DETERMINATION OF IMPURITY IN ALLOY BASED ON Nb by ICP-MS. Part II
High temperature heat-resistant alloys based on Nb have a higher operating temperature compared to other alloys used in aircraft engine building, so their use can improve the performance of gas turbine engines. However, an important task is to control the chemical composition of niobium alloys, in particular the content of trace contaminants, which include tellurium, lead, and bismuth. Determination of Te, Pb and Bi in an alloy on the basis of Nb by a mass spectrometry method with inductively connected plasma (IСP-MS) is carried out. The way of overcoming of the disturbing influence of the alloying elements (Mo, Zr and Hf) on results of definition is developed. Spectral interferences are suppressed by additives of the disturbing element in the analyzed solution that allows to improve correctness of measurements. The correctness of measurement techniques tested by the «added-found» method. The use of a reactive collision cell reduced the disturbing influence on the determination of Te, Pb and Bi and their respective detection limits for one or two orders of magnitude compared to the standard measurement mode. Also the method of dissolution of the sample and its preparation for analysisis described.