CADMIUM DETERMINATION IN HUMAN WHOLE BLOOD BY ELECTROTHERMAL ATOMIC ABSORPTION SPECTROMETRY WITH MAGNESIUM CHLORIDE AND SODIUM HYDROXIDE AS A COMBINED CHEMICAL MODIFIER

摘要

In this work, we propose a method to determine trace amounts of Cd in human whole blood samples by electrothermal atomic absorption spectrometry (ETAAS) with the combined chemical modifier including magnesium chloride and sodium hydroxide. Prior to the ETAAS analysis, dissolution of the blood samples is accomplished using a HNO3-HClO4/double closed-vessel microwave digestion technique followed by drying of the dissolved blood samples by means of an infrared lamp. In using this approach, a MgCl2 chemical modifier is added to the digested samples, then they are injected into the graphite furnace for detecting the Cd level via atomic absorption spectrometer. Besides we used a NaOH chemical modifier, which removed the matrix major elements through prior ashing at 1200 degrees C for 30 s, and the Cd is subsequently volatilized at 2200 degrees C and determined by AAS. However, the proposed method can be employed to determine the of Cd level in whole blood samples by the calibration technique and the standard-additions method. Its validity is confirmed with two certified reference whole blood materials (Seronorm Trace Elements Whole Blood Batch no. 205052 and Batch no. 203056). By using 10 mu L injections, a detection limit of 0.052 ng mL(-1) is achieved. [References: 31]