Linearity example protocol analysis

The preparation and execution should follow a validation protocol, in which the scope of the method and its validation criteria should first be defined (46). The scope of the analytical method should be clearly understood since this will govern the validation characteristics that need to be evaluated. For example, if the method is to be used for qualitative trace residue analysis, there is no need to examine and validate its linearity over the full dynamic range of the equipment. The scope of the method should also include the different types of equipment and the locations where the method will be run. In this way, experiments can be limited to what is really necessary. For example, if the method is intended for use in one specific laboratory, there is no need to include other laboratories and different equipment in the validation experiments. 

In a paper by Wasterlain et al. (2011) a new instrument developed in-lab is proposed to satisfy the requirements of electrochemical impedance studies to be led on large fuel cell plants made of numerous individual cells. Moreover, new voltammetry protocols dedicated to PEMFC stack analysis are described. They enable, for example, the study of membrane permeability and loss of platinum activity inside complete PEMFC assemblies. In the first part, a new electrochemical impedance spectrometer that makes testing large FC stacks possible has been presented. To validate this acquisition system and to demonstrate some of its capabilities, some experiments were conducted on a 20-cell PEMFC stack. In the second part, voltanunetry experiments were conducted on short FC stacks with a commercial potentiostat. The fuel crossover phenomenon in a three-cell PEMFC stack was analyzed using the linear sweep voltametric (LSV) method. The crossover rates were determined for each individual cell inside the complete assembly and for the entire stack as well. 

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