Explain in detail Titrometric methods used in environmental Analysis.
Answers
Titrimetry refers to a group of methods of quantitative analysis in which an analyte is determined basing on its stoichiometric reaction with a reagent of established concentration introduced to a sample gradually, in small portions until the analyte is consumed quantitatively. The end of the reaction can be detected visually, using a properly selected indicator or with the use of an instrumental method. The content of the analyte in the sample is calculated basing on properly measured amount of the reagent consumed in the reaction with the analyte, the reagent solution concentration and the reaction stoichiometry.
Titrimetry is one of the oldest analytical techniques. Its continued popularity stems from the simplicity of equipment and execution, wide applicability, and high accuracy and precision (greater than most instrumental techniques), all of which make it particularly applicable to the determination of major and minor components of samples. Skilled titrimetric analysis should give results with a precision lower than 0.2% at the 1 × 10− 2 mol L− 1 level.
Titrimetry may be classified with respect to the types of reaction that are involved. The major reactions are acid–base reactions (acid–base titrimetry), redox reactions (redox titrimetry), complexing reactions (complexometric titrimetry), and precipitation reactions (precipitation titrimetry). Titrimetry may also be classified by the nature of the measurement of the end point of titration. The use of electrical measurements gives rise to potentiometric and amperometric titrations. Measurement of heat changes is used in thermometric titrimetry, and of absorbance in photometric and turbidimetric titrations. Radiometric titrations measure changes in radioactivity during the titration. This article discusses the titrations that use the visual end point detection.