The Evaluation of ICP OES for the Determination of Potentially Toxic Elements in Lipsticks: Health Risk Assessment.

This study aimed to optimize and validate the inductively coupled plasma optical emission spectrometric method (ICP OES) for the simultaneous determination of eleven potentially toxic elements (Al, Cd, Cr, Co, Cu, Ni, Pb, Fe, Sb, Mn, and Zn) in lipstick samples. The method was evaluated by applying the standard addition method. The recoveries for all elements in lipsticks were between 90% and 110%, except for Cd and Pb they were <90% and >110%, respectively. The health risk assessment was determined by calculating the average daily intake (ADD), hazard quotient (HQ), and hazard index (HI). The highest mean value for ADD was for Fe (4.8×10-1 mg kg-1 day-1), and the lowest was for Co (9.3×10-6 mg kg-1 day-1). There was no significant toxic health risk for any of the elements (HQ < 1), except for Fe (HQ < 3) which indicates a potential health risk. Based on PCA, all potentially toxic elements have been classified in the three groups. The first group includes Fe, the second includes Al, and all other elements belong to the third group. The cluster analysis of the elements provided the identical grouping that was obtained on the basis of PCA. Two separate clusters were obtained when cluster analysis was applied to the analyzed samples. The first cluster contained the only sample that was brown. The second cluster was divided into two sub-clusters. The first sub-cluster included the samples belonging to category I regarding the price, while the second sub-cluster included the samples belonging to category II and III regarding the price.

Electrical properties of human skin as aging biomarkers.

A non-invasive bioimpedance spectroscopy (BIS) and Cole-Cole impedance model parameters (R0, R∞, τ and α) were used to analyze electrical properties of intact and stripped human skin for both gender subjects divided into younger and older age groups. R0, R∞ and τ significantly increased while α significantly decreased with age in stripped skin for both genders (p<0.031). Using pooled data with respect to age, gender and skin stripping, R0, R∞ and τ values were shown to increase with age (p<0.0034), R0, τ and α were different between genders (p<0.024) and R0, R∞ and τ decreased with skin stripping (p<0.000008). All of four Cole-Cole parameters were age dependent with specific differences observed for genders and intact and stripped skin layers. Therefore, Cole-Cole parameters, obtained by non-invasive BIS measurements, are a new type of age dependent biomarkers.

Fractional calculus model of electrical impedance applied to human skin.

Fractional calculus is a mathematical approach dealing with derivatives and integrals of arbitrary and complex orders. Therefore, it adds a new dimension to understand and describe basic nature and behavior of complex systems in an improved way. Here we use the fractional calculus for modeling electrical properties of biological systems. We derived a new class of generalized models for electrical impedance and applied them to human skin by experimental data fitting. The primary model introduces new generalizations of: 1) Weyl fractional derivative operator, 2) Cole equation, and 3) Constant Phase Element (CPE). These generalizations were described by the novel equation which presented parameter [Formula: see text] related to remnant memory and corrected four essential parameters [Formula: see text] We further generalized single generalized element by introducing specific partial sum of Maclaurin series determined by parameters [Formula: see text] We defined individual primary model elements and their serial combination models by the appropriate equations and electrical schemes. Cole equation is a special case of our generalized class of models for[Formula: see text] Previous bioimpedance data analyses of living systems using basic Cole and serial Cole models show significant imprecisions. Our new class of models considerably improves the quality of fitting, evaluated by mean square errors, for bioimpedance data obtained from human skin. Our models with new parameters presented in specific partial sum of Maclaurin series also extend representation, understanding and description of complex systems electrical properties in terms of remnant memory effects.