Analysis of Toxic Trace Metals in Pet Foods Using Cryogenic Grinding and Quantitation by ICP-MS, Part II

摘要

This article is the second part of a study that examines pet foods from a variety of sources to determine if there were potentially toxic elements present in the foods and also whether more expensive foods with higher quality ingredients equated to lower levels of toxic elements. A range of "budget" to "premium" grade pet foods samples were donated by pet owners or purchased in several different stores. The food samples were ground in a cryogenic freezer mill (dry samples) or blender (wet samples), digested with concentrated nitric acid, and analyzed for trace-metals content by inductively coupled plasma-mass spectrometry (ICP-MS). Results were then compared to Environmental Protection Agency Reference Dose (RfD) values and World Health Organization Tolerable Daily Intake (TDI) values, which are considered the daily oral exposure limits for the human population. Human limits were scaled to the weight of a 50-lb dog or 10-lb cat to gain perspective of an animal's potential exposure. Many of the pet foods sampled showed significant concentrations of various toxic metals. In many cases, the concentrations exceeded the extrapolated human limit values calculated to pet-size dosages.