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This module provides a context for introducing fundamental techniques used in chemical analysis (spectrophotometry, atomic absorbance spectroscopy and ion selective electrodes) along with considerations about sampling and sample preservation. Using an active learning approach, the module explores some fundamental water quality parameters such as the concentration of inorganic cations and anions that may aid in understanding why certain ponds provide a more suitable habitat for the Columbia Spotted frogs and aquatic snails.


The End Creek Wetland Restoration Project is located 15 km north of La Grande, in Union County, Oregon, USA. The approximately 550 acre restored wetland is the only natural grassland/floodplain area of any size at the north end of the Grande Ronde Valley which is mostly agricultural lands. Consequently, it protects a rare island of habitat for mammals, fish, amphibians, and reptiles and is an important harbor for threatened, endangered, or sensitive plant and animal species. The wet meadows and ponds provide stopover sites for migratory waterfowl traveling north and south through the intermountain west, and nesting and feeding habitat for those that stay. Drained and converted to agricultural land by the end of the last century and operated as a dairy farm until the mid-50s, the property became part of the Wetland Reserve Program in 2005. In 2006 plans began to restore the creek to its original sinuosity with the goals of improving fish habitat and restoring original vegetation. Creek restoration helped rebuild the water table and feed natural ponds. In 2008 Columbia Spotted Frogs were discovered in one of the ponds and a breeding population study began. Over the next few years the spotted frog population expanded, preferentially breeding in certain ponds, but has lately dwindled. In addition, three families of aquatic snails were identified but their distribution differs between ponds and seasonally.


Using analytical tools, you will learn how to approach a problem of analytical significance, from designing a sampling plan to choosing appropriate analytical methods and analyzing the data to determine whether any significant difference exists in the water composition and quality that may justify differences in frog and snail populations.





Table of Contents


  • Identifying the Problem (Word, PDF)
  • Qualitative Investigation of Cations and Anions (Word, PDF)
  • Sampling (Word, PDF)
  • Sample Pretreatment (Word, PDF)
  • Choosing the Method of Analysis (Word, PDF)
  • Analysis of Cations by Atomic Spectroscopy (Word, PDF)
  • Analysis of Anions by Spectrophotometry (Word, PDF)
  • Analysis of Cations and Anions by Ion Selective Electrodes (ISEs) (Word, PDF)
  • Data Sets for Analysis (Excel)
  • Instructor’s Guides (Word, PDF)
  • Assessment Questions: For Assessment questions that accompany this module, please contact Anna Cavinato (


Developed by:

Dr. Anna Cavinato
Eastern Oregon University

Dr. Karen Antell
Eastern Oregon University

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