Validation of total inorganic element determination in wastewater samples by on-line isotope dilution inductively coupled plasma mass spectrometry

Abstract

Current interest in analytical chemistry concerns the traceability of analytical measurements to the International System of Units (SI) and estimation of their uncertainties. Primary methods of measurement achieve traceability directly without intermediate reference standards or materials and without significant empirical correction factors. In this work, isotope dilution mass spectrometry was regarded as such a primary method and wastewater as a matrix of significant ecological and toxicological relevance. In that sense, a validation study was performed for total (dissolved + particulate) element determination (Cd, Cr, Fe, Ni, Pb and Zn) in acidified (pH < 2) wastewater samples by using on-line isotope dilution mass spectrometry with inductively coupled plasma (OID-ICP-MS) after acid extraction in a microwave system.Emphasis was placed on the OID-ICP-MS method and its validation by comparison against direct external calibration mass spectrometry with inductively coupled plasma analysis (ICP-MS), including differences in calibration strategies. Good agreement (trueness) between the two analysis methods was achieved for all trace metals involved. However, OID-ICP-MS offers more accurate and precise results with smaller measurement uncertainties, when properly applied, compared to external calibration. Thus, OID-ICP-MS proved to be an ideal solution for routine wastewater analysis, increasing the sample throughput without any previous sample handling and improving the quality and reliability of the analytical results.

Simultaneous Electrochemical Detection of Cu2+ and Zn2+ in Pig Farm Wastewater

“…Inductively coupled plasma mass spectrometry (ICP-MS) was used for quantitative detection of different metal ions, as described elsewhere [ 39 ]. In brief, 100 mL of the sample was placed into a 250 mL conical flask with 5 mL of HNO 3 and heated at 95 ± 5 °C for 30 min.…”

Accurate Determination of Trace Molybdenum in Drinking Water by Isotope Dilution Inductively Coupled Plasma Mass Spectrometry

“…11,12 To date, ID-ICPMS has found limited achievements for the determination of trace metals at ppb levels in water systems. 13,14 The application of ID-ICPMS for the quantification of Mo in drinking water still presents several challenges despite the robustness of the ID method. First, a suitable isotope pair for analysis is essential for reducing isobaric interferences.…”