Spatial Averaging for Solid Samples by Hadamard Transform Raman Spectroscopy

A method is described to avoid the effects of sample heterogeneity in Raman measurements on solid samples. A Hadamard multiplex multichannel system with a bifurcated fiber-optic bundle for excitation and collection is used. The Hadamard mask employs a 7-element code with a unit slit width of 400 μm. Results are reported for samples prepared by mixing cytosine and 5-methylcytosine powders.