed. Copper powder as the conductive medium was evenly mixed with nickel-zinc ferrites powder for tableting, and then the impurity elements in nickel-zinc ferrites were determined by GD-MS. The influence of sample preparation and the glow discharge conditions including discharge current, discharge voltage, discharge gas flow rate and pre-sputter time on discharge stability and analysis sensitivity were investigated. The mass spectrometry interferences of analytes were investigated, as well as appropriate isotopes were selected. Most of the mass spectrometry interferences were avoided by measuring in medium resolution mode and high resolution mode. Total signal of Fe, Ni, Zn, O and Cu normalization was adopted, and the impurity elements in nickel-zinc ferrites were calculate in subtraction. The results showed that the detection limits for the investigated elements were in the range of 0. 001-0. 29 μg/g, the relative standard deviations of each element were within 3 . 5%-18 . 6%. The analysis results were consistent with those obtained by inductively coupled plasma mass spectrometry.
ABSTRACT
An inductively coupled plasma mass spectrometry ( ICP-MS) was developed for the direct determination of Be, Na, Mg, Al, K, Ca, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Ga, Zr, Mo, Sr, Cd, Ba, Pd, Ag, Sn, Au and Pb in lithium hexafluorophosphate. The sample was dissolved with absolute ethyl alcohol to analyze the above 26 impurity elements in the solution by ICP-MS. The condensation and deposition of high concentrations of carbon in mass cone interface and ion lens, which will decrease the sensitivity of element analysis, can be avoided effectively by introducing O2 to plasma. The mass spectral interferences of polyatomic ions to analytes were corrected by collision reaction cell (CRC). The matrix matching method was used to corrected matrix effect. Satisfactory linearity of each working curve of 26 impurity elements was obtained. The correlation coefficients being over 0. 9995, the detection limits for the investigated elements were in the range of 0. 6-32 ng / L, the relative standard deviation of each element within 2. 5% -7. 3% , and the recovery of each element at 90. 6% -108. 6% . The method had been applied to the determination of trace elements in lithium hexafluorophosphate with satisfactory results.