This work was undertaken to demonstrate the utility of infrared spectroscopy in the identification of materials used in patient care. In the cases described herein, it was suspected that these materials had been tampered with or utilized inappropriately.
Infrared spectra of submitted materials were collected using a Nicolet model 860 Fourier transform infrared (FT-IR) spectrometer. Liquids and solutions were analyzed as thin films between barium fluoride windows, and solids and tissue specimens were placed on aluminum-coated glass slides for use with a microscope accessory.
The infrared absorption spectrum of a material can often be used to uniquely identify that material. In the first example, the presence of an antibiotic inadvertently added to a patient's intravenous fluid supply was confirmed using infrared spectroscopy. There were no adverse reactions associated with the extra medication. In another case, the efficacy of a prescription steroid hormone was questioned. Infrared spectra confirmed the identity and purity of the drug, and its unsatisfactory performance was linked to improper weighing during the preparation of the capsule. The final example is a case in which a foreign material remaining after a surgical procedure caused discomfort to the patient and slow recovery. Infrared spectra were consistent with a polyamide coating from one of the instruments. These cases are examples of the utility of FT-IR in resolving questions presented to the toxicologist.