1. Analysis of Trace Elements in Drinking Water

Principle:

Pre-treatment: All aqueous samples are preserved with suprapur nitric acid at pH<2 and kept at room temperature.

Analysis:

As, Pb; Cd, Cr, Cu, Zn. The samples shall be analysed by using high-resolution inductively coupled plasma mass spectrometry (HR-ICPMS), using the standard addition method and clean-room techniques shall be applied.

Ni, Sn, Mo: The samples shall be analysed directly by use of atomic absorption spectrometry with graphite oven techniques (ETAAS) and background correction and standard addition techniques shall be applied.

Zn (high level), Cu (high level), Pb (high level), Ni (high level): The elements shall be analysed directly by means of inductively coupled plasma atomic emission spectroscopy (ICP-AES), and measurements are made by use of a calibration curve.

References:

Measurements at HR-ICPMS: U.S. Environmental Protection Agency method 200.8:1991: Determination of trace elements in waters and wastes by inductively coupled plasma – mass spectrometry.

Measurements by ETAAS: Danish Standard DS 2211, Standard Methods for the Examination of Water and Wastewater, 3113 A+B, 18^thedition (1992 + 1994). Perkin Elmer Analytical Techniques for Furnace Atomic Absorption Spectrometry 1984.

Measurements by ICP-AES: DS/EN ISO 11885 Water Quality-Determination of 33 elements by inductively coupled plasma atomic emission spectroscopy. 1^st Ed. 1998.

Internal quality control:

The results have been checked by simultaneous analysis of certified reference materials.

Analysis uncertainty:

At a control check analysis, the analysis uncertainty found is, CV_total of 2-8%.