(527b) Characterization of Detergent Residues on Surfaces

Characterization of detergent residues on surfaces

Sadi Gurses, Alper Uzun, Can Erkey, Seda Kizilel

Department of Chemical and Biological Engineering, Koc University, Istanbul 34450, Turkey

The problem of filmy appearance on dishwasher-washed dishes has been receiving significant attention with increased health awareness of consumers. There is a need for characterization of dishware surfaces following a complete wash cycle.  Here, we focused on identifying the indicator chemical components to detect detergent residues on the dishware surfaces and their toxicity on live cells.  Spectroscopic and diffraction measurements have been carried out to determine structural information about detergent components, Fourier transform infrared spectroscopy (FT-IR) and high pressure liquid chromatography (HPLC) have been used to analyze rinsing water. Surfaces of the dishware were analyzed with X-ray photoelectron spectroscopy (XPS) and inductively coupled plasma mass spectroscopy (ICP-MS). Surface analysis results showed decomposition of penta sodium tripolyphosphate and sodium carbonate, known as builders in detergent chemistry, on surfaces upon dishwashing process. We also performed toxicity assays, where the influence of these builders on human fibroblast cell viability was investigated. Cell viability results showed decreasing trend in the number of cells cultured with increasing concentrations and exposure time of penta sodium tripolyphosphate in the medium. This study is significant for characterization of unknown detergent residues on surfaces and their possible toxicity on live cells.