Question

forensics chemist have found seized moonshine liquor samples that been adultersted with methanol to increase their apparent alcohol content. sketch an expected chromatogram if one of these moonshines samples was analyzed via the internal standard method.

Answer 1

An internal standard is a substabce that is added to to a fixed amount to all starndard solutions blank and sample, the chemica nature of the internal standard is similar to that of the substance whic is to be estimated and sholud not be present in sample matrix.

the emmisio intensities of the internal standard and the analyte(standard + sample) are determined using their appropriate filters . the ratio of the intensity oif the analyte and that of the internal standard (Ea/Ei) is plotted against the concentraion and as shown in the graph, and with the st. line the concentration of the unkown can be determined...by extrapolating the corresponding concentration fo the measured absorbance of unknown