There is speculation that the rise in cancer and heart disease rates is linked to an increasing amount of pharmaceuticals circulating in our environment. Unused prescriptions are often flushed down the toilet and other trace amounts of unchanged drugs are excreted through urination; because of this the presence of pharmaceuticals are being detected in our raw water. The current method for pharmaceutical detection and quantification is Liquid Chromatography Mass Spec/Mass Spec (LC-MS/MS) because of its sensitivity and versatility. This instrument, however, is very expensive and requires an analyst to be well trained in order to complete the method accurately and precisely.
For my project, I have tested an alternative method to drug detection in raw waters: enzyme-linked immunosorbent assay, ELISA, which is a much cheaper technique, which requires a minimal amount of training. It is often used in tandem or instead of the complex LC-MS/MS instruments. I used an Abraxis ELISA kit to quantitate caffeine in lake water and compared my results to a previous study using LC-MS/MS. My study determined the limit of detection, LOD, was approximately 0.217ppb (reported 0.150ppb)., and the Limit of Quantitation, LOQ, was approximately 0.61ppb. Except for low concentrations near the LOD, the coefficient of variation was below the 20% reported by Abraxis. In this presentation I will report percent recoveries of samples taken from Lake Wilgreen in Madison County, KY and compare these to recoveries reported by Abraxis. Overall, while this method was found to lack the accuracy and sensitivity to replace LC-MS/MS it remains a useful test for screening samples for caffeine in environmental waters.
Semester/Year of Award
Lori J. Wilson
Restricted Access Thesis
Hickerson, Julie C., "Method Validation of Caffeine ELISA for Raw Waters" (2012). Honors Theses. 46.