Development of noninvasive method of measuring copper and zinc by passive diffusion: an in vitro model

Abstract

There has been increasing interest in the determination of essential or toxic elements in human body fluids in relation to health and nutrition. The human body is composed of almost every natural element found in nature. This includes copper and zinc that are both essential if obtained at a right amount and toxic when exceeds. This study aims to develop a noninvasive method for measuring trace amounts of copper and zinc by passive diffusion. A cellulose acetate membrane was used as a model representing human skin. Different amount of permeant concentration of copper and zinc solutions such as 0.1, 0.5, and 1mM were placed inside the membrane and the samples were collected and analyzed using Atomic Absorption Spectroscopy. The amount of copper and zinc diffusing shows proportionality with time. The permeability and steady state flux were computed. Permeability of -2.39×10-7 cm/s and 6.67×10-7 cm/s were computed for copper at 0.1 mM and 0.5 mM concentrations respectively and 3.11×10-7, 4.61×10-7 and 1.75×10-6 cm/s were computed for zinc at 1, 0.5 and 0.1 mM permeant concentrations respectively. For steady state flux, the values computed are 1.22×10-3, 9.03×10-4 and 6.84×10-4 µM/cm2min for zinc at 1, 0.5 and 0.1 mM respectively and -7.84×10-4 and 1.27×10-3 µM/cm2min for copper at 0.5 and 0.1 mM permeant concentrations. The values gathered are all acceptable taking into the account previous studies regarding skin diffusions. This method presents a noninvasive alternative method to track copper and zinc trends.