A method of detecting concentration of dipicolinic acid and terbium chloride in a chemical composition with a fluorometer, wherein the fluorometer comprises an excitation source for emitting electromagnetic radiation at one or more wavelengths, and a detector module for detecting fluorescence emitted by dipicolinic acid, emitting electromagnetic radiation from the excitation source at wavelengths that induce fluorescence in dipicolinic acid-terbium chloride combination present in the chemical composition, detecting the fluorescence emitted by the dipicolinic acid-terbium chloride combination via the detector module, and determining the concentration of dipicolinic acid using predetermined relationship between fluorescence emitted and the concentration of dipicolinic acid-terbium chloride combination.