1. A method comprising: configuring a spectroscopic imaging device to: (a) irradiate a sample comprising at least one unknown particle to produce Raman scattered photons, and (b) collect the Raman scattered photons to generate a Raman chemical image representative of the sample; integrating the intensity within the spectral peak at each pixel of the Raman chemical image to generate a working image; and configuring a processor to: (c) apply a first threshold to the working image wherein the first threshold is such that all particles in the sample are detected; (d) select one of the detected particles; (e) apply a second threshold to the working image to determine at least one geometric property of the selected particle, wherein the second threshold is unique to the selected particle such that the geometric property can be determined; (f) analyze at least one spectrum, representative of the selected particle, wherein analyzing further comprises comparing at least one spectrum representative of the selected particle to at least one reference spectrum representative of a particle of interest; and if comparing results in a match between the spectrum representative of the selected particle and the reference spectrum representative of the particle of interest, identifying the selected particle as a particle of interest, and if comparing does not result in a match between the spectrum representative of the selected particle and the reference spectrum representative of the particle of interest, identifying the selected particle as not a particle of interest.