Practical pectrographic analysis
William F. Meggers, C. C. Kiess, F. J. Stimson · Scientific Papers of the Bureau of Standards · 1922
A brief review of various methods which have been proposed for chemical analyses by means of the spectrum is followed by a detailed description of the principle, apparatus, and procedure employed in making quantitative analyses from the spectra of condensed sparks.The practical application of this method is illustrated by three examples taken from the work of the spectroscopy section of the Bureau of Standards and deals with the quantitative determination of impurities in various samples of tin, gold, and platinum.Other applications to problems in chemistry, metallurgy, mineralogy, physics, biology, etc., are suggested. CONTENTS.Page.I. Introduction 235 II.The condensed spark method of spectrographic analysis 239 1. Principle of the method 239 2 The apparatus 241 III.Procedure in making an analysis 244 IV.Examples of quantitative spectrographic analysis 246 1 Analysis of tin 246 2. Analysis of gold 248 3. Analysis of platinum 249 V. General applications 252 I. INTRODUCTION.Many of the early scientists who laid the foundations of spectroscopy hoped to find in the new science simple and easy methods of making chemical analyses.Among these early investigators may be named Brewster, Herschell Talbot, Fraunhofer, Kirchhoff, and Bunsen.For a time this hope was strengthened and gave promise of actual realization as the methods of observing extended from flames to electrical arcs, sparks, and Pliicker tubes; and several new members, discovered by means of the spectroscope, were added to the family of chemical elements.Although the spectroscope is occasionally referred to for advice by the chemists of to-day, it must be admitted that spectral methods have not fulfilled the early hopes that they could be universally used for both qualitative and quantitative analyses.With the exception of a few investigators, such as Lockyer, Hartley, Pollock, and 23s s\tm!on Kiess '] Practical Spectrographs Analysis.237 ']Practical Spectrographs Analysis.245is especially recommended, because the metals are then inductively mixed to make perfectly homogeneous alloys and contamination and losses from volatilization may be reduced to a minimum.This was the method pursued at the Bureau of Standards in pre- paring standard samples of gold alloyed with silver, copper, lead,