1. Making Measurements

  1. Brian M. Tissue

Published Online: 7 JUN 2013

DOI: 10.1002/9781118647042.ch1

Basics of Analytical Chemistry and Chemical Equilibria

Basics of Analytical Chemistry and Chemical Equilibria

How to Cite

Tissue, B. M. (2013) Making Measurements, in Basics of Analytical Chemistry and Chemical Equilibria, John Wiley & Sons, Inc., Hoboken, NJ, USA. doi: 10.1002/9781118647042.ch1

Author Information

  1. Virginia Tech, Department of Chemistry, Blacksburg, VA, USA

Publication History

  1. Published Online: 7 JUN 2013
  2. Published Print: 12 JUL 2013

ISBN Information

Print ISBN: 9780470592083

Online ISBN: 9781118647042

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Keywords:

  • calibration;
  • good laboratory practice (GLP);
  • measurements;
  • outlier;
  • precision;
  • random error

Summary

This chapter describes aspects of good laboratory practice (GLP) and introduces the terminology and statistical tools used to describe and assess quantitative results. It presents an overview of the larger work environment and the issues in making analytical measurements. The chapter concentrates on individual steps and specific concepts relevant to making quantitative measurements. Quantitative measures of precision include standard deviation, standard error, and confidence limits (CL). These measures quantitate the variation or spread in the individual measurements due to random fluctuations, which are called random errors. There are a number of criteria for removing an apparent outlier from a set of measurements. The chapter illustrates Dixon's Q test and Peirce's Criterion. It explains how calibration methods can be used to obtain accurate results.