Online Standard Additions Calibration of Transient Signals for Inductively Coupled Plasma Mass Spectrometry

Abstract

An online standard additions calibration method for transient signals in ICPMS is demonstrated in which a small volume of standard is injected as a spike into the sample/carrier stream, overlaying the analyte peak. This technique provides the advantages of conventional standard additions but requires only a single sample run. The method corrects for matrix effects and is suitable for transient signals in which the severity of the matrix effect changes over the analyte peak. The method uses a peak-fitting program to determine the area of the underlying peak and is shown to be effective for the determination of trace metal concentrations in both a high ionic strength matrix and in a biological matrix (urine). Eight analytes with concentrations in the range of 0.82-233.2 mug L-1 in urine were simultaneously determined using a standard spiking solution of 75 mug L-1 injected through a 100-muL loop. The measured concentrations for analytes free of spectral interferences agreed with the certified values, and the precision achieved was comparable to that achieved by the certifying agency. Using a conventional cross-flow nebulizer and Scott-type spray chamber, the accuracy obtained for online standard additions calibration was within 2%, and the precision was within 5%.

Automatable on-line generation of calibration curves and standard additions in solution-cathode glow discharge optical emission spectrometry

“…To reduce human error and the time required for sample preparation and analysis, several studies have focused on instruments that prepare calibration standards and samples on-line, or obviate the need for several standards to be prepared. Among these studies are methods based on flowinjection [23,24], which enable on-line standard additions and calibration to be performed. Unfortunately, these methods suffer from poorer precision than traditional analyses and are difficult to fully automate.…”

Interference standard: a new approach to minimizing spectral interferences in inductively coupled plasma mass spectrometry

“…In this context, different strategies have been proposed to minimize such interferences and the most recent are based on collision-reaction cells and interfaces, and mixed-gas plasmas. [4][5][6][7][8][9][10][11] Other approaches such as mathematical correction, 5,12 cool plasma 13 and the traditional standard additions 14 and internal standardization 15,16 have also been proposed, but all have limitations and are usually effective in some few specific conditions.…”

Use of gradient dilution to flag and overcome matrix interferences in axial-viewing inductively coupled plasma-atomic emission spectrometry

“…To shorten sample preparation and analysis time, and to reduce human error and chemical impurities, high-performance liquid chromatography (HPLC) pumps, multi-peristaltic-pump systems, and flow injections have been used to mix standards and analyte solutions on-line. These approaches were used with atomic absorption [8][9][10], atomic emission [11], and mass spectrometry [12][13][14].…”