Holmium oxide can be used for this process in UV-Vis spectroscopy apparatuses. If a spectrometer appears to give poor results in this process, one can conduct a matrix spike experiment to “recover” the results. An example of this process involves adding aliquots of a known concentration to a sample, then extrapolating to find the negative (15[1])x-intercept; that process is the method of (*) standard addition. This type of sensitivity divided by the standard deviation of a signal gives analytical sensitivity. In a Beer’s Law experiment, this process involves generating an absorbance-concentration curve for known standards, which can then be used to interpolate an unknown concentration based on its signal. For 10 points, name this process of quantifying the relationship between analytical variables and validating the accuracy of an instrument. ■END■