Surface Signal Integration As a Way of Evening Physical and Chemical Factors when Analyzing Stainless Steel for Chlorine Content

The possibility of analyzing the amount of chlorine on the surface of stainless steel is investigated and a method for obtaining reproducible results by evening or eliminating the physicochemical features of surface ionization of a calibrant crystallized from a solution is described. It is shown that the main factor influencing the quality of calibration and analysis is the shape of the resulting drop and its size. It was also found that integrating the analytical signal over the entire drop is the most appropriate method for calibration and obtaining the most reproducible results. The main factors influencing the physicochemical characteristics of ionization and, as a consequence, the reproducibility of the calibration data are presented. It has been established that the method of calibration with the integration of a signal by a drop can be effectively used in the analysis of ultra-small amounts of chlorine on the surface of stainless steel in the range from 0.12 to 120 pmol/mm 2 . In this case, the proposed approach eliminates the physicochemical factors affecting the ionization efficiency, which limit the use of surface laser desorption/ionization for quantitative analysis.