More than just a “better AAS”! Simultaneous multi-element determination with High-Resolution Continuum Source AAS (HR-CS AAS) in graphite tube and flame

The commercial launch of the High-Resolution Continuum Source AAS (HR-CS AAS) has revolutionized atomic absorption spectroscopy. It was the German high-end manufacturer Analytik Jena that introduced the first HR-CS atomic absorption spectrometer in 2004. Today, the company offers a complete series of HR-CS AAS instruments:

• contrAA^® 300 – a flame spectrometer

• contrAA^® 600 – a pure graphite tube system for liquid and solid analysis.

• contrAA^® 700 – a combined flame and graphite tube system that offers all
  atomization techniques

Innovations

This innovative technology uses a Xenon short arc lamp as a continuous source of radiation, thus making it possible to analyze any wavelength of all elements than can be measured with AAS. With this technology, fast sequential multi-element methods of any number of elements and wavelengths can be freely selected and used in analytical routine without restriction. In addition, the evaluation of non-sensitive secondary lines, which is not available with ordinary radiation sources, becomes possible, for example for the analysis of high concentrations without diluting the sample.

When using a high-resolution Echelle spectrometer and a CCD detector, the absorption spectrum of a sample is displayed in the range of the analysis wavelength including all absorption lines and bands of the sample matrix. This offers the user completely new correction options for spectral interferences, further qualitative information on additional elements the sample contains and more trust in the accuracy of the measured values. Instead of simply showing the extinction as a numerical value, it is possible to see directly from the spectrum whether any spectral interferences distort the measuring results and a correction is necessary.

In addition to the traditional use for the determination of various metals, the contrAA^® opens up a completely new field of application: The determination of non-metals, e.g. halogens, sulfur and phosphorus, by means of characteristic molecule absorption bands in flame and graphite tube. HR-CS AAS is an easy, fast and reliable method also for non-metal determination with excellent detection limits and minimum sample preparation.

Analytik Jena goes yet a step further: The simultaneous evaluation of several absorption lines in the measured spectral range is now also possible. This is a particular advantage in the relatively time-consuming graphite tube technique, because it is possible to determine several elements with just one atomization.

An example for the application is the simultaneous determination of Ni, Fe and V in waste water (Fig. 1). Here, very low vanadium concentrations in the µg/L range were determined in the process waste water along with Ni and Fe concentrations in the mg/L range. The sample throughput can be tripled when measuring samples simultaneously. The three-dimensional spectra presentation (wavelengths and time-resolved extinction) supports the user in optimizing the atomization parameter.

Many additional applications, such as the simultaneous determination of Co and V as well as Cr and Fe in raw oil, or the simultaneous determination of Co, Fe and Ni in biological matrices, are described in the literature, often also including the use of the direct solid analysis in the graphite tube with solid AA^®.

Besides the determination of several analyte elements in a single atomization step, the HR-CS AAS also allows the use of internal standards for correcting matrix influences - which was so far reserved to the ICP OES and MS. With the simultaneous correction by means of internal standards, e.g. for the determination of As, Se, Cd, Pb, Ni and other elements in clinical samples, it is no longer necessary to perform the time-consuming calibration by standard addition. In addition, there is no risk of dilution errors.

The High-Resolution Continuum Source AAS is much more than just a "better AAS" - with its flexibility, new correction options, new areas of application and its simultaneous determination option it offers the user an obvious improvement in routine and research: increased productivity and deeper insights into the sample fulfill dreams scientists have been dreaming for decades since the development of AAS and that are only now becoming true. HR-CS AAS in the contrAA^® – by the technology leader from Jena!

Literature available on request.

Visit us at analytica 2012, Munich/Germany, 17-20/04/2012
in hall A1, booth 211/310.

More information at:
Analytik Jena AG
Konrad-Zuse-Str. 1
07745 Jena/Germany
Phone: +49/3641/ 77 70
Fax: +49/ 3641/77 92 79
www.analytik-jena.com | info@analytik-jena.com