Fractionation analysis and bioavailability of manganese in spinach (Spinacia oleracea L.) leaves

Abstract

This paper introduces a fractionation scheme using water, acetone, chloroform, diethyl ether, ethanol, n-hexane, and methanol as extractants for the determination of manganese in spinach samples by inductively coupled plasma-mass spectrometry (ICP-MS). Simulated gastric and intestinal digestions as well as n-octanol extraction and activated carbon adsorption were performed for the bioavailability assessments. Comparative studies of the various extraction treatments were evaluated for confirmation analysis. The total elemental concentrations were determined after digesting the samples in a microwave digestion system. The method validation parameters were defined in terms of the detection limits, accuracy, and precision. Additional validation was performed by comparing the ICP-MS method with atomic absorption spectrometry. The limits of detection and quantification were 0.046 and 0.154 mg kg-1, respectively. Additionally, the repeatability and reproducibility, calculated from the relative standard deviation (%RSD), were 2.4% and 3.7%, respectively.