1)When using flame atomic absorption spectroscopy, what is the purpose of adding releasing agents (i.e. lanthanum) to the standards and samples? a) To ensure the samples and the standards have similar surface tension and viscosity. b) To minimize atomization interferences. c) To increase the flame temperature. d) To reduce background interferences caused by the acetylene. e) To eliminate the need for probe rinsing. 我选b 2)When preparing standards for spectroscopic analysis of a sample, why is it important that the standards be similar in general composition (i.e. those constituents present in large quantity) to the unknown sample? a) To reduce any interferences caused by matrix effects. b) To reduce chemical inventories in the laboratory. c) To minimize the risk of using shelf-life expired standards. 我选a 3)What is(are) the purpose(s) of running calibration check samples at the end of an analysis run: a) To re-verify good instrument calibration. b) To evaluate instrument drift. c) To evaluate instrument reproducibility. d) All of the above e) Answers ‘B’ and ‘C’ only are correct 不确定 4)In alloy chemistry analysis, a trace element is defined as: a) The primary or matrix element in an alloy. b) A reference marker element used to verify detector calibration. c) A very low concentration residual element. 我选C