The signal for an instrumental method was measured five times in the presence of an unknown concentration of analyte and yielded the following: 10.2, 11.1, 9.7, 9.2, 10.3 mV.
a) Assuming that the noise is random calculate the signal-to-noise ratio.
b) A calibration curve was prepared from series of standards for various concentrations of this analyte and the line of best fit was determined to be S=1.56C + 0.2, where, S, is the signal in mV and, C, is the concentration in ppm (parts per million). Calculate the concentration of analyte.
c) Estimate the detection limit of this instrumental method based on measurement of the S/N for the unknown.